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Astrocytes of the suprachiasmatic nucleus (SCN) can regulate sleep-wake cycles in mammals. However, the nature of the information provided by astrocytes to control circadian patterns of behavior is unclear. Neuronal circadian activity across the SCN is organized into spatiotemporal waves that govern seasonal adaptations and timely engagement of behavioral outputs. Here, we show that astrocytes across the mouse SCN exhibit instead a highly uniform, pulse-like nighttime activity. We find that rhythmic astrocytic GABA production via polyamine degradation provides an inhibitory nighttime tone required for SCN circuit synchrony, thereby acting as an internal astrocyte zeitgeber (or "astrozeit"). We further identify synaptic GABA and astrocytic GABA as two key players underpinning coherent spatiotemporal circadian patterns of SCN neuronal activity. In describing a new mechanism by which astrocytes contribute to circadian timekeeping, our work provides a general blueprint for understanding how astrocytes encode temporal information underlying complex behaviors in mammals. Synopsis: Astrocytes can drive circadian behavior in mammals, but the nature of the temporal information generated by astrocytes is largely unknown. This study identifies GABA produced by polyamine degradation in astrocytes as a critical signal that synchronizes neuronal activity in the suprachiasmatic nucleus (SCN), which orchestrates circadian rhythms in mammals. Circadian phases of astrocytic activity are uniform across the SCN, in contrast to the phase waves of neuronal activity. Extracellular GABA levels in the SCN peak during the nighttime, mirroring the spatiotemporal organization of astrocytic rhythms, as opposed to the daytime peak of neuronal activity. Inhibition of synaptic GABA release desynchronizes neuronal circadian rhythms in the SCN, but does not affect extracellular GABA rhythms. Inhibition of astrocytic GABA synthesis disrupts circadian rhythms of extracellular GABA and desynchronizes neuronal circadian activity, suggesting a role as an internal circadian synchronizer for the SCN circuit ("astrozeit"). Inhibitory nighttime GABA produced via rhythmic polyamine degradation in astrocytes synchronizes neuronal circadian rhythms. [ABSTRACT FROM AUTHOR]

Anthropogenic impacts on primates usually discussed as a community-level variable, with very few studies dissecting into a personal factor such as human gender. There is a gender bias in utilizing forest resources, resulting in men and women having different chances encountering primates, moreover orangutans. We investigated human genders' influences on human-orangutan bi-directional receptions as it affected their reactions and analyzed their interactions in Lamandau Wildlife Reserve, Central Kalimantan. We conducted interviews with 30 locals by applying snowball and convenience sampling techniques. This study revealed that orangutans displayed more promoting behaviors towards humans. However, distinct human reactions to encountering orangutans differed by gender. There were significant relations between human genders and orangutan behaviors, suggesting that orangutans might view humans differently from their genders. We recommended that managers adapt their localbased orangutan conservation activities adapting these findings. We also encouraged further research especially in exploring the orangutan's perspectives towards human-orangutan interactions. [ABSTRACT FROM AUTHOR]

In this paper, a new metaheuristic algorithm called Orangutan Optimization Algorithm (OOA) is designed, which imitates the behaviors of Orangutans in nature. The fundamental inspiration of OOA is the foraging strategy of Orangutans and the skills of these animals in nesting. The theory of OOA is explained and then the implementation steps of OOA in two phases of exploration and exploitation are mathematically modeled. The performance of OOA in dealing with real-world applications is evaluated on twenty-two constrained optimization problems from the CEC 2011 test suite. The optimization results show that the proposed OOA approach, by balancing exploration and exploitation during the search process, is able to provide suitable solutions for the benchmark functions. Also, in order to measure the quality of OOA, the results obtained from the proposed approach are compared with twelve well-known metaheuristic algorithms. Analysis of the simulation results shows that OOA has provided superior performance by providing better results in 100% of the benchmark functions compared to competitor algorithms. [ABSTRACT FROM AUTHOR]

Simple Summary: The Chattogram Hill Tracts (CHTs) in Bangladesh support diverse wild mammal species, underscoring the need for conservation-focused monitoring. Camera traps in the Pittachhara Forest identified eight small- and medium-sized mammals, including the Bengal slow loris, northern pig-tailed macaque, and leopard cat. Activity patterns revealed the nocturnal behavior of species such as the Bengal slow loris, while the northern pig-tailed macaque was diurnal. Seasonal analysis showed significantly higher activity during summer, particularly for the large Indian civet and crab-eating mongoose, and reduced activity in winter (p < 0.05). This study highlights the need for ongoing monitoring and conservation to mitigate human impacts and ensure the survival of endangered species in this small, protected area. The Chattogram Hill Tracts (CHTs) in Bangladesh have a rich biodiversity, hosting a wide range of wild mammal species, underscoring the importance of systematic monitoring focused on conservation efforts. This study aims to assess the diversity and abundance of small- and medium-sized wild mammal species in Pittachhara Forest in the CHTs. A comprehensive wildlife monitoring survey was conducted in this forest using strategically placed camera traps to identify the wild species diversity, and we evaluated the activity patterns and seasonal variations for the period of February 2023 to August 2024. The camera trap identified eight species of small- and medium-sized wild mammals: the Bengal slow loris, northern pig-tailed macaque, leopard cat, large Indian civet, common palm civet, crab-eating mongoose, northern tree shrew, and black rat. The activity patterns showed distinct temporal behaviors among these wild mammals, with nocturnal activity dominating for the Bengal slow loris and leopard cat, while the northern pig-tailed macaque exhibited diurnal activity. Seasonal variations demonstrated a significant difference in increased activity among most wild mammal species throughout the summer, particularly the large Indian civet and crab-eating mongoose, likely due to favorable environmental conditions, and decreased activity in the winter (p < 0.05). The findings suggest an intricate connection between species-specific behaviors and environmental factors that influence activity patterns, with increased activity in summer and a decrease in winter, indicating that summer conditions may enhance the movement and foraging behaviors of mammals. This study underscores the necessity for continuous biodiversity monitoring followed by conservation efforts in Pittachhara Forest to reduce the threats of habitat fragmentation, human disturbances, and inadequate protection, thus protecting the survival of endangered wild mammal species and maintaining the environmental harmony of this small, protected area. [ABSTRACT FROM AUTHOR]

Human impacts on the environment and wildlife populations are increasing globally, threatening thousands of species with extinction. While wildlife‐based tourism is beneficial for educating tourists, generating income for conservation efforts, and providing local employment, more information is needed to understand how this industry may impact wildlife. In this study, we used motion‐activated cameras at 12 waterholes on a private game reserve in northern Namibia to determine if the presence of humans and permanent infrastructure affected mammal visits by examining their (1) number of visits, (2) time spent, and (3) diel activity patterns. Our results revealed no differences in the number of visits based on human presence for any of the 17 mammal species studied. However, giraffes (Giraffe camelopardalis) spent more time at waterholes before observer presence compared to during. Additionally, several species changed diel activity patterns when human observers were present. Notably, several carnivore and ungulate species increased overlap in their activity patterns during periods while humans were present relative to when humans were absent. These modifications of mammal temporal activity patterns due to human presence could eventually lead to changes in community structure and trophic dynamics because of altered predator–prey interactions. As humans continue to expand into wildlife habitats, and wildlife‐based tourism increases globally, it is imperative that we fully understand the effects of anthropogenic pressures on mammal behavior. Monitoring of wildlife behavioral changes in response to human activity is crucial to further develop wildlife tourism opportunities in a way that optimizes the impact of conservation goals. [ABSTRACT FROM AUTHOR]

