Prey Categories Research Articles

Relationship between Diet and Microhabitat Use of Red-legged Salamanders (Plethodon shermani) in Southwestern North Carolina

The selection of a foraging habitat may be driven by food availability or by the cost associated with the use of that habitat. This basic tradeoff can lead individuals in the same population to occupy different habitats in response to perceived risk levels. In the southeastern United States, plethodontid salamanders are often observed climbing vegetation, which represents a potential foraging habitat. We examined whether diet composition of the Red-legged Salamander, Plethodon shermani, differed between salamanders found on vegetation and on the ground surface. Contrary to the results of a previous study, we found that the overall number and mass of prey items did not differ between salamanders in these two microhabitats. Furthermore, we found no evidence that the relative use of different prey categories varied in relation to a salamander's selected microhabitat. Although salamanders of all body sizes had consumed a diverse range of prey items, we found evidence of an ontogenetic shift in prey utilizatio...

Feeding Habits, Daily Ration, and Potential Predatory Impact of Mature Female Spiny Dogfish in North Carolina Coastal Waters

AbstractThough the feeding habits of Spiny Dogfish Squalus acanthias in the northwestern Atlantic Ocean have received much attention due to their potential interactions with fisheries, currently no estimate of daily ration specific to the northwestern Atlantic population has been determined. To assess the diet of these sharks in the southern extent of their range, stomach contents were collected from 255 Spiny Dogfish captured by bottom trawl in nearshore North Carolina waters; 244 were mature females. Prey items were identified and percent index of relative importance was calculated for each prey taxon and category. To determine daily ration, 15 mature female Spiny Dogfish were captured by hook and line in North Carolina waters and kept in captivity for 2 weeks of feeding trials. Dogfish were fed preweighed frozen Atlantic Menhaden Brevoortia tryannus and allowed to digest their prey for predetermined periods, after which remaining food was removed using stomach‐tube gastric lavage. Gastric evacuation rates determined by feeding trials were combined with data collected from sampling stomach contents to determine the daily ration and the amount of important prey taxa consumed during the Spiny Dogfish overwintering period. Teleost fishes were the dominant prey category, and Atlantic Menhaden and Bay Anchovy Anchoa mitchilli were the most important prey taxa. Daily ration estimates ranged from 0.26% to 0.56% of the shark's body weight per day. Spiny Dogfish potentially consumed an equivalent of 1.55–3.33% of the Atlantic Menhaden stock while overwintering in North Carolina waters.Received July 23, 2013; accepted March 5, 2014

Conservation related conflicts in nest-site selection of the Eurasian Kestrel (Falco tinnunculus) and the distribution of its avian prey

The urban space is a permanently changing ecosystem, suffering from decreasing biodiversity, but also providing new anthropogenic habitats for some adaptable species. The Eurasian kestrel (Falco tinnunculus) is such an adaptable species, whose dense urban populations are ethologically different from rural populations in Europe. Several studies have indicated that urban kestrels increasingly prey on birds; this study even indicated avian prey as the main prey category in the inner-city habitat. We analyzed the selection of habitat and building structure parameters while controlling for differences in their availability in Vienna, Austria, a city of 1.7 million inhabitants. We then connected the nest-site selection of urban kestrels to their diet choice and annual reproduction rate. Our results indicated a trade-off between higher nest-site availability in the center and longer distances to larger open green space as optimal foraging ground. Between 2010 and 2012, a preference for breeding in close vicinity to green backyards was linked to earlier clutch dates, higher hatching rates and larger fledged brood sizes, but the overall productivity per nest still remained low in the center compared to the suburban area. In a survey of avian prey species, we found comparable abundances of prey-sized bird species in green backyards, parks and surrounding suburban areas. We thus hypothesize that kestrels use the immediate nest-surroundings to hunt, but are not as efficient in hunting avian prey as they are in hunting voles. Changes in modern city architecture and renovation of historical buildings pose conservation related threats to urban predators and prey.

