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Kill rates and functional responses are fundamental to the study of predator ecology and the understanding of predatory-prey dynamics. As the most widely distributed apex predator in the western hemisphere, pumas (Puma concolor) have been well studied, yet a synthesis of their kill rates is currently lacking. We reviewed the literature and compiled data on sex- and age-specific kill rate estimates of pumas on ungulates, and conducted analyses aimed at understanding ecological factors explaining the observed spatial variation. Kill rate studies on pumas, while numerous, were primarily conducted in Temperate Conifer Forests (

Mitigating human-caused mortality for large carnivores is a pressing global challenge for wildlife conservation. However, mortality is almost exclusively studied at local (within-population) scales creating a mismatch between our understanding of risk and the spatial extent most relevant to conservation and management of wide-ranging species. Here, we quantified mortality for 590 radio-collared mountain lions statewide across their distribution in California to identify drivers of human-caused mortality and investigate whether human-caused mortality is additive or compensatory. Human-caused mortality, primarily from conflict management and vehicles, exceeded natural mortality despite mountain lions being protected from hunting. Our data indicate that human-caused mortality is additive to natural mortality as population-level survival decreased as a function of increasing human-caused mortality and natural mortality did not decrease with increased human-caused mortality. Mortality risk increased for mountain lions closer to rural development and decreased in areas with higher proportions of citizens voting to support environmental initiatives. Thus, the presence of human infrastructure and variation in the mindset of humans sharing landscapes with mountain lions appear to be primary drivers of risk. We show that human-caused mortality can reduce population-level survival of large carnivores across large spatial scales, even when they are protected from hunting.

Pumas (Puma concolor) are solitary large carnivores that exhibit high energetic investments while hunting prey that often take multiple days to consume. Therefore, pumas should behave in a way to maximize their energetic gains, including using caching, which is a behavior used by many mammal species to preserve and store food or to conceal it from conspecifics and scavengers to limit their losses. Yet pumas do not always cache their kills. In order to understand caching behavior, we used variables associated with the kills such as prey mass, search time, climate, and habitat to test 20 ecological models (representing four a priori hypotheses: food perishability, resource pulse, consumption time, and kleptoparasitism deterrence) in an information-theoretic approach of model selection to explore factors related to the caching behavior. Models were run with information from tracked radio-collared pumas in California over a 2.5-year period and identified a total of 352 kills. Overall, we documented pumas caching 61.5% of their kills, including 71.6% of Black-tailed Deer (Odocoileus hemionus columbianus), their primary prey in the study area. The model with a quadratic effect of adjusted mass of prey on puma caching probability had all of the empirical support (w = 1.00). Specifically, pumas were most likely to cache intermediate-sized prey, such as yearling and adult female deer, and also fed from cached kills for longer periods of time. Larger prey may be too large to easily cache, making it less energetically efficient—while small prey can often be consumed quickly enough to not require caching. This suggests that intermediate-sized prey may be the optimal size for caching, allowing a puma to feed for multiple days while not greatly increasing energetic output. The hypotheses we tested were not mutually exclusive and pumas caching their prey may occur for several reasons; nevertheless, our study demonstrated that pumas use caching to extend their foraging time and maximize energetic gains when preying on intermediate-sized prey.

Puma (Puma concolor) communication with conspecifics is via indirect scent marking behaviours that are important for individuals to advertise their territory and reproductive status, but little is known about how the behaviours develop with age. To examine the development of scent marking behaviours, we monitored the behaviours of adult pumas and dependent kittens. Based on video recordings, we found that the frequency of puma communication behaviours significantly changed over time. Kittens exhibited olfactory investigation more frequently as they aged, but kittens generally did not exhibit scent marking behaviours. Kittens travel with their mothers until they disperse, so there is no need to establish territories or advertise availability to mate, but kittens are at risk of injury or mortality from other pumas. It is possible that there is no functional need for dependent kittens to scent mark until they mature, but there is a need for frequent use of investigative behaviours.

Understanding of animal responses to dynamic resource landscapes is based largely on research on temperate species with small body sizes and fast life histories. We studied a large, tropical mammal with an extremely slow life history, the Western Bornean orangutan (Pongo pygmaeus wurmbii), across a heterogeneous natural landscape encompassing seven distinct forest types. Our goals were to characterize fluctuations in abundance, test hypotheses regarding the relationship between dispersion dynamics and resource availability, and evaluate how movement patterns are influenced by abiotic conditions. We surveyed abundance in Gunung Palung National Park, West Kalimantan, Indonesia, for 99 consecutive months and simultaneously recorded weather data and assessed fruit availability. We developed a Bayesian hierarchical distance sampling model to estimate population dispersion and assess the roles of fruit availability, rainfall, and temperature in driving movement patterns across this heterogeneous landscape. Orangutan abundance varied dramatically over space and time. Each forest type was important in sustaining more than 40% of the total orangutans on site during at least one month, as animals moved to track asynchronies in fruiting phenology. We conclude that landscape-level movements buffer orangutans against fruit scarcity, peat swamps are crucial fallback habitats, and orangutans’ use of high elevation forests is strongly dependent on abiotic conditions. Our results show that orangutans can periodically occupy putative-sink habitats and be virtually absent for extended periods from habitats that are vitally important in sustaining their population, highlighting the need for long-term studies and potential risks in interpreting occurrence or abundance measures as indicators of habitat importance.

The population of the recently-described Whenua Hou diving petrel Pelecanoides whenuahouensis comprises c. 200 adults that all breed in a single 0.018 km2 colony in a dune system vulnerable to erosion. The species would therefore benefit from the establishment of a second breeding population through a translocation. However, given the small size of the source population, it is essential that translocations are informed by carefully targeted monitoring data. We therefore modelled nest survival at the remaining population in relation to potential drivers (distance to sea and burrow density of conspecifics and a competitor) across three breeding seasons with varying climatic conditions as a result of the southern oscillation cycle. We also documented breeding phenology and burrow attendance, and measured chicks, to generate growth curves. We estimated egg survival at 0.686, chick survival at 0.890, overall nest survival at 0.612, and found no indication that nest survival was affected by distance to sea or burrow density. Whenua Hou diving petrels laid eggs in mid October, eggs hatched in late November, and chicks fledged in mid January at c. 86% of adult weight. Burrow attendance (i.e. feeds) decreased from 0.94 to 0.65 visits per night as chicks approached fledging. Nest survival and breeding biology were largely consistent among years despite variation in climate. Nest survival estimates will facilitate predictions about future population trends and suitability of prospective translocation sites. Knowledge of breeding phenology will inform the timing of collection of live chicks for translocation, and patterns of burrow attendance combined with growth curves will structure hand-rearing protocols. A tuhinga whakarāpopoto (te reo Māori abstract) can be found in the Supplementary material.

