Breeding Failure Research Articles

Red-legged partridge Alectoris rufa productivity in relation to weather, land use, and releases of farm-reared birds

Productivity (offspring production) is a key demographic parameter influencing population dynamics, particularly in r-strategy species, and thus critical for implementing well-based management of populations. Accordingly, the study of factors influencing productivity is useful to develop management strategies in species of conservation concern or subject to exploitation. We studied productivity (covey size and young/adult ratio) of red-legged partridges (Alectoris rufa) in Spain through a large-scale sampling in Andalucia and Castilla-La Mancha, two large areas in central-southern Spain, the core of the distribution of the species. We evaluated potential environmental factors related with productivity that have been considered important in previous local studies (weather, land use, and intensity of releases of farm-reared partridges), using a dataset of 15,357 observations of partridges over three breeding seasons (2010, 2011, and 2012). Average productivity at the end of July was 3 young/adult, indicating 50% chick mortality between hatching and fledging and high breeding failure. We found marked effects of weather, year, and land use on partridge productivity, confirming some previous results at local scale and supporting widespread and simultaneous effects of these factors. We also detected a large-scale negative relationship with farm-bred partridge release intensities, with lower young/adult ratios in areas with high release intensity. This suggests that partridge releases may be contributing to the decline of wild populations. Our results support that correcting the effects of agricultural intensification is the main key to the long-term conservation of the species and suggest that, in dry spring years (leading to low average productivity), many populations could be exposed to overhunting. These results stress the importance of both small- and large-scale adjustments of hunting pressure to partridge productivity, in order to preserve wild populations. Poor hunting bags in “bad” years, along with the increasing demand in the hunting market, may have stimulated the widespread use of releases, further reducing productivity and leading to the current compromised conservation status of wild populations. We discuss some potential solutions to this conflicting situation from the socioeconomic and environmental points of view.

Predation behaviour of millimetre-sized hydrozoan polyps on early ivory shell juveniles

AbstractMarine hydroids, the polyp stage of hydrozoans, are assumed to be carnivores and play an important role in benthic-pelagic coupling processes by regulating zooplankton populations and transferring energy. The known hydroid diets mainly consist of zooplankton as well as some benthic diatoms and metazoans, almost all of which have smaller dimensions than the polyp. In the present study, a large-scale breeding failure of the early juveniles of the ivory shell Babylonia areolata (Mollusca: Gastropoda: Babyloniidae) was found in a local aquaculture farm in Fujian, China in July 2018. About 640,000 out of 800,000 early juveniles (80%) died due to predation by a millimetre-sized colonial hydroid species that was initially overlooked. The hydrozoan species was identified as Eirene sp. (Cnidaria: Hydrozoa: Eirenidae) via the integration of morphological and molecular data. A laboratory feeding experiment showed that the hydroid predation led to an overall mortality of ivory shell juveniles of up to 92.6% after 48 h. The predation process was observed in the laboratory and a video showing the entire process was prepared. This is the first report of hydroids preying on gastropod juveniles, revealing a previously unknown threat to mollusc aquaculture including ivory shells. Several management practices are suggested to mitigate this newly recognized threat.

On the Doorstep, Rodents in Homesteads and Kitchen Gardens.

Simple SummarySeven species were recorded during a pilot study of small mammals in commensal habitats (homesteads and kitchen gardens) in Lithuania. Homestead gardens and outbuildings without food availability were dominated by yellow-necked mice, while buildings where food was available were dominated by bank voles. The body condition of rodents in these commensal habitats, being highest in the homestead gardens, was worse than that in rodents found in other agricultural habitats. Breeding failures in the form of disrupted pregnancies were recorded in all of the most numerous species of rodents.Scarcely investigated in terms of small mammals, kitchen gardens and homesteads form a subset of environments. Using results of snap trapping, we present the first data on small mammal species diversity, gender and age structure, relative abundance, body fitness, and reproduction parameters in these commensal habitats (kitchen gardens, homestead gardens, houses, and outbuildings). We expected that (i) house mice should be the dominant species in buildings, while striped field mice should be dominant in gardens, (ii) body condition should be the highest in buildings, (iii) body condition should increase in the autumn, irrespective of the habitat, and (iv) breeding failures in the form of disrupted pregnancies should be observed. Not all of the predictions were confirmed. From the seven recorded species, gardens and outbuildings were dominated by yellow-necked mice, while bank voles dominated in buildings where food was available. The number of recorded species and diversity index increased during the autumn months. The body condition was highest in rodents that were trapped in gardens. It decreased towards winter, with the exception of the striped field mouse. Breeding disturbances were recorded in all of the most numerous species, comprising 16.7–100% of all observed pregnancies.

