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Since the video logger was attached to the penguin's back, the video image should reflect the penguin's movement trajectory and the prey position relative to it rather than the penguin's visual field. Keywords: antipredator behavior; biologging; fish; penguin; predation; prey EN antipredator behavior biologging fish penguin predation prey 1 5 5 04/05/23 20230401 NES 230401 Predation acts as a strong selective pressure on the behaviors of both predators and prey (Peterson et al., [15]; Suraci et al., [19]). Our small sample size may also be due to the low frequency of fish predation events in Adélie penguins (fish accounted for only 9% of prey composition by mass during the study period; Watanabe et al., [22]). Penguin-mounted video camera provides new insights into predator-prey interactions with prey fish. [Extracted from the article]

Large carnivores are recovering in many landscapes where the human footprint is simultaneously growing. When carnivores encounter humans, the way they behave often changes, which may subsequently influence how they affect their prey. However, little research investigates the behavioural mechanisms underpinning carnivore response to humans. As a result, it is not clear how predator–prey interactions and their associated ecosystem processes will play out in the human‐dominated areas into which carnivore populations are increasingly expanding.We hypothesized that humans would reduce predation risk for prey by disturbing carnivores or threatening their survival. Alternatively, or additionally, we hypothesized that humans would increase predation risk by providing forage resources that congregate herbivorous prey in predictable places and times.Using grey wolves Canis lupus in Jackson Hole, Wyoming, USA as a study species, we investigated 170 kill sites across a spectrum of human influences ranging from heavily restricted human activities on protected federal lands to largely unregulated activities on private lands. Then, we used conditional logistic regression to quantify how the probability of predation changed across varied types and amounts of human influences, while controlling for environmental characteristics and prey availability.Wolves primarily made kills in environmental terrain traps and where prey availability was high, but predation risk was significantly better explained with the inclusion of human influences than by environmental characteristics alone. Different human influences had different, and even converse, effects on the risk of wolf predation. For example, where prey were readily available, wolves preferentially killed animals far from motorized roads but close to unpaved trails. However, wolves responded less strongly to humans, if at all, where prey were scarce, suggesting they prioritized acquiring prey over avoiding human interactions.Overall, our work reveals that the effects of large carnivores on prey populations can vary considerably among different types of human influences, yet carnivores may not appreciably alter predatory behaviour in response to humans if prey are difficult to obtain. These results shed new light on the drivers of large carnivore behaviour in anthropogenic areas while improving understanding of predator–prey dynamics in and around the wildland–urban interface. [ABSTRACT FROM AUTHOR]

In Europe, the Eurasian lynx (Lynx lynx) has suffered from intensive persecution due to competition with hunters, resulting in its extermination in the late 19th–early 20th century in most central and western European countries. Restoration of suitable prey and conservation efforts allowed the lynx to recolonize parts of its historical range. Understanding the predation patterns of one of the top European predators is crucial for setting appropriate conservation and management measures. Using GPS telemetry data from three resident lynx males in combination with camera trapping and snow tracking, we estimated kill rates, feeding and searching time and compared lynx impact to human harvest on wild ungulates. The average annual kill rates for each individual were 65, 73 and 81 ungulates/year; 17–30% of kills were parallel to other kills. Male lynx annual kill rates were equivalent to 8.59% (19.73% roe deer, 2.48% red deer, 0.32% wild boar) of the average annual human harvest within lynx home ranges. Our results provide the first insight into hunting and feeding behaviour of the Eurasian lynx in the Western Carpathians. [ABSTRACT FROM AUTHOR]

Context: African lion (Panthera leo) populations are declining throughout Africa, but the problem is particularly acute in southern Kenya, where human–lion conflict is common. Aims: Using the Kuku Group Ranch (KGR) in southern Kenya as a case study, we investigated lion diet and the potential drivers of temporal variation in cattle depredation. Methods: Using GPS clusters, we investigated the main prey species consumed by lions to determine lion diet. Prey preference of lions in relation to prey availability was then assessed using a Jacobs index to determine whether cattle or wild prey were preferred. We used reported depredation events recorded by verification officers over 36 months (2016–2018) to investigate whether temporal variation in cattle depredation by lions was linked to variation in lag rainfall, normalised difference vegetation index (NDVI) or availability of the most important large non-domestic prey items. Key results: Six prey species (cattle, Bos taurus ; Burchell's zebra, Equus quagga ; Coke's hartebeest, Alcelaphus cokeii ; Maasai giraffe, Giraffa tippelskirchi ; blue wildebeest, Connochaetes taurinus ; and eland, Tragelaphus oryx) made up 92% of the biomass consumed by lions on KGR. Cattle are the most consumed prey item and contribute the second most to consumed biomass after giraffe. However, once prey availability is considered, lions preferred wild prey. Verification officers identified 330 cattle depredation events over 3 years, and we show that the most important predictor of monthly cattle depredation by lions was cumulative rainfall in the preceding 3 months. Conclusions: Our results on cattle depredation by lions showed that rainfall and its influence on the environment are important drivers of cattle depredation. Understanding the mechanistic link between lion depredation and rainfall enables us to predict when depredation events may increase and allows hypotheses on the reason why this spike in depredation takes place to be explored. Implications: Given that climate-change models indicate that East Africa will experience prolonged and increased seasonal rainfall, we predict that periods when cattle are vulnerable to lion depredation may increase. Therefore, it is imperative to ensure that cattle husbandry is improved during these wetter periods to minimise the risk of conflict and retaliatory killing of lions. Retaliatory killing of lions is a threat to African lion (Panthera leo) populations. Our study took place in the Tsavo–Amboseli ecosystem, Kenya, assessing lion diet and cattle depredation. The most common species consumed by lions were cattle, whereas lag rainfall was an important predictor of cattle depredation. The findings provide opportunities to develop proactive husbandry interventions to reduce cattle depredations. Photograph by Iain Olivier. [ABSTRACT FROM AUTHOR]

Several insect pests are related to the cultivation of conilon coffee, Coffea canephora (Rubiaceae), including (Hemiptera: Coccomorpha). Coccoids damage plants by sucking their sap, producing honeydew, and transmitting viruses. Parasitoids and predators are natural enemies that regulate the insect population and can be used in mealybug biological control. This study aimed to survey scale insects and natural enemies associated with C. canephora in the city of Jaboticabal, São Paulo State, Brazil. Two species of mealybugs from the family Coccidae and three from the family Pseudococcidae were collected in different plant structures. Natural enemies collected comprised hymenopteran parasitoids from the families Aphelinidae, Eulophidae, Encyrtidae, and Perilampidae; predator beetles of the family Coccinellidae; dipterans from the family Cecidomyiidae; and thrips of the family Aeolothripidae. This is the first report of the mealybug species Coccus brasiliensis, Pseudococcus longispinus, and Pseudococcus cryptus; of the parasitoids Coccophagus rusti, Aprostocetus sp., Aenasius advena, Aenasius fusciventris, Aenasius pseudococci, and Perilampus sp.; and of the predators Cycloneda conjugata, Pseudoazya nana, Diadiplosis coccidivora, Diadiplosis sp., and Franklinothrips vespiformis, associated with C. canephora. Knowledge of mealybug species and their respective natural enemies will contribute to biological control strategies in planning the integrated management of mealybugs associated with conilon coffee. [ABSTRACT FROM AUTHOR]