Unlike the top‐down cascading effects driven by apex predators, the bottom‐up effects on biological interactions originating from herbivory by large mammals, especially within mammalian assemblages, have received less attention. This study aimed to identify the multifaceted impacts driven by sika deer (Cervus nippon) during midwinters, when their herbivory impacts were expected to be strong due to deficient dietary resources. We focused on interference and exploitative competition caused by deer on the habitat use of four sympatric mammal species, namely two herbivores (Japanese serow, Capricornis crispus, and Japanese hare, Lepus brachyurus angustidens) and two mesocarnivores (red fox, Vulpes vulpes, and Japanese marten, Martes melampus melampus). To estimate the wintering behaviors of these mammals and deer herbivory pressure, we performed snow tracking and counted the fresh feeding marks of deer during midwinter in 2022 and 2023. We conducted surveys on 201‐km transects with different stages of deer population recovery (i.e., different deer population densities) in heavy snowfall regions of Japan. We then systematically quantified the deer‐driven effects on sympatric mammals using piecewise structural equation modeling (SEM). We recorded 1700 tracks of target mammals and 1327 trees with deer feeding marks. Based on these records, we constructed an SEM with acceptable performance (Fisher's C = 27.1, P = 0.30). The SEM suggested some possibilities that exploitative competition mediated by deer herbivory constrained the habitat use of mammals with dietary habits similar to that of deer, i.e., serow (effect size, −0.13) and hares (−0.14). In addition, through constricting the habitat use of hares, the deer‐driven cascading effects reduced the occurrence of their key predators, i.e., foxes (−0.12) and martens (−0.10). Thus, our observations provide novel evidence that food webs are regulated by herbivore‐driven bottom‐up cascading effects in cases where plant primary productivity is limited by heavy snowfall. [ABSTRACT FROM AUTHOR]

Central arginine vasopressin (AVP) facilitates social recognition and modulates many complex social behaviors in mammals that, in many cases, recognize each other based on olfactory and/or pheromonal signals. AVP neurons are present in the accessory olfactory bulb (AOB), which is the first relay in the vomeronasal system and has been demonstrated to be a critical site for mating-induced mate recognition (olfactory memory) in female mice. The transmission of information from the AOB to higher centers is controlled by the dendrodendritic recurrent inhibition, i.e., inhibitory postsynaptic currents (IPSCs) generated in mitral cells by recurrent dendrodendritic inhibitory inputs from granule cells. These reports suggest that AVP might play an important role in regulating dendrodendritic inhibition in the AOB. To test this hypothesis, we examined the effects of extracellularly applied AVP on synaptic responses measured from mitral and granule cells in slice preparations from 23-–36-day-old Balb/c mice. To evoke dendrodendritic inhibition in a mitral cell, depolarizing voltages of −70 to 0  mV (10  ms duration) were applied to a mitral cell using a conventional wholecell configuration. We found that AVP significantly reduced the IPSCs. The suppressive effects of AVP on the IPSCs was diminished by an antagonist for vasopressin receptor 1a (V1aR) (Manning compound), but not by an antagonist for vasopressin receptor 1b (SSR149415). An agonist for V1aRs [(Phe2 )OVT] mimicked the action of AVP on IPSCs. Additionally, AVP significantly suppressed voltage-activated currents in granule cells without affecting the magnitude of the response of mitral cells to gamma-aminobutyric acid (GABA). The present results suggest that V1aRs play a role in reciprocal transmission between mitral cells and granule cells in the mouse AOB by reducing GABAergic transmission through a presynaptic mechanism in granule cells. [ABSTRACT FROM AUTHOR]

We studied interrelationships between behavioral parameters, metabolic processes, and cytokine content in the blood of male and female rats at different stages of postnatal ontogeny after intrauterine stress (mothers were forced to swim in cold water from the 10th to the 16th day of pregnancy). Correlations between behavioral and metabolic parameters in prenatally stressed rats were revealed at an earlier age (day 21 of life) than in controls. In comparison with intact rats, in males exposed to intrauterine stress no relationships between these parameters were revealed at older age, while in females, their direction and character change on day 60 of life. In prenatally stressed males, correlations of the blood levels of IL-6 were revealed: inverse relationships with behavioral parameters on the days 21 and 30 and direct relationships with metabolic parameters on day 60 of life. In prenatally stressed females on day 30 of life, we observed negative correlations between IL-4 levels and metabolic parameters that were absent under normal conditions. Thus, intrauterine stress leads to reorganization of the relationships between the parameters of metabolic and immune processes, which are essential for the purposeful behavior of mammals. The effects of stress seem to depend on the sex of the offspring and stage of postnatal development. [ABSTRACT FROM AUTHOR]

Anthropogenic activity in coastal areas can damage marine habitats and alter marine mammal behavior and habitat use. Understanding behavioral associations with diverse habitat features in industrialized coastal areas is crucial for marine mammal conservation management. A shore-based digital theodolite was used to assess the behavioral states and habitat use of common bottlenose dolphins (Tursiops truncatus) off Port Aransas, Texas across seasons. The relationship between behavioral states and environmental and geographical variables were analyzed. Behavioral hotspots were identified. Dolphins frequently foraged (46%), indicating the area is an important feeding ground. Dolphins also traveled (25%) and milled (22%), with less frequent occurrences of socializing (6%) and resting (1% of observations). Season, time of day, and distance to shoreline were significant predictors of foraging and traveling behavioral states. Dolphins engaged in all behavioral states closer to seawall shorelines than to mangroves and natural seagrass beds, suggesting that hard shoreline features may influence daily activity patterns. Despite daily anthropogenic operations, bottlenose dolphins use features of the industrialized area (i.e., deeply dredged channels, human-engineered seawalls) to engage in a variety of behaviors. Monitoring of dolphin behavioral states and habitat use in active ship channels are needed to assess changes from baseline data from increasing coastal development and vessel activities. [ABSTRACT FROM AUTHOR]

Arginine vasopressin (AVP) and oxytocin (OT) are well-known as neuropeptides that regulate various social behaviors in mammals. However, little is known about their role in mouse female sexual behavior. Thus, we investigated the role of AVP (v1a and v1b) and OT receptors on female sexual behavior. First, we devised a new apparatus, the bilevel chamber, to accurately observe female mouse sexual behavior. This apparatus allowed for a more precisely measurement of lordosis as receptivity and rejection-like behavior (newly defined in this study), a reversed expression of proceptivity. To address our research question, we evaluated female sexual behavior in mice lacking v1a (aKO), v1b (bKO), both v1a and v1b (dKO), and OT (OTRKO) receptors. aKO females showed decreased rejection-like behavior but a normal level of lordosis, whereas bKO females showed almost no lordosis and no change in rejection-like behavior. In addition, dKO females showed normal lordosis levels, suggesting that the v1b receptor promotes lordosis, but not necessarily, while the v1a receptor latently suppresses it. In contrast, although OTRKO did not influence lordosis, it significantly increased rejection-like behavior. In summary, the present results demonstrated that the v1a receptor inhibits proceptivity and receptivity, whereas the v1b and OT receptors facilitate receptivity and proceptivity, respectively. [ABSTRACT FROM AUTHOR]

Animals migrate to access seasonally variable resources or to escape unfavorable local conditions. Partial (flexible) migration strategies offer animals a fitness trade-off in which individuals may choose whether to incur the energetic costs of migration depending on the potential benefits associated with avoiding adverse conditions. Partial migration patterns may shift because of anthropogenic land use and climate change, possibly reducing the benefits of migration and resulting in unpredictable migration cues. We examined causes, consequences, and changes in individuallevel partial migration of white-tailed deer Odocoileus virginianus by analyzing archival telemetry data (1986-2014) across four distinct populations in the Great Lakes region, North America. We hypothesized that if the costs of migration outweigh benefits, we would see migratory behavior decline. Migratory behavior declined from 75% in 1987 to 11% in 2014 independent of population identity. Annual mortality was higher for migratory white-tailed deer, whereas increasing minimum temperatures positively impacted survival but did not influence migration. Our results suggest that migratory behavior in white-tailed deer is declining over time and may be associated with declining winter severity. The loss of migratory behavior in large mammals may have ecosystem-level impacts and our study emphasizes the need to better understand and conserve these migratory traditions. [ABSTRACT FROM AUTHOR]

Variation in cooperative behavior across mammals is strongly related to the kinship composition of groups. Although the factors affecting average genetic relatedness within groups have been studied, the factors that contribute to the production of different categories of kin remain underexplored. Here, I use a mathematical model to explore the factors that determine the proportion of full siblings, maternal half-siblings, paternal half-siblings, and non-siblings within mammal groups. The results suggest that the production of paternal half-siblings is increased by high male reproductive skew and a female-biased sex ratio, the production of maternal half-siblings is increased by high female reproductive skew and male-biased sex ratio, and that there are two routes to the production of full siblings: either high reproductive skew in both sexes (as seen in cooperatively breeding species) or pair-bond stability within groups of low reproductive skew (as seen in humans). These results broadly correspond to observed variation in sibling composition across mammals. [ABSTRACT FROM AUTHOR]

