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SUMMARY: Reproductive behaviour plays a crucial role in goose production. To date, in most production systems, natural mating is favoured, which has a large impact on successful fertilisation. Two-thirds of the courtships and copulations occurred before noon in Zatorska and Grimaud geese. Depending on the breed, mating activity showed a seasonal pattern (peaking around January–February in Zatorska geese), ranged between 0.5 and 8.5 mating/day, was twice as common in the morning, varied with age and correlated with fertility. To accommodate a less stressful environment for laying and to protect the eggs, individual nest boxes (0.5 × 0.5 × 0.5 m, made of wood, bedded with straw) should be provided along the walls of the shed. Depending on the breed, oviposition interval may vary greatly (between 29 and 60 h), and egg laying may occur in specific times of the day or throughout the day. Broodiness in intensive production systems, due to artificial incubation, is an unwanted behaviour. Despite persistent selection, the occurrence of broodiness is almost 100% in some goose breeds (e.g. Magang or Zhedong geese), while in others, it is less than 5% (Rhine or Huozan geese). Parental care is not relevant in intensive production systems; however, occasionally, goslings are naturally hatched, and the observation of parental behaviours may give insight into the needs of the goslings. Proper environmental conditions and husbandry practices that mimic natural settings can enhance reproductive success, increase gosling survival rates and maintain a healthy social structure within the flock. By recognising and integrating goose reproductive behaviours into management practices, farm managers can optimise production, improve breeding outcomes and ensure the welfare of the animals. This approach leads to healthier flocks, better reproductive performance and, ultimately, more sustainable and humane goose farming operations. [ABSTRACT FROM AUTHOR]

The parental roles of males and females differ remarkably across the tree of life, and several studies suggest that parental sex roles are associated with biased sex ratios. However, there is considerable debate on the causal relationship between sex roles and sex ratios and on the relative importance of the operational sex ratio (OSR), the adult sex ratio (ASR), and the maturation sex ratio (MSR). Here, we use individual-based evolutionary simulations to investigate the joint evolution of sex-specific parental behavior and the various sex ratios in several life history scenarios. We show that typically, but not always, the sex with lower mortality or faster maturity tends to provide most of the care. The association of parental sex roles with the various sex ratios is more intricate. At equilibrium, the OSR is typically biased toward the less caring sex, but the direction and strength of OSR biases may change considerably during evolution. When the MSR or ASR is biased, a broad spectrum of parental care patterns can evolve, although the overrepresented sex generally does most of the caring. We conclude that none of the sex ratios is a driver of parental sex roles; they rather coevolve with care biases in a subtle manner. [ABSTRACT FROM AUTHOR]

Poor knowledge of animal behaviour impedes understanding of ecology and evolution and reduces human appreciation of the natural world. We call this the 'ethological shortfall', parallel to Linnean and other knowledge shortfalls in conservation biology and systematics. We analysed sound recordings of breeding spoon-billed sandpipers (Scolopacidae: Calidris pygmaea), a critically endangered species. Sixteen years of field research, and a focused short-term study, provided material for our study. All the species' calls are unique within its clade; hence our findings have immediate practical use for detecting individuals within the breeding period. No sound recordings exist for the lengthy non-breeding period, when most anthropogenic impacts occur. This gap needs to be filled, so that inventories and automated detection can be conducted in that period. We discovered information that is new and has scientific and practical applications at both the species and higher taxonomic levels (e.g., species-specificity of brief 'alarm' notes). We conclude that a useful account of endangered species' behaviour can be obtained through first-hand knowledge of natural history, a research plan based on knowledge of related species, and targeted sampling. [ABSTRACT FROM AUTHOR]

Wild animals typically organize activity around a 24-h day and daily timing across the year is optimized for both survival and reproductive success. Among-individual variation in chronotype, where individuals differ in when they begin or end their active day relative to a cue such as photoperiod, often exists within a population. Both intrinsic and extrinsic factors contribute to this variation and activity patterns may change across and within different life-history stages as energetic investment changes. Here we describe population level changes in free-living female great tit (Parus major) activity patterns of onset and offset of activity as well as assess variation and repeatability in daily activity both within- and across-breeding stages. We fitted individual females with accelerometers to track activity prior to nest building through chick rearing. Prior to clutch initiation females began their active day before sunrise, however, in the days prior to laying their first egg, activity was delayed until after sunrise. Females ended activity prior to sunset across the monitoring period and earliest during egg laying and incubation. In addition, females exhibited greater among- and within-individual variance in activity during parental care. Female daily activity was moderately repeatable within breeding stages and strongly covaried across several breeding stages. These findings expand our understanding of individual variation in activity patterns during reproduction and the potential fitness implications of chronotype in wild animals. [ABSTRACT FROM AUTHOR]

The evolution of mating systems reflects a balance of the often-conflicting interests of males and females. Polygyny, a mating system in which males have multiple mates, presents a fitness benefit to males, but the consequences for females are less clear. Females with polygynous social mates may suffer reduced fitness, especially secondary females who typically receive less male support. We used 32 yr of detailed reproductive data on a population of Savannah sparrows (Passerculus sandwichensis) breeding on Kent Island, NB, Canada, to investigate the effects of females' social mating status on 6 indices of female fitness: survival, clutch size, fledging success, number of fledglings produced per nest and annually, and recruitment of offspring. Secondary females produced fewer fledglings per nest and annually than did monogamous or primary females, and their young were less likely to recruit into the breeding population. Yearling secondary females also had lower survival rates than older secondary females. Combined with higher rates of partial brood loss among secondary females, our results suggest that secondary females are unable to provide enough care to consistently fledge all nestlings in their broods, likely due to reduced male provisioning. Given that the sex ratio of breeders in the population is female-biased, we suggest that polygyny persists despite its fitness costs because some females must mate polygynously to "make the best of a bad situation." Our study demonstrates the value of detailed, long-term population monitoring data for understanding mating systems and using multiple indices of fitness to analyze the costs of polygyny. [ABSTRACT FROM AUTHOR]

Nest defence is one component of parental investment by which individuals can increase the survival of their offspring. Aggressive behaviours and the time spent protecting nests are determining factors in the reproductive success of cichlid species. The Mexican mojarra is the only cichlid native to the Balsas River Basin in Mexico. At least four invasive cichlids have been introduced, including the convict cichlid and the spotcheek cichlid. These three species establish their nests in the River and defend them aggressively. We quantified the number of nests, aggressive behaviours and time spent in the nest by parents of the native species and these two invasive species. We expected that the invasive parents would be more aggressive during defence, spent more time protecting the eggs, and would have a higher density of nests. We also explored differences in nest defence between the sexes within each species. We found that invasive cichlids had a greater number of nests than the Mexican mojarra. In the two invasive species, there was no difference between males and females in the time spent in the nest or the number of aggressive behaviours. In contrast, male Mexican mojarras spent less time in the nest and performed fewer aggressive behaviours than their mates. The smaller number of nests and nest defence behaviour of this native species could compromise its reproductive success and population size. This differential nest defence between the Mexican mojarra and the invasive cichlids could have negative implications for the physiology, reproduction, and health of this native cichlid. [ABSTRACT FROM AUTHOR]