IntroductionUnderstanding the characteristics of hotspots of species distribution provides opportunities for habitat-based management; a vital and often missing component in the conservation of mobile marine species. Correlates of species distribution derived from species distribution models (SDMs) are assumed to represent the characteristics of important habitat, which often include physical and biological (i.e., prey) components. In this study, we integrate surveys of Hector’s dolphin (Cephalorhynchus hectori) with in-situ data on environmental characteristics and prey to identify the statistical correlates of distribution and to assess ‘what makes hotspots unique’.MethodsBetween 2014 and 2017, ca. 300 surveys were carried out at hotspots and areas not routinely used by dolphins at Banks Peninsula on the east coast of New Zealand’s South Island. A broad range of prey and environmental variables were explored as drivers of dolphin distribution using generalized additive models, and principal component analysis was employed to determine a key environmental signature for hotspots.ResultsThe relative abundance of dolphins was strongly correlated with prey abundance and a range of environmental variables representing habitat type and oceanographic conditions. The combination of high prey abundance and sandy, shallow, high current and low turbidity habitat was strongly represented at hotspots.DiscussionThese characteristics are also likely attributes of habitat with high ecological value generally, being related to high biodiversity, productivity, naturalness and ecosystem function. This study showcases the importance of targeted investigations into the characteristics of species hotspots to better guide the management of important areas for the conservation of both species and ecosystems.

With about 8000 marine benthic species, the amphipod crustaceans form one of the richest animal groups of the worldwide Ocean. They have colonized a wide range of soft- and hard-bottom natural and artificial habitats extending from the intertidal to hadal zones. Moreover, they show a broad size spectrum, with numerous giant species exceeding 20 cm in length and some species smaller than 2 mm. When biofouling artificial hard surfaces, some tube-building species can form very dense populations comprising up to 100,000 individuals per square meter. Amphipods are important prey for fish and mammals. Along with cephalopod juveniles, they are also included in the trophic diet of shorebirds that consume amphipods mostly during the low tide on tidal flats. They display diel migration, which reinforces the predation by demersal fish in the suprabenthic zone just above the sea bed, as well as by pelagic fish in the water column. Despite their importance in terms of biodiversity and trophic transfer, no general overview is available on the role of benthic amphipods in marine ecosystem food webs. Various methods, including laboratory and field experiments, as well as the analysis of stomach contents and DNA extraction, have been used to identify the prey/predator trophic links. Based on an extensive literature review, this study discusses the role of marine benthic amphipods as potential food for higher trophic levels in natural and artificial hard-bottom communities created via the construction of offshore wind farms.

Masu salmon, Oncorhynchus masou (Brevoort 1856), a commercially important fish species endemic to the North Pacific Ocean, attained national second-level protected animal status in China in 2021. Despite this recognition, knowledge about the trophic ecology of this fish remains limited. This study investigated the diet diversity of fluviatile Masu salmon in the Mijiang River, China, utilizing the gastrointestinal tract environmental DNA (GITeDNA) metabarcoding and morphological identification. The results revealed a diverse prey composition, ranging from terrestrial and aquatic invertebrates to small fishes. The fluviatile Masu salmon in general consumed noteworthily more aquatic prey than terrestrial prey. There were much more prey taxa and a higher diet diversity detected by GITeDNA metabarcoding than by morphological identification. GITeDNA metabarcoding showed that larger and older Masu salmon consumed significantly more terrestrial insects than aquatic prey species did, with 7366 verses 5012 sequences in the group of ≥20 cm, 9098 verses 4743 sequences in the group of ≥100 g and 11,540 verses 729 sequences in the group of age 3+. GITeDNA metabarcoding also showed size- and age-related diet diversity, indicating that the dietary niche breadth and trophic diversity of larger and older Masu salmon increased with food resources expanding to more terrestrial prey. Terrestrial invertebrates of riparian habitats play a vital role in the diet of fluviatile Masu salmon, especially larger individuals, highlighting their importance in connecting aquatic and terrestrial food webs. Conservation plans should prioritize the protection and restoration of riparian habitats. This study advocates the combined use of GITeDNA metabarcoding and morphological observation for a comprehensive understanding of fish diet diversity.

The Sacramento–San Joaquin Delta has been invaded by several species of non-native predatory fish that are presumed to be impeding native fish population recovery efforts. Since eradication of predators is unlikely, there is substantial interest in removing or altering manmade structures in the Delta that may exacerbate predation on native fish (contact points). It is presumed that these physical structures influence predator-prey dynamics, but how habitat features influence species interactions is poorly understood, and physical structures in the Delta that could be remediated to benefit native fish have not been inventoried completely. To inform future research efforts, we reviewed literature that focused on determining the effects of predator-prey interactions between fish, based on contact points that are commonly found in the Delta. We also performed a geospatial analysis to determine the extent of potential contact points in the Delta. We found that the effects of submerged aquatic vegetation (SAV) and artificial illumination are well studied and documented to influence predation in other freshwater systems worldwide. Conversely, other common structures in the Delta—such as docks, pilings, woody debris, revetment, and water diversions—did not have the same breadth of research. In the Delta, the spatial extent of the different types of contact points differed considerably. For example, 22% of the Delta water surface area is occupied by SAV, whereas docks only cover 0.44%. Our conclusion, based on both the literature review and spatial analysis, is that the effects of SAV and artificial illumination on predation warrant the most immediate future investigation in the Delta.

In this paper, I review the effects of the diet of ladybirds on chemical defence in this group of beetles. The tendency to reflex bleed and the diversity of autogenously produced alkaloids in different taxa may be evolutionarily related to diet and the likelihood of food limitation. Within predatory species, both prey quantity and quality have been shown to affect autogenous alkaloid production. A few ladybird predators have been suggested to adaptively sequester toxins from their prey for their own defence. However, in most cases the evidence for this is limited, with questions remaining about the costs of accumulated toxins and their defensive value, especially over and above pre-existing autogenous defence. Only a single case (Hyperaspis trifurcata and carminic acid) is well supported. In the case of ladybird predators acquiring pyrrolizidine alkaloids from the ragwort aphid Aphis jacobaeae, I show that toxin accumulation is not very costly and the aphid is even an essential prey for some ladybirds. However, the defensive value of pyrrolizidine alkaloids to ladybirds is still not investigated. Intraspecific diversity in autogenous chemical defence could be reinforced further if chemical protection is conferred via sequestered chemicals. However, to understand better how ladybird diet and chemical defence interact, we need a clearer grasp of how the defensive chemicals of food are resisted or tolerated by ladybirds.