Communication behaviors play a critical role in both an individual’s fitness as well as the viability of populations. Solitary animals use chemical communication (i.e., scent marking) to locate mates and defend their territory to increase their own fitness. Previous research has suggested that striped skunks (Mephitis mephitis) do not perform scent-marking behaviors, despite being best known for using odor as chemical defense. We used video camera traps to document behaviors exhibited by striped skunks at a remote site in coastal California between January 2012 and April 2015. Our camera traps captured a total of 71 visits by striped skunks, the majority of which (73%) included a striped skunk exhibiting scent-marking behaviors. Overall, we documented 8 different scent-marking behaviors. The most frequent behaviors we documented were cheek rubbing (45.1%), investigating (40.8%), and claw marking (35.2%). The behaviors exhibited for the longest durations on average were grooming ( $$ \overline{x} $$ = 34. 4 s) and investigating ( $$ \overline{x} $$ = 21.2 s). Although previous research suggested that striped skunks do not scent mark, we documented that at least some populations do and our findings suggest that certain sites are used for communication via scent marking. Our study further highlights how camera traps allow researchers to discover previously undocumented animal behaviors.

The interspecific interactions of apex predators are integral to the function of ecological communities, but most studies have focused on understanding their top down effects. Kleptoparasitism (the stealing of procured food) by dominant scavengers can have negative effects on populations and behaviors of apex predators. We captured 7 pumas (Puma concolor) and fitted them with GPS collars to investigate potential kill sites (n = 352), some of which we monitored with camera traps (n = 58). We analyzed whether observed kleptoparasitism by American black bears (Ursus americanus) affected puma energetics and foraging behavior. We found that black bears were the most frequent scavenger of puma kills (72.4%), and we documented bears scavenging puma kills during every month. The top model for bear detection of puma kills included prey size, temperature, and canopy cover, with bears more likely to scavenge from adult black-tailed deer (Odocoileus hemionus columbianus) carcasses in warmer temperatures and under dense canopy cover. When black bear scavenging occurred, pumas spent 22% less time at their kill and incurred energetic losses. In response, pumas shortened their inter-kill intervals by 1.3 days thus increasing their kill rates. Our results demonstrate how a dominant scavenger directly mediates the foraging behavior of an apex predator. These results suggest that community interactions do not necessarily start at the top in top-down systems, and the effects of predators on prey populations can only be understood within their respective ecological communities.

Without insights into the threats affecting species across their distributions and throughout their annual cycles, effective conservation management cannot be applied. The Whenua Hou diving petrel Pelecanoides whenuahouensis (WHDP) is a Critically Endangered small seabird whose offshore habits and threats are poorly understood. We tracked WHDPs year-round in 2015/16, 2017/18, and 2018/19 using global location-sensing immersion loggers to identify offshore distribution, movements, behaviour, and overlap with commercial fishing effort. During the breeding period, WHDPs ranged from southern Aotearoa (New Zealand) to Maukahuka (Auckland Islands). After breeding, WHDPs migrated southwest towards the Polar Front south of Australia, exhibited clockwise movements, and returned to their breeding grounds via the Subantarctic Front. During the non-breeding period, WHDPs exhibited extreme aquatic behaviour and spent >95% of their time on, or under, water. The core areas used consistently during breeding and non-breeding periods warrant listing as Important Bird and Biodiversity Areas. Spatiotemporal overlap of commercial fishing effort with breeding distributions was considerable (35%), in contrast with non-breeding distributions (0%). Spatial restrictions of anthropogenic activity around the breeding colony during the breeding period could help protect WHDPs, but such measures should be subjected to a structured decision-making framework. Our results illustrate the importance of year-round studies to inform conservation of marine species.

Funder: AZA Ape TAG Initiative, Funder: Department of Afroamerican and African Studies, University of Michigan; Id: http://dx.doi.org/10.13039/100005543, Funder: Disney Conservation Fund; Id: http://dx.doi.org/10.13039/100012168, Funder: Idea Wild; Id: http://dx.doi.org/10.13039/100007142, Funder: Leakey Foundation; Id: http://dx.doi.org/10.13039/100005966, Funder: Mohamed bin Zayed Species Conservation Fund; Id: http://dx.doi.org/10.13039/501100011672, Funder: Victoria University of Wellington; Id: http://dx.doi.org/10.13039/501100001538, Haemadipsid leeches are ubiquitous inhabitants of tropical and sub‐tropical forests in the Indo‐Pacific region. They are increasingly used as indicator taxa for biomonitoring, yet very little is known about their basic ecology. For example, to date no study has assessed the occurrence and distribution of haemadipsid leeches across naturally occurring gradients within intact habitats. We analyzed a long‐term data set (2012–2020) on the closely related tiger (Haemadipsa picta) and brown (Haemadipsa spp.) leech species to investigate if and how abiotic and biotic factors influence their occurrence across a gradient of forest types at an undisturbed tropical rainforest site in Indonesian Borneo. We compared a series of negative binomial mixed models and found that, of the abiotic factors, soil moisture had the largest positive effect on encounter rates of both leech species. Among biotic factors, forest type had differential effects on counts of the two species: while tiger leech counts were greater in low elevation forest types, brown leech counts were greater in high elevation forest types. Additionally, we found that the presence of one species had a positive effect on the presence of the other species. Finally, our results show that the tiger leech has a narrower distribution, being restricted to lower elevation forest types with higher water retention, suggesting that the tiger leech could be more sensitive to lower soil moisture levels. Abstract in Indonesian is available with online material.

Indonesia is embarking on an ambitious relocation of its capital city to Kalimantan, Borneo, bringing with it major urban and road infrastructure. Yet, despite being one of the world's most biologically diverse regions, the potential implications of this development for wildlife have yet to be fully assessed. We explored the potential impacts of the capital relocation, and road expansion and upgrades to critical habitat for medium-large mammals (1 kg) using camera trap data from 11 forested landscapes. We applied Bayesian multi-species occupancy models to predict community and species-level responses to anthropogenic and environmental factors. We extrapolated spatial patterns of occupancy and species diversity across the forests of Kalimantan and identified "critical habitats" as the top 20th percentile of occupancy and species richness values. We subsequently overlapped these critical habitat layers with infrastructure impact zones to estimate the area that could potentially be affected by direct or secondary impacts. At both the community and species-level, distance to primary roads had the strongest negative influence on habitat-use. Occupancy was also influenced by forest quality and multidimensional poverty conditions in adjacent villages, demonstrating the sensitivity of biodiversity to socio-ecological pressures. Less than 1 % of the critical habitat for the threatened mammal community lay within the direct impact zone (30 km radius) of the capital relocation. However, approximately 16 % was located within 200 km and could potentially be affected by uncontrolled secondary impacts such as urban sprawl and associated regional development. The often-overlooked secondary implications of upgrading existing roads could also intersect a large amount of critical habitat for lowland species. Mitigating far-reaching secondary impacts of infrastructure development should be fully incorporated into environmental impact assessments. This will provide Indonesia with an opportunity to set an example of sustainable infrastructure development in the tropics.