Breeding success, nest site fidelity and mate fidelity in the European Storm-petrel

The European Storm-petrel Hydrobates pelagicus is a monogamous and long-lived species with a low reproductive rate. Its nest sites are located in natural cavities under rocks or in burrows excavated by other species. Data obtained in the Molène archipelago, western France, have been analysed to study nest site fidelity and mate fidelity, and to study their relationship with breeding success and sex. Breeders were ringed and breeding success assessed from 2001–18. The influence of age and the weight of breeders on reproductive success has also been studied. Individuals were very faithful to their nest sites (94%) and to their mates (95%) from one year to the next. Breeding failure in the year t was negatively correlated with nest site fidelity and with mate retention in year t+1. Nest site fidelity was not influenced by the sex of breeding birds. Change of nest site or mate had no significant impact on the breeding success in the same year. There was a positive effect of the weight of incubating adults on reproductive success. High rates of nest site fidelity and mate fidelity may indicate good population status, with breeding habitat and mates of good quality.

旅游对鸡形目鸟类巢成功率的影响——基于人工巢试验

PDF HTML阅读 XML下载 导出引用 引用提醒 旅游对鸡形目鸟类巢成功率的影响——基于人工巢试验 DOI: 10.5846/stxb201812252804 作者: 作者单位: 作者简介: 通讯作者: 中图分类号: 基金项目: 国家自然科学基金面上项目（31872240） Effects of tourism on nest survival rate of Galliformes based on artificial nest experiment Author: Affiliation: Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:旅游快速发展对野生动物的繁衍和种群发展造成的影响不容忽视。鸡形目鸟类大多为地面营巢，易受人为活动的影响。为揭示旅游对鸡形目鸟类巢成功率的影响，于2018年3-5月在河南董寨国家级自然保护区采用地面人工巢进行了两轮模拟试验，分析了试验轮次、巢密度、代表旅游活动强度的客流量和车流量，及植被类型、海拔等栖息地影响因子对人工巢成功率的影响。结果显示：客流量和海拔在繁殖成功巢和失败巢之间均存在不同程度的差异，繁殖成功巢的客流量较大、海拔较小，且在客流量较大、海拔较小的区域中人工巢的表观存活率明显较高。其中客流量是影响巢成功率的主导因素。此外，第二轮试验人工巢表观存活率显著低于第一轮试验，捕食者组成在不同试验轮次上也存在明显的差异，第一轮试验主要是鸟类，第二轮试验则是哺乳动物。白颈鸦、貉和野猪在本研究中是对巢威胁最大的捕食者。结果表明旅游活动可能会影响鸡形目鸟类的繁殖。因此建议在开展旅游活动时应综合考虑该区域所分布的野生动物及优先保护政策，注意控制旅游活动强度，以免对野生动物造成不良影响，并加强栖息地的保护。 Abstract:It cannot be ignored that the impact of rapid development of tourism activities on reproduction and population expansion of wild animals. Most Galliformes nest on the ground and are susceptible to human activities. To investigate the impact of tourism activities on the nesting rate of Galliform species, the ground artificial nests were placed in Dongzhai National Nature Reserve, Henan Province for simulation test from March to May, 2018. We analyzed whether the experiment rounds, nest density, visitors flow rate, and vehicle flow rate representing the intensity of tourism activities had relationship with the nest survival rate. We also analyzed the influence of habitat factors such as vegetation type and altitude on the artificial nesting rate. We found that there were significant differences in altitude and visitors flow rate between the breeding success nests and failure nests. The breeding success nest were located in low altitude and large visitors flow rate area. The apparent survival rate of artificial nests was significantly higher in areas with high visitors flow rate and low altitude. The influence of visitors flow rate on nest survival rate is a dominant factor. In this study, the apparent survival rate of the artificial nest in the second round experiment was significantly lower than that in the first round experiment. Moreover, the composition of the artificial nest predators also showed significant differences in different test rounds. The first round experiment was mostly birds, and the second round experiment was mammals. Collared crow, raccoon dog, and wild boar were the most threatening predators in this study. The results suggest that the moderate tourism may affect the reproduction of Galliformes. Therefore, it is suggested that the wildlife distributed in this area and priority protection policy should be taken into account in tourism activities. The intensity of tourism activities should be controlled in order to avoid adverse effects on wildlife and strengthen the protection of habitats. 参考文献 相似文献 引证文献