In aquatic environments, many prey animals, including anuran larvae, predominantly use chemical cues to assess predation risk. In such systems, a variety of chemical cues (e.g., kairomones, alarm, dietary) affect the behavioral responses of the prey tadpoles. Many anuran tadpoles are able to discriminate different chemical cues and exhibit differential antipredator behavioral responses according to the perceived risk. The behavioral responses of tadpoles of Clinotarsus curtipes to predatory larvae of the dragonfly Pantala flavescens were studied in the laboratory. The predator’s kairomones (water conditioned by a starved predator) or its diet-derived metabolites released in excreta of a predator after consumption of conspecific (C. curtipes) or heterogeneric (Indosylvirana temporalis) prey tadpoles were used to simulate predation threat. The tadpoles of C. curtipes had no behavioral response to predator kairomones. However, the tadpoles showed antipredator behavioral responses i.e., reduced swimming movements and overall time spent swimming, and had a higher burst speed in response to water-borne cues released from the excreta of predators fed both conspecific and heterogeneric prey. The antipredator behavioral responses of tadpoles were most intense in response to cues of predators fed on conspecific prey. The findings of the present study show that tadpoles of C. curtipes are capable of assessing levels of predation threat and modulating the intensity of their defense behavior in accordance with the perceived threat.

The contraction of the global tiger population over the last 100 years into small, often isolated subpopulations has made them increasingly vulnerable to the impact of disease. Despite this, the health of wild tigers continues to be insufficiently funded and explored. For example, canine distemper virus (CDV), has been associated with localized declines and increased risk of extinction, and yet has received little research attention in most tiger range countries. The emergence of new pathogenic threats has posed fresh challenges, including African swine fever virus (ASFV), which has the potential to devastate wild boar populations, and severe acute respiratory syndrome coronavirus (SARS-CoV2) with implications for tiger conservation that remain unknown. The objective of this review is to synthesize current research on the health of tigers and their prey that impacts the conservation of tigers in the wild. Published sources are interpreted based on three mechanisms through which disease can affect the viability of tiger populations: (1) by reducing the survival of adult tigers, (2) by reducing breeding productivity, and (3) by reducing the carrying capacity of tiger habitat through decreased prey abundance. Examples of CDV, SARS-CoV2, carnivore protoparvovirus 1 and ASFV are used to illustrate these processes and inform discussion of research and mitigation priorities.

Bull shark (Carcharhinus leucas) is a near‐threatened elasmobranch species capable of moving between the fresh and salty waters of tropical and subtropical coastal areas, for which we still lack important ecological information. During their first years of life, bull sharks use estuarine systems as nursery areas, making them highly susceptible to environmental and anthropogenic pressures. We studied the trophic ecology of juveniles found in the Coyote estuary, a potential nursery area in Costa Rica, to understand the potential impact of further bull shark declines and gain knowledge that could aid in their conservation. We analysed the trophic ecology of juvenile bull sharks [81–103 cm total length (TL)] in the Coyote estuary, Costa Rica, using stable isotopes of δ15N and δ13C. Since one problem using this technique in juveniles is the confounding effect of the maternal signature, we sampled different tissues (muscle and plasma), verified the status of the shark's umbilical scar and identified the size at which the isotope signature is a result of the animal's current diet. The isotopic values of the muscle tissue reflected the maternal isotopic signature. In contrast, plasma values reflected the diet of juvenile bull sharks >95 cm TL and with a closed umbilical scar. Juvenile bull sharks fed primarily on teleost fishes of the order Anguilliformes and Siluriformes, and have a high trophic position (≥4.0) in the Coyote estuary. Our findings suggest that this estuary is an important feeding site for juvenile bull sharks of the Pacific of Costa Rica. Thus, the protection of essential habitats such as the Coyote estuary will benefit not only bull shark conservation, but also the conservation of an array of fish species that also use this habitat as a rookery, many of which are of commercial interest. [ABSTRACT FROM AUTHOR]

Between 2007 and 2021 we monitored adult hawks (Buteo spp.) nesting in the upper Columbia River Basin of Washington and Oregon using global positioning system (GPS) telemetry on 17 Ferruginous Hawks (B. regalis), 9 Red-tailed Hawks (B. jamaicensis), and 14 Swainson's Hawks (B. swainsoni). Our main objectives were to: (1) provide contemporary home-range estimates using fixes generated by the global positioning system to better inform protective buffers on Buteo ranges in the Columbia River Basin; and (2) describe prey analyzed from pellets collected at 47 Buteo territories. Breeding home ranges (Brownian bridge movement model, 95% isopleths) of Ferruginous Hawks (B. regalis) were substantially larger (x̄ = 378, sx = 133 km2) than those published previously, as were home ranges of Swainson's Hawks (x̄ = 276, sx = 146 km2) and Red-tailed Hawks (x̄ = 28, sx = 12 km2). Diets of Ferruginous Hawks on the study area were dominated (60%) by Northern Pocket Gophers (Thomomys talpoides), whereas Swainson's Hawks primarily (83%) ate grasshoppers (Apote notablis and Melanoplus spp.). Red-tailed Hawks ate a less-specialized diet of reptiles (40%), mammals (38%), and birds (13%). We provide models that show the probable degree of protection afforded by different-sized buffers when applied to species-specific home ranges and core areas for hawks in the Columbia River Basin. [ABSTRACT FROM AUTHOR]

Habitat alteration is a widespread threat severely affecting large raptors because of their low density and the huge area they inhabit. In this study, we assessed whether human-driven habitat alterations mediated dietary shifts of apex predators, focusing on the Eastern imperial eagle (Aquila heliaca). Following a bottom-up conception (before–after), we evaluated the effect of grassland change on the eagle's dietary shift and breeding success. Land use patterns underwent a significant transformation over the study period, creating a large decrease in grasslands. The territories lost an average of 25.79% of their grasslands. Habitat alteration mediated dietary shifts, but had no reproductive consequences for eagles. Eagles became 1.90 times more likely to predate on northern white-breasted hedgehog and 1.62 times more likely to forage on white stork in the period after grassland alteration. The frequency of tortoises also increased, and they were 4.04 times more likely to be predated on in the years after transformation. Conversely, brown hare was 0.51 times less likely to be consumed in the grassland loss period, while this likelihood was 0.54 times lower for rodents and 0.64 times lower for the European souslik. Doves, meanwhile, were 2.73 times more likely to be predated on in the years following grassland destruction. We found that the presence and biomass of songbirds correlated negatively with the breeding success of eagles, and biomass supply from European souslik was negatively associated with breeding success, while the white stork's presence and biomass resulted positively in more progeny. Diet diversity did not have an effect on the eagle's reproduction. The responses of these eagles may vary across territories, depending on how they rank their prey, as the territory effect was a powerful factor shaping dietary shifts for this top predator. Our results offer new evidence of the link between habitat alteration, dietary shifts, and reproductive success, contributing to our understanding of the enigmatic mechanism through which an apex predator successfully adapts to large-scale land use pattern transformation by increasing dietary specialization. We recommend restoration of habitat complexity, including preservation of field margins, grassland patches with scattered small shrub formations, and grassland margins between medium-sized arable lands, promotion of measures for traditional grassland management through gradual grazing, and a ban on the use of shredders. [ABSTRACT FROM AUTHOR]

