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The Coyote (Canis latrans) is one of the most studied species in North America with at least 445 papers on its diet alone. While this research has yielded excellent reviews of what coyotes eat, it has been inadequate to draw deeper conclusions because no synthesis to date has considered prey availability. We accounted for prey availability by investigating the prey selection of coyotes across its distribution using the traditional Jacobs' index method, as well as the new iterative preference averaging (IPA) method on scats and biomass. We found that coyotes selected for Dall's Sheep (Ovis dalli), White-tailed Deer (Odocoileus virginianus), Eastern Cottontail Rabbit (Sylvilagus floridanus), and California Vole (Microtus californicus), which yielded a predator-to-preferred prey mass ratio of 1:2. We also found that coyotes avoided preying on other small mammals, including carnivorans and arboreal species. There was strong concordance between the traditional and IPA method on scats, but this pattern was weakened when biomass was considered. General linear models revealed that coyotes preferred to prey upon larger species that were riskier to hunt, reflecting their ability to hunt in groups, and were least likely to hunt solitary species. Coyotes increasingly selected Mule Deer (O. hemionus) and Snowshoe Hare (Lepus americanus) at higher latitudes, whereas Black-tailed Jackrabbit (L. californicus) were increasingly selected toward the tropics. Mule Deer were increasingly selected at higher coyote densities, while Black-tailed Jackrabbit were increasingly avoided at higher coyote densities. Coyote predation could constrain the realized niche of prey species at the distributional limits of the predator through their increased efficiency of predation reflected in increased prey selection values. These results are integral to improved understandings of Coyote ecology and can inform predictive analyses allowing for spatial variation, which ultimately will lead to better understandings about the ecological role of the coyote across different ecosystems. [ABSTRACT FROM AUTHOR]

Predators can induce behavioral changes in prey that influence vigilance, grouping patterns, and space use, and these can ultimately affect prey demography and trophic interactions. Consequently, prey must respond to the risk of predation, but little is known about the features that drive the spatial responses of prey species to predators. We tested what factors affected the proximity of prey to the lions reintroduced to Addo Elephant National Park, South Africa. We also tested whether prey species that are preferentially killed by lions revealed greater responsiveness than those that are not, and whether prey respond to predator behavioral states and hunger. From 1588 observations of potential prey locations in relation to lions under varying wind directions, lion behaviors, and hunger states throughout the day and night, we found no evidence of wind‐driven odor responses affecting prey proximity to lions. Prey species that were not preferentially preyed upon by lions occurred closer to lions than those species that lions prefer to hunt. Prey were closer to lions performing noisy behaviors compared to those performing quiet behaviors. Prey were more likely to be closer to covertly behaving lions and further from stationary lions. Our results, compared to the published literature and accepted dogma of the primacy of odor in predator detection, suggest large vertebrate prey responses to predators in intact, multi‐species assemblages are context dependent. [ABSTRACT FROM AUTHOR]

We studied diet and prey preferences of the Eurasian lynx (Lynx lynx) inhabiting south-east Poland, based on kills found during GPS-GSM telemetry and opportunistic winter tracking. Among 64 lynx kills were roe deer (Capreolus capreolus) (91%), red deer (Cervus elaphus) (3%) and brown hare (Lepus europaeus) (6%). From the ungulate community, lynx selected roe deer (D = 0.845) and avoided all other ungulates. We recorded one case of surplus and two cases of parallel killing. Lynx visited the same killed roe deer on average for 2.3 days, and for up to six days when surplus or parallel killing occurred. High numbers of the roe deer in south-east Poland supports the persistence of the lynx, but we urge managers to take under consideration food requirements of the lynx when planning game management. [ABSTRACT FROM AUTHOR]

We studied diet and prey preferences of the Eurasian lynx (Lynx lynx) inhabiting south-east Poland, based on kills found during GPS-GSM telemetry and opportunistic winter tracking. Among 64 lynx kills were roe deer (Capreolus capreolus) (91%), red deer (Cervus elaphus) (3%) and brown hare (Lepus europaeus) (6%). From the ungulate community, lynx selected roe deer (D = 0.845) and avoided all other ungulates. We recorded one case of surplus and two cases of parallel killing. Lynx visited the same killed roe deer on average for 2.3 days, and for up to six days when surplus or parallel killing occurred. High numbers of the roe deer in south-east Poland supports the persistence of the lynx, but we urge managers to take under consideration food requirements of the lynx when planning game management. [ABSTRACT FROM AUTHOR]