Mortality site investigations of telemetered wildlife are important for cause-specific survival analyses and understanding underlying causes of observed population dynamics. Yet, eroding ecoliteracy and a lack of quality control in data collection can lead researchers to make incorrect conclusions, which may negatively impact management decisions for wildlife populations. We reviewed a random sample of 50 peer-reviewed studies published between 2000 and 2019 on survival and cause-specific mortality of ungulates monitored with telemetry devices. This concise review revealed extensive variation in reporting of field procedures, with many studies omitting critical information for the cause of mortality inference. Field protocols used to investigate mortality sites and ascertain the cause of mortality are often minimally described and frequently fail to address how investigators dealt with uncertainty. We outline a step-by-step procedure for mortality site investigations of telemetered ungulates, including evidence that should be documented in the field. Specifically, we highlight data that can be useful to differentiate predation from scavenging and more conclusively identify the predator species that killed the ungulate. We also outline how uncertainty in identifying the cause of mortality could be acknowledged and reported. We demonstrate the importance of rigorous protocols and prompt site investigations using data from our 5-year study on survival and cause-specific mortality of telemetered mule deer (

Artificial light at night (ALAN) is considered a major threat to biodiversity, yet impacts of offshore ALAN on seabirds remain poorly understood. Particularly understudied are deck strikes (collisions of seabirds with vessels due to ALAN‐induced disorientation). To infer deck strike risks to the critically endangered Whenua Hou Diving‐petrel (Pelecanoides whenuahouensis; WHDP), we estimated nightly vessel counts and associated probability of floodlight use in close proximity of their only breeding colony, number of WHDP commutes, duration of phenophases, and ultimately the cumulative exposure to floodlights using a Bayesian framework. The estimated nightly number of vessels was 0.76 (0.64–0.89), 31% (21%–38%) of which used floodlights. WHDPs were potentially exposed to 28.9 (19.7–39.7) floodlights per breeding period. There was no evidence for inter‐annual variation in vessel counts, floodlight use, or WHDP activity, despite varying environmental conditions. WHDP activity, and therefore risk, was highest during courtship and post‐guard. Yet, there was potential for deck strikes throughout the breeding period, which could impact WHDPs. We identify key research questions (likelihood of a deck strike occurring, survival of deck‐struck birds, and post‐release survival of deck‐struck birds). In the meantime, small behavioral changes of vessel operators could be a successful approach to protecting seabirds from offshore ALAN. Tuhinga whakarāpopoto Ko te rama tāwhai ite pō (ALAN) he mea whakamōrearea i te rerenga rauropi, engari ko ngā pānga ote ALAN ki ngā manu moana ki tai kāore anō kia āta whakamāramatia. Ko ngāāhuatanga kāore anō kia āta tātari ko te tukinga kāraho (ko te tūtukinga o ngāmanu moana e tāhurihuri ana ki ngā waka, nā te ALAN). Ki te whakapae atu i temōreareatanga o te tukinga kāraho ki te Kuaka Whenua Hou (Pelecanoideswhenuahouensis; WHDP) he manu e ngaro haere ana tōna whare ora, i whakatau tatate tini o ngā waka e tere i te pō me te tūponotanga e hāngai ana ki tewhakamahinga o te tūrama raharaha e pātata ana ki pūrei kōhanga anake ō rātou,te maha o ngā rerenga o ngā WHDP, te roa o te tauwāhi mātai, ā, i te otinga kuawhakamahia te anga ‘Bayesian’ ki te ine i ngā pānga tapeke o ēnei manu ki ērārama. Ko te whakatau tata o te maha o ngā waka i ia pō ko te 0.76 (0.64‐.089),31% (21%‐38%) o ēnei i whakamahia ngā tūrama rarharaha. I hōrakerake ai pea ngāWHDP kia 28.9 (19.7‐39.7) ngā wā i ia wā whakatipu. Kāore he taunakitanga i tererekētanga o te maha o ngā waka, te whakamahinga o te tūrama raharaha, te mahio te WHDP i waenga i ngā tau, ahakoa he rerekē ngā āhuatanga o te taiao. Ko temahi a ngā WHDP, waihoki ko te pānga o te mōrearea ki a rātou hoki, kua pikiake i te wā o te whakaipoipo, ā, mō muri hoki i tā rātou tūtei hua. Arā tonu tepitomata ka tukia pea te kāraho i te wā katoa o te wa whakatīpu, mā reira e pākino ai ki ngā WHDP. Ka tūtohutia e mātou ngā pātai rangahau matua (tetingatanga o te tukinga kāraho, te oranga tonutanga rānei o te manu kua tukia kite kāraho, me te oranga tonutanga o te manu kua whakamātūtū, ā, kua whakahokiakētia ki tōna ao). Āianei, mā te paku panonihanga o ngā whanonga hautū waka ongā kaihautū waka ka tiaki pai ngā manu moana i te ALAN ki tai.

Food caching is a common behavior for many mammals, but less is known about the prevalence and importance of food caching for some species. Here we report the first documented caching events by Asiatic black bears (Ursus thibetanus, n = 5) in Japan and 3 additional caching events by American black bears (U. americanus) in California, USA. We also performed a systematic literature review on caching by bears as a reference point for future investigations. Caching was most frequently reported for brown bears (U. arctos), and most caching by bears occurred with large prey. Caching is most likely used to protect large carcasses from spoiling or detection by scavengers, allowing bears to consume more of the carcass. The lack of published studies on caching by bears may be due to the behavior being infrequently used and difficult to record. We encourage an increase, but also consistency, in future reporting, including specific descriptions of caching behavior.

© 2019 The Zoological Society of London The eradication of invasive predators from islands is a successful technique to safeguard seabird populations, but adequate post-eradication monitoring of native species is often lacking. The Whenua Hou Diving Petrel (Pelecanoides whenuahouensis; WHDP) is a recently-described and ‘Critically Endangered’ seabird, restricted to Codfish Island (Whenua Hou), New Zealand. Invasive predators, considered the major threat to WHDP, were eradicated on Codfish Island in 2000. However, estimates of WHDP population size and trends remain unknown, hindering assessments of the success of the eradications. We collated intermittent burrow counts (n = 20 seasons) conducted between 1978 and 2018. To estimate the population growth rate (λ) before and after predator eradications, we used log-linear models in a Bayesian hierarchical framework while retrospectively accounting for differences in detection probabilities among burrow counts, due to differences in effort, marking and timing. The number of WHDP burrows was estimated at 40 (36–46) in 1978 and 100 (97–104) in 2018. The pre-eradication λ was estimated at 1.023 (0.959–1.088), while the post-eradications λ was estimated at 1.017 (1.006–1.029). The WHDP population appears to be increasing, yet the rate of increase is low compared to other Procellariiformes following predator eradications. The comparatively low post-eradication λ, combined with an apparent lack of change between pre- and post-eradication λ, indicates that additional threats might be limiting WHDP population growth and that further conservation management is required. The continuation of affordable and simple, albeit imperfect, monitoring methods with retrospective corrections facilitated the assessment of invasive predator eradications outcomes and should guide future management decisions. An abstract in Te Reo Māori (the Māori language) can be found in Appendix S1.

