Dietary Overlap Research Articles

Distinct resource utilization by introduced man-made grouper hybrid: an overlooked anthropogenic impact from a longstanding religious practice

AbstractAnthropogenic activities, such as the introduction of non-native aquaculture species, have significantly altered trophic interactions in marine ecosystems. The hybrid grouper (TGGG), an aquaculture product originating from an artificial F1 crossbreed between Epinephelus fuscoguttatus and E. lanceolatus, has been released into the wild through religious activities, raising concerns about the ecological implications of this man-made species. With its carnivorous diet and large body size inherited from the parental species, TGGG could pose significant impacts to the marine ecosystem. Yet, little is known about the diet composition of TGGG upon release into the natural environment as well as its dietary overlap or partitioning with closely related species. Here, we deployed gut content DNA metabarcoding to determine the prey richness and dietary niche of wild-caught TGGG and compared it to four native grouper species (Epinephelus awoara, E. bleekeri, E. coioides and E. quoyanus). Our results indicate that the TGGG exhibited five unique prey taxa, with teleosts being the predominant prey, followed by crustaceans and cephalopods. Notably, the TGGG displayed a significantly lower mean number of prey taxa compared to the other groupers, suggesting a distinct diet composition that may reflect a transition in feeding behaviour. This study provides a comprehensive analysis with high taxonomic resolution on the diet of artificial hybrids in the wild, indicating the potential for successful establishment if release events persist. Finally, these findings provide new insights into how local trophic dynamics are impacted by the under-investigated release of animals through religious practices.

Feeding ecology of two wild sympatric canids in protected areas of northeastern Argentina

AbstractThe role of mesocarnivores in wildlife communities tends to be overlooked, which has led to a large gap in natural history knowledge. In northeastern Argentina, two mesocarnivore foxes, Cerdocyon thous and Lycalopex gymnocercus, live in sympatry in noncompetitive coexistence. Their feeding habits have been studied in many occasions; however, the studies related to trophic variability in a wider spatial scale remain scarce. In this study, we aimed to analyze how the diet of these foxes varies in three protected areas in Argentina: the Mburucuyá National Park (MNP), the “San Nicolás Portal” (SN), and the Natural Reserve Rincón de Santa María (RSM). We collected fecal samples in each area, identified them using thin layer chromatography at species level, and classified the found feeding items to obtained two parameters: occurrence and relative frequency. Furthermore, we compared the diet of the two species in each site and between sites using chi‐square and estimated trophic niche breadth and overlap between the species. We found that both species consumed different food categories, with variable frequencies across study sites. We observed that in each area, the foxes differed in diet composition. However, we found no differences between the diet compositions of C. thous and L. gymnocercus, showing high niche overlap in each site. Here, we show the plasticity of both fox species in changing their diets even with small geographical variation. Both species can coexist even with a high diet overlap, possibly explained by their noncompetitive coexistence which may occur due to the current changes in the ecosystem interactions, or partitioning may exist but on a smaller niche level.

The Effect of Sampling Schedule on Assessment of Dietary Measures: Evidence From Blue Monkeys (Cercopithecus mitis stuhlmanni).

Accurately assessing primate diets is important in studies of behavioral ecology and evolution. While previous research has compared sampling methods (scan, focal), we examined how sampling schedule influences accuracy of dietary measures. We define sampling schedule as the combined distribution (random vs. consecutive) and frequency of sampling days within a given month. Under field conditions, time may be required to locate a study group, and we therefore also subtracted 1, 2, or 3 h from the beginning of all non-consecutive days in each sampling schedule to mimic observation time lost to search. From a dense (near daily) 5-year record of feeding behavior derived from focal animal follows of adult females in five wild blue monkey (Cercopithecus mitis) groups, we created data subsets matching various sampling schedules, and compared monthly dietary measures calculated from each subset to those based on the full data set. These measures included (1) the proportion of observation time feeding on fruit, (2) diet composition (three top-ranked food items), (3) species richness of plant diet, (4) Shannon-Wiener diversity index based on plant species, and (5) Holmes-Pitelka index expressing dietary overlap with the previous month. We used generalized linear mixed models to assess how frequency and sampling type (a combination of distribution and hours lost) relate to a subset's deviation from the full data set, where a smaller deviation (or higher chance of matching, for diet composition) implies greater accuracy. For all dietary measures, increasing observation frequency increased accuracy. The response to distribution varied among measures, but sampling types generally differed more at lower frequencies. Deviation varied widely within and between dietary measures, and some sampling schedules resulted in values with large percentage differences from the "full" data. Accordingly, when designing and comparing studies, researchers should consider how sampling schedules may influence the accuracy of the dietary measures of interest.