Simple Summary: Clarifying the relationship between signal variation and social interactions is important for understanding the evolution of signal complexity. While sound and color signals have been well studied, less is known about how social communication shapes the movement-based visual signals. In this study, we examined the relationship between the variation in tail displays and social interactions in the Asian agamid lizard Phrynocephalus vlangalii. We found that males significantly reduced the duration of tail coiling during the mating season, while females increased both the duration and variation in tail movements to meet the demands of parental care. Additionally, females that invested more in reproduction displayed their tails for longer periods. These findings demonstrate that social interaction influences movement-based visual signals, providing new evidence for the evolution of signal complexity from a new signal pattern. The social complexity hypothesis suggests that complex social interactions drive the evolution of sophisticated communicative signals. While the relationship between social communication and the complexity of sound and color signals has been extensively studied, the correlation between social communication and movement-based visual signal complexity remains underexplored. In this study, we selected the Asian agamid lizard, Phrynocephalus vlangalii, as our model system. Through a combination of controlled experiments, behavioral observations, and signal quantification, we examined the relationship between social communications and variation in movement-based visual signals and tested our social complexity hypothesis. Our experiments revealed that males significantly decreased the tail coil duration during the mating season to deal with high social interaction. Conversely, females significantly increased the tail display duration and variation in mean tail coil amplitude in line with the intensity of parental care, and tail display duration showed a significant and positive correlation with female reproductive investment. These findings suggest that social communication plays an important role in shaping the changes in movement-based visual signals, providing new evidence for the social complexity hypothesis. [ABSTRACT FROM AUTHOR]

Species classified as "urban-adapters" are often assumed to thrive in cities because they are commonly found across the urbanization gradient. However, urban-living populations of many urban-adapted species have been found to have lower reproductive success relative to their rural counterparts. Sturnus vulgaris (European Starling) is a common urban-adapted species found across most of the globe. While S. vulgaris have lowered reproductive success in urban areas in their native range, less is known about how urbanization impacts reproduction in their invasive ranges. We tested for differences in reproductive investment and success across urban and rural S. vulgaris populations in Georgia, which is part of their North American invasive range. We found few differences in reproductive output for urban vs. rural S. vulgaris —clutch size, egg mass, egg volume, incubation behavior, provisioning rates, brooding behavior, and nestling wing chord were all similar across S. vulgaris populations from more urban and more rural study sites. Although urban birds produced a higher number of hatchlings and rural birds produced young in higher body condition, neither of these factors influenced reproductive success because the number of fledglings produced were similar for urban and rural breeding S. vulgaris. Overall, S. vulgaris in their invasive range performed similarly well in more urban vs. more rural habitats. Future work should explore whether urbanization affects other components of fitness in starlings (e.g. adult survival). [ABSTRACT FROM AUTHOR]

Parental care is costly to parents because it consumes energy and reduces the available time for future reproduction. Hence, in theory, parents should not care for the eggs or offspring of unrelated individuals. However, parental care for unrelated offspring has been demonstrated for some animal species, although it has been unclear whether such animals distinguish their offspring from unrelated individuals. Here, we examined protection of non-offspring eggs by adult females of the predatory mite Gynaeseius liturivorus, which discriminate eggs laid by other females, against the predatory mite Neoseiulus californicus. Adult female G. liturivorus protect their eggs against predators. Several adult females of this species are sometimes found with clustered eggs in field; hence, G. liturivorus mothers may protect non-offspring eggs. When G. liturivorus eggs were kept with N. californicus in the presence of conspecific adult females that were not mothers of the eggs, their survival was higher than in the absence of conspecific females. Although adult female G. liturivorus oviposited during experiments, the addition of eggs did not increase the survival of non-offspring eggs. Adult females did not cannibalise newly hatched non-offspring larvae in the presence of food, suggesting that the presence of adult females did not affect larval survival. Furthermore, adult females protected their own eggs laid during experiments, suggesting that protection of non-offspring eggs was not costly to the females. Our results also suggest that adult female G. liturivorus may protect conspecific eggs when abundant food is available. Significance statement: Parental care is observed in a wide range of taxa and commonly provided for offspring and/or kin individuals. However, some animal species take care of unrelated individuals. This might be because such species do not discriminate between their own offspring and those of conspecifics. In this study, we experimentally demonstrated that non-offspring eggs were protected from predators by adult females of the predatory mite, Gynaeseius liturivorus, which distinguish their own eggs from conspecific eggs. Newly hatched non-offspring larvae were not cannibalised by adult female mites in the presence of food. Adult females also protected their own eggs irrespective of the presence of conspecific eggs. Our results suggest that adult female predatory mites protect non-offspring when food availability is high. [ABSTRACT FROM AUTHOR]

In the life history of avian taxa, homeothermy, egg laying and the need for rapid growth of the offspring are regarded as crucial evolutionary drivers for their social structure and the establishment of reproductive units [...]

Environmental factors have well-documented impacts on brain development and mental health. Therefore, it is crucial to employ a reliable assay system to assess the spatial preference of model animals. In this study, we introduced an unbiased quadrant chamber assay system and discovered that parental pup-gathering behavior takes place in a very efficient manner. Furthermore, we found that test mice exhibited preferences for specific environments in both spontaneous and parental pup-gathering behavior contexts. Notably, the spatial preferences of autism spectrum disorder model animals were initially suppressed but later equalized during the spontaneous behavior assay, accompanied by increased time spent in the preferred chamber. In conclusion, our novel quadrant chamber assay system provides an ideal platform for investigating the spatial preference of mice, offering potential applications in studying environmental impacts and exploring neurodevelopmental and psychiatric disorder models.

Parental care is reported in several insect orders. Usually, it involves protecting eggs, burying them, moving a batch of eggs from place to place and feeding the larvae. Insect parental care is well developed in Heteroptera and is particularly widespread in the superfamily Pentatomoidea. The species best known for their maternal care belong to the subfamily Sehirinae (Cydnidae) and the genus Parastrachia (Parastrachiidae). There are no published data on parental care in species of the genus Dismegistus (the second genus within the family Parastrachiidae). This paper provides the first reports of females of species of Dismegistus carrying and guarding egg batches in the same way as species in the genus Parastrachia and certain Sehirinae.