Multi-scale effects of nestling diet on breeding performance in a terrestrial top predator inferred from stable isotope analysis.

Inter-individual diet variation within populations is likely to have important ecological and evolutionary implications. The diet-fitness relationships at the individual level and the emerging population processes are, however, poorly understood for most avian predators inhabiting complex terrestrial ecosystems. In this study, we use an isotopic approach to assess the trophic ecology of nestlings in a long-lived raptor, the Bonelli’s eagle Aquila fasciata, and investigate whether nestling dietary breath and main prey consumption can affect the species’ reproductive performance at two spatial scales: territories within populations and populations over a large geographic area. At the territory level, those breeding pairs whose nestlings consumed similar diets to the overall population (i.e. moderate consumption of preferred prey, but complemented by alternative prey categories) or those disproportionally consuming preferred prey were more likely to fledge two chicks. An increase in the diet diversity, however, related negatively with productivity. The age and replacements of breeding pair members had also an influence on productivity, with more fledglings associated to adult pairs with few replacements, as expected in long-lived species. At the population level, mean productivity was higher in those population-years with lower dietary breadth and higher diet similarity among territories, which was related to an overall higher consumption of preferred prey. Thus, we revealed a correspondence in diet-fitness relationships at two spatial scales: territories and populations. We suggest that stable isotope analyses may be a powerful tool to monitor the diet of terrestrial avian predators on large spatio-temporal scales, which could serve to detect potential changes in the availability of those prey on which predators depend for breeding. We encourage ecologists and evolutionary and conservation biologists concerned with the multi-scale fitness consequences of inter-individual variation in resource use to employ similar stable isotope-based approaches, which can be successfully applied to complex ecosystems such as the Mediterranean.

Diet and Microhabitat Use ofBolitoglossa cf. pandi(Caudata: Plethodontidae) from the Cordillera Oriental of Colombia

Bolitoglossa cf. pandi is a terrestrial salamander that inhabits a fragment of secondary forest located in the Cordillera Oriental of the Colombian Andes. Few aspects of its biology are known. Here we studied its diet, microhabitat use, population structure, and arthropod richness at the study site during rainy and dry seasons. We also recorded perch height, substrate type, and time of capture. Encounter rate for Bolitoglossa cf. pandi was very high during rainy months and low during dry season. Juveniles were more abundant than adults. To obtain consumed items we used the stomach-flushing technique; the contents of 87 stomachs were analyzed and 1324 prey items were identified and grouped in 20 prey categories. Diet was represented by a great variety of arthropods and the most important prey categories, according to the index of relative importance (IRI), were Acari, Coleoptera, and Formicidae. No differences were found in diet between sexes; however, ontogenetic variation was found: there was a shift in consumption of ants and mites related to ontogeny. Volume of coleopterans and ants in stomachs increased with body size, whereas occurrence of mites varied inversely with body size. Only Acari consumption changed between dry and wet seasons. Bolitoglossa cf. pandi forages on the ground, as well as on herbaceous vegetation; larger individuals were found in the highest perches, usually on leaves. Diet and microhabitat use of this salamander is similar to other species of Bolitoglossa and are affected by local environmental factors, such as prey availability and climate regime, and endogenous factors, such as body size.