I evaluated the breeding biology of Red-headed Falcon (Falco chicquera) by documenting 39 breeding attempts in Surendranagar district of Gujarat, India, from 2006 to 2021. Across years, the Mayfield estimated seasonal nest survival was 0.900 ± 0.016 (95% CI), and productivity was 2.5 ± 1.4 (95% CI) fledglings per breeding attempt. Prey deliveries recorded during the study were exclusively birds, 71% of the order Passeriformes. Of the 39 breeding attempts in 18 territories, 26 nests were on high tension electricity transmission pylons and 13 were in trees. I provide the first baseline data for comparing and evaluating reproductive rate of this species in different environments across the Indian subcontinent and elsewhere. Evalué la biología reproductiva de Falco chicquera documentando 39 intentos reproductivos en el distrito de Surendranagar de Gujarat, India, de 2006 a 2021. A lo largo de los años, la supervivencia estacional de los nidos, estimada por el método de Mayfield, fue de 0.900 ± 0.016 (IC del 95%), y la productividad fue de 2.5 ± 1.4 (95% IC) volantones por intento reproductivo. Las entregas de presas registradas durante el estudio fueron exclusivamente aves, con el 71% pertenecientes al Orden Passeriformes. De los 39 intentos reproductivos en 18 territorios, 26 nidos fueron colocados sobre postes eléctricos de alta tensión y 13 en árboles. Proporciono los primeros datos de referencia para comparar y evaluar la tasa reproductiva de esta especie en diferentes ambientes en el subcontinente indio y en otros lugares. [Traducción del equipo editorial] [ABSTRACT FROM AUTHOR]

Context: The behaviours used by mammalian predators to track, kill, and consume prey are some of the most dynamic interspecific interactions in nature. However, they are often challenging to follow through the landscape and observe directly without disturbing the animals being watched. Aims: We describe the behaviours used by wild dingoes while hunting macropods in Namadgi National Park, Australian Capital Territory, Australia. Methods: Footage was initially captured by wildlife cinematographers on behalf of documentary programs and was made available for viewing after production. Hunting events were filmed from an altitude of >50 m by using a 'long lens' fitted to either a drone or helicopter. Results: We recorded a suite of hunting behaviours that would have been extremely challenging to observe from the ground via traditional methods. This includes some of the first video records published in the scientific literature of the behaviours used by dingoes to hunt and kill macropod prey, as well as some rare observations of mother and pup hunting dynamics. We did not observe any signs of disturbance as a result of filming for either predator or prey. Conclusions: The varied repertoire of predatory behaviours displayed by dingoes is similar to that documented in wolves and asserts them as a behaviourally complex top predator in the Australian landscape. In addition, we highlight the use of drones as a valuable approach for directly observing wild behaviours. They offer a minimally invasive and relatively inexpensive and accessible alternative to helicopters. This project is also a case study exemplifying the value of collaborations between filmmakers and researchers that enable the sharing of archival documentary footage for the study of wild animal behaviour. Implications: Future studies of wild animal behaviour should consider employing drones (at a safe distance and in accordance with published best practices and guidelines) as an additional tool to collect types of data that would be challenging using other methods. The behaviours that dingoes use to capture and kill their prey are highly dynamic and can be challenging to observe directly without disturbance. This study reports a series of direct observations of wild hunting behaviour filmed using cameras attached to either a helicopter or drone. This project contributes to our knowledge of dingo ecology and also acts as a case study highlighting the utility of drones for directly observing dynamic behaviours in the wild. Images by Daniel Hunter and Edward Saltau. [ABSTRACT FROM AUTHOR]

Many carnivores exhibit demographic and functional responses to changes in prey abundance. Demographic responses often include changes in population size, litter size, and recruitment of young into the adult population. Functional feeding responses are commonly reported for many carnivore species. We investigated demographic and functional responses of kit foxes (Vulpes macrotis Merriam, 1888) to changes in prey abundance during 2010–2013 in western Utah, USA. Between 2010 and 2013, litter size averaged 3.9 (±1.4) pups/litter. Survival rates of kit fox pups were 0.07, 0.01, 0.46, and 0.16, respectively, and there was a correlation between pup survival rates and rodent abundance; leporid (family Leporidae Fischer, 1817) abundance did not influence pup survival. There was a functional response as occurrence of kangaroo rat in the diet closely followed changes in kangaroo rat abundance. The occurrence of rodents in kit fox diet followed declines in rodent abundance (excluding Dipodomys spp. Gray, 1841). Leporid consumption by kit foxes was not correlated to leporid density. Kit fox survival was dependent on rodent abundance and more specifically, kangaroo rats. Understanding which population parameters of kit foxes are influenced by prey is critical for the conservation of this native mesocarnivore. [ABSTRACT FROM AUTHOR]

The water–air interface is a globally widespread habitat for interactions between prey and predators. We experimentally manipulated water surface conditions (flat, smooth waves, three levels of current-induced turbulence) and digitally quantified the visual integrity of above-surface models from a subsurface perspective. Progressive fragmentation was present in each of the models (upright heron, crouched heron, vertical block, horizontal block) with increased departure from flat surface conditions. Smooth directional waves produced multiple horizontal bands (shadows) that moved across the models while surface currents distorted the profile, including progressive disintegration of the models appearance into multiple fragments of different sizes. This fragmentation is caused by scattered surface irregularities interacting with waves and is accentuated at the broken periphery of the optical window, reducing recognition of the models. Unexpectedly, we found that bands and fragments emerging from different surface conditions resemble common frontal plumage patterns on some Ardeidae and shorebirds (Charadriiformes). While these natural plumages are widely recognized to reflect a diversity of adaptations, including camouflage in terrestrial habitats, we suggest that their resemblance to water surface-induced fragmentation might also reflect foraging adaptations of predators though the water–air interface. [ABSTRACT FROM AUTHOR]

