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The Etruscan shrew (Suncus etruscus) is one of the smallest mammals on earth and is used in many fields of research, including physiology, behavioral science and neuroscience. However, establishing and maintaining a breeding colony of this species in the laboratory can be challenging, as it requires specific husbandry conditions that greatly differ from those of more common laboratory species such as mice or rats. Over the past 15 y, we have successfully established a long-term thriving colony of 150 to 200 animals originating from 36 founders. The colony shows longer life expectancy and larger litter sizes than wild conspecifics. Breeding occurs year-round, independent of seasons, and a breeding pair can regularly produce 2 to 6 offspring with an average life expectancy of more than 3 y. The shrews are housed in glass or plastic enclosures on a specific soil-sand-mixture bedding and are provided with hideouts and nesting material consisting of moss, wood, or bark. Due to their high basal metabolic rate, the shrews require food intake greater than their body weight per day, can hunt arthropods as large as themselves, and cannot survive more than a few hours without food. Live feed such as crickets or mealworms is crucial and must be provided daily or, at the very least, every 2 d. Although our husbandry practices have constantly been adapted and refined, shrew husbandry remains challenging, and great care is necessary to meet the specific needs of this species. Here, we describe the establishment of a long-term stable colony of Etruscan shrews in a research animal facility and the specific husbandry requirements for animal wellbeing.

The ability to discriminate between conspecifics functions in mate choice, kin-selected cooperation and territory defence. In mammals, olfaction plays a key role in such social interactions. Olfactory cues may be particularly important for subterranean mammals, for which visual and acoustic cues are less effective. Damaraland mole-rats live in groups comprising a breeding pair and their nonbreeding offspring. They are xenophobic, obligate outbreeders and independent dispersal represents the usual route to reproduction for both sexes. As yet, little is known about how dispersing individuals locate mates. Using a series of behavioural experiments, we reveal that mole-rats can discriminate between unfamiliar breeding groups and solitary, nonbreeders of the opposite sex by using odour cues. Our experiments showed that subjects spent more time investigating sand taken from other mole-rat groups than control sand, indicating an ability to recognize substrate-borne conspecific odours. Mole-rats also spent more time digging and sweeping in sand taken from the tunnels of unfamiliar, solitary animals of the opposite sex than sand taken from unfamiliar breeding groups and removed a higher volume of this sand during the experiments. Together, these results suggest an olfactory preference in both sexes for solitary, opposite-sex animals over breeding groups. Our results are supported by observations from the field that immigration into breeding groups is rare, with dispersing females typically establishing new groups, where they are subsequently joined by unfamiliar males. This study supports olfaction as a potential recognition cue which may facilitate adaptive dispersal.

The reproductive costs of cooperatively breeding callitrichid mothers are remarkable, and they have to rely on fathers and other group members to raise their offspring. Consequently, maternal responsiveness to and investment in infants tends to be conditional, and especially sensitive to infant cues and signals of vigour. Since fathers do not bear the same excessive reproductive costs, their threshold to invest in a dying immature may be lower than in mothers. We present an anecdotal report of reactions of a first-time breeding pair of captive common marmosets (Callithrix jacchus) to their dying infant. We found a male bias in all interactions with the dying infant that did not show typical cues of infant vigour. These results show that the dying infant elicited more investment by the father than the mother. Because of this conditional maternal investment, infants of cooperatively breeding primates may be under selection to advertise their viability, in particular to their mothers.

During the last half-century, the distribution of golden jackals (Canis aureus) has rapidly increased throughout Europe. Today, golden jackals are thriving in human-dominated landscapes across Southeastern and Central Europe. Most studies on golden jackals have focused on large-scale distribution patterns; to date, little is known about the species’ fine-scale spatial ecology. In this study, we analyzed the movement behavior, space-use and resource selection of six golden jackals fitted with GPS-GSM collars in two study areas in Hungary and Serbia. Two of the jackals were a breeding pair. We found that home range size averaged 11.2 km2 (90% autocorrelated kernel density estimation), and was characterized by significant individual-level variability (range 1.3–32.5 km2). Golden jackal movements and resource selection were strongly influenced by circadian patterns: during the day, jackals travelled an average of 300 m every 6 h, and all monitored individuals selected for vegetation cover, often near edges. At night, golden jackals travelled significantly further (1 km 6 h−1), and were more likely to venture outside of cover into agricultural areas. Movement analysis of the breeding pair revealed that the male and female tended to remain in close proximity during the day, but ranged more independently at night. Altogether, our findings suggest that golden jackals’ ability to thrive in human-dominated landscapes rely on a fine spatio-temporal avoidance of humans.

Petrels (Procellariidae) are a highly diverse family of seabirds, many of which are globally threatened due to the impact of invasive species on breeding populations. While predation by invasive cats and rats has led to the extinction of petrel populations, the impact of invasive house mice Mus musculus is slower and less well documented. However, mice impact small burrow-nesting species such as MacGillivray9s prion Pachyptila macgillivrayi, a species classified as endangered because it has been extirpated on islands in the Indian Ocean by introduced rodents. We use historic abundance data and demographic monitoring data from 2014 to 2020 to predict the population trajectory of MacGillivray9s prion on Gough Island with and without a mouse eradication using a stochastic integrated population model. Given very low annual breeding success (0.01 fledglings per breeding pair in 9poor9 years (83%) or 0.38 in 9good9 years (17%), n = 320 nests over 6 years) mainly due to mouse predation, our model predicted that the population collapsed from ~3.5 million pairs in 1956 to an estimated 175,000 pairs in 2020 despite reasonably high adult survival probability (O invasive alien species; population model; MacGillivray9s prion; Mus musculus; island restoration.