Globally, grassland degradation is an acute ecological problem. In alpine grassland on the Tibetan Plateau, increased densities of various small mammals in degraded grassland are assumed to intensify the degradation process and these mammals are subject to lethal control. However, whether the negative impact of small mammals is solely a result of population size or also a result of activity and behavior has not been tested. In this study, we use plateau pika as a model to compare population size, core area of colony, and the number of burrow entrances and latrines between lightly and severely degraded grassland. We test whether the alleged contribution of pika to grassland degradation is a result of increased population size or increased burrowing activities of individuals in response to lower food abundance. We found that grassland degradation resulted in lower plant species richness, plant height, and biomass. Furthermore, the overall population size of pika was not significantly affected by location in lightly and severely degraded grassland. However, pika core areas in severely grassland degradation were significantly larger and had significantly higher densities of burrows and latrines. Our study provides convincing evidence that habitat‐induced changes in the behavior of small, burrowing mammals, such as pika, can exacerbate grassland degradation. This finding has significant implications for managing small mammals and restoring degraded grassland ecosystems. [ABSTRACT FROM AUTHOR]

Background: Intestinal microbial composition not only affects the health of the gut but also influences centrally mediated systems involved in mood, through the "gut-brain" axis, a bidirectional communication between gut microbiota and the brain. In this context, the modulation of intestinal microbiota and its metabolites through the administration of probiotics seems to represent a very promising approach in the treatment of the central nervous system alterations. Early postnatal life is a critical period during which the brain undergoes profound and essential modulations in terms of maturation and plasticity. Maternal separation (MS), i.e., the disruption of the mother–pup interaction, represents a pivotal paradigm in the study of stress-related mood disorders, by inducing persistent changes in the immune system, inflammatory processes, and emotional behavior in adult mammals. Results: We conducted experiments to investigate whether sustained consumption of a multi-strain probiotic formulation by adult male mice could mitigate the effects of maternal separation. Our data demonstrated that the treatment with probiotics was able to totally reverse the anxiety- and depressive-like behavior; normalize the neuro-inflammatory state, by restoring the resting state of microglia; and finally induce a proneurogenic effect. Mice subjected to maternal separation showed changes in microbiota composition compared to the control group that resulted in permissive colonization by the administered multi-strain probiotic product. As a consequence, the probiotic treatment also significantly affected the production of SCFA and in particular the level of butyrate. Conclusion: Gut microbiota and its metabolites mediate the therapeutic action of the probiotic mix on MS-induced brain dysfunctions. Our findings extend the knowledge on the use of probiotics as a therapeutic tool in the presence of alterations of the emotional sphere that significantly impact on gut microbiota composition. AdianNxLDM2uLY8oFPQcaD Video Abstract [ABSTRACT FROM AUTHOR]

In an effort to ameliorate the impacts of climate change, forest managers in Central Europe increasingly turn to conifer species that produce higher yields and are better adapted to projected future climatic conditions. Though small mammals are an important component of the forest ecosystem, the impacts of enriching native broadleaf forests with conifers on small mammal communities are not well understood. We conducted mark–recapture surveys of small mammals to ascertain differences in their community structure among stands of two conifers (native Norway spruce Picea abies and non-native Douglas fir Pseudotsuga menziesii) and the dominant broadleaf in the region, European beech (Fagus sylvatica). After estimating the density of two common species, the yellow-necked mouse Apodemus flavicollis and bank vole Clethrionomys glareolus, we found that the population density of each is positively related to the proportion of beech and negatively to the proportion of conifers in each stand, though these effects of stand composition are smaller than the positive effect of herb cover. Increasing Norway spruce proportion reduced monthly survival of small mammals, while Douglas fir proportion had a positive effect on survival. We conclude that the two conifer species have similar impacts on small mammal density, though overall small mammal survival was significantly lower on plots with Norway spruce. This suggests that increasing the proportion of Douglas fir at the expense of Norway spruce may be possible without significantly changing local patterns of small mammal population density, but further research is necessary to elucidate the exact impacts of these two conifer species on small mammal demography and behavior. [ABSTRACT FROM AUTHOR]

Considering that infanticide can oppose the interests between offspring and parents, as well as between the two sexes, the aggressive behavior of adults against infants is considered a fundamental part of the organisms' strategy. Thus, this article aims to describe the types of infanticide, explaining the advantages of each biparental infanticidal behavior. The research was carried out using the Publish or Perish© software, with keywords such as "ethology", "infanticide" and "mammals", in English, Portuguese and Spanish. After selection and discarding, we selected 51 works, including scientific articles, theses and dissertations, covering a period of 40 years. We organized them systematically, separating the references into two approaches: (a) physiological and (b) sociobiological/ecological. The results indicate that infanticide behavior in mammals can be influenced by different factors, such as environmental stress, hormonal pathways, mainly oxytocin and vasopressin. Furthermore, studies have shown that there are individual differences in the behavioral response to parental care and infanticidal behavior, influenced by both the genotype and the environment in which individuals were raised. Infanticide behavior can also be seen as an adaptive parental strategy to increase the chances of survival and future reproduction. Ultimately, our results highlight the complexity of mammalian infanticide behavior, pointing to the importance of considering physiological, sociobiological and ecological factors in its analysis and interpretation. [ABSTRACT FROM AUTHOR]

Passive acoustic monitoring (PAM) has become a popular method for studying both marine mammal behavior and distribution, especially among cetaceans. The Antarctic minke whale (Balaenoptera bonaerensis) occurs in the Southern Hemisphere, and our knowledge concerning its vocal behavior is very limited. Along the coast of Uruguay, minke whales constitute one of the species with the most stranding data collected. Until now, sounds of Antarctic minke whales had never been recorded off the Uruguayan coast. Two different bio-duck call types were recorded along the Atlantic Ocean and the Río de la Plata River coasts by employing PAM stations off the coast of Uruguay in five different positions. One call was recorded off the Atlantic coast, and the four other calls were recorded along the Río de la Plata River, including the classic bio-duck call. In addition to the aforementioned bio-duck call, evidence of a novel call, the bio-duck pulse train, was found. This call was produced in an environment very different from the oceanic environment. The bioduck pulse train has never been described in previous works, making the findings of the present work all the more novel. [ABSTRACT FROM AUTHOR]

The neuropeptidergic mechanisms controlling socio‐sexual behaviours consist of complex neuronal circuitry systems in widely distributed areas of the brain and spinal cord. At the organismal level, it is now becoming clear that "hormonal regulations" play an important role, in addition to the activation of neuronal circuits. The gastrin‐releasing peptide (GRP) system in the lumbosacral spinal cord is an important component of the neural circuits that control penile reflexes in rats, circuits that are commonly referred to as the "spinal ejaculation generator (SEG)." Oxytocin, long known as a neurohypophyseal hormone, is now known to be involved in the regulation of socio‐sexual behaviors in mammals, ranging from social bonding to empathy. However, the functional interaction between the SEG neurons and the hypothalamo‐spinal oxytocin system remains unclear. Oxytocin is known to be synthesised mainly in hypothalamic neurons and released from the posterior pituitary into the circulation. Oxytocin is also released from the dendrites of the neurons into the hypothalamus where they have important roles in social behaviours via non‐synaptic volume transmission. Because the most familiar functions of oxytocin are to regulate female reproductive functions including parturition, milk ejection, and maternal behaviour, oxytocin is often thought of as a "feminine" hormone. However, there is evidence that a group of parvocellular oxytocin neurons project to the lower spinal cord and control male sexual function in rats. In this report, we review the functional interaction between the SEG neurons and the hypothalamo‐spinal oxytocin system and effects of these neuropeptides on male sexual behaviour. Furthermore, we discuss the finding of a recently identified, localised "volume transmission" role of oxytocin in the spinal cord. Findings from our studies suggest that the newly discovered "oxytocin‐mediated spinal control of male sexual function" may be useful in the treatment of erectile and ejaculatory dysfunction. [ABSTRACT FROM AUTHOR]

