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Predator–prey games emerge when predators and prey dynamically respond to the behavior of one another, driving the outcomes of predator–prey interactions. Predation success is a function of the combined probabilities of encountering and capturing prey, which are influenced by both prey behavior and environmental features. While the relative importance of encounter and capture probabilities have been evaluated in a spatial framework, temporal variation in prey behavior and intrinsic catchability are likely to also affect the distribution of predation events. Using a single-predator-single-prey (puma-vicuña) system, we evaluated which factors predict predation events across both temporal and spatial dimensions of the components of predation by testing the prey-abundance hypothesis (predators select for high encounter probability) and the prey-catchability hypothesis (predators select for high relative capture probability) in time and space. We found that for both temporal and spatial analyses, neither the prey-abundance hypothesis nor the prey-catchability hypothesis alone predicted kill frequency or distribution; puma kill frequency was static throughout the diel cycle and pumas consistently selected a single habitat type when hunting, despite temporal and spatial variation in encounter rates and intrinsic catchability. Our integrated spatiotemporal analysis revealed that an interaction between time of day and habitat influences kill probability, suggesting that trade-offs in the temporal and spatial components of predation drive the probability of predation events. These findings reinforce the importance of examining both the temporal and spatial patterns of the components of predation, rather than unidimensional measures of predator or prey behavior, to comprehensively describe the feedbacks between predator and prey in the predator–prey game.

Animal carcass decomposition is an often-overlooked component of nutrient cycles. The importance of carcass decomposition for increasing nutrient availability has been demonstrated in several ecosystems, but impacts in arid lands are poorly understood. In a protected high desert landscape in Argentina, puma predation of vicuñas is a main driver of carcass distribution. Here, we sampled puma kill sites across three habitats (plains, canyons, and meadows) to evaluate the impacts of vicuña carcass and stomach decomposition on soil and plant nutrients up to 5 years after carcass deposition. Soil beneath both carcasses and stomachs had significantly higher soil nutrient content than adjacent reference sites in arid, nutrient-poor plains and canyons, but not in moist, nutrient-rich meadows. Stomachs had greater effects on soil nutrients than carcasses. However, we did not detect higher plant N concentrations at kill sites. The biogeochemical effects of puma kills persisted for several years and increased over time, indicating that kills do not create ephemeral nutrient pulses, but can have lasting effects on the distribution of soil nutrients. Comparison to broader spatial patterns of predation risk reveals that puma predation of vicuñas is more likely in nutrient-rich sites, but carcasses have the greatest effects on soil nutrients in nutrient-poor environments, such that carcasses increase localized heterogeneity by generating nutrient hotspots in less productive environments. Predation and carcass decomposition may thus be important overlooked factors influencing ecosystem functioning in arid environments.

The effects of predation risk on prey populations have been studied extensively; yet, how risk is manifested in a trophically linked guild—scavengers—has been overlooked. Risk could be particularly consequential for obligate scavengers that are vulnerable while foraging and rely on carrion provisioned by, and shared with, apex predators. We investigated whether Andean condors (Vultur gryphusM) respond to predation risk in a landscape where the main source of carrion are camelids killed by pumas (Puma concolor). We hypothesized that condors would exhibit different behavioral responses to predation risk while they search, encounter, and exploit carrion. We explored condor habitat selection while flying by tracking nine birds with satellite transmitters and monitored via camera traps 41 natural carcasses and 25 experimental carrion stations. We found that condors searched for carrion in areas with a high probability of occurrence of puma kills. However, condors avoided exploiting carrion in areas featuring tall vegetation and steep slopes—selected by pumas to stalk prey—suggesting that condors manage risk primarily through the identification of safe foraging sites prior to landing. Our finding that condors avoided foraging near stalking cover for pumas highlights the importance of risk effects beyond predator–prey interactions, particularly for obligate scavengers.

1. The ungulate-carnivore-vulture complex is a key trophic module of many terrestrial ecosystems, but one that is globally under threat. Few have explored cross-species dependencies in this module, and the degree to which vultures rely on trophic facilitation by apex carnivores is rarely known and almost never quantified. 2. We investigated the importance of puma Puma concolor prédation on its native camelid prey, vicuñas Vicugna vicugna and guanacos Lama guanicoe, in food provisioning for Andean condors Vultur gryphus in the high Andes of north-western Argentina. We evaluated the origin of wild food sources through carcass surveys. We quantified condor feeding habits via foraging observations and through the analysis of pellet contents and stable isotopes from moulted feathers. 3. Of the 102 fresh camelid carcasses we monitored, nearly all (94%) resulted from puma prédation, and the majority (85%) of camelid carcasses used by condors were killed by pumas. Camelids represented 88% of the prey items identified from 183 condor pellets, and isotopic analyses of moulted feathers from 86 individuals identified via multilocus genotyping revealed that camelids and Small livestock were the most important prey items, representing 45-58% and 28-38% of condor assimilated biomass, respectively. 4. Synthesis and applications. Our results show that puma predation plays a key role in the foraging ecology of Andean condors, and highlight the importance of predatory processes that make carrion available to scavengers. We contend that targeting the conservation of ungulate-carnivore-vulture modules, rather than a species-specific approach, will be a more effective strategy to ensure the long-term persistence of Andean condors and other obligate scavengers.