There is increasing evidence that competent handling of social interactions among conspecifics has positive effects on individual fitness. While individual variation in social competence has been appreciated, the role of long‐term experience in the acquisition of superior social skills has received less attention. With the goal of promoting further research, we integrate knowledge across disciplines to assess social expertise, defined as the characteristics, skills and knowledge allowing individuals with extensive social experience to perform significantly better than novices on a given social task. We focus on three categories of social behaviour. First, animals can gain from adjusting social behaviour towards individually recognised conspecifics that they interact with on a regular basis. For example, there is evidence that some territorial animals individually recognise their neighbours and modify their social interactions based on experience with each neighbour. Similarly, individuals in group‐living species learn to associate with specific group members based on their expected benefits from such social connections. Individuals have also been found to devote considerable time and effort to learning about the spatial location and timing of sexual receptivity of opposite‐sex neighbours to optimise reproduction. Second, signallers can enhance their signals, and receivers can refine their response to signals with experience. In many birds and insects, individuals can produce more consistent signals with experience, and females across a wide taxonomic range can adaptively adjust mating preferences after perceiving distinct male signals. Third, in many species, individuals that succeed in reproducing encounter the novel, complex task of caring for vulnerable offspring. Evidence from a few species of mammals indicates that mothers improve in providing for and protecting their young over successive broods. Finally, for social expertise to evolve, heritable variation in social expertise has to be positively associated with fitness. Heritable variation has been shown in traits contributing to social expertise including social attention, empathy, individual recognition and maternal care. There are currently limited data associating social expertise with fitness, most likely owing to sparse research effort. Exceptions include maternal care, signal refinement, and familiarity with neighbours and group members. Overall, there is evidence that individuals in many species keep refining their social skills with experience throughout life. Hence we propose promising lines of research that can quantify more thoroughly the development of social expertise and its effects on fitness. [ABSTRACT FROM AUTHOR]

Birds employ various methods to defend their nests against predators, such as nest defense behavior. The males of the Eurasian Wren (Troglodytes troglodytes) are polygamous and build multiple dome-shaped nests. Although previous studies report a moderately high predation rate for Eurasian Wren nests, its predator assemblage is poorly understood. To investigate the Eurasian Wren's potential nest predators through the breeding cycle, we conducted direct observations and surveillance using trail cameras on Shikoku Island, Japan. Our recordings revealed several predators and potential threats to wren nests, including Eurasian Jays (Garrulus glandarius), a crow (Corvus sp.), and a Japanese weasel (Mustela itatsi), which were found to attack the nests at different reproductive stages. Notably, we observed a nest-constructing male wren encounter a Japanese striped snake (Elaphe quadrivirgata) and interact with it in an intriguing way. Instead of attacking the snake or sounding an alarm, the wren flew out of the nest and repeatedly approached the snake before backing away to maintain a cautious distance from the nest. This behavior consequently led the snake away from the nest, with the wren accompanying the snake to alter its path effectively. This "lead-away" behavior may thus be a distraction display. Our finding underscores the possibility of proactive nest defense behavior occurring even before mating. It is essential to explore how birds behave to ensure the safety of nesting sites at the early stage of the nesting cycle. 要旨 (Japanese 日本語) —鳥類は、巣の防衛行動など、様々な方法で捕食者から巣を守る。ミソサザイ Troglodytes troglodytes のオスは一夫多妻で、1&#12473個体のオスがドーム型の巣を複数作る。先行研究では本種の巣の捕食率が高いことが報告されているが、その捕食者相はほとんど分かっていない。本種の繁殖サイクルにおける潜在的な巣の捕食者の動物相を明らかにするため、四国にて、直接観察とトレイルカメラによる監視を実施した。その結果、繁殖サイクルのさまざまな段階で、カラス Corvus sp. 、 カケス Garrulus glandarius、 ニホンイタチ Mustela itatsi が巣を攻撃する様子が記録され、これらが捕食者あるいは潜在的な脅威であることが判明した。特筆すべきことに、巣作りの最中にあるミソサザイのオスがシマヘビ Elaphe quadrivirgata と遭遇し、興味深い反応を示すことが観察できた。このオスは、ヘビを認識すると巣から飛び出し、ヘビを攻撃したり警戒声を発したりすることなく、巣との間に注意深く距離を保ちながら、ヘビに接近しては遠ざかるという行動を繰り返した。このオスは、ヘビを先導しつつ伴い、巣から遠く離れていき、その結果、ヘビの進路を変化させた。このオスの行動は、ある種のディストラクション・ディスプレイである可能性がある。この発見は、巣の防衛行動が交尾よりも前に生じうることを強調するものである。営巣サイクルの初期段階で巣場所の安全を確保するために鳥がどう振る舞うかを探索することが不可欠である。 [ABSTRACT FROM AUTHOR]

Arctic‐breeding birds exhibit around‐the‐clock activity, and these activity cycles are postulated to maximize reproductive success during the short breeding season characteristic of high‐latitude regions. Two closely related species of arctic‐breeding songbirds, Lapland longspurs (Calcarius lapponicus; ground‐nesting) and snow buntings (Plectrophenax nivalis; cavity‐nesting) exhibit extended activity cycles throughout the polar day (71° N) except for 4–5 h of daily quiescence. Ground‐nesting Lapland longspurs experience higher levels of nest predation than cavity‐nesting snow buntings, and this difference is reflected in elevated nest vigilance in male longspurs compared with snow buntings. In this study, we examined the effect of melatonin supplementation upon male parental care, corresponding measures of nestling growth, and ability to reduce activity (and increase sleep). A pharmacological dose of melatonin in captive snow buntings dampened the amplitude of activity rhythms over the polar day with no detectable phase‐shifting compared with control‐implanted birds. Melatonin treatment reduced nest visits and overall time spent on the nest by male snow buntings compared with controls. There was no significant increase in time spent by female snow buntings on the nest to compensate for this, and there was no significant effect on offspring growth rates. There were no effects of melatonin supplementation on longspur adults or offspring, suggesting behavioral insensitivity to exogenous melatonin treatment. These differences in sensitivity underscore the importance of nest defense in ground‐nesting longspurs compared with cavity‐nesting snow buntings, which participate minimally in nest defense. Research Highlights: Melatonin supplementation altered male parental care in a cavity‐nesting arctic‐breeding bird, the snow bunting (Plectrophenax nivalis).Melatonin supplementation dampened activity rhythms.Lapland longspurs (Calcarius lapponicus), a ground‐nesting congener, were unaffected by melatonin treatment. [ABSTRACT FROM AUTHOR]