Lontra longicaudis Olfers, 1818 is a semi-aquatic carnivore widely distributed in the Neotropical region. Understanding their diet contributes to an indirect understanding of their ecology and the composition of the local fauna. To this end, we analyzed 109 fecal samples and identified 238 morphological structures; these samples were collected between May 2006 and September 2007 from the Santa Lúcia Biological Station (SLBS) in southeastern Brazil. The area is intersected by the Timbuí River, which arrives at the site after crossing the urban perimeter of the city of Santa Teresa in the state of Espírito Santo. We found a predominance of fish in the otters' diets (82%), mainly cichlids (50%), which are fish with sedentary habits and low mobility levels. The crustacean Trichodactylus fluviatilis Latreille, 1828 was the third most consumed taxon; this occurred mainly during the rainy season, corresponding to the crustacean's reproductive period, when it is more vulnerable to predation. Otters exhibited a seasonal variation in their prey selectivity. Furthermore, they displayed opportunistic foraging behavior, as the most preyed fish were those with both low mobility and a high frequency in the environment, followed by fish with high mobility and high frequency, and then those with low mobility and low frequency. We concluded that the feeding habits of the otters in the SLBS are in line with the optimal foraging theory since prey selection was optimized through the balance between net energy gained and the energy costs of foraging. [ABSTRACT FROM AUTHOR]

Jaguars (Panthera onca) are a landscape species of conservation importance and our understanding of environmental and anthropogenic drivers of jaguar occurrence is necessary to improve conservation strategies. We reviewed available literature to simply describe environmental and anthropogenic variables used and found to be significant in occurrence modeling. We reviewed 95 documents published from 1980 to 2021 that focused on jaguar occurrence and that used 39 variable types (21 anthropogenic, 18 environmental) among different techniques, scales, and approaches. In general, these variables included both anthropogenic (roads, land use, human activities, and population) and environmental (climate, vegetation, ecological interactions, topographic, water, and others) factors. Twelve variables were identified as affecting jaguar occurrence overall, eleven at local scale and seven at broad scales (regional and continental). Focusing more specifically on the variables that correlate with occurrence should help researchers to make better predictions in areas without quantitative jaguar data. [ABSTRACT FROM AUTHOR]

Apex predators ideally require vast intact spaces that support sufficient prey abundances to sustain them. In a developing world, however, it is becoming extremely difficult to maintain large enough areas to facilitate apex predators outside of protected regions. Free-roaming leopards (Panthera pardus) are the last remaining apex predator in the Greater Cape Floristic Region, South Africa, and face a multitude of threats attributable to competition for space and resources with humans. Using camera-trap data, we investigated the influence of anthropogenic land modification on leopards and the availability of their natural prey species in two contrasting communities--primarily protected (Cederberg) and agriculturally transformed (Piketberg). Potential prey species composition and diversity were determined, to indicate prey availability in each region. Factors influencing spatial utilisation by leopards and their main prey species were also assessed. Estimated potential prey species richness (Cederberg = 27, Piketberg = 26) and diversity indices (Cederberg--H' = 2.64, Ds = 0.90; Piketberg--H' = 2.46, Ds = 0.89), supported by both the Jaccard's Index (J = 0.73) and Sørensen's Coefficient (CC = 0.85), suggested high levels of similarity across the two regions. Main leopard prey species were present in both regions, but their relative abundances differed. Grey rhebok, klipspringer, and rock hyrax were more abundant in the Cederberg, while Cape grysbok, Cape porcupine, chacma baboon, and common duiker were more abundant in Piketberg. Leopards persisted across the agriculturally transformed landscape despite these differences. Occupancy modelling revealed that the spatial dynamics of leopards differed between the two regions, except for both populations preferring areas further away from human habitation. Overall, anthropogenic factors played a greater role in affecting spatial utilisation by leopards and their main prey species in the transformed region, whereas environmental factors had a stronger influence in the protected region. We argue that greater utilisation of alternative main prey species to those preferred in the protected region, including livestock, likely facilitates the persistence of leopards in the transformed region, and believe that this has further implications for human-wildlife conflict. Our study provides a baseline understanding of the potential direct and indirect impacts of agricultural landscape transformation on the behaviour of leopards and shows that heavily modified lands have the potential to facilitate mammalian diversity, including apex predators. We iterate that conservation measures for apex predators should be prioritised where they are present on working lands, and encourage the collaborative development of customised, cost-effective, multi-species conflict management approaches that facilitate coexistence. [ABSTRACT FROM AUTHOR]

Reptiles can be on the diet of some bird species, and the glass lizard Ophiodes fragilis seems to be no exception. Although predation events are not easily recorded, in this work we document a new record of predation by C. cristata upon O. fragilis. The event occurredin November 2017 in the municipality of Viçosa, state of Minas Gerais, Brazil, and helps to fill a gap in trophic relationships between the lizard and its predators.

Predatory behaviour is a relevant part of the behavioural repertoire of dogs, which often entails negative or desirable implications, depending on the context and target to which it is directed. It is also considered one of the most characterising aspects of breed-specific behaviour. Despite its relevance, there is surprisingly little scientific knowledge about the topic. In the present study we sought to develop an ethogram of the predatory sequence of dogs, with the aim of providing a sufficiently general structure to be applicable to dogs at large, without eluding peculiar aspects of the species' specific behaviour. Sixty videos of dogs of different breeds expressing predatory acts, including both videos obtained from public internet repositories and videos made on purpose, were described in detail by two different observers. From descriptions, a general sequence was identified, consisting of four functional phases, i.e. search, approach, chase and bite. The descriptions of the behaviours included in each phase were organised into three levels, characterised by different levels of detail and focusing on different aspects of the behaviour. When appropriate, these descriptions highlighted differences in behaviour expressed by dogs belonging to different working groups. The ethogram proposed in the present paper could represent a useful starting point for improving knowledge about the predatory behaviour of dogs and answering relevant questions about both its evolution and ontogeny. • 60 videos of dogs expressing different predatory behaviour were analysed. • The functional phases of the predatory sequence: search, approach, chase, bite. • Behaviours in each phase is organized into 3 levels of detail and behavioural focus. • Ethogram shows consistency in the sequence and breed-specific differences in phases. [ABSTRACT FROM AUTHOR]

In addition to feeding on plants, Mormon crickets Anabrus simplex Haldeman, 1852 predate on invertebrates, including one another, which effectively drives their migration. Carnivory derives from lack of dietary protein, with Mormon crickets deprived of protein having less phenoloxidase (PO) available to combat foreign invaders, such as fungal pathogens. Because Mormon crickets commonly occur with grasshoppers that feed on the same plants, we investigated interactions between grasshoppers and Mormon crickets, and hypothesized that if Mormon crickets are predatory on grasshoppers, grasshopper abundance would influence the protein available to Mormon crickets and their immunity. In a field setting, we varied densities of Mormon crickets (0, 10, or 20 per cage) and grasshoppers Melanoplus borealis (0, 15, 30, or 45) in 68 1-m2 cages. After one month, we measured Mormon cricket dietary preferences and PO activity. As predicted, artificial diet consumption shifted away from protein as grasshopper density increased, and immunocompetence, as measured by PO activity, also increased with grasshopper availability. Although nitrogen availability in the vegetation decreased with increasing insect density, predation became an important source of protein for Mormon crickets that enhanced immunity. Grasshoppers can be an important source of dietary protein for Mormon crickets, with prey availability affecting Mormon cricket immunity to diseases.