When spiders take over: the expulsion of giant Amazonian ants from their nest

Spiders have been documented using nests of various ant species. In this study, we recorded the non-harmonious use of a nest and the expulsion of giant Amazonian ants from their nest by a Diplura spider. Both species inhabit South American forests, including the Amazon rainforest and Cerrado. This event took place in the northern Cerrado of Brazil during the rainy season. The expropriation process lasted 13 days, beginning with the simultaneous occupation of the anthill and culminating in the complete eviction of the ants. Over the last two days, we observed intense ant activity at a second entrance to the anthill and the construction of a new nest. We propose that the funnel-web spider was using the ant nest as shelter. However, the simultaneous coexistence may have been limited due to the spider web blocking an entrance and dietary overlap leading to competitive exclusion.

Dietary partitioning of fishers and martens in a rapidly changing landscape

Niche partitioning is critical for the stable coexistence of competing species that share limited resources. Yet, niches are dynamic, especially in the face of rapid environmental change. Carnivores exhibit particularly strong forms of competition and are differentially affected by change. Fishers (Pekania pennanti) and martens (Martes caurina) are two species of carnivores that overlap in space, time, and resources. In the Sierra Nevada of California, these two species share habitats that are undergoing a sudden restructuring due to drought and the subsequent mortality of more than half of all trees. Using a long-term dataset from across the affected region of the Sierra Nevada, we quantified the diet, as well as dietary niche overlap and niche shift of fishers and martens during summer months before, during, and after these disturbances and as a function of spatial overlap. The summer diet of fishers and martens did not appear to be affected by change in live forest canopy and tree mortality. While fisher diet was unaffected by elevation, martens exhibited an increasing reliance on vertebrate prey at higher elevations. Our results suggest that during summer months the diet of fishers is highly diverse, even including fungi and insects, but the diet of martens is less diverse and more reliant on vertebrate prey. These different consumption patterns — which were largely unaffected by changing environmental conditions, except elevation — have led to unexpectedly low overlap in trophic niche space during the timeframe measured. Our findings demonstrate that the coexistence of martens and fishers regionally is likely facilitated, in part, through partitioning along the trophic niche axis. If drought conditions persist and lead to continued or increasingly reduced snowpack and altered vegetation, future research should assess how niche partitioning of fishers, martens, and other members of the broader carnivore community will endure.

The repatriation of wolves to Isle Royale alters the foraging of meso-carnivores

Abstract Due to the disproportionate role that large carnivores can have on communities and their global decline over the last century, carnivores are increasingly being repatriated across their historic ranges. The reintroduction of gray wolves (Canis lupus) can precipitate substantive changes to communities and ecosystems. Notably, wolves could have strong effects on smaller and subordinate carnivores, especially in altering their foraging behavior and prey selection. Past studies investigating wolf effects on other carnivores, however, have generally been conducted in relatively complex communities featuring a diverse assemblage of carnivores and prey and have lacked baseline (i.e., pre-repatriation) data. Consequently, researchers have quantified what a community looks like after wolf return, with little information on how the community behaved before. To better understand the effect of large carnivore repatriation on the foraging ecology of a carnivore community, we investigated the impact of reintroduced gray wolves on 2 meso-carnivores: Red Fox (Vulpes vulpes); and American Marten (Martes americana) within an insular and simple vertebrate community at Isle Royale National Park before and after wolf reintroduction. We analyzed >600 scats from 20 individual martens and 63 individual foxes as well as the stable isotopes of 9 and 22 tissue samples from martens and foxes, respectively, at both individual and population levels. We found that the wolf reintroduction had little effect on marten diet but strongly influenced fox diet depending on the analysis conducted. At the population level, our analysis revealed that both foxes and martens were dietary generalists consuming an array of food items including small prey, berries, and human food regardless of wolf presence. However, at the individual level, we found that prior to wolf repatriation foxes primarily consumed berries and small prey but following wolf repatriation the diet of foxes shifted to berries and human foods as well as large carrion. This post-wolf reintroduction shift in diet increased the dietary overlap between foxes and martens. Our work provides new insights into how the return of a large carnivore can alter the foraging ecology of small-bodied carnivores and act both to provision carrion resources as well drive other carnivores to consume more human food and increase dietary overlap.