Delayed predator-prey collapses: the case of black-legged kittiwakes and Iberian sardines

MEPS Marine Ecology Progress Series Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsTheme Sections MEPS 631:201-207 (2019) - DOI: https://doi.org/10.3354/meps13164 Delayed predator-prey collapses: the case of black-legged kittiwakes and Iberian sardines A. Martínez-Abraín1,*, P. Santidrián Tomillo2, J. Mouriño3, S. Tenan4, D. Oro5,6 1Universidade da Coruña, Facultad de Ciencias, Evolutionary Biology Group, Campus da Zapateira s/n, 15071 A Coruña, Spain 2The Leatherback Trust, Goldring-Gund Marine Biology Station, Playa Grande, Costa Rica 3Arcea, Xestión de Recursos Naturais S.L., Velázquez Moreno 9, oficina 305, 36201 Vigo, Spain 4MUSE - Museo delle Scienze, Sezione di Zoologia dei Vertebrati, Corso del Lavoro e della Scienza, 3, 38122 Trento, Italy 5Instituto Mediterráneo de Estudios Avanzados IMEDEA (CSIC-UIB), Miquel Marquès 21, 07190 Esporles, Spain 6Centre d’Estudis Avançats de Blanes CEAB (CSIC), Acces Cala Sant Francesc 14, 17300 Blanes, Spain *Corresponding author: a.abrain@udc.es ABSTRACT: We analysed the long-term (1975-2017) population response of a colony of a marine top predator, the black-legged kittiwake Rissa tridactyla, to the population dynamics of sardine Sardina pilchardus, its main local prey. The study site (Sisargas Islands, Spain) is located at the southernmost edge of the geographical distribution of the predator. Kittiwake counts of breeding pairs started with the discovery of the colony (1975), likely close to the actual year of first colonization. Sardine landings by age class (1978-2016) were taken from the International Council for the Exploration of the Sea (ICES) database. Sequential t-test analysis revealed that a regime shift of the oldest sardine age class (age 6+) took place in 1991 and that kittiwakes experienced a regime shift in the number of breeding pairs in 1993, 2 yr after the prey shift. Multiple autocorrelation functions for the detrended time series of sardines and kittiwakes indicated an autocorrelation with a time lag of 2 yr. Despite much reduced fishing effort, sardine densities have not recovered since the collapse, likely due to changes in large-scale atmospheric circulation in the Northern Hemisphere in the late 1990s. Kittiwakes at Sisargas have not recovered demographically, remaining nearly extinct during the last ca. 20 yr. Although we lack detailed demographic data for the studied kittiwake population, we suggest that massive breeding failure and subsequent dispersal to higher-quality patches might explain the rapid non-linear collapse in breeding population density. We discuss some behavioural social responses that may have occurred during and after the collapse to explain the dynamics of the study colony. KEY WORDS: Population crash · Black-legged kittiwakes · Time delay · Non-linearities · Predator-prey dynamics · Food availability · Iberian sardine · Fisheries collapse Full text in pdf format Supplementary material PreviousNextCite this article as: Martínez-Abraín A, Santidrián Tomillo P, Mouriño J, Tenan S, Oro D (2019) Delayed predator-prey collapses: the case of black-legged kittiwakes and Iberian sardines. Mar Ecol Prog Ser 631:201-207. https://doi.org/10.3354/meps13164 Export citation RSS - Facebook - Tweet - linkedIn Cited by Published in MEPS Vol. 631. Online publication date: November 21, 2019 Print ISSN: 0171-8630; Online ISSN: 1616-1599 Copyright © 2019 Inter-Research.