Parental care is defined as any behavioral trait of the parents that improves the fitness of the offspring, and that probably evolved or is currently maintained by this function. There is variation in the type and amount of care allocated by parents depending on fluctuation in brood demands that respond to growth and developmental environment. Each sex, within the breeding pair, may respond differently to changing brood demands, and such variation might impact offspring development and fitness. Even though there is a plethora of studies evaluating sex differences in parental care, proximate factors influencing distribution of parental duties within the breeding pairs have received far less attention. In a wild population of Western Bluebirds, we assessed sex differences in parental care (i.e. brood attendance, food deliveries, nest cleaning) through nestling development, and evaluated whether distribution of parental care between sexes is associated with offspring growth. We found that females adjusted their parental behavior according to changes in brood demands more often than males, and fed, attended, and cleaned more than males. Moreover, a more female-biased distribution of care through nestling development was positively associated with the growth of fledglings. We conclude that sex differences in parental care may be a measure of specialization in parental duties within breeding pairs favored by natural selection. These findings are in marked contrast to earlier studies in Northern populations of Western Bluebirds that have failed to detect differences in parental care between sexes, and suggest that differences in the social environment or ecological conditions between populations of the same species might lead to differences in parental cooperation between males and females.

There is a tendency for the wolves of a pack to stay together assuming that there is a social bond between the pack members. A rough estimate of the strength of this bond can be obtained by measuring the distances between pack members. The aim of this study was to determine the inter-individual distance by calculating the Euclidian distance to determine the Iberian wolf cohesion in different pack compositions. The study subjects were seven captive Iberian wolves (Canis lupus signatus) housed at the Barcelona Zoo. Multifocal sampling methods were used for data collection, and instantaneous scans were made at 15-min during different sessions. Proximity relationships among these wolves in different pack composition were visualized using two-dimensional scaling analysis. The pair leader without offspring and the breeding pair with their offspring were significantly closer than the rest of the dyads which combinations were equidistant. During the pregnancy period, the breeding pair was significantly further than during the juvenile period. More studies in field and captivity by using Euclidian distance are necessary to improve social husbandry techniques, animal welfare and conservation programs.

In birds that breed cooperatively in family groups, adult offspring often delay dispersal to assist the breeding pair in raising their young. Kin selection is thought to play an important role in the evolution of this breeding system. However, evidence supporting the underlying assumption that helpers increase the reproductive success of breeders is inconsistent. In 10 out of 19 species where the effect of helpers on breeder reproductive success has been estimated while controlling for the effects of breeder and territory quality, no benefits of help were detected. Here, we use phylogenetic meta-analysis to show that the inconsistent evidence for helper benefits across species is explained by study design. After accounting for low sample sizes and the different study designs used to control for breeder and territory quality, we found that helpers consistently enhanced the reproductive success of breeders. Therefore, the assumption that helpers increase breeder reproductive success is supported by evidence across cooperatively breeding birds.

This study investigated the home range and habitat characteristics in tawny owls (Strix aluco), a grade II endangered wildlife species from South Korea. We tracked a breeding pair in Gyeongbuk during their brooding period using an attached radio transmitter through a satellite tracking system (WT-300: GPS-Mobile phone based Telemetry). The subjects had consecutively reproduced in a same nest for two years (2016–2017). The female's location data (six coordinates) were collected in 2016, whereas the male's (12 coordinates) were collected in 2017. Kernel density estimates were used to determine the pair's core habitats; the male had a greater movement range (2,133,971 m2) at 95% kernel density estimate than the female (19,572 m2). The male's core habitat was mostly mixed forest (50.6%), followed by coniferous forest (13.4%), nonirrigated land (10.9%), natural grassland (10.1%), and inland bodies of water (8.2%). The female's core habitat was dominated by mixed forest (36.8%), followed by non-natural barren land (21.7%), nonirrigated land (14.4%), residential areas (10%), and transportation areas (7.9%). This study is the first to track a breeding tawny owl pair on the Korean peninsula through direct satellite. Our results provide fundamental data as a case study regarding home range behavior of an owl breeding pair for developing conservation and management plan.

A solitary breeding pair of Australian Eurasian Coots Fulica atra australis on a small wetland in Sydney, New South Wales, was monitored during the 2015–2016 breeding season. Three breeding attempts were observed, during which two nest-platforms were built. Adults incubated eggs for 20–35 minutes at a time. Our monitoring recorded two observations of copulation and 58 observations of aggression towards a conspecific or other waterbird species. Aggression events most frequently involved lone or multiple Dusky Moorhens Gallinula tenebrosa . Of five chicks recorded in one breeding attempt, only one survived >5 months.

Swooping is a defensive behavior used against potential nest predators. Here, we tested the hypothesis that swooping intensity in a pair of Brown Goshawks (Accipiter fasciatus) rearing chicks would differ according to the number of human observers present near the nest. We standardized the number of swoops per min for 16 visits during which there were combinations of one, two and four observers. There was a significant difference in swooping intensity between one-observer and two-observer visits. Intensity ranged from 0.10 to 0.40 swoops per min during single-observer visits, in contrast to only one of four two-observer visits recording a single swoop, and goshawks performing no swoops during four-observer visits, thus confirming our hypothesis. Despite being based on a single breeding pair of goshawks, these observations demonstrate variation in nest defense towards humans.