Wildfires cause profound challenges for animals to overcome due to their reliance on vegetation. This study addresses the impact of three levels of forest burn severity (unburned, low, and high burn severity) on the foraging behavior of small mammals in the Pinaleño Mountains (AZ, USA) using the giving up density (GUD) experiment approach. Overall, burn severity affected the foraging behavior of small mammals that spent less time foraging in high burn severity patches. Vegetation characteristics influenced GUD differently based on the level of burn severity. Higher canopy cover was perceived as areas with a higher predation risk (higher GUD) in unburned and low burn severity patches, while cover provided by logs and shrubs decreased the GUD (increased foraging). This suggests a complicated interaction between horizontal (logs, grass, shrub cover) and vertical vegetation cover in relation to burn severity. Fires affected the foraging behavior of the small mammals but did not impact all species in the same way. Generalists, such as Peromyscus sp. and Tamias dorsalis, seemed to forage across all burn severities, while specialist species, such as tree squirrels, tended to avoid the high burn severity patches. Clarifying the complex impacts of fires on small mammals' foraging behaviors contributes to our understanding of the intricate interactions, at micro-habitat levels, between vegetation structure and the behavioral responses of animals and it can help managers to plan actions to reduce the negative impacts of wildfires. [ABSTRACT FROM AUTHOR]

Maternal behavior in mammals encompasses a complex repertoire of activities that ensure the survival of the offspring and shape their neural and behavioral development. The laboratory rat has been employed as a classic model for investigating maternal behavior, and recently with the use of advanced techniques, the knowledge of its neural basis has been expanded significantly. However, the standard laboratory testing conditions in which rats take care of a single litter impose constraints on the study of maternal flexibility. Interestingly, the reproductive characteristics of this species, including the existence of a fertile postpartum estrus, allow us to study maternal behavior in more complex and ethologically relevant contexts, even in laboratory settings. Here we review how maternal and sexual motivations interact during the postpartum estrus, shaping the behavioral response of females according to the presence of the pups and males. Next, we describe how impregnation during the postpartum estrus creates a new reproductive context in which mothers simultaneously care for two successive litters, adapting their responses to different behavioral and physiological demands of pups. These findings illustrate the behavioral adaptability of maternal rats to pups’ needs and the presence of other reinforcers, as well as its dependence on the context. In our view, future perspectives in the field, by incorporating the use of cutting-edge techniques, should analyze maternal flexibility and its neural substrates in models that incorporate complex and challenging contexts. This approach would allow a more comprehensive understanding of brain circuits involved in the adaptive and flexible nature of parenting. [ABSTRACT FROM AUTHOR]

Aging disrupts circadian clocks, as evidenced by a reduction in the amplitude of circadian rhythms. Because the circadian clock strongly influences sleep-wake behavior in mammals, age-related alterations in sleep-wake patterns may be attributable, at least partly, to functional changes in the circadian clock. However, the effect of aging on the circadian characteristics of sleep architecture has not been well assessed, as circadian behaviors are usually evaluated through long-term behavioral recording with wheel-running or infrared sensors. In this study, we examined age-related changes in circadian sleep-wake behavior using circadian components extracted from electroencephalography (EEG) and electromyography (EMG) data. EEG and EMG were recorded from 12 to 17-weekold and 78 to 83-week-old mice for 3 days under light/dark and constant dark conditions. We analyzed time-dependent changes in the duration of sleep. Rapid eye movement (REM) and non-REM (NREM) sleep significantly increased during the night phase in old mice, whereas no significant change was observed during the light phase. The circadian components were then extracted from the EEG data for each sleep-wake stage, revealing that the circadian rhythm in the power of delta waves during NREM sleep was attenuated and delayed in old mice. Furthermore, we used machine learning to evaluate the phase of the circadian rhythm, with EEG data serving as the input and the phase of the sleep-wake rhythm (environmental time) as the output. The results indicated that the output time for the old mice data tended to be delayed, specifically at night. These results indicate that the aging process significantly impacts the circadian rhythm in the EEG power spectrum despite the circadian rhythm in the amounts of sleep and wake attenuated but still remaining in old mice. Moreover, EEG/EMG analysis is useful not only for evaluating sleep-wake stages but also for circadian rhythms in the brain. [ABSTRACT FROM AUTHOR]

Glycine receptors (GlyRs) are ligand-gated chloride channels comprising alpha (α1–4) and β subunits. The GlyR subunits play major roles in the mammalian central nervous system, ranging from regulating simple sensory information to modulating higher-order brain function. Unlike the other GlyR subunits, GlyR α4 receives relatively little attention because the human ortholog lacks a transmembrane domain and is thus considered a pseudogene. A recent genetic study reported that the GLRA4 pseudogene locus on the X chromosome is potentially involved in cognitive impairment, motor delay and craniofacial anomalies in humans. The physiologic roles of GlyR α4 in mammal behavior and its involvement in disease, however, are not known. Here we examined the temporal and spatial expression profile of GlyR α4 in the mouse brain and subjected Glra4 mutant mice to a comprehensive behavioral analysis to elucidate the role of GlyR α4 in behavior. The GlyR α4 subunit was mainly enriched in the hindbrain and midbrain, and had relatively lower expression in the thalamus, cerebellum, hypothalamus, and olfactory bulb. In addition, expression of the GlyR α4 subunit gradually increased during brain development. Glra4 mutant mice exhibited a decreased amplitude and delayed onset of the startle response compared with wild-type littermates, and increased social interaction in the home cage during the dark period. Glra4 mutants also had a low percentage of entries into open arms in the elevated plus-maze test. Although mice with GlyR α4 deficiency did not show motor and learning abnormalities reported to be associated in human genomics studies, they exhibited behavioral changes in startle response and social and anxiety-like behavior. Our data clarify the spatiotemporal expression pattern of the GlyR α4 subunit and suggest that glycinergic signaling modulates social, startle, and anxiety-like behaviors in mice. [ABSTRACT FROM AUTHOR]

Tagging of animals induces a variable stress response which following release will obscure natural behavior. It is of scientific relevance to establish methods that assess recovery from such behavioral perturbation and generalize well to a broad range of animals, while maintaining model transparency. We propose two methods that allow for subdivision of animals based on covariates, and illustrate their use on N=20$$ N=20 $$ narwhals (Monodon monoceros) and N=4$$ N=4 $$ bowhead whales (Balaena mysticetus), captured and instrumented with Acousonde™ behavioral tags, but with a framework that easily generalizes to other marine animals and sampling units. The narwhals were divided into two groups based on handling time, short (t<58$$ t<58 $$ min) and long (t≥58$$ t\ge 58 $$ min), to measure the effect on recovery. Proxies for energy expenditure (VeDBA) and rapid movement (jerk) were derived from accelerometer data. Diving profiles were characterized using two metrics (target depth and dive duration) derived from depth data. For accelerometer data, recovery was estimated using quantile regression (QR) on the log‐transformed response, whereas depth data were addressed using relative entropy (RE) between hourly distributions of dive duration (partitioned into three target depth ranges) and the long‐term average distribution. Quantile regression was used to address location‐based behavior to accommodate distributional shifts anticipated in aquatic locomotion. For all narwhals, we found fast recovery in the tail of the distribution (<3 h) compared with a variable recovery at the median (∼1–10 h) and with a significant difference between groups separated by handling time. Estimates of bowhead whale recovery times showed fast median recovery (<3 h) and slow recovery at the tail (>6 h), but were affected by substantial uncertainty. For the diving profiles, as characterized by the component pair (target depth, dive duration), the recovery was slower (narwhals‐long: t<16$$ t<16 $$ h; narwhals‐short: t<10$$ t<10 $$ h; bowhead whales: <9 h) and with a difference between narwhals with short vs long handling times. Using simple statistical concepts, we have presented two transparent and general methods for analyzing high‐resolution time series data from marine animals, addressing energy expenditure, activity, and diving behavior, and which allows for comparison between groups of animals based on well‐defined covariates. [ABSTRACT FROM AUTHOR]