Nestlings of altricial birds are not typically provisioned water. For the first time in a wild altricial bird we provide annotated video documentation of adult pied crows (Corvus albus) gathering water with their bills and provisioning it to their nestlings in a similar manner as food is delivered. The circumstances of this provisioning suggest that the function is to dislodge anthropogenic food (mainly boiled rice, which has a sticky consistency) from the parent's bill, flush it into the mouth of the nestling, and facilitate swallowing. The means by which the adults gather the water without swallowing and transport it is also unusual. Water provisioning by pied crows is a previously undescribed example of corvid ingenuity, likely in an effort to handle novel food in a human-altered environment. [ABSTRACT FROM AUTHOR]

Simple Summary: Parental care in birds is a common area of interest for bird experts and behavior scientists. Raising chicks can take a lot of energy and may influence the health, survival and future breeding success of the parents. Typically, mates contribute similarly to the work of caring for their young. This study looks at the breeding behavior of a bearded vulture (Gypaetus barbatus) pair on the island of Crete (Greece), focusing on how the male and the female bird share parental care throughout the breeding season. The results show that both parents contributed similarly to caring for their young but with some differences. The male spent more time incubating the eggs and watching over the chick, while the female focused more on keeping the chick warm, feeding it, and maintaining the nest. Incubation and brooding tasks were steady throughout the day, while feeding happened more often during the early morning. As the breeding season went on, the parents' behavior became more relaxed. On average, the birds switched roles in the nest about 2.3 times a day depending on the local environment and their need to find food. This study investigates the breeding behavior of the bearded vulture (Gypaetus barbatus) with regard to the role of the sexes in parental care and the stages of the breeding season. Fieldwork took place in western Crete, where one pair was monitored through an automated surveillance system during 2003–2005, recording 892 h of data. A continuous focal sampling method was pursued, marking the behavioral pattern of each parent bird in the nest. Our results show minimal sexual differences in parental investment, though variations were detected in the frequency and the time spent on certain breeding duties. The male was more often recorded attending the chick and incubated the clutch for longer bouts. Conversely, the female contributed more in brooding and feeding the young as well as in maintaining the nest in good condition. Incubation and brooding were consistent throughout the daytime, while feeding was more often recorded during early morning hours. All behavioral patterns relaxed as the breeding season progressed. Social interactions culminated during 5–7 weeks after egg hatching. The mean frequency of nest changeovers was 2.3 ± 1.49 per day or ca. every 3.7 h, varying through the breeding season, depicting the local environmental conditions and the time budget spent in foraging by the adult birds. [ABSTRACT FROM AUTHOR]

ABSTRACT Parents may experience a trade‐off between caring for offspring and protecting themselves from predators. The reproductive value hypothesis predicts that parents should take more risks for older, more valuable offspring, whereas the harm to offspring hypothesis predicts that parents should risk more for vulnerable offspring that would suffer most from a lack of parental care at the moment. After exposing parent mountain bluebirds (Sialia, currucoides) to a model predator, we recorded latency times for them to touch, to look into, and to enter their nestbox and the number of times they inspected the box across three breeding stages: nest‐building, incubation and nestling‐rearing. Females took greater risks than males during the nest‐building and incubation stages by inspecting and entering boxes sooner and more times, consistent with their role in parental care at those early breeding stages that requires them to enter the box. Risk‐taking in males was consistent with the reproductive value hypothesis, increasing across breeding stages. In contrast, females took the greatest risk during incubation, consistent with the harm to offspring hypothesis. Furthermore, the riskiest behaviours were not correlated between pair members, and both sexes assumed the risk to first inspect the nestbox approximately equally. This suggests there is not a ‘war of attrition’ between mates over risk‐taking, but neither was there cooperation by the male to facilitate the rapid resumption of parental care by his mate. The results highlight that patterns of investment in nest defense in birds may be sex‐specific. [ABSTRACT FROM AUTHOR]

This paper looks at the relationship between child care choices and children's cognitive skills at an early age. The care choices include parental care, center care, relative care and non-relative care. I use children's motor and mental scores at 9 months as a baseline control for their innate ability and their reading and maths scores in kindergarten as outcome measures of cognitive development. My estimates show that non-parental care is related to better scores for children from less-educated households. Further analysis on some parenting activity and parenting style measures shows that reading to children more frequently and a healthy parenting approach have the potential to reduce the parental and non-parental care gap. [ABSTRACT FROM AUTHOR]

Principles of social evolution have long been used retrospectively to interpret social interactions, but have less commonly been applied predictively to inform conservation and animal husbandry strategies. We investigate whether differences in developmental environment, facilitated by divergent social conditions, can predict resilience to environmental change. Upon exposure to harsh novel environments, populations that previously experienced more benign social environments are predicted either to suffer fitness losses (the "mutation load hypothesis" and "selection filter hypothesis") or maintain fitness (the "beneficial mutation hypothesis"). We tested these contrasting predictions using populations of burying beetles Nicrophorus vespilloides we had evolved experimentally for 45 generations under contrasting social environments by manipulating the supply of post-hatching parental care. We exposed sexually immature adults from each population to varying heat stress and measured the effect on survival and reproduction. The greater the level of parental care previously experienced by a population, the better its survival under heat stress during sexual maturation. Although this is consistent with the "beneficial mutation hypothesis," it is also possible that populations that had evolved without post-hatching care were simply more prone to dying during maturation, regardless of their thermal environment. Overall, we suggest that stochastic genetic variation, probably due to founder effects, had a stronger influence on resilience. We discuss the implications for translocation and captive breeding programs. [ABSTRACT FROM AUTHOR]

In many animal species, including most birds, parental care is performed by both parents, which has important implications for mate choice (good parent hypothesis) and parental investment strategies. Partitioning the variance in measures of parental care into heritable and nonheritable components is important to understand the evolvability of parental investment and its potential role in mate choice. We employed an automated system to monitor provisioning behavior at 817 blue tit nests over 10 years (totaling ~3 million visits). Daily provisioning rates of males and females were moderately repeatable between years (Radj = 0.16 and 0.15, respectively), which was almost entirely explained by additive genetic effects. While this degree of heritability is sufficient for parental investment to respond to selection, we argue that the modest level of repeatability provides limited potential for a "provisioning phenotype" to be used as a criterion in mate choice. Daily visit rates were positively correlated between pair members, but after accounting for shared environmental factors, this relationship became clearly negative, thereby providing support for models of partial compensation. Visit rates also differed substantially between years, and between days within a year. Thus, it is important to account for these variables when comparing the parental investment between individuals. Our results highlight the interplay between genetic, social, and environmental influences on provisioning behavior. [ABSTRACT FROM AUTHOR]