Many wildlife species rely on unique features of trees during daily activities and fundamental parts of their life cycle. The fisher (Pekania pennanti) is a forest-dwelling carnivore of conservation concern in western North America that uses unique habitat elements as refuges during resting bouts and for reproduction. Prior to this study, little was known about the fine-scale habitat used during reproduction at the southernmost extent of the fisher’s range. Between 2007 and 2015, we attached radio-collars to 55 male and 72 female fishers in the southern Sierra Nevada and documented resting locations of males on 216 occasions (196 structures) and females on 824 occasions (737 structures). Beginning in 2008, we also monitored females over 8 reproductive seasons, confirming 45 females at dens and documenting 95 natal dens (83 structures) and 206 maternal dens (192 structures). We established 3 comparisons to guide our assessment of fine-scale habitat: resting males versus resting females, natal dens versus maternal dens, and resting fishers (both sexes) versus denning fishers (all dens). We expected the need for physical security and thermal protection in combination with morphology, predation risk, and aspects of reproductive ecology would influence patterns of use. Both sexes used a variety of microsites for resting, but females selected tree cavities most frequently (47%) while males used branch platforms most often (39%). For resting structures, live conifers were used most often by both sexes (males 44%, females 34%), but live hardwoods (males 16%, females 28%) and conifer snags (males 16%, females 22%) were also important. Comparing natal and maternal dens, we found that cavity microsites used early in the den season tended to be higher than those used later, and large live hardwoods comprised roughly half of all natal (46%) and maternal (51%) den structures. For resting versus denning, we found that large diameter hardwoods were an important source of cavities for both activities, live conifers used for denning were larger than those used for resting, and den structures tended to be on steeper slopes than rest structures. White fir (Abies concolor), California black oak (Quercus kelloggii), and ponderosa pine (Pinus ponderosa) were selected most often by both sexes for resting. In contrast, denning females relied on California black oak (55%), but also used white fir (24%) and incense cedar (Calocedrus decurrens; 12%). As noted in studies further north, our findings highlight the value of large trees with decay to support fisher reproduction and daily refugia.

We conducted DNA capture-recapture monitoring of grizzly bears (Ursus arctos) from 5 to 17 years after hunting was stopped in two adjacent but genetically distinct populations in southwestern British Columbia, Canada. We used spatial capture-recapture and non-spatial Pradel robust design modelling to estimate population density, trends, and the demographic components of population change for each population. The larger population had 21.5 bears/1000 km2 and was growing (λPradel = 1.02 ± 0.02 SE; λsecr = 1.01 ± 4.6 × 10−5 SE) following the cessation of hunting. The adjacent smaller population had 6.3 bears/1000 km2 and was likely declining (λPradel = 0.95 ± 0.03 SE; λsecr = 0.98 ± 0.02 SE). Estimates of apparent survival and apparent recruitment indicated that lower recruitment was the dominant factor limiting population growth in the smaller population. Factors limiting reproductive rates and population density could include poor habitat quality, particularly the abundance of high-energy foods, genetic Allee effects due to a long period of population isolation, or demographic effects affecting infanticide rates. The cessation of hunting was insufficient to promote population recovery for the low density, isolated population. Our research highlights the importance of considering mortality thresholds in addition to small population effects and habitat quality when recovering large carnivore populations.

Seabirds are considered ecosystem engineers, because they facilitate ecosystem functioning (e.g., nutrient cycling), crucial for other marine and terrestrial species, including reptiles. However, studies of seabird-reptile interactions are limited. Here, we assessed the influence of the ‘Critically Endangered’ Whenua Hou Diving Petrel (Pelecanoides whenuahouensis) on the occurrence of two threatened skinks, Stewart Island green skink (Oligosoma aff. chloronoton) and southern grass skink (O. aff. polychroma). We surveyed skinks for 26 consecutive days at 51 sites with and 48 sites without Diving Petrel burrows in the dunes on Codfish Island (Whenua Hou), New Zealand. We used occupancy modelling to assess the influence of burrows on the occurrence of skinks, while accounting for other factors affecting occupancy (Ψ) and detection probabilities (p). Diving Petrel burrows had a contrasting effect on the occurrence of skinks. On average, Ψ of Stewart Island green skinks was 114% higher at sites with burrows compared to sites without, while Ψ of southern grass skinks was only 2% higher. Occurrence of both skinks was negatively influenced by the presence of the other skink species. On average p were low: 0.013 and 0.038 for Stewart Island green and southern grass skinks, respectively. Stewart Island green skinks appear attracted to burrows, which might facilitate thermoregulation (i.e., shelter from temperature extremes). The larger Stewart Island green skinks may subsequently exclude the smaller southern grass skinks at burrows, causing the contrasting relationships. We suggest that these interspecific interactions should be considered when implementing conservation management, e.g., through the order of species reintroductions.

Species assemblages often have a non-random nested organization, which in vertebrate scavenger (carrion-consuming) assemblages is thought to be driven by facilitation in competitive environments. However, not all scavenger species play the same role in maintaining assemblage structure, as some species are obligate scavengers (i.e., vultures) and others are facultative, scavenging opportunistically. We used a database with 177 vertebrate scavenger species from 53 assemblages in 22 countries across five continents to identify which functional traits of scavenger species are key to maintaining the scavenging network structure. We used network analyses to relate ten traits hypothesized to affect assemblage structure with the “role” of each species in the scavenging assemblage in which it appeared. We characterized the role of a species in terms of both the proportion of monitored carcasses on which that species scavenged, or scavenging breadth (i.e., the species “normalized degree”), and the role of that species in the nested structure of the assemblage (i.e., the species “paired nested degree”), therefore identifying possible facilitative interactions among species. We found that species with high olfactory acuity, social foragers, and obligate scavengers had the widest scavenging breadth. We also found that social foragers had a large paired nested degree in scavenger assemblages, probably because their presence is easier to detect by other species to signal carcass occurrence. Our study highlights differences in the functional roles of scavenger species and can be used to identify key species for targeted conservation to maintain the ecological function of scavenger assemblages., ESG, ZMR, JMB and LNA were supported by Generalitat Valenciana (SEJI/2018/024, APOSTD/2019/016, CIDEGENT/2020/030 and ACIF/2019/056, respectively), JMB, JMPG and CGC by Juan de la Cierva contracts (MEC; IJCI-2017-32149, FJCI-2015-25632 and IJC2018-036642-I, respectively), ACA by the Govern de les Illes Balears (PD/039/2017) and ESG and MM by Ramón y Cajal contracts (MEC; RYC-2019-027216-I, RYC-2015-19231). EA was supported by La Caixa-Severo Ochoa International PhD Program 2015. NS was partly supported by the National Science Centre in Poland (2013/08/M/NZ9/00469 and 2016/22/Z/NZ8/00). MK and KJ were supported by the Slovenian Research Agency (P4-0059). Contributions of HG, KLT, EFA, OER, TLD, and JCB were partially supported through funding from U.S. Department of Agriculture and the U.S. Department of Energy under (DE-EM0004391) to the University of Georgia Research Foundation. HG was also supported by the Institute of Environmental Radioactivity at Fukushima University. ALB and JDA were partially supported by Queens College and the Graduate Center at the City University of New York. JDA is currently supported by a Ramón y Cajal contract (RYC-2017-22783). ERB and EF were supported by the USA National Science Foundation Graduate Research Fellowship (1256065). CK completed study with support from Hawk Mountain Sanctuary, The Peregrine Fund, and via Pompeo M. Maresi Memorial Fund via Princeton University. JAS and CCW were supported by the USA National Science Foundation #1255913, the American Association for University Women, and the Gordon and Betty Moore Foundation. HUW acknowledges funding from the California Department of Fish & Wildlife (P0880013). PLP was supported by the Rufford Foundation and University of Wisconsin-Madison. JB and JdT thank the Percy Sladen Memorial Fund and Mr Rodney Fuhr. Several authors were funded by funds from the MEC (CGL2012-40013-C02-01/02, CGL2015-66966-C2-1-R, CGL2015-66966-C2-1-R2, CGL2017-89905-R, RTI2018-099609-B-C21 and RTI2018-099609-B-C22) and from the Junta de Andalucía (RNM-1925). POV was supported by a research contract by the University of Lleida. EES and TMN were funded and supported by Australian Geographic, Bush Heritage Australia, Australian Academy of Sciences, Ecological Society of Australia, NSW Office of Environment and Heritage, NESP Threatened Species Recovery Hub, Emirates Wolgan Valley One and Only Resort. EP, YA, MS and UY completed study under research permit by The Republic of Turkey Ministry of Agriculture and Forestry. SAL thanks PICT (BID) 0725/2014, and IAATE. ALB and JDA would like to thank the Edmund Niles Huyck Preserve, Lyme Adirondack Forest Company, and LandVest Timberland.