Underwater passive acoustics is used worldwide for multi-year monitoring of marine mammals. Yet, the large amount of audio recordings raises the need to automate the detection of acoustic events. For instance, the increasing number of Offshore Wind Farms (OWF) raises key environmental and societal issues relating to their impacts on wildlife. In this context, monitoring marine mammals along with information on their acoustic environment throughout the OWF life cycle is crucial. The objective of this study is to evaluate the ability of a single deep learning model to precisely detect and localize, in time and in frequency, the marine mammal sounds over a wide frequency range and classify them by species and sound types. A broadband hydrophone, deployed at the Fécamp OWF (Normandy, France), recorded the underwater soundscape including sounds from marine mammals occurring in the area. To visualize these sounds, 15-s spectrograms were computed. From these images, dolphin (D) and porpoise (P) sounds were manually annotated, including different types of sounds: Click-Trains (D CT , P CT), Buzzes (D B , P B) and Whistles (D W). The spectrograms were then split into five-fold cross-validation datasets, each containing one half of manual annotations and one half of only background noise. A Faster R-CNN model was trained to precisely detect and classify the marine mammal sounds in the spectrograms. Three model output configurations were used: (1) overall detection of marine mammals (presence vs. absence), (2) detection and classification of species (two classes: dolphin, porpoise) and (3) sound types (five classes: D CT , D B , D W , P CT , P B). For the simplest configuration (1) 15.4 % of the spectrogram dataset had detections while missing only 6.6 % of annotated spectrograms. For the more precise configurations, (2) and (3), the mean Average Precision (mAP) achieved were 92.3 % (2) and 84.3 % (3), and the macro average Area under the curve (AUC) 95.7 % (2) and 94.9 % (3). This model will help to speed up the annotation processes, by reducing the spectrogram quantity to be manually analyzed and having time-frequency boxes already drawn. Several model parameters can be adjusted to trade off missed detections and false positives which need to be carefully considered and adapted to the problem. For instance, these adjustments would be particularly relevant depending on the human resources available to manually check the model detections and the criticality of missing marine mammal sounds. These models are promising, ranging from the simple detection of marine mammal presence to precise ecological inferences over the long term. • Deep learning is needed and promising to monitor marine mammal sounds. • An object detection model is proposed to detect and classify underwater sounds. • Presence and behavior of marine mammals around the wind farm can be inferred. [ABSTRACT FROM AUTHOR]

Monitoring animal behavior is crucial for protecting ecosystems, maintaining ecological balance, and improving animal welfare. By utilizing various monitoring devices, a wealth of behavioral data can be collected, which machine learning techniques can then analyze to identify specific behaviors. Artificial neural networks are particularly important in movement ecology. However, current research on animal behavior recognition faces several limitations. Many existing datasets are limited by homogeneous species categories, simplistic environmental conditions, restricted video perspectives, and a lack of alignment with the complexity of real-world environments. Consequently, there is significant room for improvement in the robustness and generalization of automatic animal behavior recognition models. To address these challenges, this paper introduces a diverse dataset of wild mammal behaviors. This dataset includes a wide variety of typical wild mammal species, providing a foundation for enhancing the generality and robustness of recognition models. The videos in this dataset capture different environmental contexts where wild mammals reside, across various times of day. Based on this dataset, a novel and highly efficient wild mammal behavior recognition model, EDNN, is proposed. The EDNN model integrates both temporal and spatial scales and achieves an average recognition accuracy of 79.17 % for basic locomotion behaviors, with a Top-1 accuracy of 81.37 % and a Top-5 accuracy of 98.04 %. These results demonstrate the feasibility of automating animal behavior recognition using large datasets collected from modern monitoring devices. The EDNN model is highly effective for behavior recognition and can be readily applied across diverse species and scenarios. It efficiently processes various video data and contributes to a deeper understanding of the movement ecology of species that are challenging to observe. • Presents a dataset dedicated to studying wild mammal behavior. • EDNN can effectively recognize wild mammal behavior. • Effectively removes redundant information from the video. • Automated monitoring of wildlife behavior can improve the efficiency of ecological research. [ABSTRACT FROM AUTHOR]

The significant extinctions in Earth history have largely been unpredictable in terms of what species perish and what traits make species susceptible. The extinctions occurring during the late Pleistocene are unusual in this regard, because they were strongly size-selective and targeted exclusively large-bodied animals (i.e., megafauna, >1 ton) and disproportionately, large-bodied herbivores. Because these animals are also at particular risk today, the aftermath of the late Pleistocene extinctions can provide insights into how the loss or decline of contemporary largebodied animalsmay influence ecosystems. Here, we review the ecological consequences of the late Pleistocene extinctions on major aspects of the environment, on communities and ecosystems, as well as on the diet, distribution and behavior of surviving mammals. We find the consequences of the loss of megafauna were pervasive and left legacies detectable in all parts of the Earth system. Furthermore, we find that the ecological roles that extinct andmodernmegafauna play in the Earth system are not replicated by smaller-bodied animals. Our review highlights the important perspectives that paleoecology can provide for modern conservation efforts. [ABSTRACT FROM AUTHOR]

Activity patterns are an important aspect of the behavior and ecology of mammals, and their study can provide relevant information for their conservation; however, this topic has been little studied in multiple Neotropical species. In order to understand these patterns, photo-trapping stands out as one of the techniques that allows information to be obtained from various species of mammals, including some that are difficult to record or study with other methods. In this study, we document the activity patterns of ten species of medium-sized mammals recorded in forest fragments in Marquetalia (Caldas), a municipality located in the central Andes, whose natural ecosystems face various threats such as the expansion of the agricultural frontier and urbanization. For this, camera traps were installed in three forest fragments, and the data were analyzed according to the frequency of records obtained over time, classifying the species as diurnal, nocturnal, crepuscular, or cathemeral. For the species with the highest number of records (Didelphis marsupialis, Dasyprocta punctata and Syntheosciurus granatensis) showing little variation compared to that reported by other authors in areas different degrees of disturbance. These findings are relevant to contribute to understanding some of the factors that influence behavioral aspects of terrestrial mammals and the influence of various pressures and threats on them. [ABSTRACT FROM AUTHOR]

Simple Summary: Maternal behavior involves active and passive responses associated with the willingness to nurse and protect the young. In some species, its expression is very selective toward individuals that are recognized as their own and may be long-lasting, whereas in other species the expression is not as selective or may be short-lasting. Brain processes of acceptance, social recognition, inhibition of rejection/fear, and increase in care motivation mediate its expression. The neurocircuitry of maternal behavior is activated upon exposure to the right natural stimuli, such as those that occur during pregnancy, parturition, and lactation. However, even virgin females and males can respond with maternal behaviors if they develop sensitization to the offspring via cohabitation or cross-sensitization via mating. Herein, we discuss behavioral expression in different species, the natural triggering stimuli, and the putative neurocircuitries of acceptance, social recognition, motivation, and rejection during maternal behavior. Among the different species of mammals, the expression of maternal behavior varies considerably, although the end points of nurturance and protection are the same. Females may display passive or active responses of acceptance, recognition, rejection/fear, or motivation to care for the offspring. Each type of response may indicate different levels of neural activation. Different natural stimuli can trigger the expression of maternal and paternal behavior in both pregnant or virgin females and males, such as hormone priming during pregnancy, vagino-cervical stimulation during parturition, mating, exposure to pups, previous experience, or environmental enrichment. Herein, we discuss how the olfactory pathways and the interconnections of the medial preoptic area (mPOA) with structures such as nucleus accumbens, ventral tegmental area, amygdala, and bed nucleus of stria terminalis mediate maternal behavior. We also discuss how the triggering stimuli activate oxytocin, vasopressin, dopamine, galanin, and opioids in neurocircuitries that mediate acceptance, recognition, maternal motivation, and rejection/fear. [ABSTRACT FROM AUTHOR]

Social behavior studies in mammals are commonly found in the literature. However, nothing is known on the hierarchical relationships of American marsupials, which are mainly composed of cryptic, nocturnal species. We aim to examine the existence of a domination and subordination relationship among Didelphis aurita females. For such purpose, we used capture and recapture data of five resident female individuals in a forest patch for 1 year. Comparative analyses among females were performed in relation to the temporal variation in body size, the spatial segregation in their home ranges, and the individual differences in their diets, all focusing on hierarchical relationships. Behavioral differences were observed between the hypothetically dominant female and other resident females, corroborating the hypothesis of hierarchy among D. aurita females. The dominant female presented larger home range, larger territory, stronger dominance over the patch center, and a mostly different diet regarding young females. Its diet changed from specific food items to a more diversified strategy in the following season, possibly due to the increased competition among adult females during the breeding season. After the disappearance of the dominant female, the central patch area was invaded by another large-sized, well-conditioned, and older female that lived in peripheral areas of the patch. Although the data are from a limited number of individuals and while we think that dominance hierarchy is the most likely explanation for the patterns observed, other interpretations are also possible, and further studies with more data and individuals are needed, to confirm the existence of dominance hierarchy in this species. [ABSTRACT FROM AUTHOR]