In many cooperative societies, including our own, helpers assist with the post-natal care of breeders’ young, and may thereby benefit thepost-nataldevelopment of offspring. Here we present evidence of a novel mechanism by which such post-natal helping could also have hitherto unexplored beneficial effects onpre-nataldevelopment: by lightening post-natal maternal workloads, helpers may allow mothers to increase their pre-natal investment per offspring. We present the findings of a decade-long study of cooperatively breeding white-browed sparrow weaver,Plocepasser mahali, societies. Within each social group, reproduction is monopolized by a dominant breeding pair, and non-breeding helpers assist with nestling feeding. Using a within-mother reaction norm approach to formally identify maternal plasticity, we demonstrate that when mothers have more female helpers they decrease their ownpost-natalinvestment per offspring (feed their nestlings at lower rates) but increase theirpre-natalinvestment per offspring (lay larger eggs, which yield heavier hatchlings). That these plastic maternal responses are predicted by female helper number, and not male helper number, implicates the availability of post-natal helpingper seas the likely driver (rather than correlated effects of group size), because female helpers feed nestlings at substantially higher rates than males. We term this novel maternal strategy “maternal front-loading” and hypothesize that the expected availability ofpost-natalhelp allows helped mothers to focus maternal investment on thepre-natalphase, to which helpers cannot contribute directly. Such cryptic maternally mediated helper effects on pre-natal development may markedly complicate attempts to identify and quantify the fitness consequences of helping.

In the last decade, studies in bird breeding biology have shown that infidelity is prevalent in socially monogamous species. Here, we describe an extra-pair copulation (EPC) event in the Rufous Hornero (Furnarius rufus), a socially monogamous bird with year-round territoriality and low levels of extra-pair paternity. Before the EPC, a within-pair copulation (WPC) occurred inside the pair’s territory. The WPC occurred on the ground and between a banded male (ca. 6 years-old) and an unbanded female. Ten minutes later this breeding pair invaded a neighboring territory, presumably to forage. The territorial male was chased back to its territory by an unbanded male neighbor after being detected. The male neighbor was paired with an unbanded female that did not participate in the aggressive interaction. When flying back to its territory the male neighbor copulated with the territorial female on the ground (ie. EPC). The territorial male flew, vocalized, and perched above the male neighbor, interrupting the EPC. The aggressive interaction then ceased as each pair resumed foraging in their respective territories. These observations suggest that Rufous Horneros can use EPC to obtain immediate benefits (food access in a neighbor’s territory). Moreover, WPC may be detected by neighbors and physical mate guarding and/or frequent WPC may be necessary to prevent EPC in the Rufous Hornero.

Domestication has greatly changed the social and reproductive behavior of dogs relative to that of wild members of the genus Canis, which typically exhibit social monogamy and extended parental care. Unlike a typical gray wolf pack that consists of a single breeding pair and their offspring from multiple seasons, a group of free-ranging dogs (FRDs) can include multiple breeding individuals of both sexes. To understand the consequences of this shift in reproductive behavior, we reconstructed the genetic pedigree of an FRD population and assessed the kinship patterns in social groups, based on genome-wide single-nucleotide polymorphism genotypes. Consistent with behavioral observations, the mating system of the study population was characterized by polygynandry. Instead of the discreet family units observed in wolves, FRDs were linked by a network of kinship relationships that spread across packs. However, we also observed reproduction of the same male–female pairs in multiple seasons, retention of adult offspring in natal packs, and dispersal between neighboring packs—patterns in common with wolves. Although monogamy is the predominant mating system in wolves, polygyny and polyandry are occasionally observed in response to increased food availability. Thus, polygynandry of domestic dogs was likely influenced by the shift in ecological niche from an apex predator to a human commensal., In groups of free-ranging dogs, many males and females mate and produce puppies with more than one partner. Sometimes, a female delivers a litter with more than one father. This mating system contrasts with the predominantly monogamous system of the ancestor, the grey wolf. The likely cause is the access to human waste, allowing dogs to better cope with the energetic costs of reproduction leading to a higher number of reproductive animals of both sexes.

Gray Wolves (Canis lupus) are territorial, group living carnivores that live in packs typically consisting of a dominant breeding pair and their offspring. Breeding tenures are relatively short and competitive, with vacancies usually occurring following a breeder’s death, and are often filled by unrelated immigrants or by relatives of the previous breeder. The frequency and conditions of active breeder displacements are poorly understood. Position changes in the dominance hierarchy are common yet rarely documented in detail. We describe a turnover in male breeding position in a wolf pack by males from a neighboring pack in mid-summer 2016 in Yellowstone National Park. Over the course of two months, three males from the Mollie’s pack displaced the breeding male of the neighboring Wapiti Lake pack, joined the pack’s two adult females, and subsequently raised the previous male’s four approximately three-month old pups. In the four years following the displacement (2017 to 2020), at least one of the intruding males has successfully bred with the dominant female and most years with a subordinate female (who was one of the pups at the time of displacement). The pack reared pups to adulthood each year. Male breeding displacements are likely influenced by male-male competition and female mate choice. These changes are the result of individuals competing to improve breeding position and may lead to increased pack stability and greater reproductive success. We report in detail on the behavior of a closely observed breeding displacement and we discuss the adaptive benefits of the change.

Eusociality is exhibited by colonial-living organisms where only a few individuals within a colony reproduce; the remaining members are nonbreeders and support reproduction of the breeders. Damaraland mole-rats, Fukomys damarensis, are one of two mammal species considered eusocial. Colonies include a breeding pair and their offspring. Unusual aspects of reproductive behaviour include the observation that both sexes display all components of mating even after long-term absence of gonadal hormones. Mating does not occur between siblings or offspring and parents, but nonbreeders from one colony will mate with individuals from other colonies. However, following 5 weeks of separation from each other, siblings will exhibit mutual sexual behaviour. Thus, familiarity through frequent proximity, rather than genetic identity, mediates inbreeding avoidance. One caveat is that breeding pairs maintain a mating relationship for years, although they obviously become familiar with each other. Among Damaraland mole-rats that are familiar with each other, two types of relationships can form, a mating relationship or a ‘sibling-like’ relationship marked by inbreeding avoidance. The factors determining the relationship between pairs of Damaraland mole-rats remain undefined. This experiment tested the hypothesis that the behaviour during the initial meeting of a pair of Damaraland mole-rats determines which relationship forms, i.e. mating versus ‘sibling-like’. The initial pairing occurred either with unrestrained physical contact (allowing for mating behaviours) or with the two animals separated from each other by a mesh barrier (no mating could occur). This initial pairing was followed by daily 20 min pairings with the barrier in place for 2 weeks and then a final pairing without any restraint. Results indicate that the nature of the interaction within the first 20 min of meeting determines the long-term sexual relationship between pairs of Damaraland mole-rats. The results suggest a mechanistic basis for establishment and maintenance of the reproductive hierarchy in this eusocial species.