The European conger, Conger conger, is a benthic marine fish species with a geographical distribution extending through the northeastern Atlantic and the Mediterranean. Despite being extensively distributed and widely appreciated by Spanish consumers, studies regarding parasite presence in this fish are scarce. In the present work, a hundred and eight specimens from the Mediterranean coast of northeastern Spain (Catalan waters) were surveyed for the presence of nematode parasites. Several species were morphologically identified: third-stage larvae of Anisakis type I (sensu Berland, 1961) (n = 131), third-stage larvae of Anisakis type II (sensu Berland, 1961) (n = 18), third- and fourth-stage larvae and adults of Hysterothylacium spp. (n = 48), adults of Cucullanus sp. (n = 391), and adults of Cristitectus congeri (n = 69). Moreover, some fish and decapode species were also observed as part of the host’s diet, with the most detected preys being Micromesistius poutassou, Sardina pilchardus, Macropipus sp., and Goneplax rhomboides. This represents the first survey of nematode parasites infecting C. conger from the northeastern Spanish Mediterranean waters. Among the parasite species detected, the presence of Anisakis species should be highlighted as the ingestion of C. conger parasitized with these larvae could potentially lead to anisakiasis in consumers.

The European roller (Coracias garrulus) is an endangered species whose breeding in Serbia depends almost entirely on nest boxes. The aim of the present study was to assess the influence of prey availability and foraging habitat characteristics on nest-box occupancy and breeding parameters. Data from 20 roller foraging sites over 5 breeding seasons were used in a set of linear regression models to evaluate which factors affect the diversity and biomass of roller prey, as well as nest-box occupancy and breeding parameters. Our analyses revealed that prey availability parameters were significantly affected by the grazing regime and biophysical parameters. An area under grassland negatively affected nest-box occupancy, clutch size and fledging success. In contrast, grazing intensity showed positive effects. Although grazing negatively affected prey diversity and quantity, it potentially increased the likelihood of a successful hunt by forming short vegetation. These results indicate that the habitat characteristics linked to the ability of the species to hunt successfully should be considered when installing nest boxes as a part of the broader management of roller breeding sites. Furthermore, nest-box installation in open agricultural habitats other than grasslands should be considered in the conservation strategy for the species in Serbia.

Apex predators ideally require vast intact spaces that support sufficient prey abundances to sustain them. In a developing world, however, it is becoming extremely difficult to maintain large enough areas to facilitate apex predators outside of protected regions. Free-roaming leopards (Panthera pardus) are the last remaining apex predator in the Greater Cape Floristic Region, South Africa, and face a multitude of threats attributable to competition for space and resources with humans. Using camera-trap data, we investigated the influence of anthropogenic land modification on leopards and the availability of their natural prey species in two contrasting communities—primarily protected (Cederberg) and agriculturally transformed (Piketberg). Potential prey species composition and diversity were determined, to indicate prey availability in each region. Factors influencing spatial utilisation by leopards and their main prey species were also assessed. Estimated potential prey species richness (Cederberg = 27, Piketberg = 26) and diversity indices (Cederberg—H′ = 2.64, Ds = 0.90; Piketberg—H′ = 2.46, Ds = 0.89), supported by both the Jaccard’s Index (J = 0.73) and Sørensen’s Coefficient (CC = 0.85), suggested high levels of similarity across the two regions. Main leopard prey species were present in both regions, but their relative abundances differed. Grey rhebok, klipspringer, and rock hyrax were more abundant in the Cederberg, while Cape grysbok, Cape porcupine, chacma baboon, and common duiker were more abundant in Piketberg. Leopards persisted across the agriculturally transformed landscape despite these differences. Occupancy modelling revealed that the spatial dynamics of leopards differed between the two regions, except for both populations preferring areas further away from human habitation. Overall, anthropogenic factors played a greater role in affecting spatial utilisation by leopards and their main prey species in the transformed region, whereas environmental factors had a stronger influence in the protected region. We argue that greater utilisation of alternative main prey species to those preferred in the protected region, including livestock, likely facilitates the persistence of leopards in the transformed region, and believe that this has further implications for human-wildlife conflict. Our study provides a baseline understanding of the potential direct and indirect impacts of agricultural landscape transformation on the behaviour of leopards and shows that heavily modified lands have the potential to facilitate mammalian diversity, including apex predators. We iterate that conservation measures for apex predators should be prioritised where they are present on working lands, and encourage the collaborative development of customised, cost-effective, multi-species conflict management approaches that facilitate coexistence.

Even prey that successfully evade attack incur costs when responding to predators. These nonlethal costs can impact their reproductive success and survival. One strategy that prey can use to minimize these costs is to adjust their antipredator behavior based on the perceived level of risk. We tested whether humans adopt this strategy by presenting participants with photographic arrays of predators (lions) that varied in their level of risk. While their eye movements were recorded, the participants searched for a forward-facing predator (signifying potential predator interest; high-risk target) among an array of inattentive predators that were facing away (low-risk distractors) or searched for a predator that was facing away from them among an array of forward-facing predators. As a control, participants also searched through similar arrays that displayed a potential prey species (impalas) rather than predators. Participants detected forward-facing predators more quickly than predators facing away from them. Unexpectedly, they were also quicker at detecting forward-facing prey versus prey facing away from them, but slower to detect these forward-facing prey compared with forward-facing predators. They were slower to detect predators and prey facing away from them because they spent more time looking at the forward-facing distractors and looked at more of those distractors. The results indicate that human attention is drawn toward dangerous predators with forward-facing orientations, and this could allow humans to quickly assess predator intentions. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

Recruitment to the Faroe Plateau cod (Gadus morhua) stock (62°N, 6.8°W) is highly variable between years, and availability of suitable prey during the early life stages may determine the year class strength. Here we first investigate interannual variability in recruitment (1983–2017) of cod based on survey data and data from stock assessments. Positive relationships between the spawning stock biomass and larval abundance and between juvenile abundance and recruitment at year 1 were detected. However, the relationship between larval abundance and juvenile abundance was not statistically significant, indicating variable survival during the larval/early juvenile stages. We then investigated if food availability at the larval and early juvenile stages could explain the variability in recruitment using an 8-year long time series of larval and juvenile gut content. Feeding at the early larval stage, present during the pre-bloom, was relatively stable between years. However, large interannual variability in feeding at the early juvenile stage was detected. When juvenile survival and mean length were high, juveniles clearly had less food in their guts. This contradiction is suggested to be due to intense grazing pressure on the zooplankton at high juvenile abundances. However, years with high larval survival coincided with years when the phytoplankton spring bloom was early and intense, suggesting that production of suitable prey during the larval stages determines larval growth and survival and that this production is dependent on the phytoplankton spring bloom characteristics. [ABSTRACT FROM AUTHOR]