In many taxa, young can recognize their parents using olfactory cues. Yet this possibility has been overlooked in birds, because they were long assumed to have a poor sense of smell. While evidence is growing that birds use odours to communicate, olfactory parent recognition has only been documented in two altricial bird species. Whether chicks of precocial species use olfaction to recognize parents is currently unknown. Parent recognition is particularly important in precocial species, as chicks leave the nest shortly after hatching, and may lose contact with their parents and encounter other conspecific adults. We conducted Y-maze trials in the wild to test whether chicks of a precocial shorebird, the white-fronted plover, Anarhynchus marginatus , can recognize parents via olfaction. We tested first whether chicks show a preference for the odour (preen oil) of an unfamiliar adult over a control (no odour), and second whether chicks show a preference for the odour of a parent over that of an unfamiliar adult. Plover chicks spent as much time with the odour of an unfamiliar adult as with the control, and as much time with the odour of a parent as with that of an unfamiliar adult. Therefore, we found no evidence that chicks react to the preen oil odour of a conspecific adult, nor that they can discriminate a parent using preen oil odours. It may be that chicks of this species can discriminate parental and foreign odours but that our experiment failed to detect it, that they rely on other (e.g. auditory) cues, or that they do not need to discriminate between parents and foreign conspecific adults. • Young can recognize their parents using olfactory cues in many taxa. • Plover chicks are precocial and could benefit from parent recognition. • Odour preferences of wild plover chicks were tested using a Y-maze in the field. • Plover chicks did not prefer parental odours (preen oil). • We found no evidence of olfactory parent recognition in white-fronted plovers. [ABSTRACT FROM AUTHOR]

Temporal variation in resource availability, amplified by global change, may have strong impacts on species breeding at temperate and high latitudes that cue their reproduction to exploit seasonal resource pulses. This study examines how resource availability and parental care influence niche partitioning between and within age classes in the rufous‐collared sparrow, which provides extensive parental care. We hypothesized juveniles would exhibit narrower niches focused on high‐quality resources compared to adults, regardless of resource availability. We used stable isotope analysis to quantify individual and population niches in juveniles and adults across the breeding season in two cohorts experiencing contrasting resource landscapes. Contrary to our initial hypothesis, juveniles exhibited greater among‐individual diet variation and smaller total niche widths (i.e. higher levels of individual specialization, IS) during periods of high food availability in comparison to periods of food scarcity. Interestingly, total niche width and IS of adults remained stable across seasons despite a shift in trophic level, highlighting their potential role in providing a consistent diet for their young. These findings reveal a dynamic interplay between resource availability, parental care, and IS, with important implications for understanding population resilience under variable resource scenarios. The study also suggests that adult sparrows modify their provisioning strategies based on resources, potentially buffering offspring from environmental fluctuations. Understanding age‐specific responses to resource variation is crucial for predicting species responses to ecological conditions, particularly in regions like central Chile where seasonal resource limitation is expected to become more variable in response to climate change. [ABSTRACT FROM AUTHOR]

Settlement patterns of juvenile fish shape coral reef communities. During the recruitment process, predation rates are extremely high. However, the role that parental care plays in reducing mortality, especially by cryptic natural enemies such as parasites, remains largely unstudied. We investigated whether parental care in the spiny chromis damselfish (Acanthochromis polyacanthus) protects juveniles from parasite-induced mortality by gnathiid isopods (Gnathia aureamaculosa). Using laboratory experiments, we found that survival of recently hatched juveniles when exposed to gnathiids was higher when parents were present (77%) than when parents were absent (25%). Investigation of their faeces in the field and laboratory indicates that adults consume gnathiids. Together, our data suggest that parental care plays a key role in reducing parasite-induced mortality of juvenile spiny chromis via parental consumption of gnathiids. This highlights the overlooked role of parasites as a source of high mortality in juvenile coral reef fishes and the composition of coral reef fish communities. [ABSTRACT FROM AUTHOR]

Background: Adolescence is a period characterized by rapid biological and psychological change, and adolescents have a heightened risk of depression. Parental rearing is an important influencing factor for depression in adolescence. However, the mechanism of influence needs further exploration. Methods: A total of 1839 adolescents were recruited from a junior and a senior high school in Zhongshan City, Guangdong Province, China. They were requested to completed the Parental Bonding Instrument (PBI), Self-Compassion Scale (SCS), and Depression Anxiety and Stress Scale-21(DASS-21). Results: Adolescents recalled their mothers as being more caring and controlling than their fathers. Parental care (maternal care, paternal care) and parental encouragement of autonomy (maternal encouragement of autonomy, paternal encouragement of autonomy) were both negative predictors of depression, while parental control (maternal control, paternal control) was positive predictor of depression. Self-compassion mediated all relationships between parental rearing styles (parental care, parental encouragement of autonomy, and parental control) and depression but played different mediating roles (complete or incomplete mediating role) in different relationships. Conclusion: Self-compassion plays a mediator role in all relationships between perceived parental rearing styles (parental care, parental encouragement of autonomy, and parental control) and depression. Adolescents who grown up with less parental care, less parental encouragement of autonomy, and high parental control deserve special attention. Educators and clinicians could help those adolescents reduce the occurrence of depression by increasing their level of self-compassion. [ABSTRACT FROM AUTHOR]

Mortality generally is higher around birth and then progressively declines through the juvenile stage. In species where offspring depend upon their parents during maturation, a factor behind this mortality decline could be sibling replacement: offspring sacrifice their survival to benefit future or present siblings as early as possible in order to minimize losses in parental investment. Here, we propose a kin-selection model of sibling replacement. Theoretical analysis of the model and its application to demographic data of mammals suggest that sibling replacement consistently generates a selective incentive for increasing juvenile mortality at early ages when this mortality increment is the result of positive selection for juvenile altruism within the nuclear family. The model highlights how sibling replacement goes beyond optimal allocation of parental resources into dependents and can provoke greater mortality closer to birth also in response to a more favorable ratio of actors to recipients of altruism among siblings. [ABSTRACT FROM AUTHOR]

In species with biparental care, coordination of parental activities can have important fitness consequences. However, specific behavioral mechanism allowing the coordination of breeding partners remains largely unexplored. Prevalence of biparental care in seabirds makes this group particularly interesting for investigation of behavioral underpinnings of parental coordination. Here, we examined vocal behavior at the nest site of breeding partners and its role in shaping their parental share during incubation in the little auk (Alle alle). We evaluated two hypotheses related to the mechanisms involved in parental coordination: (1) behavioral adjustment, where a parent adjusts its effort according to the preceding effort of its partner and (2) vocal negotiation, where effort is adjusted based on information exchanged during the preceding vocal interaction. We found that little auk partners equally share their incubation time, although, duration of nest attendance is highly variable. No immediate reciprocity between partners in the time allocated to parental activity was observed as predicted by behavioral adjustment. However, nest attendance appeared to be related to the vocal interaction between partners during turn-taking. The duration of a given attendance was positively associated to the pair's vocal activity and amount of vocal overlap occurring during turn-taking at the nest. Our results suggest a role of vocalization for coordinating between breeding pairs, providing a potential mechanism for the communication of information enabling this complex interaction. [ABSTRACT FROM AUTHOR]