Polymorphic diversity, such as elytra patterns of insects, is regarded as an external phenotypic characteristic driven by both genetics and environmental pleiotropy. The multicolored Asian ladybird, Harmonia axyridis (Coleoptera: Coccinellidae), both an efficient natural enemy of herbivores and an invasive species with a worldwide distribution, shows a multitude of elytral patterns and strong environmental adaptability. Some studies have documented differences of ecological adaptability among H. axyridis morphotypes, but none compared their predatory performance under differing environmental conditions, to further understand the evolutionary significance of elytral pattern diversity. We evaluated predation (number of prey consumed per time unit) on three different herbivores by melanic/succinic and male/female adults of H. axyridis, under different temperatures (10, 15, 20, 25, 30, 35°C). and photoperiods (4:20, 8:16, 12:12, 16:8, 20:4). We found significant differences in prey consumed by the predator between gender and polymorphic types, including under comparable environment parameters. Furthermore, there were also significant differences in predation when temperature and photoperiod regimes varied. Our results hinted a high plasticity in prey consumption relative to polymorphic type and gender in H. axyridis. These findings could be informative for developing further biological control programs relying on H. axyridis, notably for optimizing the effectiveness of predator releases according to polymorph to be used and environment targeted. [ABSTRACT FROM AUTHOR]

Intraspecific variation in key traits of widespread species can be hard to predict, if populations have been very little studied in most of the distribution range. Asian populations of the Eurasian lynx (Lynx lynx), one of the most widespread felids worldwide, are such a case in point. We investigated the diet of Eurasian lynx from feces collected Mediterranean, mixed forest‐steppe, and subalpine ecosystems of Turkey. We studied prey preferences and functional responses using prey densities obtained from Random Encounter Modelling. Our analysis revealed that the main prey was brown hare (Lepus europaeus) in all three areas (78%–99% of biomass consumed) and lynx showed a strong preference for brown hare (Chesson's selectivity index, α = 0.90–0.99). Cannibalism contributed at least 5% in two study areas. The type II functional response of lynx populations in Turkey was similar to the Canada lynx (Lynx canadensis) and daily food intake in grams per lynx matched that of Canada lynx and Iberian lynx (Lynx pardinus), both lagomorph specialists, rather than those of Eurasian lynx from Europe. Therefore, lynx in Turkey may be better described as a lagomorph specialist even though it coexists with ungulate prey. We suggest that ungulate‐based foraging ecology of Eurasian lynx in Europe may be a recent adjustment to the availability of high densities of ungulates and cannot be representative for other regions like Turkey. The status of lagomorphs should become an essential component of conservation activities targeted at Eurasian lynx or when using this species as a flagship species for landscape preservation. This research is from very different ecosystems in Asian Turkey and showed that the Eurasian lynx is lagomorph specialist, far more variable in diet, prey preferences and functional responses than might be expected. This study documents a far greater amount of cannibalism than had previously been thought possible amongst cat species. The comparative perspective across all similar‐sized lynx species and populations reveals that there is a need for a major readjustment of "European" perspective of what Eurasian lynx are about. [ABSTRACT FROM AUTHOR]