We analyzed the diet of Athene cunicularia cunicularia in order to identify and compare prey items in dune populations in Santa Catarina, Brazil: Interpraias (INT), Praia Brava (BRA), Praia Central (NAV) and Peninsula (BVE). Due to the characteristics of urbanization in these regions, we hypothesized that there would be greater abundance and consumption of urban insect pests in the areas of BRA, NAV, and INT than in BVE. We collect owl pellets monthly in 2017. The non-parametric analysis ANOVA was applied to identify differences in pellet weights and niche amplitude between populations and seasons and PERMANOVA was applied to identify differences between prey items. Were collected 1064 pellets containing 20 prey items, including: invertebrates (Arachnida, Insecta and Crustacea Malacostraca – 83%), vertebrates (Osteichthyes, amphibians, Reptilia, birds and Mammalia – 8.6%), seeds (6.38%) and miscellaneous materials of anthropic origin (0.19%). There was no difference in the pellet weights, but the diets observed in INT and BRA were significantly different, a result that may be a reflection of the microenvironments in which the burrowing owl lives. This shows that, in addition to a generalist diet, this species has the capacity to adapt to urban changes. [ABSTRACT FROM AUTHOR]

Deimatic behaviours, also referred to as startle behaviours, are used against predators and rivals. Although many are spectacular, their proximate and ultimate causes remain unclear. In this review we aim to synthesise what is known about deimatic behaviour and identify knowledge gaps. We propose a working hypothesis for deimatic behaviour, and discuss the available evidence for the evolution, ontogeny, causation, and survival value of deimatic behaviour using Tinbergen's Four Questions as a framework. Our overarching aim is to direct future research by suggesting ways to address the most pressing questions in this field. [ABSTRACT FROM AUTHOR]

Caiman latirostris is an opportunistic predator found in rivers, mangroves, and wetlands throughout eastern South America. We report here the predation of Tamandua tetradactyla by Caiman latirostris in an old cattle dam in the Serra da Bodoquena National Park, Brazil. The adult caiman was accompanied by its hatchlings that fed on the lacerated parts of the Lesser anteater and possibly the insects attracted by the carcass. Although Caiman latirostris acts as a fundamental organism for the balance of ecosystems, most of the species` diet records are anecdotal, making this record relevant for understanding the ecology of the species. [ABSTRACT FROM AUTHOR]

Food availability and utilization are among the most critical factors influencing the distribution of free-ranging animals. Little is known about the feeding habit of the tiger (Panther tigris) outside the tiger reserves. We collected data on food habits of tigers in Dabka Watershed Area (DWA) of Kumaon Himalaya, Uttarakhand, India. Scats analysis was used to determine the food habit of the tiger. A total of 55 scats were collected and analyzed. The overall diet diversity of tigers in DWA (Shannon-Wiener Index H') was 2.923. Scat contents were analyzed in terms of both the relative frequency of occurrence and the relative prey biomass consumed. A minimum of 13 different prey species were identified, of which chital constituted 30.91% of the diet followed by sambar (21.82%). The wild prey constituted 77.36% of the diet, whereas domestic prey constituted 23.64% of the diet. Prey selectivity analysis indicated that selective predation by tigers was directed towards prey species with large body mass. This highlights the importance of adjacent forests around protected areas that helps large carnivores to disperse spatially and temporally during resource crunch, competition, and dispersal. [ABSTRACT FROM AUTHOR]

Studies on the diet composition of bird species provide valuable insights on their habitat use, trophic interactions and prey selection. Prey abundance can drive movements of raptors in their wintering grounds. But such links have been difficult to establish due to the lack of dietary information for most raptor species. Estimating the wintering diet of raptors is a challenge that requires extensive fieldwork across a large geographical area which is often not possible. The methods used in breeding sites such as nest observations are not available in the non-breeding regions. Recently, several studies have demonstrated the use of web-sourced photographs as a tool for understanding the diet of raptors and also the need for combining multiple approaches to get a comprehensive overview of diet. In this study, we use a novel approach by using web-sourced photographs and pellets to estimate the variations in the diet of Montagu's Harrier Circus pygargus, a species in decline, across its wintering range in India. A total of 232 photographs and 391 pellets collected across western India, Deccan and south India during autumn, winter and early spring seasons were analysed. About 53% of photographs and 71% of pellets contained orthopterans, forming the major component of the harrier's diet. The proportion of reptiles, eggs and birds in the diet were similar across both methods. Presence of other insects in the diet was better estimated by photographs (23%) than pellets (8%) while rodent presence was higher in pellets (17%) than photographs (4%). Pellet analysis and photographs showed similar variation in diet across seasons while only pellets showed variation in diet across regions. Photographs also showed that there is significant variation in diet between the sexes of the species, with higher presence of insects and reptiles in the diet of males than females. Our results suggest that a combination of photographs and pellet analysis provide better estimates of wintering diet of Montagu's Harriers. [ABSTRACT FROM AUTHOR]

This article compares various disciplines to show that the concept of predation is associated with notions that are relevant to the economic domain, such as equilibrium, risks, and hidden societal costs. We review the economic literature in some of the top-ranked economic journals on the subject of predation dating back a hundred years. Our analysis shows that economic academics use the concept of predation differently and at times in an erroneous or overly narrow way. This article argues that economic theory must take into consideration predator-prey dynamics during one-on-one interactions between sellers acting as predators of sorts by using information asymmetry to their advantage, and their prey in the form of naïve clients, who undergo economic/financial harm as a result. We propose that a better understanding of the concept of predation may enhance the drafting of government policies. To our knowledge, this is the first article that examines the concept of predation in its original sense across the literature and across decades and that demonstrates its relevance in economic theory. [ABSTRACT FROM AUTHOR]

The Scythians, nomads who roamed between the Pontic steppe and the Altai mountains throughout the 7th to 3rd centuries BC, are well known for their iconic animal style art. Composed of vivid stylised representations of animals, but depicting few humans, this art poses a challenge to interpretation. The Scythians left no written sources to give insight on their beliefs, and scholars have often had to make recourse to non-nomadic Greek and Persian sources, but these sources are not without their issues. In this paper I will propose the anthropological concept of cosmological perspectivism, first developed by Eduardo Viveiros de Castro, as a new way through which to think about and develop a better understanding of what Scythians thought and believed about the animal subjects of their art. I will explore the importance of predators, prey, and the contest between them in both perspectivism and Scythian art, and demonstrate how perspectivism might help us approach these works. Turning to a number of objects that combine Hellenistic and Scythian styles, I will examine how they support a perspectivist reading and explore what they can tell us about how the Scythians thought about animals and how they used them to represent human stories. [ABSTRACT FROM AUTHOR]