© 2021 The Authors. Refuges can be ecologically important, allowing access only to some species or individuals and providing prey protection from predators. Creation of refuges can be used to protect threatened species from introduced predators, which can have large negative impacts that are difficult to attenuate via other means. To design refuges for conservation purposes, refuge accessibility to different species must be understood. Traditional techniques are not adequate to measure or describe complex three-dimensional spaces which are often important refuges. We designed a novel predictive method for modeling three-dimensional refuge space using video game software that simulates real-world physics (Unity, PhysX). We use the study system of endemic New Zealand skinks (Oligosoma spp.), their introduced predators, house mice (Mus musculus), and the habitat of interstitial spaces within rock piles to demonstrate how this modeling technique can be used to inform design of habitat enhancement for conservation. We used video game software to model realistic rock piles and measure their interstitial spaces, and found that the spaces we predicted matched those we measured in real rock piles using computed tomography (CT) scanning. We used information about the sizes of gaps accessible to skinks and mice and the results of our modeling to determine the optimal size of rocks to create refuges which would protect skinks from mice. We determined the ideal rock size to be those with graded diameters of 20–40 mm. The approach we developed could be used to describe interstitial spaces in habitats as they naturally occur, or it could be applied to design habitats to benefit particular species.

Understanding of animal responses to dynamic resource landscapes is based largely on research on temperate species with small body sizes and fast life histories. We studied a large, tropical mammal with an extremely slow life history, the Western Bornean orangutan (Pongo pygmaeus wurmbii), across a heterogeneous natural landscape encompassing seven distinct forest types. Our goals were to characterize fluctuations in abundance, test hypotheses regarding the relationship between dispersion dynamics and resource availability, and evaluate how movement patterns are influenced by abiotic conditions. We surveyed abundance in Gunung Palung National Park, West Kalimantan, Indonesia, for 99 consecutive months and simultaneously recorded weather data and assessed fruit availability. We developed a Bayesian hierarchical distance sampling model to estimate population dispersion and assess the roles of fruit availability, rainfall, and temperature in driving movement patterns across this heterogeneous landscape. Orangutan abundance varied dramatically over space and time. Each forest type was important in sustaining more than 40% of the total orangutans on site during at least one month, as animals moved to track asynchronies in fruiting phenology. We conclude that landscape-level movements buffer orangutans against fruit scarcity, peat swamps are crucial fallback habitats, and orangutans' use of high elevation forests is strongly dependent on abiotic conditions. Our results show that orangutans can periodically occupy putative-sink habitats and be virtually absent for extended periods from habitats that are vitally important in sustaining their population, highlighting the need for long-term studies and potential risks in interpreting occurrence or abundance measures as indicators of habitat importance.

Kill rates and functional responses are fundamental to the study of predator ecology and the understanding of predatory-prey dynamics. As the most widely distributed apex predator in the western hemisphere pumas (Puma concolor) have been widely studied yet a biogeographical synthesis of their kill rates is currently lacking. We reviewed the literature and compiled data on sex- and age-specific kill rate estimates of pumas on ungulates, and conducted analyses aimed at understanding ecological factors explaining the observed variation across their range. Kill rate studies on pumas, while numerous, were primarily conducted in Temperate Conifer Forests (< 10% of puma range), revealing a dearth of knowledge across much of their range, especially from tropical and subtropical habitats. Across studies, kill rates in ungulates/week were highest for adult females with kitten(s) (1.24 ± 0.41 ungulates/week) but did not vary significantly between adult males (0.84 ± 0.18) and solitary adult females (0.99 ± 0.26). Kill rates in kg/day did not differ significantly among reproductive classes. Kill rates of adult pumas increased with ungulate density. Ungulate species richness had a weak negative association with adult male kill rates. Neither scavenger richness, the proportion of non-ungulate prey in the diet, nor regional human population density had a significant effect on ungulate kill rates. Our results had a strong temperate-ecosystem bias highlighting the need for further research across the diverse biomes pumas occupy in order to make species level inferences. Data from more populations would also allow for multivariate analyses providing deeper inference into the ecological and behavioural factors driving kill rates and functional responses of pumas, and apex predators in general.

Where predation is a major limiting factor, it has been postulated that woodland caribou (Rangifer tarandus caribou (Gmelin, 1788)) reduce movements to minimize contact with predators and exhibit fidelity to seasonal ranges. We examined fidelity behaviour within season and among years of woodland caribou based on locations of 65 radio-collared individuals in British Columbia, Canada. We used average linear distances between all possible pairs of radiolocations of individuals to assess fidelity. Among-year interlocation distances were similar to within-season interlocation distances during summer, indicating that caribou did not shift their distribution during seasons when they were most vulnerable to predation. Among-year interlocation distances were significantly greater than within-season interlocation distances during both early winter and late winter, indicating that individual caribou shifted their distribution among winters. The amount that an individual's distribution shifted among winters varied among and within individuals over different years. During early winter this behavioural plasticity was correlated with snow accumulation, with individuals having greater interlocation distances in years with high snow accumulation. Our results indicate that site fidelity outside the calving season is unlikely solely influenced by predator avoidance. We suggest that seasonal shifts in the importance of limiting factors vary from predation in summer to food in winter. © 2006 NRC.