Long-term recording of a person's activity (actimetry or actigraphy) using devices typically worn on the wrist is increasingly applied in sleep/wake, chronobiological, and clinical research to estimate parameters of sleep and sleep-wake cycles. With the recognition of the importance of light in influencing these parameters and with the development of technological capabilities, light sensors have been introduced into devices to correlate physiological and environmental changes. Over the past two decades, many such new devices have appeared from different manufacturers. One of the aims of this review is to help researchers and clinicians choose the data logger that best fits their research goals. Seventeen currently available light-and-motion recorders entered the analysis. They were reviewed for appearance, dimensions, weight, mounting, battery, sensors, features, communication interface, and software. We found that all devices differed from each other in several features. In particular, six devices are equipped with a light sensor that can measure blue light. It is noteworthy that blue light most profoundly influences the physiology and behavior of mammals. As the wearables market is growing rapidly, this review helps guide future developments and needs to be updated every few years. [ABSTRACT FROM AUTHOR]

A "walking" gait has been identified in a range of vertebrate species with different body plans, habitats, and life histories. With increased application of this broad umbrella term, it has become necessary to assess the physical characteristics, analytical approaches, definitions, and diction used to describe walks. To do this, we reviewed studies of slow-speed locomotion across a range of vertebrates to refine the parameters used to define walking, evaluate analytical techniques, and propose approaches to maximize consistency across subdisciplines of zoology. We summarize nine key parameters used to characterize walking behaviors in mammals, birds, reptiles, amphibians, and fish. After identifying consistent patterns across groups, we propose a comprehensive definition for a walking gait. A walk is a form of locomotion where the majority of the forward propulsion of the animal comes from forces generated by the appendages interacting with the ground. During a walk, an appendage must be out of phase with the opposing limb in the same girdle and there is always at least one limb acting as ground-support (no suspension phase). Additionally, walking occurs at dimensionless speeds <1 v * and the average duty factor of the limbs is always >0.5. Relative to other gaits used by the same species, the stance duration of a walk is long, the cycle frequency is low, and the cycle distance is small. Unfortunately, some of these biomechanical parameters, while effectively describing walks, may also characterize other, non-walking gaits. Inconsistent methodology likely contributes to difficulties in comparing data across many groups of animals; consistent application of data collection and analytical techniques in research methodology can improve these comparisons. Finally, we note that the kinetics of quadrupedal movements are still poorly understood and much work remains to be done to understand the movements of small, ecothermic tetrapods. [ABSTRACT FROM AUTHOR]

Tropical forests experience high levels of anthropogenic pressure from human activities for the collection of forest products, hunting, and movement of domestic animals that affect circadian temporal activity patterns of mammals. Areas with different protection statuses might show differences in mammal circadian activity because of variation in human use intensity. In this study, we assess if human activity could be a predictor shaping the mammal circadian activity patterns in the Eastern Ghats, a neglected tropical forest landscape in India that experiences high human activity. We present results from camera trap surveys of mammal circadian temporal activity patterns in Papikonda National Park (PNP) and its buffer in the Northern Eastern Ghats hill region. We observed a high overlap between human and mammal activity patterns, particularly with herbivorous species. Mammals displayed high crepuscular activity, particularly herbivores; carnivores, however, were also active during the day. This study provides the first insights on circadian temporal activity patterns of mammals in a protected area and its buffer in India's poorly known Eastern Ghats. We discuss these findings in the context of hunting pressure by humans, protection status, and its implications for mammal behavior in the Eastern Ghats and tropical forests across India. Abstract in Telugu is available with online material. [ABSTRACT FROM AUTHOR]

Background: Studying the anti-predatory behavior of mammals represents an important challenge, especially for fossorial small mammals that hide in burrows. In the Arctic, such behaviors are critical to the survival of lemmings considering that predation risks are high every summer. Because detailed information about how lemmings use burrows as hideouts is still lacking, we developed a 1.59 g photosensitive collar to record any event of a small mammal moving between a dark area (e.g., burrow) and a bright area (e.g., outside the burrow). Tests of how collars affected lemming behavior were conducted in captivity in Cambridge Bay, Nunavut, Canada, in November 2019 and field tests were conducted on Bylot Island, Nunavut, Canada, in August 2021. Results: The device was made of two chemical batteries and a printed circuit board (PCB) equipped with a photosensor and a real-time clock that recorded amplitude transient thresholds of light (lux) continuously. In accordance with ethical use of such devices, we verified that no abnormal loss of body mass was observed in captive or free-ranging lemmings, and no difference in recapture rates were observed between those with and without a collar, though we could not test this for periods longer than 108 h. Measurements of light intensities revealed consistent patterns with high lux levels at mid-day and lowest during the night. Lemmings showed clearly defined behavioral patterns alternating between periods outside and inside burrows. Despite 24-h daylight in the middle of the summer, August nighttime (i.e., 11 PM to 4 AM) lux levels were insufficient for amplitude transient thresholds to be reached. Conclusion: By taking advantage of the long periods of daylight in the Arctic, such technology is very promising as it sets new bases for passive recording of behavioral parameters and builds on the prospect of further miniaturization of batteries and PCBs. [ABSTRACT FROM AUTHOR]

The interest in studying the neural circuits related to mating behavior and mate choice in monogamous species lies in the parallels found between human social structure and sexual behavior and that of other mammals that exhibit social monogamy, potentially expanding our understanding of human neurobiology and its underlying mechanisms. Extensive research has suggested that social monogamy, as opposed to non-monogamy in mammals, is a consequence of the neural encoding of sociosensory information from the sexual partner with an increased reward value. Thus, the reinforced value of the mate outweighs the reward value of mating with any other potential sexual partners. This mechanism reinforces the social relationship of a breeding pair, commonly defined as a pair bond. In addition to accentuated prosocial behaviors toward the partner, other characteristic behaviors may appear, such as territorial and partner guarding, selective aggression toward unfamiliar conspecifics, and biparental care. Concomitantly, social buffering and distress upon partner separation are also observed. The following work intends to overview and compare known neural and functional circuits that are related to mating and sexual behavior in monogamous mammals. We will particularly discuss reports on Cricetid rodents of the Microtus and Peromyscus genus, and New World primates (NWP), such as the Callicebinae subfamily of the titi monkey and the marmoset (Callithrix spp.). In addition, we will mention the main factors that modulate the neural circuits related to social monogamy and how that modulation may reflect phenotypic differences, ultimately creating the widely observed diversity in social behavior. [ABSTRACT FROM AUTHOR]

The superior colliculus is a midbrain structure that plays important roles in visually guided behaviors in mammals. Neurons in the superior colliculus receive inputs from retinal ganglion cells but how these inputs are integrated in vivo is unknown. Here, we discovered that high-density electrodes simultaneously capture the activity of retinal axons and their postsynaptic target neurons in the superior colliculus, in vivo. We show that retinal ganglion cell axons in the mouse provide a single cell precise representation of the retina as input to superior colliculus. This isomorphic mapping builds the scaffold for precise retinotopic wiring and functionally specific connection strength. Our methods are broadly applicable, which we demonstrate by recording retinal inputs in the optic tectum in zebra finches. We find common wiring rules in mice and zebra finches that provide a precise representation of the visual world encoded in retinal ganglion cells connections to neurons in retinorecipient areas. The superior colliculus receives visual information from retinal ganglion cells, but it remains unclear how this information is organized and integrated in vivo. Here the authors describe how high-density electrodes can simultaneously capture the activity of incoming axons and target neurons in the superior colliculus, and demonstrate isomorphic mapping and strong and specific connections in mice and zebrafinches. [ABSTRACT FROM AUTHOR]