Foraging in corallivorous butterflyfish varies with wave exposure

Understanding the foraging patterns of reef fishes is crucial for determining patterns of resource use and the sensitivity of species to environmental change. While changes in prey availability and interspecific competition have been linked to patterns of prey selection, body condition, and survival in coral reef fishes, rarely has the influence of abiotic environmental conditions on foraging been considered. We used underwater digital video to explore how prey availability and wave exposure influence the behavioural time budgets and prey selectivity of four species of obligate coral-feeding butterflyfishes. All four species displayed high selectivity towards live hard corals, both in terms of time invested and frequency of searching and feeding events. However, our novel analysis revealed that such selectivity was sensitive to wave exposure in some species, despite there being no significant differences in the availability of each prey category across exposures. In most cases, these obligate corallivores increased their selectivity towards their most favoured prey types at sites of high wave exposure. This suggests there are costs to foraging under different wave environments that can shape the foraging patterns of butterflyfishes in concert with other conditions such as prey availability, interspecific competition, and territoriality. Given that energy acquisition is crucial to the survival and fitness of fishes, we highlight how such environmental forcing of foraging behaviour may influence the ecological response of species to the ubiquitous and highly variable wave climates of shallow coral reefs.

Food resource exploitation strategies of two reedbed specialist passerines: Reed Parrotbill and Oriental Reed Warbler

We studied the nestling diet of two reedbed specialist passerines, Reed Parrotbill (Paradoxornis heudei) and Oriental Reed Warbler (Acrocephalus orientalis) in a tidal reedbed in the Changjiang River Estuary, China. Reed Parrotbills delivered mainly Homoptera, Diptera, and Leptidoptera to their nestlings, and Oriental Reed Warblers delivered mainly Diptera, Hymenoptera, Araneida, and Lepidoptera to their nestlings. More than 98% of the diet of nestling Reed Parrotbills consisted of wingless items and .97% consisted of concealed items, indicating that Reed Parrotbills are limited in their ability to catch winged prey capable of strong flight and rather they retrieve prey from within reed shoots using their large and strong beaks. About 85% of the diet of nestling Oriental Reed Warblers consisted of winged items and .99% consisted of exposed items, indicating that Oriental Reed Warblers are limited in their ability to retrieve prey from within reed shoots and depend on their flight ability to catch prey capable of flight. Oriental Reed Warblers had significantly more taxonomic categories of prey in their diet, significantly wider diet niche, and significantly higher diversity in nestling diet than Reed Parrotbills. Our study demonstrates that although these two species breed sympatrically in reedbeds as reedbed specialist, Reed Parrotbills and Oriental Reed Warblers use different strategies in their exploitation of food resources. Received 14 May 2013. Accepted 26 October 2013.

The Diet of Eurasian Otters in the Jajrood River System, Iran

Abstract The diet and feeding habits of Eurasian otters (Lutra lutra) were studied by spraint analysis over a one year period on the four sections of the Jajrood River, eastern Tehran. Two methods were used to estimate the proportions of different prey consumed: frequency of occurrence and score-bulk estimate. The number of prey categories in a spraint varied between one and four. Fish, crabs, birds and insects were found in the spraints. Fish is the main prey. Otters mainly eat fish, preferring three species: the chub (Leuciscus cephalus), riffle minnow (Alburnoides bipunctatus) and various barbel (Capoeta spp.) species. The otters' diet differed significantly across four sites positive for otter sign. Seasonal variation was also found: birds were taken more in the cold season and insects in the warm season. The proportion of crab in the diet was almost constant throughout the year. Leuciscus cephalus was the most taken fish species in the cold season and Capoeta spp. in the warm season. Only L. Cephalus...

Stomach contents of cetaceans in the Alboran Sea and Gulf of Cadiz.

Stomach contents of cetaceans in the Alboran Sea and Gulf of Cadiz.

Feeding habits of the sand lizard, Lacerta agilis, from North-Western Italian Alps

The dietary habits of a population of the sand lizard Lacerta agilis were studied in the Alpine valley Stura di Demonte, Northwestern Italy. The faecal contents of 33 adults (16 females and 17 males) and 8 juveniles were analysed. There were negligible sexual differences in terms of trophic diversity and of the overall diet based on taxonomic prey categories. Juveniles had a lower prey diversity value in comparison with females but not with males. There was a positive relationship between the total number of prey items found in individual faecal contents and lizard body size, and this result may explain the more diverse diet of adults in comparison to juveniles. When the adult trophic strategy was analysed by means of the relativized electivity index, that takes into account prey availability, it was observed that the main taxonomic prey groups were eaten according to their proportion in the environment, with the only exception of ants (Formicidae) that were highly avoided by lizards.