Prey preferences and feeding-related behaviour of two Central European speci es of Scydmaeninae, Cephennium majus and Cephennium ruthenum, were studied under laboratory conditions. These beetles capture mites by using unique premental suckers and then penetrate the prey's cuticle by slowly scraping a hole with their short mandibles. A mechanism for interlocking the sides of beetle's labrum with closed mandibles was discovered, confirming that the predator's mouthparts can be tightly sealed around the penetration site, which enables them to inject digestive juices and ingest liquefied tissues of the prey through a tiny hole. The feeding behaviour of Cephennium can be divided into three phases: (i) attack and stabilization of the attachment site (4-5 min); (ii) penetration of the mite's cuticle (ca. 40 min); and (iii) feeding (several hours). Results of prey choice experiments using over 1200 identified mites belonging to 23 families of Oribatida (55 species) and 6 families of Mesostigmata (9 species) demonstrated that C. majus feeds mostly on members of the Oribatida: Phthiracaridae (72.07% of offered phthiracarids, 26.7% of eaten oribatids), Ceratozetidae (100% and 24.7%, respectively), Achipteriidae (95.59% and 21.7%) and Liacaridae (61.97% and 14.7%); C. ruthenum fed mostly on Phthiracaridae (48.68% and 41.6%), Achipteriidae (37.29% and 24.7%) and Ceratozetidae (82.35% and 15.7%). The entire feeding behaviour from attack to completion of feeding in C. majus took 2.00-10.37 h when eating oribatids ranging in body length from 0.34 to 0.70 mm. Interestingly, it took much longer for C. majus to kill ptyctimous Phthiracarus, body length 0.39-0.45 mm, than any non-ptyctimous oribatids, including the much larger (0.64-0.70 mm) Chamobates subglobulus. The two species of Cephennium differed greatly in their preference for eating Liacaridae due to their large size, which was acceptable for the larger C. majus, but at the edge of acceptability for the smaller C. ruthenum. Comparative analysis of mites eaten by all the studied species of Scydmaeninae resulted in a preliminary identification of morphological types of Oribatida acceptable and non-acceptable for ant-like stone beetles. The most readily accepted oribatids are typically subglobose, with a rigid cuticle, smooth or only shallowly and finely microreticulate surface of the idiosoma, covered with sparse setae or nearly asetose and with short or moderately long legs. In contrast, rejected mites have one or a combination of the following characters: body flattened, not subglobose; the cuticle relatively soft; idiosoma deeply sculptured or coarsely reticulate; legs long and spiny; the body covered with a protective crust of soil particles. Crotonioidea, Carabodidae, Damaeidae and Hermanniellidae seem to be particularly well-protected against scydmaenine predators. [ABSTRACT FROM AUTHOR]

The recent increase in temperature and freshwater runoff in the Arctic will influence the functioning of the plankton ecosystem and hence the life of the fish larvae residing in these areas. Here, we studied the strength of physical–biological linkages and the adaptability of individual larval fish species to changing hydrographical and feeding environments in a sub-Arctic area in Greenland. The study was carried out along a transect covering a wide range of physical conditions from the deep ocean to the icecap in the Godthåbsfjord on the south-western Greenland coast. Along the transect, we identified a series of distinct zooplankton and larval fish assemblages which showed linkage to water mass characteristics, to the presence of frontal structures and to availability of preferred prey. Spawning site location and water circulation was also likely to influence distributional patterns of the individual larval fish species. Larvae were feeding on a variety of prey taxa and sizes; some larval species were generalists, while others were more specialized or fed on alternative prey taxa. Differences in feeding strategies might have the consequence that the species will be differently affected by changes in the plankton community. Accordingly, fish larvae that have a greater feeding flexibility and that are more adaptable to environmental variability may cope better with climate related changes. [ABSTRACT FROM PUBLISHER]

How predators impact on prey population dynamics is still an unsolved issue for most wild predator-prey communities. When considering vertebrates, important concerns constrain a comprehensive understanding of the functioning of predator-prey relationships worldwide; e.g. studies simultaneously quantifying 'functional' and 'numerical responses' (i.e., the 'total response') are rare. The functional, the numerical, and the resulting total response (i.e., how the predator per capita intake, the population of predators and the total of prey eaten by the total predators vary with prey densities) are fundamental as they reveal the predator's ability to regulate prey population dynamics. Here, we used a multi-spatio-temporal scale approach to simultaneously explore the functional and numerical responses of a territorial predator (Bonelli's eagle Hieraaetus fasciatus) to its two main prey species (the rabbit Oryctolagus cuniculus and the red-legged partridge Alectoris rufa) during the breeding period in a Mediterranean system of south Spain. Bonelli's eagle responded functionally, but not numerically, to rabbit/partridge density changes. Type II, non-regulatory, functional responses (typical of specialist predators) offered the best fitting models for both prey. In the absence of a numerical response, Bonelli's eagle role as a regulating factor of rabbit and partridge populations seems to be weak in our study area. Simple (prey density-dependent) functional response models may well describe the short-term variation in a territorial predator's consumption rate in complex ecosystems. [ABSTRACT FROM AUTHOR]