Parental practices and stress are associated with both CU and autistic traits, with parents of children with these traits facing challenges that other parents do not encounter. However, the majority of available studies focused mainly on the unique effects of CU and autistic traits with parental stress and practices without exploring their interaction. The current study examines the distinct associations and interactions between CU and autistic traits with parental practices (parental involvement, poor monitoring, inconsistent discipline, and corporal punishment), care, and distress after considering the effect of conduct problems (CPs), age and sex in a Greek-Cypriot sample (N = 146, Mage = 7.30, SD = 1.43). Hierarchical multiple regression analysis revealed that children with CU traits were more likely to experience negative parenting, while parents showed heightened levels of distress. Notably, the study found no association between CU traits and positive parental practices. Further analysis indicated no significant relation between autistic traits and interactions with the target variables, signifying that these traits are not associated with difficulties in parenting and distress. No sex differences were found in all analyses. Age was negatively significant only in relation to parental distress These findings provide valuable insights into the impact of CU traits and underscore the need for additional studies investigating the impact of autistic traits, possibly within clinical samples. [ABSTRACT FROM AUTHOR]

The provision of care to offspring is a costly endeavour that can be hijacked by others—known as brood parasitism. Females can choose to lay eggs in the nest of a conspecific female, resulting in extra‐pair maternity (EPM).Burying beetles of the genus Nicrophorus use small vertebrate carcasses for reproduction and provide biparental care to their offspring. Carcasses are a rare resource; thus, competition often occurs among adults of the same sex.A previous study examined the outcomes of competition and subsequent parental care of Nicrophorus vespilloides using laboratory experiments. Larvae of losing females were sometimes cared for by the winning females, which is generally an evidence of EPM.However, the presence of EPM in burying beetles under natural conditions has not yet been well established. Here, we focused on the reproduction of N. quadripunctatus in the field. To examine the presence of EPM, maternity analysis was performed on 149 offspring and their caring females in 10 broods, using 8 microsatellite DNA loci.Seven larvae originating from three broods were unrelated to their caring females. There were one to three unrelated larvae in each of the three broods. Thus, EPM occurs in N. quadripunctatus reproduction under natural conditions. [ABSTRACT FROM AUTHOR]

Alternative reproductive tactics (ARTs) are thought to be more abundant in males than in females owing to higher fitness variance in males and higher female investment in reproduction, but there are no strong empirical or theoretical studies that support this. Whereas male ARTs tend to act pre-mating (focusing on fertilization), female ARTs can occur at various stages of reproduction (from mate finding to brood care) and form complex networks of decision points. The evolutionary dynamics of female ARTs can be condition- and frequency-dependent, and can be influenced by factors including sexual antagonism and intralocus tactical conflict. Evidence for female ARTs is abundant, and they are more common than is often appreciated. However, their eco-evolutionary drivers are not well understood, calling for future research. It is often argued that anisogamy causes alternative reproductive tactics (ARTs) to be more common in males than females. We challenge this view by pointing out logical flaws in the argument. We then review recent work on the diversity of female ARTs, listing several understudied types such as solitary versus communal breeding and facultative parthenogenesis. We highlight an important difference between male and female ARTs that caused female ARTs to be overlooked: male ARTs tend to focus on successful fertilization, whereas female ARTs occur at many stages of reproduction and often form complex networks of decision points. We propose to study correlated female ARTs as a whole to better understand their drivers and eco-evolutionary dynamics. [ABSTRACT FROM AUTHOR]

Avian brood parasitism is an evolutionarily derived behavior for which the neurobiological mechanisms are mostly unexplored. We aimed to identify brain regions that have diverged in the brood‐parasitic brain using relative transcript abundance of social neuropeptides and receptors. We compared behavioral responses and transcript abundance in three brain regions in the brown‐headed cowbird (BHCO), a brood parasite, and a closely related parental species, the red‐winged blackbird (RWBL). Females of both species were treated with mesotocin (MT; avian homolog of oxytocin) or saline prior to exposure to nest stimuli. Results reveal that MT promotes approach toward nests with eggs rather than nests with begging nestlings in both species. We also examined relative transcript abundance of the five social neuropeptides and receptors in the brain regions examined: preoptic area (POA), paraventricular nucleus (PVN) and bed nucleus of the stria terminalis (BST). We found that MT‐treated cowbirds but not blackbirds exhibited lower transcript abundance for two receptors, corticotropin‐releasing factor 2 (CRFR2) and prolactin receptor (PRLR) in BST. Additionally, MT‐treated cowbirds had higher PRLR in POA, comparable to those found in blackbirds, regardless of treatment. No other transcripts of interest exhibited significant differences as a result of MT treatment, but we found a significant effect of species in the three regions. Together, these results indicate that POA, PVN, and BST represent neural nodes that have diverged in avian brood parasites and may serve as neural substrates of brood‐parasitic behavior. [ABSTRACT FROM AUTHOR]

Among vertebrates, ray-finned fishes (Actinopterygii) display the highest diversity in parental care, and their diversification has been hypothesized to be related to phylogenetic changes in fertilization modes. Using the most comprehensive, sex-specific data from 7,600 species of 62 extant orders of ray-finned fishes, we inferred ancestral states and transitions among care types and caring episodes (i.e. the stage of offspring development). Our work has uncovered 3 novel findings. First, transitions among different care types (i.e. male-only care, female-only care, biparental care, and no care) are common, and the frequencies of these transitions show unusually diverse patterns concerning fertilization modes (external, or internal via oviduct, mouth, or brood pouch). Second, both oviduct and mouth fertilization are selected for female-biased care, whereas fertilization in a brood pouch is selected for male-biased care. Importantly, internal fertilization without parental care is extremely unstable phylogenetically. Third, we show that egg care in both sexes is associated with nest building (which is male-biased) and fry care (which is female-biased). Taken together, the aquatic environment, which supports considerable flexibility in care, facilitated the diversification of parenting behavior, creating the evolutionary bases for more comprehensive parenting to protect offspring in semiterrestrial or terrestrial environments. [ABSTRACT FROM AUTHOR]

Extant birds stand out among vertebrates in the diversity of parental care types they present, spanning absence of care to uniparental care by either sex, biparental care, or even cooperative care. Despite years of research, key questions remain regarding parental care evolution in birds. Firstly, the parental care type in the most recent ancestor of extant birds is a matter of controversy, with proposed ancestral states including no care, uniparental male or female care, and biparental care. Another unsolved question is the direction, order, and frequency of transitions between parental care types. We address these key questions using a database of 5,438 bird species (~50% of extant diversity) and modern phylogenetic comparative methods controlling simultaneously for model and phylogenetic uncertainty as well as potential confounding effects of state-dependent diversification. Our results indicate that the most likely ancestral state for extant birds is male-only care, with a posterior probability of 0.8. Transition rates across parental care types were generally low and heterogeneous; loss of parental care virtually never occurs and transitions away from female-only or cooperative care most often lead to biparental care. Given the low transition rates, future research should analyze the factors favoring the maintenance of care types. [ABSTRACT FROM AUTHOR]