Diet of the insectivorous batPipistrellus nathusiiduring autumn migration and summer residence

Migration is widespread among vertebrates, yet bat migration has received little attention and only in the recent decades has a better understanding of it been gained. Migration can cause significant changes in behaviour and physiology, due to increasing energy demands and aerodynamic constraints. Dietary shifts, for example, have been shown to occur in birds before onset of migration. For bats, it is not known if a change in diet occurs during migration, although breeding season-related dietary preference has been documented. It is known that a diet rich in fats and the accumulation of fat deposits do increase the flight range of migratory bats. Some bat species can be regarded as long-distance migrants, covering up to 2000km between summer and winter roosting areas. Pipistrellus nathusii (Vespertilionidae), a European long-distant migrant, travels each year along the Baltic Sea from north-eastern Europe to hibernate in central and southern Europe. This study presents data on the dietary habits of migrating Pipistrellus nathusii compared with those during the breeding season. We analysed faecal samples from bats on fall migration caught at the Ornithological Field Station in Pape, Latvia and from samples collected in North-Latvian summer roosts. We applied both morphological identification and molecular methods, as morphological methods also recognize life stages of prey and can contribute frequency data. The diets of bats on migration and breeding bats were similar, with Diptera and Lepidoptera comprising the major prey categories. However, certain prey groups could be explained by the different hunting habitats exploited during migration vs. summer residence.

Food partitioning among carnivores within feeding guild structure of fishes inhabiting a mudflat ecosystem of Indian Sundarbans

The present study was aimed to determine dietary composition and feeding guild structure of the fishes inhabiting mudflat habitat of Indian Sundarbans. In addition, partitioning of food resources by the fish species belonging to the carnivorous feeding guild was also performed to understand the survival strategies of fish in a mudflat estuarine habitat. Seventeen prey categories were isolated from the stomachs of 31 studied fish species. Overall, five feeding guilds (viz. plankti-benthivore: 12 species, herbivore: one species, detritivore: three species, omnivore: one species and carnivore: 14 species) were identified on the basis of the prey abundance within their stomachs, considering 64 % Bray–Curtis similarity. Among the carnivorous, maximum trophic richness was obtained for Uroconger lepturus followed by Ophichthus apicalis. Teleost and decapods were the main animal prey items preferred by majority of the carnivorous fishes. However, O. apicalis and Terapon jarbua showed their preference toward maximum number of prey categories among carnivores, which was also ratified by the high values for standardized niche breadth presented by them. The maximum degree of interspecific dietary overlap was found between Uropterygius marmoratus and Pseudapocryptes elongatus as both of them were recognized as cranci-piscivore. The lowest was observed between Hyporhamphus limbatus and Coilia neglecta. As food resources are not limiting in the mudflats of Indian Sundarbans, the general patterns of resource partitioning and niche differentiation in resident ecological communities will improve the understanding of the mechanisms underlying species coexistence and community structure.

Assessing the impact of introduced cats on island biodiversity by combining dietary and movement analysis

AbstractPopulations of feral (not owned by humans) and domestic cats Felis catus coexist in most inhabited islands, and they have similar impacts on native species. Feral cats are generally believed to vary their diet according to prey availability; however, no previous studies of diet have tested this hypothesis on insular ecosystems with a limited range of available prey. Because domestic cats kill prey independently of hunger, the spatial extent of their impact on wildlife will be influenced by home‐range size. In this study, we combined dietary information with cat movements to assess the impacts of feral and domestic cats on island biodiversity. We quantified the diet of cats from scat samples collected across one year and tested whether diet varies by season. The abundance of main prey categories was also estimated to document seasonal variation in prey availability for cats. Finally, we tracked domestic cats by global positioning system units in all four seasons to examine whether home‐range patterns varied seasonally. The diet of cats constituted three prey groups (rodents, birds and invertebrates), and the seasonal variation in consumption of each taxon matched the seasonal variation in prey availability, thus supporting the generalist behaviour of cats on oceanic islands. Roaming behaviour varied among individuals and across seasons, but could not be explained by availability of prey. Unconfined cats had larger home‐ranges than confined cats, but most domestic cats strayed <1 km from home. Thus, confinement of domestic cats might reduce the spatial extent of cat impact on native prey populations on oceanic islands.