Economic evaluation of genetic markers for cow-calf operations differentiated by forage type and breed

When selecting breeding stock, the use of genetic marker information in beef cattle (Bos taurus L., and Bos indicus L.) is expected to enhance herd performance and thereby producer returns. Cattle performance data from experimental trials, tracking the single nucleotide polymorphism (SNP) P450 C994G and HSP70 CDS G2033C genotypic distributions in Angus (AA; Bos taurus), Brahman (BB; Bos indicus), and their reciprocal cross (RC) cows were investigated to determine economic performance differences when grazing endophyte infected tall fescue [Lolium arundinaceum (=Festuca arundinacea)] compared to Bermudagrass (BG; Cynodon dactylon L.) pastures. Since open cows were not culled, the study provides unique lifetime data on cow-calf breeding failure rates. These data are essential for economic comparisons of spring calving herds that were either exposed to fungal endophyte [Epichloë coenophiala (=Neotyphodium coenophialum=Acremonium coenophialum)] infected tall fescue grazing and hay (E+) or not (BG). The Forage and Cattle Analysis and Planning (FORCAP) decision support software was used to assess impact on profitability of birth weight, weaning weight, and breeding failure rate differences across treatment. Results showed that added SNP marker information did little to separate animal performance. A neural network approach also was used to assess the impact of genetic marker information to predict economic performance. Using either gene SNP, less than 5% of variation in economic returns was affected by genetic information, with the largest driver of profitability being breeding failure rate. Using the two genetic markers of this study to predict breeding failure rate showed little evidence to suggest that breeding decisions could be improved using genetic marker information. With more data, this conclusion may well change as observed least square mean differences by SNP were larger than the cost of obtaining the information but not statistically significant.

Managed marshes can be good alternatives to natural marshes as breeding habitats for birds

Loss of natural tidal marshes has caused rapid population declines for many bird species, raising the question about whether managed marshes can be used for bird conservation. Although many studies have indicated that managed marshes can provide a complementary habitat for birds, it is unclear how the breeding habitats provided by managed marshes compare with those provided by natural marshes. We compared habitat conditions (vegetation and food) and breeding performance of a common reed specialist, the Oriental reed warbler (Acrocephalus orientalis), in natural and managed artificial reed marshes (about 2 km × 5 km) at Chongming Dongtan, an estuarine wetland in China. We found that vegetation was denser and warbler food resources were greater in managed than in natural marshes. The density of breeding territories, nest density, clutch size, egg size, and fledgling number per nest were greater in managed than in natural marshes. Breeding failure was reduced in managed marshes because of a reduced risk of nest predation. However, the high nest position on the reeds in the managed marshes increased the risk of nest destruction by strong wind. The better breeding performance in managed than in natural marshes could be attributed to the following factors: the high and stable water level in the managed marshes increased reed growth and arthropod reproduction and decreased access by terrestrial predators; dense vegetation helped conceal nests from predators; and human activities in the managed marshes deterred nest predators. The results suggest that managed marshes can provide quality breeding habitat for the Oriental reed warbler and probably for other marsh birds and can therefore help compensate for the loss of natural marshes. The preference of the Oriental reed warbler for managed marshes largely depends on the suitable habitat conditions. The current study highlights the importance of maintaining a relatively high and stable water level.