Inclusive fitness theory posits that altruistic behaviors, which are directed more likely towards relatives, should be favored by natural selection. However, the prevalence of alternative parenting behaviors in offspring selection, including rejecting their own offspring and accepting the offspring of others, remains poorly understood within the context of parental care evolution. In order to investigate the factors that prompt the occurrence of alternative parenting behaviors, we designed a series of experiments in the Azure-winged Magpie (Cyanopica cyanus). By manipulating the nest spatial position or offspring age/number and parent-offspring familiarity, we addressed how parents provided parental care for the manipulated offspring. In the nest resettlement experiment, the probability of parents rejecting their own offspring significantly increased with nest-moving distances while decreased with offspring ages. In the cross-fostering experiments, the probability of parents provisioning unrelated young significantly decreased with the age difference between cross-fostered chicks. In the nest duplication experiments, where parents were given a choice between familiar offspring and unfamiliar unrelated chicks or between unfamiliar offspring and familiar unrelated chicks, the probability of both alternative parenting behaviors was significantly influenced by the time when parental association with their offspring was deprived. We conclude that as offspring phenotypic traits become individualized and fixed at a special developmental stage, parents gradually acquire the capacity for offspring recognition by associating with them. Any factors that disrupt parent–offspring association or introduce unrelated young into the nest prior to this critical timeline can result in the occurrence of alternative parenting behaviors.

As a result of a warming global climate, understanding how organisms adjust their behaviour to environmental thermal conditions has become an increasingly important question in animal biology. Temperature‐driven adjustments in parental care are potentially important given the repercussions on offspring size, quality and survival. In 2015 and 2016 we monitored parental care for 83 zebra finch Taeniopygia castanotis breeding attempts in the wild with known brood sizes. We recorded the frequency of parental visits to the nest together with mean maximum ambient temperature experienced between day 7 and 14 of the nestling period. We found that for each increase of 1°C in the daytime temperature there was a 0.91% reduction in the hourly rate of parental visits, whilst also accounting for other variables such as nestling age, time of season, and wind speed. Our data suggest that nestlings may receive less food under thermally challenging conditions, which is consistent with recent studies that demonstrate offspring are smaller when reared during periods of high temperature. Understanding the behavioural drivers that may contribute to the production of smaller offspring in extreme heat conditions could prove useful to forecast long‐term consequences for fitness triggered by climate change.

Amphibians exhibit an incredible diversity of reproductive and life-history strategies, including various forms of nest construction and nesting behaviour. Although anuran amphibians (frogs and toads) are not known for their nests, nesting behaviour in this clade-broadly defined as a location chosen or constructed for eggs and young-is tightly linked to the amphibious lifestyle of this group. Transitions to increasingly terrestrial living have driven reproductive diversity in anurans, including the repeated, independent evolution of nests and nesting. Indeed, a core feature of many notable anuran adaptations-including nesting behaviour-is the maintenance of an aquatic environment for developing offspring. The tight link between increasingly terrestrial reproduction and morphological, physiological and behavioural diversity in anurans provides inroads for studying the evolutionary ecology of nests, their architects and their contents. This review provides an overview of nests and nesting behaviour in anurans, highlighting areas where additional work may be particularly fruitful. I take an intentionally broad view of what constitutes nesting to highlight what we can learn from thinking and researching comparatively across anurans and vertebrates more broadly. This article is part of the theme issue The evolutionary ecology of nests: a cross-taxon approach.

Mammalian infants depend on parental care for survival, with numerous consequences for their behavioral development. We investigated the epigenetic and neurodevelopmental mechanisms mediating the impact of early biparental care on development of alloparenting behavior, or caring for offspring that are not ones own. We find that receiving high parental care early in life leads to slower epigenetic aging of both sexes and widespread male-specific differential expression of genes related to synaptic transmission and autism in the nucleus accumbens. Examination of parental care composition indicates that high-care fathers promote a male-specific increase in excitatory synapses and increases in pup retrieval behavior as juveniles. Interestingly, females raised by high-care fathers have the opposite behavioral response and display fewer pup retrievals. These results support the concept that neurodevelopmental trajectories are programmed by different features of early-life parental care and reveal that male neurodevelopmental processes are uniquely sensitive to care by fathers.

The emergence of complex social interactions is predicted to be an important selective force in the diversification of communication systems. Parental care presents a key social context in which to study the evolution of novel signals, as care often requires communication and behavioral coordination between parents and is an evolutionary stepping-stone toward increasingly complex social systems. Anuran amphibians (frogs and toads) are a classic model of acoustic communication and the vocal repertoires of many species have been characterized in the contexts of advertisement, courtship, and aggression, yet quantitative descriptions of calls elicited in the context of parental care are lacking. The biparental poison frog, Ranitomeya imitator, exhibits a remarkable parenting behavior in which females, cued by the calls of their male partners, feed tadpoles unfertilized eggs. Here, we characterized and compared calls across three social contexts, for the first time including a parental care context. We found that egg-feeding calls share some properties with both advertisement and courtship calls but also had unique properties. Multivariate analysis revealed high classification success for advertisement and courtship calls but misclassified nearly half of egg feeding calls as either advertisement or courtship calls. Egg feeding and courtship calls both contained less identity information than advertisement calls, as expected for signals used in close-range communication where uncertainty about identity is low and additional signal modalities may be used. Taken together, egg-feeding calls likely borrowed and recombined elements of both ancestral call types to solicit a novel, context-dependent parenting response.