Comparing pellet and stable isotope analyses of nestling Bonelli's Eagle Aquila fasciata diet

Diet analyses are central to the study of avian trophic ecology, and stable isotope analyses have made an increasing contribution in the last two decades. Few isotopic studies have assessed the diet of raptor species, which are more frequently analysed by conventional diet methods such as pellet analysis. In this study, we compare prey consumption estimates of nestling Bonelli's Eagles Aquila fasciata from conventional pellet analysis (in terms of items and biomass) and stable isotopic mixing models (SIAR) using δ13C, δ15N and δ34S of feathers. The pellet analysis showed that European Rabbits Oryctolagus cuniculus, pigeons (mainly Common Wood Pigeons Columba palumbus and Domestic Pigeons Columba livia dom.), Red‐legged Partridges Alectoris rufa, passerines, Yellow‐legged Gulls Larus michahellis and Eurasian Red Squirrels Sciurus vulgaris were the main prey, so they were selected for diet reconstructions in SIAR. At the population level, mean prey consumption estimates were similar for pellets (both items and biomass) and SIAR. At the territory level, the weighted kappa statistic showed good ordinal scale agreement in main prey consumption between items or biomass and SIAR. Although the intraclass correlation coefficient showed poor method agreement when considering all prey in the same analysis, the intraclass correlation coefficients for each prey category showed significant agreement between pellets and SIAR when estimating the consumption of Rabbits, pigeons and Gulls, with lower agreement for passerines and Squirrels. Lastly, there was poor method agreement for estimates of Partridges. Our results suggest an overall agreement between the pellet analysis and SIAR when estimating nestling Bonelli's Eagle diet at both the population and, to a lesser extent, the territory level, supporting the usefulness of isotopic mixing models when identifying the terrestrial and marine components of raptor diets.

Variaciones estacionales en el tamaño corporal y dieta de la estrella de mar Astropecten marginatus (Paxillosida, Astropectinidae) frente a la costa de Paraná, sur de Brasil

The sea star Astropecten marginatus has a neotropical distribution and is a highly abundant and frequent species in shrimp trawling by-catchin many places along the Brazilian coast. This has caused its threat to extinction and in addition, its bio-ecological aspects are poorly known. Thus, the main objective of this study was to analyze the seasonal variations of population length structure and feeding habits of the sea stars A. marginatus inhabiting off state of Paraná, Southern Brazil. The analyzed specimens were collected in February (summer), April (fall), June (winter) and October (spring) of 2008 from shrimp by-catch trawling. In the laboratory, each individual had its length measured and then weighed on an analytical scale. Afterwards, the stomach contents of 10 individuals of each of two most frequent length classes were seasonally analyzed. The relative frequency and abundance for each prey category was determined and, then combined into an index of alimentary importance. A total of 994 individuals of A. marginatus were collected with length ranging from 7.0 to 56.2mm, but most individuals were in the 20.1-25mm length classes. Individuals larger than 40mm were only collected in the spring while a few recruits (<10mm) were found in fall and winter. The total weight of individuals ranged from 0.1 to 15.3g and the weight-length relationships showed a negative allometric growth (b<2.54). Regarding its food consumption, this sea star explored eleven food items, with cumaceans and mollusks as the most frequent items. High frequency of empty stomach was recorded at fall. Seasonal differences in the amount explored preys and ingested items as well as in the prey composition were also observed. Higher amount of explored prey categories and ingested items were recorded at winter-spring than summer-fall periods. Predominance in prey category changed from gastropods (summer and fall) to cumaceans (winter and spring). The importance of gastropods as main prey category at summer and fall should be carefully considered since it was coincidently observed with high frequency of empty stomach and low amount of ingested items. The observed seasonal differences in feeding behavior pattern were mainly associated to low prey availability and to changes in the sea star feeding rates, and probably reflected in some biological traits such as small body size of the population inhabiting waters off the Paraná coast, Southern Brazil.