Guilty or innocent? Could the exotic lizard Hemidactylus mabouia (Squamata, Gekkonidae) be responsible for the displacement of the native species Notomabuya frenata (Squamata, Mabuyidae) in anthropic environments?

Hemidactylus mabouia is a gecko species that has successfully colonized southern North, Central, and South America. In Paraguay, there is a commonly held belief that this species has displaced the native skink Notomabuya frenata in urban areas. In this study, we compared several ecological features of N. frenata and H. mabouia to better understand the degree of their niche overlap. A comparative analysis was conducted based on a literature survey and the examination of museum specimens from Asunción (Paraguay). Furthermore, differences in microhabitat use between H. mabouia and N. frenata were investigated through a review of observational records available on iNaturalist. Our findings indicate that the two species share only a few biological traits, such as an insectivore diet, an ability to adapt to living close to human dwellings, and the use of mimesis as a primary defensive strategy. Both lizards are generalist feeders, although there are notable differences in their frequency of prey consumption. Regarding habitat use, the majority of N. frenata specimens were documented on grass or other natural substrates, as well as on trees and shrubs. In the case of H. mabouia, the majority of records originate from smooth and brick walls, including metal and glass surfaces. Consequently, there is no evidence to suggest that dietary overlap could induce competition between these species. Therefore, it can be posited that the displacement of the native lizard N. frenata is a consequence of human activities that have altered its preferred microhabitat while expanding potential habitat for H. mabouia.

Toxoplasma gondii Exposure and Dietary Habits of Two Sympatric Carnivores in the Valdivian Temperate Rainforest, Southern Chile.

Toxoplasma gondii, a parasitic protozoan, may infect most warm-blooded animals, including humans and carnivores. Our study focused on alien-invasive American minks (Neogale vison) and domestic cats (Felis catus) in the Valdivian Temperate Rainforest, Chile. The main goal was to investigate the relationship between their dietary habits and T. gondii exposure in the Valdivia River watershed. To detect T. gondii exposure, blood serum samples from 49 domestic cats and 40 American minks were analyzed using an ELISA, and stable isotope analysis of δ15N and δ13C from vibrissae was performed to determine the dietary habits of both species. Relationships between T. gondii exposure and dietary habits were explored using generalized linear mixed-effects models. American minks that were T. gondii seropositive exhibited a broader prey range compared to seropositive domestic cats, with minimal dietary overlap between the two groups. Exposure of domestic cats to T. gondii had no significant association with any isotope value or prey item in their diet. In American minks, we found a positive and significant association between the proportion of Domestic chicken (Gallus gallus domesticus) in the diet and high δ15N values with T. gondii exposure. This suggests that domestic species prey related to anthropogenic areas, and the consumption of high-trophic-level prey, may contribute to T. gondii exposure in American minks. Conversely, contrary to previous hypotheses, consumption of rodents showed no significant association with T. gondii exposure in either species. Our findings emphasize the importance of further research to investigate trophic interactions in the transmission dynamics of T. gondii in the Valdivian Temperate Rainforest.

Dietary overlap of invasive cyprinids and common carp in fishponds of Central Europe

Freshwater fishponds are an important part of the global aquaculture fish production, but they also are a source of invasive species with potentially negative impacts on pond ecosystems. In this study, we investigated dietary competition between common carp (Cyprinus carpio) and two invasive cyprinids, Pseudorasbora parva and Carassius gibelio, in fishponds of Central Europe. Using δ13C and δ15N stable isotopes analysis, we evaluated the extent of isotopic niche overlaps and the utilization of dietary sources by these species in fishponds that differ in the intensity of fish production. The isotopic niche of C. carpio and the invasive cyprinids overlap more in ponds with intensive (south-eastern Czechia) and semi-intensive (northern Austria) fish production then in ponds with low intensity production (eastern Slovakia). Our results also suggest that both invasive species opportunistically adjust their diet to their gape size and that they predominantly assimilate dietary energy from zooplankton and macroinvertebrates rather than from primary producers and detritus. Our study highlights the high potential of these invasive cyprinids to compete with C. carpio in fishponds of Central Europe.