Africa supports Earth's richest assemblage of large predators, which coexist despite a high degree of dietary overlap. This study used reviews of the prey preferences of African wild dog Lycaon pictus, cheetah Acinonyx jubatus, leopard Panthera pardus, lion P. leo, and spotted hyaena Crocuta crocuta to investigate the degree of dietary overlap and dietary niche breadth amongst the guild. Wild dogs and cheetahs exhibited the greatest dietary overlap and smallest dietary niche breadth, while lions exhibited the least dietary overlap and, with leopards, had the broadest dietary niche breadth. Increased extinction risk within the guild was related to lower dietary niche breadth. The behavioural and morphological specializations of the two most threatened predators (wild dogs and cheetahs) limit the prey available to them, and increases the potential for dietary competition. Conversely, the large body mass and group hunting strategy of lions and the predatory flexibility of leopards and spotted hyaenas minimizes the effects of dietary overlap, assuring a more secure status. This study intimates reasons why cheetahs and African wild dogs are naturally less common than lions, leopards and spotted hyaenas in unmodified landscapes. The methods used can be applied to all adequately studied faunal guilds and could highlight previously undetected competitors. [ABSTRACT FROM AUTHOR]

Shifting prey selection has been identified as a mechanism potentially regulating predator-prey interactions, but it may also lead to different outcomes, especially in more complex systems with multiple prey species available. We assessed changing prey selection by lions, the major predator for 12 large herbivore species in South Africa's Kruger National Park. The database was provided by records of found carcasses ascribed to kills by lions assembled over 70 years, coupled with counts of changing prey abundance extending over 30 years. Wildebeest and zebra constituted the most favored prey species during the early portion of the study period, while selection for buffalo rose in the south of the park after a severe drought increased their vulnerability. Rainfall had a negative influence on the proportional representation of buffalo in lion kills, but wildebeest and zebra appeared less susceptible to being killed under conditions of low rainfall. Selection by lions for alternative prey species, including giraffe, kudu, waterbuck, and warthog, was influenced by the changing relative abundance and vulnerability of the three principal prey species. Simultaneous declines in the abundance of rarer antelope species were associated with a sharp increase in selection for these species at a time when all three principal prey species were less available. Hence shifting prey selection by lions affected the dynamics of herbivore populations in different ways: promoting contrasting responses by principal prey species to rainfall variation, while apparently being the main cause of sharp declines by alternative prey species under certain conditions. Accordingly, adaptive responses by predators, to both the changing relative abundance of the principal prey species, and other conditions affecting the relative vulnerability of various species, should be taken into account to understand the interactive dynamics of multispecies predator-prey webs. [ABSTRACT FROM AUTHOR]

1. Size relationships are central in structuring trophic linkages within food webs, leading to suggestions that the dietary niche of smaller carnivores is nested within that of larger species. However, past analyses have not taken into account the differing selection shown by carnivores for specific size ranges of prey, nor the extent to which the greater carcass mass of larger prey outweighs the greater numerical representation of smaller prey species in the predator diet. Furthermore, the top-down impact that predation has on prey abundance cannot be assessed simply in terms of the number of predator species involved. 2. Records of found carcasses and cause of death assembled over 46 years in the Kruger National Park, South Africa, corrected for under-recording of smaller species, enabled a definitive assessment of size relationships between large mammalian carnivores and their ungulate prey. Five carnivore species were considered, including lion ( Panthera leo), leopard ( Panthera pardus), cheetah ( Acinonyx jubatus), African wild dog ( Lycaon pictus) and spotted hyena ( Crocuta crocuta), and 22 herbivore prey species larger than 10 kg in adult body mass. 3. These carnivores selectively favoured prey species approximately half to twice their mass, within a total prey size range from an order of magnitude below to an order of magnitude above the body mass of the predator. The three smallest carnivores, i.e. leopard, cheetah and wild dog, showed high similarity in prey species favoured. Despite overlap in prey size range, each carnivore showed a distinct dietary preference. 4. Almost all mortality was through the agency of a predator for ungulate species up to the size of a giraffe (800–1200 kg). Ungulates larger than twice the mass of the predator contributed substantially to the dietary intake of lions, despite the low proportional mortality inflicted by predation on these species. Only for megaherbivores substantially exceeding 1000 kg in adult body mass did predation become a negligible cause of mortality. 5. Hence, the relative size of predators and prey had a pervasive structuring influence on biomass fluxes within this large-mammal food web. Nevertheless, the large carnivore assemblage was dominated overwhelmingly by the largest predator, which contributed the major share of animals killed across a wide size range. [ABSTRACT FROM AUTHOR]