Feeding habits ofSchizothorax oconnoriLloyd, 1908 in the Yarlung Zangbo River, Tibet

Seasonal, ontogenetic and sexual feeding habits of Schizothorax oconnori in the Yarlung Zangbo River were studied using percentages by number, weight and index of relative importance (IRI). The Schoener overlap index was applied to compare diets related to season, fish size and sex. The feeding intensity exhibited seasonal trends, with a minimum food intake in summer. Overall, 103 prey taxa belonging to seven prey categories (diatoms, green algae, cyanophytes, other algae, small invertebrates, macroinvertebrates and remains) were identified in 136 guts. Highest feeding diversity and evenness were recorded in summer, while lowest values of both indices occurred in autumn. S. oconnori fed almost exclusively on periphyton. Diatoms were the most important prey in terms of number, weight and IRI, followed by macroinvertebrates; other prey were also occasionally ingested. S. oconnori is a generalized and opportunistic feeder relying upon a wide trophic spectrum, but mainly feeds on diatoms as they are the most prevalent periphyton. There were high diet overlaps among seasons, fish sizes and between sexes. S. oconnori showed no dietary preference for any of the other prey available in the periphyton community.

Seasonal use of ponds as foraging habitat by Eurasian otter with description of an alternative handling technique for common toad predation

Research in freshwater ecology has traditionally focused on water courses or large still waters. However, ponds support proportionately high levels of biodiversity relative to other inland waters in Europe, and foraging by Eurasian otter Lutra lutra (L., 1758) could have considerable impacts on species composition in these small water bodies. The aim of the present study was to analyse otter spraints around ponds during two contrasting seasons (winter and spring) in north Norfolk (eastern England), where both otter and ponds are of particular conservation concern. Spraint density, prey diversity and the consumption of river-associated species were higher in spring than winter. In both seasons, birds were the most important prey category as ingested biomass. European eel Anguilla anguilla (L., 1758) and amphibians, specifically common frog Rana temporaria L., 1758 and common toad Bufo bufo (L., 1758), were more consumed in spring, whereas northern pike Esox lucius L., 1758 and tench Tinca tinca (L., 1758) were taken in winter. Non-native common carp Cyprinus carpio L., 1758 was important in both seasons, whereas threatened native crucian carp Carassius carassius (L., 1758) was a minor prey item. Massive kills of common toad, which involved a new handling technique for predation on this species, were observed mainly in spring. The study demonstrated otters to display great plasticity in foraging behaviour and contributes to the understanding of otter predatory pressure on pond biodiversity, with implications for landscape management.

A Comparative Analysis of Feeding and Trophic Level Ecology in Stingrays (Rajiformes; Myliobatoidei) and Electric Rays (Rajiformes: Torpedinoidei)