Simple Summary: The study aimed at chemically characterizing the marking fluid of both breeding and non-breeding male cheetahs (Acinonyx jubatus). Specifically, it focused on identifying potential differences in pheromones related to sexual behavior/attraction in this species. Furthermore, it aimed at providing more information as a basis for future studies, such as the investigation of specific semiochemicals in the reproductive behavior of cheetahs. The results of this study support the hypothesis of differences in the relative concentration of volatile organic chemicals between male cheetahs; however, they highlight the importance of diet and age on the presence of volatile organic chemicals in the marking fluid. Scent is known to play an important role in the reproduction of cheetahs and other felids. In fact, the presence/odor of a male cheetah has been noted to trigger the estrous cycle in females. The objective of this study was to analyze the marking fluid (MF) of male cheetahs from different breeding groups to determine the composition of volatile organic compounds (VOCs) present, with the aim of identifying potential pheromones relating to sexual behavior/attraction in this species. Four breeding (B; age: 8.9 ± 1.3 years old) and four non-breeding (NB; age: 5.5 ± 0.8 years old) males were selected for this study. Samples were collected into a glass beaker, transferred immediately into a 20 mL glass screw-cap vial with a polytetrafluoroethylene (PTFE) coated silicone septum, and stored until analyzed by headspace solid-phase microextraction (HS-SPME) using gas chromatography–mass spectrometry. A contingency test with Fisher's exact test, using the frequency (FREQ) procedure of SAS 9.4, was conducted to determine the difference between the number of VOCs identified per breeding group; furthermore, differences in relative concentration (RC) of the identified VOCs between breeding groups were analyzed using ANOVA for repeated measures with the GLIMMIX procedure. From the 13 MF samples analyzed, 53 VOCs were identified, and 12 were identified in all the samples. Five of these (dimethyl disulfide, benzaldehyde, acetophenone, phenol, and indole) are known to be involved in attraction/sexual behavior in mammals. Between the two groups, the RC of indole was significantly higher in the NB group, whereas the RC of dodecanoic acid was significantly higher in the B group. Although not significant, the RC of benzaldehyde was higher in the B versus the NB group. The results of this study do support the hypothesis of differences in VOCs' between B and NB male cheetahs. However, the overlapping of age and breeding status and the diet differences could not be controlled. Still, the evidence of changes in MF composition in male cheetahs necessitates further studies on possible strategies to improve reproduction in captivity. [ABSTRACT FROM AUTHOR]

Environmental cues (e.g., light-dark cycle) have an immediate and direct effect on behavior, but these cues are also capable of "masking" the expression of the circadian pacemaker, depending on the type of cue presented, the time-of-day when they are presented, and the temporal niche of the organism. Masking is capable of complementing entrainment, the process by which an organism is synchronized to environmental cues, if the cues are presented at an expected or predictable timeof-day, but masking can also disrupt entrainment if the cues are presented at an inappropriate time-of-day. Therefore, masking is independent of but complementary to the biological circadian pacemaker that resides within the brain (i.e., suprachiasmatic nucleus) when exogenous stimuli are presented at predictable times of day. Importantly, environmental cues are capable of either inducing sleep or wakefulness depending on the organism's temporal niche; therefore, the same presentation of a stimulus can affect behavior quite differently in diurnal vs. nocturnal organisms. There is a growing literature examining the neural mechanisms underlying masking behavior based on the temporal niche of the organism. However, the importance of these mechanisms in governing the daily behaviors of mammals and the possible implications on human health have been gravely overlooked even as modern society enables the manipulation of these environmental cues. Recent publications have demonstrated that the effects of masking weakens significantly with old age resulting in deleterious effects on many behaviors, including sleep and wakefulness. This review will clearly outline the history, definition, and importance of masking, the environmental cues that induce the behavior, the neural mechanisms that drive them, and the possible implications for human health and medicine. New insights about how masking is affected by intrinsically photosensitive retinal ganglion cells, temporal niche, and age will be discussed as each relates to human health. The overarching goals of this review include highlighting the importance of masking in the expression of daily rhythms, elucidating the impact of aging, discussing the relationship between dysfunctional masking behavior and the development of sleeprelated disorders, and considering the use of masking as a non-invasive treatment to help treat humans suffering from sleep-related disorders. [ABSTRACT FROM AUTHOR]

The success of conception in buffalo is greatly dependent on precise estrus detection and time of artificial insemination (AI). Various visual, behavioral, biochemical and gyneco-clinical parameters have been tracked closely and a cost-effective combinatorial model has been developed to detect estrus in buffaloes. Pheromones play pivotal roles in reproduction and behavior of mammals. Urine, an easily available biological material which reflects the internal status of an animal, was recruited for profiling the pheromone compounds during the various phases of estrous cycle using gas chromatography-mass spectrometry (GC-MS) analysis. Among the identified compounds, 4-methyl phenol (4-mp, p-Cresol) and 9-octadecenoic acid (Oleic acid) were found to be estrusspecific and would be promising estrus-indicators. Similarly, detection of luteinizing hormone (LH) in urine was also focused to predict the time of ovulation in buffaloes. Partial success has been obtained in the attempt to develop a cost-effective bioassay kit for estrus detection. The ongoing venture of the relevant research team is to develop a biosensor to identify estrus-specific pheromone compounds in urine. Development of a nanoparticle-based bioassay kit for detection of urinary LH for effective prediction of estrus or ovulation is also in progress. [ABSTRACT FROM AUTHOR]

Dopamine plays important roles in motivational and social behaviors in mammals, and it has been implicated in several human neurological and psychiatric disorders. Rodents are used extensively as experimental models to study dopamine function in health and disease. However, interspecies differences of dopamine systems remain incompletely characterized. Here, we assessed whether the commonly referenced anatomical organization of dopamine systems in Mus musculus differs from another rodent species, Peromyscus californicus, which exhibits unique social behaviors such as biparental care. We applied tyrosine hydroxylase immunofluorescence labeling and high-throughput microscopy to establish whole-brain maps of dopamine systems in P. californicus. By comparing these maps to those from M. musculus, we identified unexpected anatomical similarity and difference between these two species. A sex difference in dopamine neurons at the anteroventral periventricular nucleus of hypothalamus, which has been implicated in regulating the maternal behaviors of the uniparental M. musculus, is similarly present in the biparental P. californicus. In contrast, major interspecies differences from M. musculus are found in the ventral midbrain and striatum of P. californicus, including the expansion of midbrain dopamine neurons into the ventral substantia nigra and the presence of an internal capsule-like white matter tract that demarcates a dorsomedial area from the rest of the striatum. These features identified in P. californicus resemble the anatomical organization of the primate brain more closely compared to those in M. musculus. Our findings suggest that P. californicus is a unique model organism for studying the evolution of dopamine systems in mammals and the disorders of dopamine systems. [ABSTRACT FROM AUTHOR]

Ambient temperature considerably affects the physiology and behavior of mammals. Thermosensory and thermoregulatory abilities play an important role in the response to changing ambient temperature in endotherms. However, the molecular mechanisms of behavioral thermoregulation remain poorly understood. Transient receptor potential vanilloid‐1 (TRPV1) is activated by changes in ambient temperature and is involved in acute thermoregulation. Here, we aimed to determine whether TRPV1 is involved in behavioral thermoregulation in wild rodents by conducting 2 experiments. In the first, 42 adult Mongolian gerbils (Meriones unguiculatus; 14 per treatment) were randomly assigned to 3 housing temperatures (4, 23, and 36°C) for 4 weeks. In the second, 20 gerbils (10 per treatment) were randomly injected with capsaicin (TRPV1 agonist) or AMG517 (TRPV1 antagonist). The results showed a significant decrease in food intake and non‐shivering thermogenesis in the gerbils housed at 36°C. Additionally, there was a significant increase in the preference of gerbils housed at 4°C to low temperatures. The expression of TRPV1 protein in the brown adipose tissue (BAT) and liver was significantly positively correlated with that of protein kinase A (PKA). The expression of TRPV1 and PKA proteins in the BAT was positively correlated with the temperature preference of the gerbils. The gerbils injected with capsaicin preferred significantly lower temperatures than the control group gerbils. These findings suggest that TRPV1 and PKA are involved in behavioral thermoregulation in Mongolian gerbils. [ABSTRACT FROM AUTHOR]