The use of radio frequency identification (RFID) technology is common in animal-monitoring applications in the wild and in zoological and agricultural settings. RFID is used to track animals and to collect information about movements and other behaviors, as well as to automate or improve husbandry. Disney's Animal Kingdom® uses passive RFID technology to monitor nest usage by a breeding colony of northern carmine bee-eaters. We implemented RFID technologies in various equipment configurations, initially deploying low-frequency (LF) 125 kHz RFID and later changing to high-frequency (HF) 13.56 MHz RFID technology, to monitor breeding behavior in the flock. We installed antennas connected to RFID readers at the entrances of nest tunnels to detect RFID transponders attached to leg bands as birds entered and exited tunnels. Both LF-RFID and HF-RFID systems allowed the characterization of nest visitation, including the timing of nest activity, breeding pair formation, identification of egg-laying females, participation by nonresidents, and detection of nest disruptions. However, we collected a substantially larger volume of data using the increased bandwidth and polling speed inherent with HF-RFID, which permitted tag capture of multiple birds simultaneously and resulted in fewer missed nest visits in comparison to LF-RFID. Herein, we describe the evolution of the RFID setups used to monitor nest usage for more than 7 years, the types of data that can be gained using RFID at nests, and how we used these data to gain insights into carmine bee-eater breeding behavior and improve husbandry.

Cooperative breeding is rare in shorebirds, and when found it is thought to be due to polygamous mating (cooperative polygamy). Here we describe the social structure of cooperatively breeding groups in Southern Lapwing Vanellus chilensis and test the prediction that offspring sex ratio is skewed towards the sex that helps. The social groups consisted of a breeding pair with one or two young (mostly males, 68%) from the previous breeding season, and offspring sex ratio was not skewed. Cooperative breeding in the Southern Lapwing is not the consequence of cooperative polygamy, but rather groups were formed by a mated pair and some of their offspring from previous nests as helpers.

There are numerous reports on envenomation, even fatal, secondary to bee attacks in humans and other mammals. In birds, reports on those incidents are scarce and there are none regarding honeybee (Apis mellifera) stings in toucans. In the first case presented, an adult female red-breasted toucan (Ramphastos dicolorus) received at least five bee stings in the periophthalmic area. Within 5 h the bird was lethargic and dehydrated. The urates were yellowish. Three days later the bird showed a moderate anemia, but no changes in the leukocyte count, beyond an elevated heterophil: lymphocyte ratio. Blood chemistry showed hyperglycemia, hypoalbuminemia and elevated aspartate aminotransferase and creatine kinase. Alterations in electrolyte values were also noted. Fourteen days later bile acid elevation was observed. Hematocrit levels normalized after 2 wk. A second incident involved a breeding pair of toco toucans (Ramphastos toco). While the female toco toucan received 10 stings and showed mild clinical manifestations, the male toco toucan was more severely attacked, receiving 40 stings, and died overnight. Despite the relative gravity of the attack (in terms of number of stingers in relation to body weight) both surviving birds recovered in less than 2 wk. To the authors' knowledge, fatal bee envenomation in birds has been reported only in pigeons and macaws. The findings described in this report suggest that toucans are less sensitive to bee venom when compared with pigeons and may have higher tolerance to bee venom compared with mammals. Honeybee envenomation must be considered a potential threat when considering toucan husbandry in zoos and collections.

In many species, within-group conflict leads to immediate avoidance of potential aggressors or increases in affiliation, but no studies have investigated delayed post-conflict management behaviour. Here, we experimentally test that possibility using a wild but habituated population of dwarf mongooses (Helogale parvula). First, we used natural and playback-simulated foraging displacements to demonstrate that bystanders take notice of the vocalisations produced during such within-group conflict events but that they do not engage in any immediate post-conflict affiliative behaviour with the protagonists or other bystanders. We then used another playback experiment to assess delayed effects of within-group conflict on grooming interactions: we examined affiliative behaviour at the evening sleeping burrow, 30–60 min after the most recent simulated foraging displacement. Overall, fewer individuals groomed on evenings following an afternoon of simulated conflict, but those that did groomed more than on control evenings. Subordinate bystanders groomed with the simulated aggressor significantly less, and groomed more with one another, on conflict compared to control evenings. Our study provides experimental evidence that dwarf mongooses acoustically obtain information about within-group contests (including protagonist identity), retain that information, and use it to inform conflict-management decisions with a temporal delay., eLife digest Social animals that live in groups often have disagreements over access to mates and food. Even fleeting in-group disputes can be costly, disrupting relationships, wasting time and energy, or causing injury if aggression escalates. So, much like humans, many social animals, including primates, birds and dogs, have evolved conflict management strategies to prevent and resolve in-group disagreements. In the immediate aftermath of a conflict, this usually involves changes in the interactions between those involved in the disagreement, or between bystander groupmates and either the victim or aggressor. Less is known about whether social animals can recall past disputes and if they can use conflict management strategies some time after a quarrel has occurred. That is, do aggressive interactions between groupmates influence later social decisions of bystanders in the group? To investigate, Morris-Drake et al. studied groups of wild dwarf mongooses (Helogale parvula) that have become accustomed to living alongside humans in Limpopo Province, South Africa. Dwarf mongooses live in groups of up to 30 individuals, with one dominant breeding pair and lower-ranked helpers. When disagreements arise over food, an aggressor growls deeply and hip-slams the victim away from their foraging patch, stealing the victim’s prey in the process. Victims often produce high-pitched squeals in retreat. Using recordings of these calls, Morris-Drake et al. devised a field experiment to investigate how mongooses responded to nearby conflicts between other group members. Recordings simulating a conflict over food were played to groups of foraging mongooses over the course of an afternoon, so that group members effectively heard what sounded like repeated squabbles between two out-of-sight individuals. Similar to natural conflicts, the mongooses did not engage in any obvious conflict management behaviour immediately after hearing these disputes. But when the group returned to their sleeping burrow that evening, subordinate group members shunned the perceived aggressors from grooming, a key social activity. This work provides evidence that dwarf mongooses keep tabs on conflicts that occur between groupmates. It shows these animals can extract information about conflicts from vocal cues alone and that bystanders use this information when making later social decisions impacting group dynamics. It also adds to growing evidence from baboons, monkeys and chimpanzees that social animals can remember past events and take these into account when interacting with groupmates.