© 2017 American Society of Mammalogists. Global positioning system (GPS) technology has revolutionized the study of carnivores. Researchers commonly estimate kill rates with GPS data using the following steps. Firstly, researchers mark individual animals and fit them with GPS collars. Next, they visit a subset of "GPS clusters" (aggregated location data) during field surveys and assign spatiotemporal covariates associated with predation and non-predation events. Lastly, they develop predictive models with data collected in the field to estimate the probability that each cluster they did not visit in the field was a predation event. Such predation models help reduce field efforts and save money; however, these models are prone to error when carnivores eat prey of different sizes or exhibit shorter-than-expected handling times. We simulated reduced field efforts to investigate the reliability of predictive modeling in determining diet composition and detecting predation events for 3 puma (Puma concolor) populations with different prey assemblages and potential effects on handling time of carcasses. We visited a total 1,896 clusters in Chilean Patagonia, Colorado, and California, of which 1,752 clusters (∼92%) were included to build and test predation models. Across all study areas, the total time a puma spent at a cluster was the only reliable predictor of a cluster being a predation event. When we reduced field efforts by selectively removing GPS clusters < 12 and < 24 h in length, model performance improved but produced inaccurate results. Predation models underestimated the number of predation events in California and Colorado and significantly over-or underestimated the number of predation events in Patagonia. Selectively reducing field efforts also reduced the diversity and evenness of prey we recorded in puma diets. Randomly reducing field efforts, in contrast, reduced the precision of model estimates. Our results highlight the importance of conducting intensive fieldwork over predation modeling to measure prey selection and kill rates of carnivores.

©The Author(s) 2018. Published by Oxford University Press. Remotely activated cameras are increasingly used worldwide to investigate the distribution, abundance and behaviour of animals. The number of studies using remote cameras in urban ecosystems, however, is low compared to use in other ecosystems. Currently, the time and effort required to classify images is the main constraint of this monitoring technique. To determine whether, or not, citizen science might help overcome this constraint, we investigated the engagement, accuracy and efficiency of citizen scientists providing crowd-sourced classifications of animal images recorded by remote cameras in Wellington, New Zealand. Classifications from individual citizen scientists were in 84.2% agreement with the classifications of professional ecologists. Aggregating the classifications from three citizen scientists per image, and excluding false triggers and unclassifiable classifications increased their overall accuracy to 97.6%. Classifications by citizen scientists also improved if animal movement was highlighted in the images. The likelihood of citizen scientists correctly classifying images was influenced by their previous accuracy, their self-assessed confidence, and the species reported. Weighting the citizen scientist classifications based on their ability to correctly identify animals reduced from 3 to 2 the number of classifications required per sequence to classify >95% of the photographs containing cats. Citizen science is an accurate and efficient approach for classifying remote camera data from urban areas, where most of the animals are familiar to the participants. We demonstrated how appropriate tools and accounting for the accuracy of citizen scientists, allows project managers to maximise the effort of citizen scientists while ensuring high-quality data.

© 2018 The Authors. Ecology and Evolution published by John Wiley & Sons Ltd. Humans are primary drivers of declining abundances and extirpation of large carnivores worldwide. Management interventions to restore biodiversity patterns, however, include carnivore reintroductions, despite the many unresolved ecological consequences associated with such efforts. Using multistate capture–mark–recapture models, we explored age-specific survival and cause-specific mortality rates for 134 pumas (Puma concolor) monitored in the Greater Yellowstone Ecosystem during gray wolf (Canis lupus) recovery. We identified two top models explaining differences in puma survivorship, and our results suggested three management interventions (unsustainable puma hunting, reduction in a primary prey, and reintroduction of a dominant competitor) have unintentionally impacted puma survival. Specifically, puma survival across age classes was lower in the 6-month hunting season than the 6-month nonhunting season; human-caused mortality rates for juveniles and adults, and predation rates on puma kittens, were higher in the hunting season. Predation on puma kittens, and starvation rates for all pumas, also increased as managers reduced elk (Cervus elaphus) abundance in the system, highlighting direct and indirect effects of competition between recovering wolves and pumas over prey. Our results emphasize the importance of understanding the synergistic effects of existing management strategies and the recovery of large, dominant carnivores to effectively conserve subordinate, hunted carnivores in human-dominated landscapes.

Understanding the distribution of biodiversity across the Earth is one of the most challenging questions in biology. Much research has been directed at explaining the species latitudinal pattern showing that communities are richer in tropical areas; however, despite decades of research, a general consensus has not yet emerged. In addition, global biodiversity patterns are being rapidly altered by human activities. Here, we aim to describe large-scale patterns of species richness and diversity in terrestrial vertebrate scavenger (carrion-consuming) assemblages, which provide key ecosystem functions and services. We used a worldwide dataset comprising 43 sites, where vertebrate scavenger assemblages were identified using 2,485 carcasses monitored between 1991 and 2018. First, we evaluated how scavenger richness (number of species) and diversity (Shannon diversity index) varied among seasons (cold vs. warm, wet vs. dry). Then, we studied the potential effects of human impact and a set of macroecological variables related to climatic conditions on the scavenger assemblages. Vertebrate scavenger richness ranged from species-poor to species rich assemblages (4–30 species). Both scavenger richness and diversity also showed some seasonal variation. However, in general, climatic variables did not drive latitudinal patterns, as scavenger richness and diversity were not affected by temperature or rainfall. Rainfall seasonality slightly increased the number of species in the community, but its effect was weak. Instead, the human impact index included in our study was the main predictor of scavenger richness. Scavenger assemblages in highly human-impacted areas sustained the smallest number of scavenger species, suggesting human activity may be overriding other macroecological processes in shaping scavenger communities. Our results highlight the effect of human impact at a global scale. As species-rich assemblages tend to be more functional, we warn about possible reductions in ecosystem functions and the services provided by scavengers in human-dominated landscapes in the Anthropocene., SG, JMPG, and ACA were supported by Juan de la Cierva contracts (Ministerio de Economía y Competitividad, MEC; IJCI‐2015‐24947, FJCI‐2015‐25632, and IJCI‐2014‐20744, respectively). ESG was also supported by Generalitat Valenciana (SEJI/2018/024), ACA by the Govern de les Illes Balears (PD/039/2017), and MM by a Ramón y Cajal contract (MEC; RYC‐2015‐19231). EA was supported by La Caixa‐Severo Ochoa International PhD Program 2015. NS was partly supported by the National Science Centre in Poland (2013/08/M/NZ9/00469). SAL thanks PICT (BID) 0725/2014. MK and KJ were supported by the Slovenian Research Agency (P4‐0059). Contributions of KT and JCB were partially supported through funding from U.S. Department of Agriculture, the U.S. Department of Energy under (DE‐EM0004391) to the University of Georgia Research Foundation. EB and EF were supported by the USA National Science Foundation. CK completed study under research permit NCST/5/002/R/448 with support from Hawk Mountain Sanctuary, The Peregrine Fund, and via Pompeo M. Maresi Memorial Fund via Princeton University. JAS and CCW were supported by the USA National Science Foundation #1255913 and the Gordon and Betty Moore Foundation. Several authors were funded by funds from the MEC (CGL2012‐40013‐C02‐01/02, CGL2015‐66966‐C2‐1‐R and CGL2017‐89905‐R) and from the Junta de Andalucía (RNM‐1925).