Evidence for resource partitioning in weakfishes from a coastal upwelling ecosystem

Resource partitioning plays an important role in supporting species coexistence. In a coastal upwelling ecosystem two weakfish species, Cynoscion guatucupa and C. jamaicensis co-occur and are key commercial species. The present study aimed to provide a comprehensive assessment of the feeding ecology of both species, including to; (i) quantitatively assess diet, (ii) evaluate ontogenetic and seasonal diet variations, and (iii) estimate dietary overlap in the context of competition or resource partitioning, using an integrated approach combining stomach content (SCA) and stable isotope analyses (SIA). Our results revealed that both C. guatucupa and C. jamaicensis prey mainly on pelagic fish and shrimp with ontogenetic and seasonal changes in diet detected. Weakfishes consume a large proportion of similar prey throughout the year and high isotopic niche overlap confirmed the SCA results. Despite the similar use of food resources by both species, the availability and abundance of prey promoted by seasonal upwellings and the possible spatial segregation between C. guatucupa and C. jamaicensis may promote their co-occurrence in an upwelling ecosystem. Due to their commercial value and fisheries importance in the southwestern Atlantic, these results contribute insights to support sustainable fisheries management.

Domestic dogs and vultures feed on the same carcasses in Wayanad Wildlife Sanctuary, Kerala, India

AbstractVultures are essentially scavengers but their population decline is exacerbated by competition with stray dogs for carcasses. Our study, using camera traps to monitor carcass visitation, revealed dietary overlap and competition intensity are linked more to carcass size than habitat type. Addressing dog presence is critical for vulture survival.

Different coexistence patterns between apex carnivores and mesocarnivores based on temporal, spatial, and dietary niche partitioning analysis in Qilian Mountain National Park, China.

Carnivores play key roles in maintaining ecosystem structure and function as well as ecological processes. Understanding how sympatric species coexist in natural ecosystems is a central research topic in community ecology and biodiversity conservation. In this study, we explored intra- and interspecific niche partitioning along spatial, temporal, and dietary niche partitioning between apex carnivores (wolf Canis lupus, snow leopard Panthera uncia, Eurasian lynx Lynx lynx) and mesocarnivores (Pallas's cat Otocolobus manul, red fox Vulpes vulpes, Tibetan fox Vulpes ferrilata) in Qilian Mountain National Park, China, using camera trapping data and DNA metabarcoding sequencing data. Our study showed that apex carnivore species had more overlap temporally (coefficients of interspecific overlap ranging from 0.661 to 0.900) or trophically (Pianka's index ranging from 0.458 to 0.892), mesocarnivore species had high dietary overlap with each other (Pianka's index ranging from 0.945 to 0.997), and apex carnivore and mesocarnivore species had high temporal overlap (coefficients of interspecific overlap ranging from 0.497 to 0.855). Large dietary overlap was observed between wolf and snow leopard (Pianka's index = 0.892) and Pallas's cat and Tibetan fox (Pianka's index = 0.997), suggesting the potential for increased resource competition for these species pairs. We concluded that spatial niche partitioning is likely to key driver in facilitating the coexistence of apex carnivore species, while spatial and temporal niche partitioning likely facilitate the coexistence of mesocarnivore species, and spatial and dietary niche partitioning facilitate the coexistence between apex and mesocarnivore species. Our findings consider partitioning across temporal, spatial, and dietary dimensions while examining diverse coexistence patterns of carnivore species in Qilian Mountain National Park, China. These findings will contribute substantially to current understanding of carnivore guilds and effective conservation management in fragile alpine ecosystems.

Spatial and Ontogenetic Patterns in the Trophic Ecology of Two Predatory Fishes in a Large River