Conservation partners are concerned that oil and gas development in the Prairie Pothole Region may reduce the abundance of breeding duck pairs using associated wetland habitat. We conducted wetland-based surveys for breeding pairs of 5 species of dabbling ducks in the Bakken oil field during 2015–2017 across a gradient of oil and gas development intensity to test the hypothesis that the abundance of breeding duck pairs on survey wetlands would decrease as the development of oil and gas resources increased. We included covariates traditionally used to predict breeding duck pairs (i.e. wetland size and class) and a spatiotemporal index of disturbance when developing zero-inflated Poisson models relating pair abundance to environmental predictors. Similar to past analyses, pair abundance was strongly associated with wetland size. Our results were mixed and suggested that the abundance of early and late nesting species was positively and negatively related, respectively, to an index of disturbance that was largely driven by oil and gas development. Regardless of the direction of the relationship, effect sizes were small and not considered biologically significant. Our findings indicate that in our study area, strategies to conserve wetland resources for breeding duck pairs should not deviate from previous prioritization metrics within the range of oil and gas development we observed. We believe that our findings may have implications to similar landscapes within the Bakken.LAY SUMMARY Since 2008, the oil and gas development in the North Dakota and Montana portion of Bakken Oil Formation has increased dramatically. There is considerable overlap between the Bakken Oil Formation and important Prairie Pothole Region wetlands critical for waterfowl production. We surveyed breeding Blue-winged Teal, Gadwall, Mallard, Northern Pintail, and Northern Shoveler pairs from 2015 to 2017 to determine if breeding pair abundance was lower in proximity to a gradient of disturbance from oil and gas development. Our results were mixed but regardless, changes in pair abundance were small and we considered the potential biological effect to be small. We recommend that existing conservation tools continue to be used to identify important grassland and wetland resources in the region given that we did not observe a biologically significant reduction in breeding duck pairs.

Assortative mating by telomere lengths has been observed in several bird species, and in some cases may increase fitness of individuals. Here we examined the relationship between telomere lengths of Blue-footed Booby (Sula nebouxii) mates, long-lived colonial seabirds with high annual divorce rates. We tested the hypothesis that interactions between maternal and paternal telomere lengths affect offspring and parental survival. We found that relative telomere lengths (RTL) were strongly positively correlated between members of a breeding pair. In addition, RTL of both parents interacted to predict fledgling recruitment, although fledglings with two very long-RTL parents performed only averagely. Telomere lengths also predicted adult survival: birds with long telomeres were more likely to survive, but birds whose mate had long telomeres were less likely to survive. Thus, having long telomeres benefits survival, while choosing a mate with long telomeres benefits reproductive output while penalizing survival. These patterns demonstrate that while a breeder's RTL predicts offspring quality, assortative mating by RTL does not enhance fitness, and a trade-off between different components of fitness may govern patterns of assortative mating by telomere length. They also illustrate how testing the adaptive value of only one parent’s telomere length on either survival or reproductive success alone may provide equivocal results.

The current study presents and analyses the results from the recently completed 11-year-establishment phase, following the start of the local re-introduction of the Griffon Vulture (Gyps fulvus) in Kotlenska Planina SPA and Sinite Kamani Nature Park in the Eastern Balkan Mountains of Bulgaria in the period 2010-2020. As a result of the re-introduction efforts and release of 153 individuals, the Griffon Vulture has been successfully reproducing again in the Eastern Balkan Mountains since 2016, after more than 40-50 years of absence. At 2020, the local population consists of some 80 local and up to 80-115 birds, together with sojourn individuals. Amongst them, 23-25 breeding pairs, located in five different colonies and two more frequently used roosting sites. The current average productivity remains relatively low: 0.41 fledglings/territorial pair and fledging success of 0.61 fledglings/breeding pair between 2016 and 2020, but shows a trend to increase with time and the growing experience of the young locally re-introduced population. The mortality confirmed between 2010-2021 accounts for 33%, mostly due to electrocution as a post-release effect in the first six months following their release. Our data show that the newly established population in the Eastern Balkan Mountains mostly forages on feeding sites, having a comparatively small 95% home range: 281.88 ± 91 km2 and 50% core area: 6.6 ± 2.28 km2 (range 4.7–8.5 km2). We, therefore, consider the establishment phase of the re-introduction of Griffon Vulture in this particular site as successfully completed, but management should continue. Furthermore, the area of the Eastern Balkan Mountains can currently be regarded as a "source" for the species within the source-sink population regulation concept in the national and Balkan context.