Supplementary material (available online as Appendix ecog- 05083 at ). Appendix 1–2., All data necessary to reproduce the analyses presented in this study are included in the Supplementary material Appendix 1 and available from Figshare Digital Repository: (SebastiánGonzález et al. 2020)., The organization of ecological assemblages has important implications for ecosystem functioning, but little is known about how scavenger communities organize at the global scale. Here, we test four hypotheses on the factors affecting the network structure of terrestrial vertebrate scavenger assemblages and its implications on ecosystem functioning. We expect scavenger assemblages to be more nested (i.e. structured): 1) in species‐rich and productive regions, as nestedness has been linked to high competition for carrion resources, and 2) regions with low human impact, because the most efficient carrion consumers that promote nestedness are large vertebrate scavengers, which are especially sensitive to human persecution. 3) We also expect climatic conditions to affect assemblage structure, because some scavenger assemblages have been shown to be more nested in colder months. Finally, 4) we expect more organized assemblages to be more efficient in the consumption of the resource. We first analyzed the relationship between the nestedness of the scavenger assemblages and climatic variables (i.e. temperature, precipitation, temperature variability and precipitation variability), ecosystem productivity and biomass (i.e. NDVI) and degree of human impact (i.e. human footprint) using 53 study sites in 22 countries across five continents. Then, we related structure (i.e. nestedness) with its function (i.e. carrion consumption rate). We found a more nested structure for scavenger assemblages in regions with higher NDVI values and lower human footprint. Moreover, more organized assemblages were more efficient in the consumption of carrion. However, our results did not support the prediction that the structure of the scavenger assemblages is directly related to climate. Our findings suggest that the nested structure of vertebrate scavenger assemblages affects its functionality and is driven by anthropogenic disturbance and ecosystem productivity worldwide. Disarray of scavenger assemblage structure by anthropogenic disturbance may lead to decreases in functionality of the terrestrial ecosystems via loss of key species and trophic facilitation processes., Juan de la Cierva contracts (Ministerio de Economia y Competitividad, MEC) IJCI-2015-24947 IJCI-2017-32149 FJCI-2015-25632, Generalitat Valenciana SEJI/2018/024 ACIF/2019/056, Govern de les Illes Balears PD/039/2017, Spanish Government RYC-2015-19231, La Caixa-Severo Ochoa International PhD Program 2015, European Social Fund (ESF) APOSTD/2019/016, National Science Centre in Poland 2013/08/M/NZ9/00469 2016/22/Z/NZ8/00, ANPCyT (BID) 0725/2014, Slovenian Research Agency - Slovenia P4-0059, EU Life DinAlp Bear LIFE13 NAT/SI/000550, United States Department of Agriculture (USDA) DE-EM0004391, United States Department of Energy (DOE) DE-EM0004391, Inst. of Environmental Radioactivity at Fukushima Univ., Queens College at the City Univ. of New York, Graduate Center at the City Univ. of New York, Ramón y Cajal contract - Spanish Ministry of Science RYC-2017-22783, Agencia Estatal de Investigacion, European Social Fund (ESF), USA National Science Foundation Graduate Research Fellowship 1256065, Hawk Mountain Sanctuary, The Peregrine Fund, and via Pompeo M. Maresi Memorial Fund via Princeton Univ., National Science Foundation (NSF) 1255913, American Association for Univ. Women, Gordon and Betty Moore Foundation, California Dept of Fish and Wildlife P0880013, Rufford Foundation, Univ. of Wisconsin-Madison, Percy Sladen Memorial Fund, Spanish Government CGL201240013-C02-01/02 CGL2015-66966-C2-1-R CGL2015-66966C2-1-R2 CGL2017-89905-R RTI2018-099609-B-C22, Junta de Andalucía RNM-1925, Univ. of Lleida, Australian Geographic, Bush Heritage Australia, Australian Academy of Sciences, Ecological Society of Australia, NSW Office of Environment and Heritage, Emirates Wolgan Valley One and Only Resort

© Published by Oxford University Press on behalf of American Society of Mammalogists 2018. Quantifying reproductive parameters is essential for developing effective conservation plans for species of concern; however, studying reproduction in wild settings can be challenging and local data are frequently unavailable. The fisher (Pekania pennanti) is an elusive forest-dwelling carnivore of conservation concern that occurs across much of boreal North America and reaches the southernmost limit of its distribution in the southern Sierra Nevada (SSN) in California. Data on fisher reproduction in this region are limited and applicability of parameters from other areas is uncertain. To clarify how fisher populations in the SSN compare with those elsewhere in North America, we conducted a comprehensive review of available literature on reproduction throughout the species' range in North America. We then compared findings from the review with data we collected during 7 years in the SSN, focusing on the proportion of females reproducing, litter size, and the parturition date. On average across the fisher's range, the proportion of adult females that reproduced was 0.71 (range: 0.40-1.00; n = 16 studies), litter size was 2.5 (range: 1-4; n = 16 studies), and parturition occurred on 25 March (range: 3 March-17 April; n = 16 studies). In our study area, we tracked 42 adult female fishers, 35 of which reproduced and used 257 reproductive dens (74 natal, 175 maternal, 8 early failures); 0.86 of our females attempted denning (range: 0.79-1.0; n = 93 opportunities) and 0.75 were successful (range: 0.64-1.0; n = 91 opportunities monitored through the den season). Mean litter size was 1.57 (range: 1-3; n = 75 litters) and mean parturition date was 30 March (range: 17 March-12 April; n = 69 natal dens initiated). Female fishers at the southern limit of their distribution in the SSN reproduced at a rate comparable to or higher than elsewhere in North America, but average litter size was the lowest reported for the species. Female fishers in the SSN gave birth at similar or later dates than elsewhere in their range. We explore factors that might explain patterns of variation in fisher reproductive parameters and discuss conservation implications of our findings.

WILEY: "This is the peer reviewed version of the following article: Esperanza C. Iranzo Heiko U. Wittmer Juan Traba Pablo Acebes Cristina Mata Juan E. Malo, Predator occurrence and perceived predation risk determine grouping behavior in guanaco (Lama guanicoe), Ethology 124.5 (2018): 1699-1711, which has been published in final form at DOI: http://doi.org/10.1111/eth.12727. This article may be used for non-commercial purposes in accordance with Wiley Terms and Condictions for Use Self-Archived Version, Grouping behavior of social ungulates may depend on both predator occurrence and perceived predation risk associated with habitat structure, reproductive state, and density of conspecifics. Over 3 years, we studied grouping behavior of guanaco (Lama guanicoe) families in Chilean Patagonia during the birthing season and determined their response to variation in predator occurrence and perceived predation risk (habitat structure, calf/adult rate, and density of conspecifics). We considered the effect of two predators, puma (Puma concolor) and culpeo fox (Lycalopex culpaeus). We measured two common (family group size and vigilance) and one novel (family group cohesion) behavioral responses of guanaco. Our results show that guanaco family groups adapted their grouping behavior to both predator occurrence and perceived predation risk. Larger family groups were found in open habitats and areas with high puma occurrence, while guanacos stayed in small family groups in areas with high shrub cover or low visibility. Group cohesion increased in areas with higher occurrence of pumas and culpeo foxes, and also increased in smaller family groups and in areas with low guanaco density. Vigilance (number of vigilant adults) was mainly related to group size and visibility, increasing in areas with low visibility, while residual vigilance (vigilance after removing the group-size effect) did not vary with the explanatory variables examined. Our results suggest that a mix of predator occurrence and perceived predation risk influences guanaco grouping behavior and highlights the importance of evaluating different antipredator responses together and considering all predator species in studies aimed at understanding ungulate behavior, Funding was provided by Program UAM‐CEAL (Santander Bank) during 2011‐2012, 2013‐2014, and 2015‐2016; Foreign Affairs Ministry, Spanish Agency for Development and International Cooperation (A/9875/07, A/016431/08, and A/024945/09); Agriculture Ministry and Environment Ministry, Chile, Servicio Agrícola y Ganadero 2011‐2012; and the REMEDINAL‐3CM network (S2013/MAE‐2719). ECI was supported by a PhD grant from the Spanish Ministry of Education (FPU) and is currently supported by a post‐doctoral grant from National Scientific and Technical Research Council (CONICET)