Prospecting of breeding adult Common terns in an unstable environment

With increasing advances in telemetry technology, prospecting behaviour was identified in many seabirds; mostly in immatures, but also in adults – during pre-breeding and post-breeding periods and among failed breeders. However, prospecting has not yet been documented among active breeders. We equipped 17 Common terns Sterna hirundo with GPS-UHF data-loggers and tracked their movements during late incubation and chick rearing in continental Croatia. We monitored the fate of their clutches until chicks left the nest. Birds of both sexes visited other breeding colonies within relatively short distances, while they still had active nests. These results confirm for the first time the presence of prospecting trips during incubation and chick-rearing in active breeders. Such behaviour probably developed because quick and unpredictable changes in their freshwater habitats can cause failure of whole colonies, forcing them to renest at other sites during the same breeding season. Prospecting during the first breeding attempt might shorten the renesting interval, and increase renesting success when multiple breeding sites are available on an easily accessible area. With increasing vulnerability of colony sites due to climate change, studies of scattered colonies are needed to better understand renesting and adult prospecting strategies.

Chronic, sublethal effects of high temperatures will cause severe declines in southern African arid-zone birds during the 21st century

Birds inhabiting hot, arid regions are among the terrestrial organisms most vulnerable to climate change. The potential for increasingly frequent and intense heat waves to cause lethal dehydration and hyperthermia is well documented, but the consequences of sublethal fitness costs associated with chronic exposure to sustained hot weather remain unclear. Using data for species occurring in southern Africa's Kalahari Desert, we mapped exposure to acute lethal risks and chronic sublethal fitness costs under past, present, and future climates. For inactive birds in shaded microsites, the risks of lethal dehydration and hyperthermia will remain low during the 21st century. In contrast, exposure to conditions associated with chronic, sublethal costs related to progressive body mass loss, reduced nestling growth rates, or increased breeding failure will expand dramatically. For example, by the 2080s the region will experience 10-20 consecutive days per year on which Southern Pied Babblers (Turdoides bicolor) will lose ∼4% of body mass per day, conditions under which this species' persistence will be extremely unlikely. Similarly, exposure to air temperature maxima associated with delayed fledging, reduced fledgling size, and breeding failure will increase several-fold in Southern Yellow-billed Hornbills (Tockus leucomelas) and Southern Fiscals (Lanius collaris). Our analysis reveals that sublethal costs of chronic heat exposure are likely to drive large declines in avian diversity in the southern African arid zone by the end of the century.

A Diallel of the Mouse Collaborative Cross Founders Reveals Strong Strain-Specific Maternal Effects on Litter Size.

Reproductive success in the eight founder strains of the Collaborative Cross (CC) was measured using a diallel-mating scheme. Over a 48-month period we generated 4,448 litters, and provided 24,782 weaned pups for use in 16 different published experiments. We identified factors that affect the average litter size in a cross by estimating the overall contribution of parent-of-origin, heterosis, inbred, and epistatic effects using a Bayesian zero-truncated overdispersed Poisson mixed model. The phenotypic variance of litter size has a substantial contribution (82%) from unexplained and environmental sources, but no detectable effect of seasonality. Most of the explained variance was due to additive effects (9.2%) and parental sex (maternal vs. paternal strain; 5.8%), with epistasis accounting for 3.4%. Within the parental effects, the effect of the dam’s strain explained more than the sire’s strain (13.2% vs. 1.8%), and the dam’s strain effects account for 74.2% of total variation explained. Dams from strains C57BL/6J and NOD/ShiLtJ increased the expected litter size by a mean of 1.66 and 1.79 pups, whereas dams from strains WSB/EiJ, PWK/PhJ, and CAST/EiJ reduced expected litter size by a mean of 1.51, 0.81, and 0.90 pups. Finally, there was no strong evidence for strain-specific effects on sex ratio distortion. Overall, these results demonstrate that strains vary substantially in their reproductive ability depending on their genetic background, and that litter size is largely determined by dam’s strain rather than sire’s strain effects, as expected. This analysis adds to our understanding of factors that influence litter size in mammals, and also helps to explain breeding successes and failures in the extinct lines and surviving CC strains.