Petrels (Procellariidae) are a highly diverse family of seabirds, many of which are globally threatened due to the impact of invasive species on breeding populations. While predation by invasive cats and rats has led to the extinction of petrel populations, the impact of invasive house mice Mus musculus is slower and less well documented. However, mice impact small burrow-nesting species such as MacGillivray’s prion Pachyptila macgillivrayi, a species classified as endangered because it has been extirpated on islands in the Indian Ocean by introduced rodents. We use historic abundance data and demographic monitoring data from 2014 to 2020 to predict the population trajectory of MacGillivray’s prion on Gough Island with and without a mouse eradication using a stochastic integrated population model. Given very low annual breeding success (0.01 fledglings per breeding pair in ‘poor’ years (83%) or 0.38 in ‘good’ years (17%), n = 320 nests over 6 years) mainly due to mouse predation, our model predicted that the population collapsed from ~3.5 million pairs in 1956 to an estimated 175,000 pairs in 2020 despite reasonably high adult survival probability (ϕ = 0.901). Based on these parameters, the population is predicted to decline at a rate of 9% per year over the next 36 years without a mouse eradication, with a 31% probability that by 2057 the MacGillivray’ prion population would become extremely vulnerable to extinction. Our models predict population stability (λ = 1.01) and a lower extinction risk (

The global breeding population of Eleonora's Falcon (Falco eleonorae) is distributed from the Canary Islands in the west, across the Mediterranean Sea, to Cyprus in the east. The remoteness of nesting colonies, which are predominantly located on sea cliffs and islets, renders breeding success estimation a challenging task, requiring a composite approach to assess each of the breeding stages. Early estimates of the breeding success of Eleonora's Falcon suggested that the Akrotiri colony in Cyprus had the lowest breeding success among all the colonies throughout the species' breeding range, at a level seemingly unsustainable, suggesting the colony might have been in danger of gradual extinction. Here we use a diversity of survey methods including boat, ground, and aerial surveys, with the incorporation of photography and photogrammetry, to reassess the breeding success and the effect of nest characteristics on the Eleonora's Falcon breeding population in Cyprus. During a 6-yr study, we found that Cyprus hosts ∼138 ± 8 breeding pairs and that breeding success equals 1.54 ± 0.85 fledglings per breeding pair, and thus is considerably higher than previous estimates. In addition, by analyzing temporal variation in breeding and nest characteristics, we found that early breeding and reuse of nests positively influence breeding success, but physical nest characteristics have a limited effect on colony productivity. The range of survey methods employed, as well as the array of photography techniques utilized, enhanced the efficiency and accuracy of this study, allowing us to overcome the challenge of inaccessibility of nesting cliffs. LAY SUMMARY In this study we reassessed the breeding success and population status of Eleonora's Falcon in Cyprus, a species nesting on inaccessible sea cliffs. Low breeding success estimates from previous surveys suggested that the breeding population was unsustainable. We used ground, aerial (drone), and boat surveys, combined with photogrammetry for nesting cliff 3-D modeling, to assess breeding success and nest site suitability. Our results show that breeding success of Eleonora's Falcon is higher than previous estimates and that the population is stable. The methods employed enhanced the efficiency and accuracy of our surveys, allowing us to overcome the challenge of inaccessibility of nesting cliffs.

Current methods for eradicating Corynebacterium bovis, such as depopulation, embryo transfer, and cesarean rederivation followed by cross fostering, are expensive, complex, and time-consuming. We investigated a novel method to produce immunocompromised offspring free of C. bovis from infected NOD. Cg-PrkdcscidIl2rgtm1Wgl/SzJ (NSG) breeding pairs. Adult NSG mice were infected with C. bovis, paired, and randomly assigned to either a no-antibiotic control group (NAB, n = 8) or a group that received amoxicillin–clavulanic acid (0.375 mg/mL) in their drinking water for a mean duration of 7 wk (AB group, n = 7), spanning the time from pairing of breeders to weaning of litters. The AB group also underwent weekly cage changes for 3 wk after pairing to decrease intracage C. bovis contamination, whereas the NAB mice received bi-weekly cage changes. Antibiotics were withdrawn at the time of weaning. All litters (n = 7) in the AB group were culture- and qPCR-negative for C. bovis and remained negative for the duration of the study, whereas all litters in the NAB group (n = 6) remained C. bovis positive. A single adult from each breeding pair was sampled at weaning and at 5 and 10 wk after weaning to confirm the maintenance of (NAB) or to diagnose the reemergence (AB) of C. bovis infection. By the end of the study, C. bovis infection had returned in 3 of the 7 (43%) tested AB adults. Our data suggest that metaphylactic antibiotic use can decrease viable C. bovis organisms from adult breeder mice and protect offspring from infection. However, using antibiotics with frequent cage changing negatively affected breeding performance. Nevertheless, this technique can be used to produce C. bovis-free NSG offspring from infected adults and may be an option for salvaging infected immunocompromised strains of mice that are not easily replaced.

The adaptive potential of invasive species is thought to decrease during founding events due to reduced genetic diversity, limiting the new population’s ability to colonize novel habitats. Barbary ground squirrels (Atlantoxerus getulus) were purportedly introduced as a single breeding pair to the island of Fuerteventura but have expanded to over a million individuals spread across the island in just over 50 years. We estimated the number of founders and measured the level of genetic diversity in this population using the mitochondrial displacement loop and microsatellite markers. Island samples (n= 19) showed no variation in the d-loop, suggesting a single founding female, while Moroccan samples (n= 6) each had unique mitochondrial haplotypes. The microsatellite data of the island population (n= 256 individuals) revealed a small effective population size, low levels of heterozygosity, and high levels of inbreeding, supporting a founding population size of two to three individuals. Our results suggest thatA. getulushas undergone an intense genetic bottleneck during their colonization of the island. They are one of the few species where introduction effort does not explain invasion success, although further investigation may explain how they have avoided the worst expected effects following an extreme genetic bottleneck.