In this paper, I review the effects of the diet of ladybirds on chemical defence in this group of beetles. The tendency to reflex bleed and the diversity of autogenously produced alkaloids in different taxa may be evolutionarily related to diet and the likelihood of food limitation. Within predatory species, both prey quantity and quality have been shown to affect autogenous alkaloid production. A few ladybird predators have been suggested to adaptively sequester toxins from their prey for their own defence. However, in most cases the evidence for this is limited, with questions remaining about the costs of accumulated toxins and their defensive value, especially over and above pre-existing autogenous defence. Only a single case (Hyperaspis trifurcata and carminic acid) is well supported. In the case of ladybird predators acquiring pyrrolizidine alkaloids from the ragwort aphid Aphis jacobaeae, I show that toxin accumulation is not very costly and the aphid is even an essential prey for some ladybirds. However, the defensive value of pyrrolizidine alkaloids to ladybirds is still not investigated. Intraspecific diversity in autogenous chemical defence could be reinforced further if chemical protection is conferred via sequestered chemicals. However, to understand better how ladybird diet and chemical defence interact, we need a clearer grasp of how the defensive chemicals of food are resisted or tolerated by ladybirds. [ABSTRACT FROM AUTHOR]

In the French Mediterranean plain, the northern extreme of its native range, the Iberian gray shrike, Lanius meridionalis, predominantly feeds on arthropods. Its type of loral plumage plays a key role in protecting its eyes while transporting large prey. The aims are to understand the role played by feathers in protecting the animal from various types of defensive prey. I combine an inspection of large insect prey types found on larders with a review of bird specimens found in museum collections to examine the morphometric characteristics of rictal feathers and culmen. In addition, precision photographs are used to observe the posture of the plumage in natura. I could identify four categories of protective feathers: clustered bristles, semi‐bristles, semi‐plumes distributed in the loral area, and semi‐plumes above the eyes. My results suggest that the Iberian gray shrike has a complex structure of loral feathers, specific to its foraging activity and prey types. The presence of these rictal bristles is probably a protection against the movements of larger prey items, which might damage loral zone of Lanius meridionalis. [ABSTRACT FROM AUTHOR]

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The behavioral mechanisms by which predators encounter prey are poorly resolved. In particular, the extent to which predators engage in active search for prey versus incidentally encountering them has not been well studied in many systems and particularly not for neonate prey during the birth pulse. Parturition of many large herbivores occurs during a short and predictable temporal window in which young are highly vulnerable to predation. Our study aims to determine how a suite of carnivores responds to the seasonal pulse of newborn ungulates using contemporaneous global positioning system (GPS) locations of four species of predators and two species of prey. We used step‐selection functions to assess whether coyotes, cougars, black bears, and bobcats encountered parturient adult female ungulates more often than expected by chance in a low‐density population of mule deer and a high‐density population of elk. We then assessed whether the carnivore species that encountered parturient prey more often than expected by chance did so by shifting their habitat use toward areas with a high probability of encountering neonates. None of the four carnivore species encountered GPS‐collared parturient mule deer more often than expected by chance. By contrast, we determined that cougar and male bear movements positioned them in the proximity of GPS‐collared parturient elk more often than expected by chance which may provide evidence of searching behavior. Although both male bears and cougars exhibited behavior consistent with active search for neonates, only male bears used elk parturition habitat in a way that dynamically tracked the phenology of the elk birth pulse suggesting that maximizing encounters with juvenile elk was a motivation when selecting resources. Our results suggest that there is high interspecific and intersexual variability in foraging strategies among large mammalian predators and their prey. [ABSTRACT FROM AUTHOR]

There is an increasing emphasis in conservation strategies for large carnivores on facilitating their coexistence with humans. Justification for coexistence strategies should be based on a quantitative assessment of currently remaining large carnivores in human‐dominated landscapes. An essential part of a carnivore's coexistence strategy has to rely on its prey. In this research, we studied snow leopards Panthera uncia whose habitat mainly comprises human‐dominated, unprotected areas, to understand how a large carnivore and its primary prey, the bharal Pseudois nayaur, could coexist with human land use activities in a large proportion of its range. Using a combination of livestock census, camera trapping and wildlife surveys, across a broad gradient of livestock grazing intensity in a 363 000 km2 landscape on the Tibetan Plateau, we found no evidence of livestock grazing impacts on snow leopard habitat use, bharal density and spatial distribution, even though livestock density was 13 times higher than bharal density. Bharal were found to prefer utilizing more rugged habitats at higher elevations with lower grass forage conditions, whereas livestock dominated in flat valleys at lower elevations with higher productivity, especially during the resource‐scarce season. These findings suggest that the spatial niche separation between bharal and livestock, together with snow leopards' specialized bharal diet, minimized conflicts and allowed snow leopards and bharal to coexist in landscapes dominated by livestock grazing. In recent years, reduced hunting and nomadic herder's lifestyle changes towards permanent residence may have further reinforced this spatial separation. Our results indicated that, for developing conservation strategies for large carnivores, the niche of their prey in relation to human land‐use is a key variable that needs to be evaluated. [ABSTRACT FROM AUTHOR]

The microbial community associated with animals (microbiome) is essential for development, physiology, and health of host organisms. A critical step to understand the assembly of microbiomes is to determine how effectively bacteria colonize and establish within the host. Bacteria commonly colonize hosts through vertical transmission, passively from the environment, or through food consumption. Using the prey feeding method (PFM), we test transmittance of Bacillus velezensis, Pseudoalteromonas spiralis , and Vibrio alginolyticus to Nematostella vectensis using two prey, Artemia salina and Brachionus plicatilis. We compare PFM to a solution uptake method (SUM) to quantify the concentration of bacteria in these host organisms, with plate counts. Larvae had a similar uptake with SUM at 6 h but had greater concentrations at 48 h versus PFM. Juveniles acquired similar concentrations at 6 h for SUM and PFM using B. plicatilis and A. salina. At 2 days, the quantity of bacteria vectored from PFM increased. After 7 days the CFUs decreased 2-fold with B. plicatilis and A. salina relative to the 2-day concentrations, and further decreased after 14 days. Therefore, prey-mediated methods provide greater microbe transplantation than SUM after 24 h, supporting this approach as a more successful inoculation method of individual bacterial species. [ABSTRACT FROM AUTHOR]