Emperors on thin ice: three years of breeding failure at Halley Bay

AbstractSatellite imagery is used to show that the world's second largest emperor penguin colony, at Halley Bay, has suffered three years of almost total breeding failure. Although, like all emperor colonies, there has been large inter-annual variability in the breeding success at this site, the prolonged period of failure is unprecedented in the historical record. The observed events followed the early breakup of the fast ice in the ice creeks that the birds habitually used for breeding. The initial breakup was associated with a particularly stormy period in September 2015, which corresponded with the strongest El Niño in over 60 years, strong winds, and a record low sea-ice year locally. Conditions have not recovered in the two years since. Meanwhile, during the same three-year period, the nearby Dawson-Lambton colony, 55 km to the south, has seen a more than tenfold increase in penguin numbers. The authors associate this with immigration from the birds previously breeding at Halley Bay. Studying this ‘tale of two cities’ provides valuable information relevant to modelling penguin movement under future climate change scenarios.

Hormone-induced sperm-release in the critically endangered Booroolong frog (Litoria booroolongensis): effects of gonadotropin-releasing hormone and human chorionic gonadotropin.

Research into the development of reproductive technologies for amphibians has increased in recent years due to the rapid decline of amphibian species globally. Reproductive technologies have great potential to overcome captive breeding failure and improve the propagation and genetic management of threatened species. However, the incorporation of these technologies into conservation breeding programs has been protracted, primarily as a result of trial-and-error approaches to the refinement of hormone therapies. The present study investigated the effects of: (1) GnRH-a dose (0, 0.5, 1, 2, 4, 8 or 16 μg g-1), and (2) hCG dose (0, 2.5, 5, 10, 20 or 40 IU g-1), on the sperm-release response of the critically endangered Booroolong frog. Administration of GnRH-a at a dose of 0.5 μg g-1 resulted in the greatest number of sperm released (mean total sperm = 3.5 ×106, n = 11). Overall, hCG was more effective at eliciting spermiation in Booroolong frogs, with peak sperm release (mean total sperm = 25.1 ×106, n = 10) occurring in response to a dose of 40 IU g-1. Sperm output in response to 40 IU g-1 hCG was greatest between 1 and 6 h and steadily declined between 8 and 24 h post-hormone administration. Percent sperm motility peaked between 4 and 10 h (58.1-62.7%), and sperm velocity between 4 and 12 h (24.3-27.2 μm s-1). Booroolong frogs join a small, but growing number of amphibian species that exhibit improved spermiation in response to hCG. Further research is required to identify optimal hormone-induction protocols for threatened amphibians and expedite the incorporation of reproductive technologies into CBPs.

Two Recent Massive Breeding Failures in an Adélie Penguin Colony Call for the Creation of a Marine Protected Area in D'Urville Sea/Mertz

In the d’Urville Sea in East Antarctica, a population of roughly 20,000 pairs of Adelie penguins of Iles des Petrels (Terre Adelie) has experienced two massive breeding failures, with no chick surviving the 2013–14 and 2016–17 breeding seasons. In both seasons the extent of sea ice in front of the colony persisted throughout the breeding cycle of the birds. The timing of sea-ice recession differed greatly between seasons and the absence of polynya in a crucial phase of the cycle were paramount in driving these failures. The change in the icescape in front of Ile des Petrels following the calving of the Mertz glacier in 2010, together with increase in precipitations and changes in sea-ice firmness explain this situation and are discussed in the present manuscript. To prevent additional future impacts on this colony, like competition with fisheries for instance, we strongly support a scientific research zone in the d’Urville Sea—Mertz area, one of the three zones of proposed Marine Protected Area in East Antarctica to the Commission for the Conservation of Antarctic Marine Living Resources.