While several methods have been employed to estimate shorebird abundance and productivity, little attention has been given to differences in methods used to collect these data. Within central North America, Interior Least Tern (Sternula antillarum athalassos; hereafter, Least Tern) and Piping Plover (Charadrius melodus) monitoring is often accomplished through surveys from a distance or within the nesting colony. Four years (2013-2016) of season-long monitoring (April- mid-September) were implemented from inside and outside nesting colonies at off-channel nesting sites along the central Platte River, Nebraska, USA to compare estimates of resulting productivity components. Each method was found to have observational strengths and weaknesses, depending on the species and reproductive component. Outside Least Tern monitoring resulted in higher fledgling counts (256 total fledglings) and lower breeding pair estimates (242 total pairs), resulting in higher fledge ratios compared to inside monitoring (192 total fledglings, 261 total pairs). Differences in Piping Plover fledge ratios were annually variable (total pairs: inside estimate = 116, outside estimate = 103; total fledglings: inside estimate = 142, outside estimate = 117). Overall, both inside and outside monitoring can produce reasonable estimates of species abundance and productivity despite substantial differences in monitoring effort and cost.

The global breeding population of Eleonora’s falcon is distributed from the Canary Islands in the west, across the Mediterranean Sea, to Cyprus in the east. The remoteness of nesting colonies, which are predominantly located on sea cliffs and islets, renders breeding success estimation a challenging task, requiring a composite approach to assess each of the breeding stages. Early estimates of the breeding success of Eleonora’s falcon suggested that Akrotiri colony in Cyprus had the lowest breeding success among all the colonies throughout the species’ breeding range, at a level seemingly unsustainable, suggesting the colony might have been in danger of gradual extinction. Here we use a diversity of survey methods using boat, ground and aerial surveys, with the incorporation of photography and photogrammetry, to reassess the breeding success and the effect of nest characteristics on the Eleonora’s falcon breeding population in Cyprus. During a six-year study, we found that Cyprus hosts ~138 ± 8 breeding pairs and that breeding success equals 1.54 ± 0.85 fledglings per breeding pair, thus considerably higher than previous estimates. In addition, by analyzing temporal variation in breeding and nest characteristics, we found that early breeding and reuse of nests positively influence breeding success, but physical nest characteristics have a limited effect on colony productivity. The range of survey methods employed, as well as the array of photography techniques utilized, highly enhanced the efficiency and accuracy of this study, allowing us to overcome the challenge of inaccessibility of nesting cliffs.

The developmental environment an animal experiences can have a pervasive and sustained effect on phenotype throughout its life. Animals exposed to suboptimal conditions during development can experience physiological trade-offs, leading to seemingly negative phenotypic changes in later life that have been hypothesised to have detrimental effects on fitness. However, few studies have investigated how exposure to suboptimal developmental conditions affects an animal’s reproductive behavior and fitness. Here, we determine if elevated levels of corticosterone (CORT; the dominant avian stress hormone) during development affect fitness via changes in reproductive investment in adult zebra finches (Taeniopygia guttata). To do this, we exposed nestling zebra finches to either CORT supplemented or control treatments and assessed their mate selection and reproductive investment as adults, using free choice breeding experiments. We found that breeding pairs of birds from matched developmental treatments (CORT or control) had a shorter latency to lay clutches compared to pairs with mismatched developmental treatments. We found no indication that clutch size or egg mass were affected by developmental treatment. Also, we found no evidence that birds choose mates to match their own developmental treatment. Our results demonstrate that developmental experience may affect reproductive investment through changes to reproductive timing and add to the literature suggesting that pairs with similar developmental backgrounds can coordinate their reproduction more effectively. Developmental stress may reduce the fitness of a breeding pair as a result of its detrimental effect on phenotype and performance. Alternatively, individuals could use indicators of developmental stress to influence mate choice in order to compensate for a poor start to life. Previous studies suggest that birds do assortatively mate by developmental environment, but this has not been tested in a free choice mating context. Using a free choice breeding experiment, we show that pairs of breeding birds lay eggs faster when they have matching developmental environments, regardless of the quality of their developmental environment. This evidence suggests that assortatively mated pairs can potentially offset a bad start to life and maintain fitness in spite of the deleterious effects of developmental stress.

Maize is one of the dominant crops in Ukraine and the world. Food, processing, medical, microbiological, brewing industries as well as fuel and energy sectors of the country are interested in its grain production, as it is a high-energy raw material for the industrial production of bioethanol and other fuel materials. The research was aimed at developing and identifying the self-pollinated lines resistant to main diseases and pests; finding out the determinative sig ns for the development of principles of the breeding pair selection when creating the maize hybrids resistant to the complex of entomopathogens and phytopathogens adapted to the conditions of the Right-Bank Forest-Steppe of Ukraine (Palamarchuk 2018; Tanchik 2009).

In cooperatively breeding societies dominant breeders are assisted by other individuals in raising their young. In many of these species helping behaviours and their benefits for breeders have been studied by investigating the helpers' contribution to direct offspring care, even though a significant proportion of help is not targeted specifically to offspring. Here, we investigated how breeders and helpers share the effort in shelter maintenance and how their investment is influenced by the presence of dependent young in the cooperatively breeding cichlid Neolamprologus savoryi. Shelters provide essential protection from predators, independently of a group's breeding status. Shelter maintenance is costly in terms of time investment and energy expenditure. In the field we manipulated the workload of groups that differed in the presence and number of helpers and the reproductive state of breeders by increasing the need for digging out the breeding shelter. Helper presence correlated with workload reduction of dominant females, even in the absence of dependent young. This emphasizes the importance of shelters for the whole group, independently of the current reproductive status of the breeding pair. The described benefits increased with the number and body size of the helpers. Additionally, breeding females and helpers visited the breeding chamber more often if young were present, and helper presence enhanced the reproductive success of breeders. These findings highlight the importance of studying the role of helpers and their benefits to breeders not only in the context of direct brood care, but also for other cooperative tasks, in order to understand the evolution of complex animal societies.