Context Understanding how animals respond to the energy landscape is crucial for elucidating the mechanisms of habitat selection, movement strategies, and connectivity dynamics. However, assessing the responses of highly mobile and long-lived species is challenging, as movement behaviors related to distinct life-history requirements may operate at extreme spatial and temporal scales. Objectives We combined movement and genetic data to investigate how energy landscape features influence ecologically and evolutionarily relevant dispersal patterns in an extreme soaring specialist, the Andean condor ( Vultur gryphus ). Methods We analyzed GPS data via Resource Selection Functions and conducted Landscape Genetic models for Andean condors from southern South America, considering static and dynamic landscape features. Connectivity models were used to identify conservation priority areas by integrating behavioral states critical for ecological (encamped and exploratory movements) and evolutionary processes (gene-flow). Results Topographic features emerged as key determinants of gene-flow patterns, while climatic variables were crucial for exploratory and encamped flights. Condors increased space use and connectivity during summer. While Resource Selection Function failed to predict gene-flow routes via path-based analysis, landscape-wide approaches identified connectivity barriers in flat terrain with poor uplift conditions for soaring. Conclusions Our study revealed the critical role of the energy landscape and life-history requirements in shaping habitat selection and population connectivity in Andean condors. The distinct, yet complementary patterns of habitat usage across various flight behaviors highlight the nuanced and complex use of the landscape. These findings highlight how variation in movement behaviors affects connectivity planning, urging conservation studies to incorporate movement-mode distinctions.

The late Quaternary megafauna extinctions reshaped species assemblages, yet we know little about how extant obligate scavengers responded to this abrupt ecological change. To explore whether obligate scavengers persisted by depending on contemporary community linkages or via foraging flexibility, we tested the importance of the trophic interaction between pumas ( Puma concolor ) and native camelids ( Vicugna vicugna and Lama guanicoe ) for the persistence of Andean condors ( Vultur gryphus ) in southern South America, and compared the demographic history of three vultures in different continents. We sequenced and compiled mtDNA to reconstruct past population dynamics. Our results suggest that Andean condors increased in population size >10 KYA, whereas vicuñas and pumas showed stable populations and guanacos a recent (<10 KYA) demographic expansion, suggesting independent trajectories between species. Further, vultures showed positive demographic trends: white-backed vultures ( Gyps africanus ) increased in population size, matching attenuated community changes in Africa, and California condors ( Gymnogyps californianus ) exhibited a steep demographic expansion ~20 KYA largely concurrent with North American megafaunal extinctions. Our results suggest that dietary plasticity of extant vulture lineages allowed them to thrive despite historical environmental changes. This dietary flexibility, however, is now detrimental as it enhances risk to toxicological compounds harbored by modern carrion resources.

Aim Evaluating the patterns of genetic variation and population connectivity is fundamental to effectively designing and implementing conservation strategies for threatened species. However, connectivity patterns in highly mobile vertebrates, and especially in avian species, are often overlooked as it is generally assumed to be driven by demographic panmixia or isolation by distance. Herein, we investigated the genetic structure and patterns of connectivity across four biomes in a highly vagile bird, the Andean condor (Vultur gryphus). Location Four major Neotropical biomes of Argentina (>300,000 km2): Puna, Monte, Chaco and Patagonia. Methods We genotyped 13 polymorphic microsatellite loci plus one sex‐determining gene in 300 moulted feathers from 13 roosting sites in the core of species distributional range. We quantified levels of genetic differentiation, population structure, effective gene flow, genetic diversity and assessed sex‐biased dispersal events. Results We detected genetic structure with a moderate differentiation between the north (Puna and Chaco) and south (Patagonia) regions with a contact zone in the central area (Monte). We observed a spatial pattern of genetic patches with higher levels of gene flow along the Andes range. Although we found no indication of bottlenecks or inbreeding, we observed larger effective population sizes in the south compared to the northern region. Main conclusions Our study revealed that, despite the high dispersal potential of condors, demographic panmixia is not consolidated, even in the core of this species range. Our analyses further suggest that gene flow rate is modulated by topographic features, as condors may disperse more following the natural updrafts and lifts along the Andean mountains. Conservation initiatives should prioritize the protection of the Andean corridor to maintain connectivity between the apparent source from Patagonia to the northern biomes.

Social living can be facilitated by cooperative advantages, yet also incurs in important competitive interactions, leading to complex patterns of spatial genetic structure. Vultures provide a valuable example of complex social animals, with potential conflicts between cooperative and competitive behaviors. Yet, little is known about the socio-genetic structure of this guild because of the inherent difficulties of sampling highly mobile species with large geographical ranges. Herein, we genotyped 300 non-invasive samples from Andean condor (Vultur gryphus) with microsatellite markers to investigate the social dynamics in this highly vagile vulture that possess a despotic social system and communal roosting behavior. We explored the role of age and sex in the dispersion and relatedness patterns of the Andean condor across the central region of Argentina. We provided evidence of age-biased dispersal, supporting the idea that immature condors are largely nomadic using temporary roosting sites during exploratory flights. Our results also insinuated that sex-biased dispersal is age-dependent, with male-biased dispersal during the early life stage, suggesting habitat exclusion by adult male despotic competition. Finally, our kinship analysis showed that regional clusters are composed of highly related adults, indicating the retention of intergenerational family members. Collectively, these results demonstrate that kin associations are driven by adult philopatry, and possibly maintained by fitness benefits of social cooperation for this species.

The publisher regrets to inform the readers that the typesetter misinterpreted the correction from the author.