Standardised diets and trophic level (T L) estimates were calculated for 75 ray species from the suborders Myliobatoidei (67 spp.) and Torpedinoidei (8 spp.). Decapod crustaceans (31.71±3.92%) and teleost fishes (16.45±3.43%) made the largest contribution to the standardised diet of the Myliobatoidei. Teleost fishes (37.40±16.09%) and polychaete worms (31.96±14.22%) were the most prominent prey categories in the standardised diet of the suborder Torpedinoidei. Cluster analysis identified nine major trophic guilds the largest of which were decapod crustaceans (24 species), teleost fishes (11 species) and molluscs (11 species). Trophic level estimates for rays ranged from 3.10 for Potamotrygon falkneri to 4.24 for Gymnura australis, Torpedo marmorata and T. nobiliana. Secondary consumers with a T L <4.00 represented 84% of the species examined, with the remaining 12 species (16%) classified as tertiary consumers (T L ≥4.00). Tertiary consumers included electric rays (Torpedo, 3 spp. and Hypnos, 1 sp.), butterfly rays (Gymnura, 4 spp.), stingrays (2 spp.) and Potamotrygonid stingrays (2 spp.). Feeding strategies were identified as the primary factor of influence with respect to Myliobatoidei and Torpedinoidei T L estimates with inter-family comparisons providing the greatest insight into Myliobatoidei and Torpedinoidei relationships.

Dieta de la carpa &lt;i&gt;Notropis moralesi&lt;/i&gt; (Pisces: Cyprinidae) en el río Amacuzac, Morelos, México

Notropis moralesi, locally known as “carpa tepelneme”, is a small endemic fish of the Papaloapan River. We analyzed its diet and feeding habits. Specimens were captured monthly from Amacuzac, River, Morelos, Mexico. The gut content of 294 specimens was identified to the most specific taxonomic category possible. We quantified gut content by the numerical and frequency of occurrence methods and used the Levin’s amplitude of trophic niche indices and MacArthur and Levin`s indices for niche overlaping. The N. moralesi diet was composed by eleven prey categories, ten of which were of animal item. Chironomids and mayfly were the most consumed prey, independently of season and fish sex or size. We found ten nutritional components in the dry season, and eight in the rainy season. The estimated amplitude of trophic niche (Levin’s method) revealed high values in both seasons. The diet had ten nutritional components in immatures, eight in females and five in males. A Chi-squared test showed not significant differences in the diet by development stage, sex, and season. The niche overlaping index was high (above 0.60) for all analyses. N. moralesi is a carnivorous species with entomophagus tendencies.

Hard boundaries influence African wild dogs' diet and prey selection

Summary Human‐mediated changes in habitat structure may disturb predator–prey relationships. We investigated the influence of perimeter fences on the diet of a reintroduced population of African wild dogs Lycaon pictus Temminck 1820 in a 316 km2, fenced reserve in South Africa, by tracking radio‐collared individuals during hunting periods to determine dietary composition from observed kills. Nutritional status of impala Aepyceros melampus and kudu Tragelaphus strepsiceros prey, as measured by the percentage of femur marrow fat, was significantly lower than that of unselectively culled individuals. This supports the hypothesis that wild dog predation is at least partially compensatory. Fence‐impeded kills (those for which escape was deemed to be compromised by the fence) comprised 40·5% of kills (n = 316), and 54·1% of all edible biomass consumed. Compared with fence‐unimpeded kills, fence‐impeded kills comprised larger species (32·9 vs. 25·0 kg, W = 25667·0, P ≪ 0·001), older age classes for one prey category (female kudu: Fisher's exact test, P = 0·02, n = 65) and animals in better condition for adult impala males (Mann–Whitney, W = 111·0, P = 0·012, n = 28). Fence‐impeded kills also provided greater catch per unit hunting effort (27·3 vs. 12·2 kg km−1; χ2 = 7·89, P = 0·005), resulting in longer interkill intervals. Movement of the pack towards the fence at the start of each hunting period suggested a decision to exploit the advantage that fences conferred for capturing prey. Synthesis and applications. By enabling coursing predators to capture prey that would otherwise have escaped, fences may reduce the compensatory nature of predation, causing shifts in predator–prey dynamics that could influence the ability of small reserves to support such predators. The establishment of larger conservation areas to reduce perimeter‐to‐area ratios should be encouraged to limit the undesired effects of fences on predator–prey dynamics.