Nesting behaviour and breeding success of Willow Tits Poecile montanus in north-west England

ABSTRACTThe British Willow Tit Poecile montanus has undergone a substantial decline in abundance and a severe contraction in range since the 1970s, for reasons that are poorly understood. Breeding failure, due to nest-site competition and predation, has been suggested as a potential factor in the decline, but limited data exist for the nesting ecology and breeding productivity of the species in Britain. We studied a sample of 128 Willow Tit nests in a habitat mosaic of early successional woodland, scrub and wetland in a post-industrial landscape in north-west England, which is increasingly becoming a key refuge for the species in Britain. Results showed that nesting began in April, with standing deadwood of silver birch Betula pendula, common elder Sambucus nigra and black alder Alnus glutinosa being the most frequent nest sites, and the characteristics of nest sites are described. Daily survival rates and overall probability of nest survival are calculated, and details are given for the timing of breeding, clutch size, nestling survival and number of fledglings produced. Overall, 55% of nesting attempts were successful, although many first breeding attempts failed due to Willow Tits being evicted from their nest cavity by Blue Tits Cyanistes caeruleus, or nests being predated by Great Spotted Woodpeckers Dendrocopos major and, potentially, grey squirrels Sciurus carolinensis. Repeat breeding attempts were relatively more successful, but produced fewer fledglings on average. The results are discussed in the context of other studies of Willow Tits and some related species, and also the implications for the conservation of Willow Tits in Britain.

Survival estimates strongly depend on capture–recapture designs in a disturbed environment inducing dispersal

Capture–recapture (CR) approaches are extensively used to estimate demographic parameters. Their robustness relies on the selection of suitable statistical models, but also on the sampling design and effort deployed in the field. In colonial or territorial species showing breeding site fidelity, recurrent local perturbations, such as predation‐induced breeding failure, may lead individuals to disperse locally or regionally. This might induce heterogeneity in individual CR histories and biases in demographic parameter estimates. Here, we assessed the effect of buffer areas and multi‐site designs on annual survival estimate accuracy and precision. First, using simulated data with and without a multi‐site design, we compared survival estimates for different scenarios involving contrasted local and regional dispersal. Then, using data from a local multi‐site long‐term monitoring survey carried out in a colony of black‐legged kittiwakes, we tested the homogeneity of individual CR histories and compared survival estimates from three datasets including one or several breeding cliffs with or without buffer areas. Results from simulations highlighted that a single‐site design consistently led to underestimated or less precise survival values compared to a multi‐site design. Similarly, a multi‐site design allowed detecting significant temporal trends while a single‐site one did not. In the field‐based study, adding buffer areas reduced individual heterogeneity, but all three datasets suffered from strong trap‐dependence possibly due to individual breeding success affecting nest‐site fidelity. Implementing a multi‐site design significantly improved the accuracy and precision of annual survival estimates, regardless of CR models applied. Adapting the spatial scale of sampling design to the local environment and species behaviour is essential to provide robust parameters of key relevance for population monitoring and management. We show that implementing buffer areas and/or multi‐site designs may be especially beneficial for long‐lived species facing regular local perturbation events leading to local dispersal.

Fine-scale genetic structure and helping decisions in a cooperatively breeding bird.

In animal societies, characteristic demographic and dispersal patterns may lead to genetic structuring of populations, generating the potential for kin selection to operate. However, even in genetically structured populations, social interactions may still require kin discrimination for cooperative behaviour to be directed towards relatives. Here, we use molecular genetics and long-term field data to investigate genetic structure in an adult population of long-tailed tits Aegithalos caudatus, a cooperative breeder in which helping occurs within extended kin networks, and relate this to patterns of helping with respect to kinship. Spatial autocorrelation analyses reveal fine-scale genetic structure within our population, such that related adults of either sex are spatially clustered following natal dispersal, with relatedness among nearby males higher than that among nearby females, as predicted by observations of male-biased philopatry. This kin structure creates opportunities for failed breeders to gain indirect fitness benefits via redirected helping, but crucially, most close neighbours of failed breeders are unrelated and help is directed towards relatives more often than expected by indiscriminate helping. These findings are consistent with the effective kin discrimination mechanism known to exist in long-tailed tits and support models identifying kin selection as the driver of cooperation.