Climate change is driving both higher mean temperatures and a greater likelihood of heatwaves, which are becoming longer and more intense. Previous work has looked at these two types of thermal stressors in isolation, focusing on the effects of either a small, long-term increase in temperature or a large, short-term increase in temperature. Yet, a fundamental gap in our understanding is the combined effect of chronic and acute thermal stressors and, in particular, its impact on vital processes such as reproduction. Here, we investigated the independent and interactive effects of higher constant temperatures and short-term heatwave events on reproductive success and offspring fitness in an insect study system, the burying beetle Nicrophorus vespilloides. We found a substantial reduction in key fitness traits (fecundity, hatching success and offspring size) after exposure to both a heatwave and higher constant temperatures, but not after exposure to only one of these thermal stressors. This indicates that the effects of chronic and acute thermal stressors are amplified when they act in combination, as is very likely to occur in natural populations. Our findings, therefore, suggest that, by not considering the potential multiplicative effects of different types of thermal stressors, we may be underestimating the effects of climate change on animal fertility. [ABSTRACT FROM AUTHOR]

The modern zoo relies on the persistence of genetically and physiologically healthy populations of endangered species, which is enabled through breeding programmes globally and regionally. Many species commonly held in zoos are poorly studied in the wild, leading to a lack of in-depth knowledge surrounding breeding behaviours and subsequent parental behaviours and early life development of young. Knowledge of this information is critical to make informed management decisions which promote successful rearing of young in zoos. While the critically endangered Sumatran tiger is popular in zoos, rates of cub survival in the first 5 months are lower than 50%, highlighting the need for scientific evidence driving management decisions. This study monitors nursing and cub grooming behaviours in a first-time mother Sumatran tiger (Panthera tigris sumatrae) and her cubs throughout four stages of cub development. The social proximity of cubs and dam were recorded to describe social interactions within the group throughout cub aging. A series of Friedman tests and post-hoc tests found significant decreases in both cub grooming (c2 (3, N = 96) = 14.20, p < 0.01) and nursing (c2 (3, N = 96) = 25.77, p < 0.001) behaviours between the birth and weaning of the cubs, as well as within different phases of cub development between those times. Cub-to-cub proximity was maintained from birth to weaning, with cubs spending significant amounts of time in close proximity (within one adult body length) of each other (c2 (3, N = 96) = 15.231, p = 0.001) throughout the study. The dam was found to spend significantly less time with the cubs as they reached weaning age (c2 (3, N = 96) = 27.88, p < 0.001). These results are thought to be the first of their kind to detail timings of cub development and early life socialisation, providing evidence for timing of first food provision to young and promote the provision of space for the dam to spend time away from the cubs, while allowing the cubs to become confident, mobile, and independent. [ABSTRACT FROM AUTHOR]

Chemical cues and signals, especially in insects, play a pivotal role in mediating interactions between individuals. Past studies have largely focused on adult semiochemicals and have neglected those of juvenile stages. Especially in the context of parental care, the larval odor might have a profound impact on parenting behavior, guiding parents in how much resources they should allocate to the different developmental stages. However, whether ontogenetic changes occur in subsocial species and whether larval-emitted scents influence parent–offspring interactions is largely unknown. Using 3 different sampling techniques, we analyzed the cuticular and VOC profile of the 3 larval instars of the burying beetle Nicrophorus vespilloides , which is known for its elaborate parental care. We found distinct differences in the cuticular and VOC profiles across the 3 larval stages. Second-instar larvae, which receive more frequent feedings from parents than the other larval stages, released greater amounts of acetophenone, methyl geranate, and octanoic acid isopropyl ester than the first and third instar. Additionally, using a newly developed bioassay with automated video tracking, we found that adding the odor of second-instar larvae to first-instar larvae increased the number of maternal feeding trips. Our results suggest that the odor produced by larvae plays an important role in mediating parent–offspring interactions. Given these findings, burying beetles might emerge as a promising candidate for identifying a potential begging pheromone. [ABSTRACT FROM AUTHOR]

To our knowledge, there are no studies of mother-offspring recognition in Liolaemus lizards, even though many species have a refined discrimination capacity based on chemical signals, and some of them are viviparous with a close relationship between mothers and offspring. We studied the reciprocal chemical mother-offspring recognition in the viviparous species Liolaemus zullyae, evaluating whether both mothers and offspring can discriminate between their consanguineous relative from another who is not genetically related. Six females gave birth in the laboratory. Once the offspring were born, crossover experiments were carried out. The results suggest that mothers showed no clear evidence of discrimination of their own and other's newborns. In contrast, newborns rubbed their faces for longer when scents were from other females than from their own mothers, suggesting that newborns may recognize their mothers. We discuss the asymmetric mother-offspring recognition detected in this study. [ABSTRACT FROM AUTHOR]

The giant gourami (Osphronemus goramy Lacepede, 1801), a popular aquaculture species in Southeast Asia, exhibits unique cooperative biparental care behaviour. To support captive breeding efforts, this study aimed to visually document the reproductive activity of giant gourami, elucidate each stage in detail, and provide insights into the distinct parenting roles of males and females. Underwater cameras were used to observe a breeding pair of gourami in a pond for five days, conducted three times with different pairs during different spawning periods. The male and female contributions to nest building were quantitatively analysed using the T-test, while their parental care involvement was qualitatively assessed and statistically analysed using the Mann-Whitney U test. The results revealed three main phases of giant gourami reproduction: pre-spawning (including adaptation, nest building, and courtship), spawning and fertilisation, and post-spawning with parental care. Our observation confirmed the biparental tendency, with males being more involved in prespawning activities and females taking on a prominent role in post-spawning care. In conclusion, males focused on mating preparations and courtship, while females invested more in parental care. [ABSTRACT FROM AUTHOR]

Abandoning a brood to maximize lifetime reproductive success may result from the current costs affecting future reproductive opportunities. In certain contexts, clutch abandonment can be an evolved breeding strategy rather than a generalized response to stressors such as inclement weather and predation. Obligate brood parasitism, a reproductive strategy in which a parasitic species relies solely on other species to raise its young, imposes fitness costs to hosts and could serve as a trigger for clutch abandonment. This cost, and the resulting clutch abandonment strategy, may vary according to contact with the parasite, sensitivity to parasitism and the value of the current reproductive effort (i.e. brood value). We conducted a phylogenetically controlled meta-analysis covering 85 host species of the three generalist cowbird species (Molothrus sp.) in which we examined the following effects on the abandonment (nest desertion and egg burial) of parasitized versus unparasitized clutches: habitat at a small scale (higher host–parasite encounter frequency in open versus forested habitats) and at a large scale (longer interaction between parasites and hosts in prairie versus nonprairie regions), brood value (relative value of a clutch) and host species sensitivity to brood parasitism (relative body mass). Parasitism increased clutch abandonment overall. This increase was strongest in open nonforested habitats, with smaller, more sensitive hosts being more likely to abandon their clutch. Brood value and occurrence in prairie regions did not affect clutch abandonment, indicating that recent, more fine-scale host–parasite interactions were more important than coevolutionary history. Therefore, the abandonment of a brood can be used in diverse parental care strategies, including antiparasitic defences of brood-parasitic hosts. • We examined responses of hosts to parasitism by cowbirds (Molothrus sp.). • Parasitism increased clutch abandonment overall. • Abandonment strongly affected host sensitivity and current exposure to parasitism. • We found no effect of brood value or coevolutionary history. • Host behavioural plasticity may modulate host defences more than previously thought. [ABSTRACT FROM AUTHOR]