Summary Objective: Tortoise picornavirus (ToPV) has been speculated to play an important role in the frequently seen disease pattern of juvenile shell softening. This study aimed to determine ToPV prevalence among German tortoise collections. Material and methods: A total of 334 animals selected from 27 different collections were included. Seven species of four genera of the family Testudinidae (Testudo graeca, T. hermanni, T. marginata, T. horsfieldii, Centrochelys sulcata, Stigmochelys pardalis, Chelonoidis carbonarius) were sampled. The tortoises were clinically investigated and none of the adults showed any signs of shell softening. Seven hatchlings of a ToPV-positive T. graeca breeding pair showed retarded growth and a progressive shell weakness that resulted in death. Each animal was sampled by conjunctival, pharyngeal and cloacal swabs (990 swabs in total) and blood sampling (293 in total). All three swabs of one animal were pooled and tested by reverse transcriptase polymerase chain reaction (RT-PCR) for tortoise picornavirus RNA. Blood samples were investigated by virus neutralisation test (VNT) for specific anti ToPV antibodies. All titres equal to or higher than log2 = 2 were considered positive. Results: In total, 35 adult and 11 juvenile animals were tested positive for ToPV RNA. The serological investigation did detect specific antibodies against ToPV in 44 adult tortoises and one juvenile. In total, 76 animals were tested positive in either one of the investigations, 16 animals in both. The highest number of ToPV-positive animals was found for T. graeca, with a prevalence of 32 %. No specimens of C. carbonarius, C. sulcata, or S. pardalis were tested positive. Conclusion and clinical relevance: The results propose a predisposition in T. graeca, as well as a high prevalence of ToPV in T. graeca, whereas other species showed only single or no positive animals, but may function as virus carriers.

Tag‐recovery data from organisms captured and marked post breeding are commonly used to estimate juvenile and adult survival. If annual fecundity could also be estimated, tagging studies such as European and North American bird‐ringing schemes could provide all parameters needed to estimate population growth. I modified existing tag‐recovery models to allow estimation of annual fecundity using age composition and recapture probabilities obtained during routine banding operations of northern pintails (Anas acuta) and dark‐eyed juncos (Junco hyemalis), and I conducted simulations to assess estimator performance in relation to sample size. For pintails, population growth rate from band‐recovery data (λ = 0.93, SD: 0.06) was similar but less precise than count‐based estimates from the Waterfowl Breeding Pair and Habitat Survey (λ: 0.945, SE: 0.001). Models with temporal variation in vital rates indicated that annual population growth in pintails was driven primarily by variation in fecundity. Juncos had lower survival but greater fecundity, and their estimated population growth rate (λ: 1.01, SD: 0.19) was consistent with count‐based surveys (λ: 0.986). Simulations indicated that reliable (CV 1,000 within‐season live encounters. Although precision of survival estimates depended primarily on numbers of adult recoveries, estimates of fecundity and population growth were most sensitive to total number of live encounters. Synthesis and applications: Large‐scale ring‐recovery programs could be used to estimate annual fecundity in many species of birds, but the approach requires better data curation, including accurate assessment of age, better reporting of banding totals, and greater emphasis on obtaining and reporting within‐season live encounters.

In Damaraland mole-rats (Fukomys damarensis), non-breeding subordinates contribute to the care of offspring born to the breeding pair in their group by carrying and retrieving young to the nest. In social mole-rats and some cooperative breeders, dominant females show unusually high testosterone levels and it has been suggested that high testosterone levels may increase reproductive and aggressive behavior and reduce investment in allo-parental and parental care, generating age and state-dependent variation in behavior. Here we show that, in Damaraland mole-rats, allo-parental care in males and females is unaffected by experimental increases in testosterone levels. Pup carrying decreases with age of the non-breeding helper while the change in social status from non-breeder to breeder has contrasting effects in the two sexes. Female breeders were more likely than female non-breeders to carry pups but male breeders were less likely to carry pups than male non-breeders, increasing the sex bias in parental care compared to allo-parental care. Our results indicate that testosterone is unlikely to be an important regulator of allo-parental care in mole-rats.

As nature-based recreation grows in popularity, there is concern for reduced fitness of animals exposed to chronic disturbance by these activities. Golden Eagles (Aquila chrysaetos) and other raptors are sensitive to human recreation near their nests, and managers of these species need strategies to mitigate negative effects. We used simulation models to separate the effects of trail density and configuration, land cover configuration, and volume of human recreation on the effectiveness of 2 trail closure strategies to manage disturbance. We simulated a breeding pair of Golden Eagles at 3 territories with varying degrees of trail density under current and increased levels of human activity. We simulated a baseline scenario, a scenario with a 600 m restrictive buffer around the nest, and a scenario where we closed all but the most popular trails to human recreation. We also conducted a trail-swapping simulation with trail configurations of each territory placed into the land cover of the other ter...

The honey badger is a widespread, but understudied African carnivore, with high potential as a bone accumulator in cave and fossil deposits. This study serves as the first investigation into the taphonomic modifications of this species when feeding on small to medium-sized prey. Domestic rabbit (Oryctolagus cunniculus) carcasses where fed experimentally to a breeding pair of captive honey badgers housed at the Johannesburg Zoo. Bones from the feeding refuse and the carnivore scats were analysed for anatomical composition, fragmentation patterns, tooth marks and digestion. The results were compared with feeding studies with various small carnivores on leporid prey. Honey badgers preferentially opened their prey at the belly and focussed their feeding on nutritionally high-yield soft parts, often discarding low-yield parts like distal appendages, crania and the skins. Bones from the refuse assemblage were often complete and unmodified but stripped of flesh. Bones from the scat assemblage displayed very high fragmentation, light digestive modification and high numbers of tooth marked bones. This latter character was particularly diagnostic for the honey badger. This study investigates a carnivore that has received little interest and shows the high potential of this carnivore to act as a bone accumulator. Further taphonomic research into this species will greatly enhance our understanding of this species and its activity in the fossil record.