Lay SummaryReturning to previously used areas (site fidelity) or place of birth (philopatry) are important behavioral adaptations in many species, with known fitness benefits. The combined population level consequences of site fidelity and philopatry, however, have received little attention. Based on GPS location data and mitochondrial DNA we demonstrate how high levels of fidelity and philopatric behavior in the matrilineage of black-tailed deer can lead to fine-scale population structure and discuss possible implications for population dynamics.

SummarySmall seabird species are often threatened by predation from invasive species at their breeding colonies and considerable efforts are invested into mitigating this threat. However, invasive predators may not be the only onshore threat affecting small seabird species. The South Georgia Diving-petrel Pelecanoides georgicus (SGDP) is a small seabird species, considered ‘Nationally Critical’ in New Zealand. Our objective was to identify terrestrial threats to the species at their sole remaining breeding colony in New Zealand, Codfish Island (Whenua Hou), following the successful eradication of invasive predators. To achieve our objective, we assessed the influence of five physical, three competition/attraction and three plant variables on SGDP nest site selection with generalised linear models (GLMs) and compared models using an information theoretic approach. Models including the distance to sea, slope, aspect, and sand flux outperformed other models and showed selection for steep seaward-facing foredunes with mobile soils. No invasive plant and competition/attraction variables were included in the best performing models. These results suggest that, due to the proximity of their preferred nesting habitat to the springtide line and the overall fragility of the foredunes, SGDPs on Codfish Island are extremely vulnerable to stochastic events and catastrophes, such as storms and storm surges. Eradication efforts directed at invasive predators on Codfish Island appear thus insufficient to safeguard this SGDP colony, necessitating further conservation strategies to secure the continued survival of this population.

Understanding how top–down and bottom–up effects influence population dynamics of ungulates is essential for effective management and conservation, and there is an emerging consensus that forage productivity and quality interact with predation to influence survival. From 2009 to 2013, we captured and monitored 135 neonatal black-tailed deer Odocoileus hemionus columbianus in coastal California to study possible interactions between forage and predation on survival. We estimated seasonal and annual survival rates, assessed the cause of all mortalities (n = 93), measured available forage and diet quality, estimated relative abundances of predators on summer range each year, and used remote sensing to quantify habitat types on winter range. We evaluated the relationship between fawn survival and environmental covariates with cumulative incidence and proportional hazards functions. Summer survival rates averaged 0.40 (SE = 0.05) across all years and the mean annual survival rate was 0.26 (SE = 0.04). We found that most juvenile mortality resulted from predation during summer, and spatial differences in summer survival persisted until recruitment. Variation in mortality risk from all causes was related to the birth weight of juveniles and available oak forage but not predator abundance. The risk of black bear predation, the single largest cause of mortality, was unrelated to birth weight and showed an interaction between bear abundance and the amount of oak forage. Additionally, the good body condition of adult females in spring and a lack of relationship between mortality risk and variation in deer density did not provide evidence for purely bottom–up limitation. Rather our results provide evidence that both bottom–up and top–down effects were influencing fawn survival in this declining population, and that predator identity and the timing of mortality affected the impact of predation.

The Sacramento Valley red fox Vulpes vulpes patwin of California is a newly named subspecies recently found to be distinct both from other native red foxes and nearby introduced populations. The Sacramento Valley red fox experienced a historical demographic bottleneck resulting in a critically small genetic effective population size, causing concern over its current status and management requirements, yet little is known about its contemporary abundance, demographic trajectory, or habitat use. The hot, arid Sacramento Valley contrasts starkly in climate and physiography with the boreal habitats of other indigenous red foxes in western North America, indicating the need to obtain information specifically on the habitat requirements of this subspecies. A 3-y effort to locate reproductive den sites throughout the Sacramento Valley resulted in 42 independent dens, which we used to obtain preliminary information on habitat use and to develop a distribution model for this subspecies, and 28 Sacramento Valley red foxes killed by vehicles, which we used as independent data to test the models. Foxes were present significantly more than expected in grasslands and less than expected in wetlands and flooded agriculture and also tended to occur in proximity to human development, potentially as refuges from coyotes Canis latrans. We used Maxent to build predictive models. The best model, which incorporated vegetation/land-use classes and proximity to human development, identified 24% of the study area as predicted-presence habitat, which contained 76% of the den sites used to construct the model and 89% of independent locations used to test the model. Our model greatly narrowed the area over which foxes are predicted to occur and will facilitate future surveys to assess occupancy and ultimately abundance and population trends.

The riparian brush rabbit Sylvilagus bachmani riparius is restricted to areas of dense cover along rivers and tributaries in the Central Valley of California, USA, and is considered endangered under the U.S. Endangered Species Act. An approved recovery plan for this subspecies recommended establishment of three additional self-sustaining populations within its historical range. Concurrent with habitat restoration efforts that included revegetation of levees and provision of flood refugia, we reintroduced 325 captive-bred individuals to the San Joaquin River National Wildlife Refuge between July 2002 and July 2005, and monitored their survival with radiotelemetry. Using available survival estimates and estimated reproductive parameters, we developed a population viability analysis model to determine the risk of extinction of the reintroduced population under a series of alternate scenarios including different release strategies. All model scenarios resulted in high probabilities of extinction over 20 y in the absence of either ongoing supplementations or significant improvements to vital rates. Extinction risks over 20 y appeared independent of initial release strategies. The risk of extinction remained high (>99%) even when the initial founder population was supplemented with captive-bred brush rabbits for up to 10 y. Supplementing the population annually for the entire 20-y period would be required for the population to persist given current estimates of vital rates. These results suggest that the reintroduced population is not self-sustaining and continued releases will not provide the anticipated long-term benefits. Additionally, our understanding of the integral components of habitat and potential limiting factors should be refined to address their influence on demographics and the cause of brush rabbit declines at the release site in a comprehensive way. These results underscore the importance of viability analyses and developing testable hypotheses about potential limiting factors early in reintroduction efforts to more efficiently guide data-gathering and monitoring criteria, identify data deficiencies, and refine reintroduction techniques in the early stages of management.