Anthropogenic noise has dramatically increased over the past decades with potentially significant impacts on wildlife and their community interactions. Using giving‐up densities (GUDs) paired with camera traps, we examined the concurrent influence of chronic road noise and predation risk on free‐living small mammals. Specifically, we looked for differences in foraging and vigilance behavior during various noise treatments. We found that small mammals significantly reduced food intake when exposed to predation risk; however, concurrent exposure to road noise eliminated this effect; small mammals increased food intake when exposed to road noise and risk compared to risk alone. Furthermore, road noise reduced the number of visits and time spent at foraging trays while it increased vigilance behavior of small mammals in risky situations, meaning they were able to increase their foraging efficiency. Mice also ate less when moon illumination was greater; however, this had no effect on our overall results. This is one of the first studies to concurrently examine the effects of road noise and predation risk on free‐living prey. It shows the complex responses of prey exposed to chronic noise conditions as they attempt to gain reliable information about predation risk and respond appropriately. We highlight the potential consequences road noise may have on the survival of prey as it interferes with their appropriate risk responses. [ABSTRACT FROM AUTHOR]

In the Anthropocene, understanding the impacts of anthropogenic influence on biodiversity and behavior of vulnerable wildlife communities is increasingly relevant to effective conservation. However, comparative studies aimed at disentangling the concurrent effect of different types of human disturbance on multifaceted biodiversity and on activity patterns of mammals are surprisingly rare. We applied a multiregion community model to separately estimate the effects of cumulative human modification (e.g., settlement, agriculture, and transportation) and human presence (aggregated presence of dogs, people, and livestock) on species richness and functional composition of medium‐ and large‐bodied mammals based on camera trap data collected across 45 subtropical montane forests. We divided the detected mammal species into three trophic guilds–carnivores, herbivores, and omnivores–and assessed the nocturnal shifts of each guild in response to anthropogenic activities. Overall, species richness tended to increase (β coefficient = 0.954) as human modification increased but richness decreased as human presence increased (β = –1.054). Human modification was associated with significantly lower functional diversity (mean nearest taxon distance [MNTD], β = –0.134; standardized effect sizes of MNTD, β = –0.397), community average body mass (β = –0.240), and proportion of carnivores (β = –0.580). Human presence was associated with a strongly reduced proportion of herbivores (β = –0.522), whereas proportion of omnivores significantly increased as human presence (β = 0.378) and habitat modification (β = 0.419) increased. In terms of activity patterns, omnivores (β = 12.103) and carnivores (β = 9.368) became more nocturnal in response to human modification. Our results suggest that human modification and human presence have differing effects on mammals and demonstrate that anthropogenic disturbances can lead to drastic loss of functional diversity and result in a shift to nocturnal behavior of mammals. Conservation planning should consider concurrent effects of different types of human disturbance on species richness, functional diversity, and behavior of wildlife communities. [ABSTRACT FROM AUTHOR]

These thoughts open the discussion of Chapter 2, "Conserving Marine Mammal Spaces and Habitats" by Erich Hoyt, which describes the challenge to identify special areas for marine mammals, using monitoring and management tools. This book represents an amazing journey through one of the most interesting cetology topics: the relationship between humans and marine mammals. It is interesting how these examples offer different perspectives on how to facilitate marine mammal scientists and indigenous people to understand and trust each other in favor of marine mammal conservation and peaceful coexistence. [Extracted from the article]

Time is a fundamental component of ecological processes. How animal behavior changes over time has been explored through well-known ecological theories like niche partitioning and predator-prey dynamics. Yet, changes in animal behavior within the shorter 24-hr light-dark cycle have largely gone unstudied. Understanding if an animal can adjust their temporal activity to mitigate or adapt to environmental change has become a recent topic of discussion and is important for effective wildlife management and conservation. While spatial habitat is a fundamental consideration in wildlife management and conservation, temporal habitat is often ignored. We formulated a temporal resource selection model to quantify the diel behavior of 8 mammal species across 10 US cities. We found high variability in diel activity patterns within and among species and species-specific correlations between diel activity and human population density, impervious land cover, available greenspace, vegetation cover, and mean daily temperature. We also found that some species may modulate temporal behaviors to manage both natural and anthropogenic risks. Our results highlight the complexity with which temporal activity patterns interact with local environmental characteristics, and suggest that urban mammals may use time along the 24-hr cycle to reduce risk, adapt, and therefore persist, and in some cases thrive, in human-dominated ecosystems. [ABSTRACT FROM AUTHOR]

Mammals can show conspicuous behavioral responses to thermal variation, including changes in movement patterns. We used an integrative approach to understand how environmental temperature can drive the movement behavior of a mammal with low capacity for physiological thermoregulation, the giant anteater (Myrmecophaga tridactyla). We tracked 52 giant anteaters in 7 areas throughout the Brazilian savannah. We estimated the distance moved, area used, use of forest areas, and mean environmental temperature for each monitoring day of each individual. We modeled these data with Mixed Structural Equations — considering the possible interactions between our variables and controlling for sex and body mass. Giant anteaters reduced displacement and increased forest use with decreasing environmental temperature, probably because of their low body heat production. It is possible that they reduce distance moved and area used by reducing the duration of activity. With decreasing temperature, forest habitats become warmer than open ones, besides buffer rain and chilly winds. Reducing displacement and using forests are important strategies to reduce body heat loss and the energetic costs of thermoregulation. However, decreasing movement can limit food access and, consequently, fitness. Therefore, we highlight the importance of forests as thermal shelters. With increasing frequency and intensity of extreme weather events, we showed the need to preserve forest patches to offer suitable conditions for tropical mammals' behavioral thermoregulation. In this context, policies favoring deforestation on Brazilian territory are especially worrisome. Finally, we emphasize the need of integrative approaches to understand the complex interactions between organisms and the environment. [ABSTRACT FROM AUTHOR]

Aedes albopictus (Skuse, 1894) has an opportunistic feeding behavior with preference for mammals in different ecological landscapes. However, little is known of the host-seeking behavior and how host selection affects Ae. albopictus. Previously, we found the sex and physiological stage of rats [Rattus norvegicus (Berkenhout), strain Wistar] affected the attraction of Ae. albopictus females. Here, we studied whether blood from different sexes and physiological stages of rats affected the reproduction of Ae. albopictus females in laboratory. The gonotrophic cycle of female mosquitoes fed blood from immature female rats was shorter than those fed blood from mature rats. Time to egg hatching ranged from 1.85 to 1.89 days. Mean time of larval development of Ae. albopictus varied from 8.44 to 8.50 days, and the mean time of duration of the pupal stage of Ae. albopictus varied from 2.01 to 2.07 days depending on the type of blood source the females were fed. The mean total time for development of immature Ae. albopictus was 10.48 to 10.50 days. Female mosquitoes laid more eggs, the percentage of eggs that hatched was greater, and emerged adults had a female-biased sex ratio when fed blood from immature female rats compared to those fed other rat sources of blood. Results of the study are relevant, considering Ae. albopictus might be a potential vector of zoonotic and human arboviruses. [ABSTRACT FROM AUTHOR]

Although arboreal camera trapping is a growing field, it has rarely been used for monitoring plant‐frugivore interactions in the trees. Frugivore foraging behavior generally occurs in trees, hence arboreal camera trapping can be a potentially useful tool for frugivory research. We developed a camera trap sampling method to monitor plant‐frugivore interactions during mature fruiting periods. We used this method to monitor 318 individuals (camera sites) of 18 fleshy‐fruit plant species on 22 subtropical land‐bridge islands in the Thousand Island Lake, China. We recorded a total of at least 52 frugivorous animals, including a ground‐foraging bird species (Lophura nycthemera) and several mammals with foraging behaviors in the trees. We also recorded 4399 independent interaction events, including 275 unique plant‐bird interactions. We proposed a framework to classify interaction types and performed a sampling completeness test. We found that a sampling strategy that covered approximately a third of the fruit maturation period when most fruits were ripe was sufficient to sample plant‐frugivore interactions. Our results demonstrated that our sampling method with camera transects is reliable to monitor plant‐frugivore interactions in a fragmented landscape. This study helps to lay the methodological foundation for building networks of plant‐frugivore interactions with arboreal camera trapping on large spatial/temporal scales. As a non‐invasive, labor‐saving, and largely unbiased sampling method, the field application of arboreal camera trapping in different regions can advance the technology of biodiversity monitoring and lead to more accurate biodiversity inventories in arboreal environments. [ABSTRACT FROM AUTHOR]