The price of success: integrative long‐term study reveals ecotourism impacts on a flagship species at a UNESCO site

AbstractDisturbance of wildlife by ecotourism has become a major concern in the last decades. In the Mediterranean, sea‐based tourism and related recreational activities are increasing rapidly, especially within marine protected areas (MPAs) hosting emblematic biodiversity. We investigated the impact of ecotourism in the Scandola MPA (UNESCO World Heritage Site, Corsica island), on the population of a conservation flagship, the Osprey Pandion haliaetus. Over the 37‐year study period, tourists flow increased sharply. Osprey breeding performance initially increased, but then dropped for pairs nesting within the MPA compared to those breeding elsewhere in Corsica. We examined several hypotheses that could explain such reduction in breeding performance. Recent osprey breeding failures in the MPA are not caused by food scarcity. Using underwater fish surveys, we showed that fish consumed by ospreys were more numerous within the MPA. Focal observation at nests revealed that the overall number of boat passages within 250 m of osprey nests were three times higher inside the MPA compared to a control area. Elevated boat traffic significantly modified osprey time‐budgets, by decreasing prey provisioning rate by males, and increasing time spent alarming and flying off the nest in females. This caused stress, and corticosterone levels in chick feathers were three times higher in high‐traffic areas compared to places with lower touristic flow in Corsica, the Balearic Islands and Italy. Overall, our integrative, long‐term study demonstrates the negative impact of sea‐based ecotourism on the Corsican osprey population. This stresses the worldwide importance of rigorously implementing sustainable ecotourism, within well‐enforced MPAs.

Predation and food–weather interactions drive colony collapse in a managed metapopulation of Arctic Terns (Sterna paradisaea)

Seabirds are considered bioindicators of bottom-up ecosystem processes, owing to seabirds’ dependence on marine prey. However, ground-nesting seabirds are susceptible to predation, which can limit their use as bioindicators. Machias Seal Island (MSI) supported the largest colony of Arctic Terns (Sterna paradisaea Pontoppidan, 1763) in the Gulf of Maine metapopulation, but prolonged breeding failure led ∼90% of terns to abandon the colony in 2006. We analyzed 12 years of food, weather, and predation data using logistic regression models to determine which had the strongest influence on breeding success. Food–weather interactions were important; under low rainfall, more euphausiids (northern krill, Meganyctiphanes norvegica (M. Sars, 1857)) in the diet increased breeding success, but euphausiids had a negative effect as rainfall became moderate or high. Predation by Herring Gulls (Larus argentatus Pontoppidan, 1763) increased following the cessation of lethal predator control; we identified a predation threshold of 25%, beyond which terns could not breed successfully. The collapse of MSI’s tern colony can be attributed entirely to gull predation. The breeding success of terns at MSI cannot be used as a bottom-up ecosystem bioindicator without accounting for predation. Managers of ground-nesting seabirds should consider predation and food as equally valid potential causes of population or reproductive declines.

Sharing mutations: are biobanks still required in the post-CRISPR/Cas9 era?

Cryopreservation is seen as a key aspect of good colony management which supports the drive towards improvements in animal care and the implementation of the 3Rs. However, following the advent of gene editing technologies, the generation of new mouse models is quicker and cheaper than ever before. This has led some to question the future value of biobanks around the world. In the following commentary, we argue that the need to cryopreserve mouse strains and distribute them from well-funded repositories is as strong as it has ever been. Repositories are not simply archives for unwanted mouse strains. Biobanks distribute identical QC verified mouse strains to the community and eliminate the need to recreate mice. They provide a check point in the development of mouse strains that minimises genetic drift and breeding failures. What is more, cryopreservation makes resource sharing easier, cheaper and improves animal care by eliminating the need for live animal shipments.