1. Caves are often assumed to be predator-free environments for cave fishes. This has been proposed to be a potential benefit of colonising these otherwise harsh environments. In order to test this hypothesis, the predator–prey interaction of a belostomatid (predator) and a cave fish (prey) occurring in the Cueva del Azufre (Tabasco, Mexico) was investigated with two separate experiments. 2. In one experiment, individual Belostoma were given a chance to prey on a cave fish, the cave form of the Atlantic molly ( Poecilia mexicana), to estimate feeding rates and size-specific prey preferences of the predator. In the other experiment, population density of Belostoma was estimated using a mark–recapture analysis in one of the cave chambers. 3. Belostomatids were found to heavily prey on cave mollies and to exhibit a prey preference for large fish. The mark–recapture analysis revealed a high population density of the heteropterans in the cave. 4. The absence of predators in caves is not a general habitat feature for cave fishes. None the less predation regimes differ strikingly between epigean and hypogean habitats. The prey preference of Belostoma indicates that cave-dwelling P. mexicana experience size-specific predation pressure comparable with surface populations, which may have implications for life-history evolution in this cave fish. [ABSTRACT FROM AUTHOR]

Simple Summary: Neogobius melanostomus is a highly invasive fish that has colonized most major European rivers and is dispersing into their tributaries. Its foraging behaviour does not show particular prey preferences, which makes predicting its interactions with endangered members of the macrozoobenthic community in tributaries a challenge. We observed the interaction of N. melanostomus and crayfish juvenile or A. aquaticus in single- and multiple-prey systems to better predict its ecological impact. The results suggest an impact of N. melanostomus on crayfish similar to that on A. aquaticus, potentially making it a threat to crayfish population stability. Destabilization of a keystone species such as crayfish in river tributaries may lead to a trophic cascade in the ecosystem with irreversible consequences. Despite the spread of round goby Neogobius melanostomus into freshwater streams, there is a lack of information with respect to its effect on macroinvertebrate communities, especially crustaceans. We studied foraging efficiency of N. melanostomus on Procambarus virginalis and Asellus aquaticus, using a functional response (FR) approach. Stocking density of the prey species was manipulated to determine its effect on consumer utilization, with prey offered separately or combined at 1:1, 3:1, and 1:3 at each tested density. For both prey species, N. melanostomus exhibited type II FR, occasionally with a high proportion of non-consumptive mortality. Procambarus virginalis suffered a significantly higher attack rate compared to A. aquaticus. Neogobius melanostomus killed significantly more of the most prevalent prey, regardless of species. In trials with prey species of equal proportions, a difference in the number of each species killed was observed only at the highest density, at which P. virginalis was preferred. Neogobius melanostomus may be an important driver of population dynamics of prey species in the wild. The non-selective prey consumption makes N. melanostomus a potential threat to macrozoobenthic communities of river tributaries. [ABSTRACT FROM AUTHOR]

Three different types of prey-preference tests were carried out using Dysdera crocata, a spider frequently described as a specialist predator of woodlice. None of these tests provided evidence that Dysdera crocata prefers woodlice over a variety of insect prey (house flies, beetle larvae, mirid bugs, moths and crickets). We also ran prey preference tests with two species of woodlice that differ in their behavioural and chemical defences, and there was no evidence of preference for either of these species over the other. The broader question of whether D. crocata is a specialized predator in any respect is discussed. [ABSTRACT FROM PUBLISHER]

Previous research using computer animation and lures made from dead prey has demonstrated that the East African salticid Evarcha culicivora Wesolowska & Jackson (Araneae: Salticidae) feeds indirectly on vertebrate blood by actively choosing blood-carrying female mosquitoes as prey, and also that it singles out mosquitoes of the genus Anopheles (Diptera: Culicidae) by preference. Here, we demonstrate that E. culicivora's preference is expressed when the species is tested with living prey and that it is unique to E. culicivora. As an alternative hypothesis, we considered the possibility that the preference for blood-fed female anopheline mosquitoes might be widespread in East African salticids. When live-prey choice tests were carried out in 19 additional species, there were no instances in which blood-carrying mosquitoes were chosen significantly more often than other prey. Combined with the findings of previous work, these results suggest that it is possible that specialized predators play a role in the biological control of disease vectors. [ABSTRACT FROM AUTHOR]