ABSTRACTFishes use a variety of physical and biological resources that shift ontogenetically, seasonally and spatially. Quantifying what resources such as prey are required for persistence can improve understanding of ecological needs of fishes and riverine macrosystem functioning. Bowfin (Amia ocellicauda) and largemouth bass (Micropterus nigricans) cohabitate in their native range and potentially compete with one another. Yet, there have been no direct comparisons of their diets across spatial gradients to assess whether they partition resources or shift in prey use. We used multiple univariate and multivariate analyses to compare diet composition, diet overlap, feeding strategy, prey importance and diet partitioning between largemouth bass and bowfin across three reaches of the Upper Mississippi River. Largemouth bass ontogenetically shifted their diet from aquatic invertebrates to fishes and a more diverse assemblage of aquatic invertebrates. Bowfin and adult largemouth bass were top predators which consumed mostly crayfish and fish and overlapped in their diets. Despite overlapping diets, predators partitioned resources by consuming different lengths and abundances of prey, and largemouth bass had greater trophic plasticity. Within a predator group, few differences in diets existed spatially, underscoring the relative homogeneity in resource use potentially from similarities in the river's physical structure. Combined, prey use likely differed sufficiently to reduce potential competition between largemouth bass and bowfin, allowing long‐term coexistence in this system. Our results also highlighted the importance of crayfishes to riverine food webs and underscored the use of multiple prey and habitat types that sustain these predators.

Assessing biological invasion predatory impacts through interaction strengths and morphological trophic profiling

Biological invasions are a major stressor on ecosystems worldwide, but tools to predict their predatory impact remain limited. Here, we quantified invader impacts using two complementary approaches: functional responses (to reveal per capita and multiple predator interaction strengths) and ecomorphology (to reveal trophic profiles and competitive overlap). We compared Mozambique tilapia Oreochromis mossambicus, a native southern African cichlid, and a near-trophically analogous invasive congener, the Nile tilapia Oreochromis niloticus. Both Nile tilapia and Mozambique tilapia exhibited a potentially prey population destabilizing Type II functional response. In both single and multiple predator pairings, invasive Nile tilapia had significantly greater prey consumption rates than native Mozambique tilapia, and thereby a greater predatory impact than its native congeneric. Attack rates were greater for Nile tilapia than Mozambique tilapia, with both species showing more similar handling times and maximum feeding rates. No evidence for multiple predator effects was detected within or between these species, and therefore impacts of both species increased additively in the presence of conspecific or heterospecific competitors. Morphological trait analyses found general differences between these two species, with the invasive Nile tilapia having distinctively larger lower jaw closing force, gill resistance and gill raker length, which facilitated greater feeding capacities over the native species. Trophic profiles predicted using morphological trait differences showed high dietary overlap and served as evidence for potential exploitative competition between the two species. These results reveal superior interaction strengths and ecomorphological trait profiles of an invasive over native species which could influence impact and native species replacement dynamics. Novel applications of functional response and ecomorphology provide complementary insights into predatory and competitive impacts from invasive species, aiding impact prediction across environmental contexts.

Seasonal Occurrence of Honey Bees in Coriander

A multi-location trail was carried out at the Beekeeping Unit, TCA, Dholi (Muzaffarpur District, India) and University Apiary, RPCAU, Pusa (Samastipur District, India) during Rabi 2021-22 on Rajendra Dhania-2 variety of coriander. Spatial distribution of bee species in Pusa and Dholi showed that occurance of Italian bee Apis mellifera (F) was comparatively higher at Pusa (19.03± 6.29/ m2 / 10 min) as compared to Dholi (16.56± 5.47/ m2 / 10 min). Other species of honey bees viz. Indian hive bee, Apis cerana (F), rock bee Apis dorsata (F) and little bee Apis florea (F) were more abundant in Dholi as compared to Pusa. Maximum (number of bee/ m2 / 10 min) of Apis mellifera (24.02, 27.60), Apis dorsata (16.88, 14.89), Apis cerana (14.55, 11.64) and Apis florea (10.47, 8.63) were observed at 13:00, 15:00, 11:00 and 09:00 at Dholi and Pusa, respectively. The underlying factors of this distribution were identified as body size and dietary overlap. This study highlights the complexity of interactions between Apis spp. genus and shows how factors like body size and diet influence their distribution patterns.

Restorative function of offshore longline mussel farms with ecological benefits for commercial crustacean species

Offshore ocean aquaculture is expanding globally to meet the growing demand for sustainable food production. At the United Kingdom's largest longline mussel farm, we assessed the potential for the farm to improve the habitat suitability for commercially important crustaceans. Modelled distribution patterns (GAM & GLM) predicted the low complexity seabed beneath the mussel farm was 34–94 % less suitable for European lobster (Homarus gammarus) and brown crab (Cancer pagurus) than nearby rocky reefs. The mussel farm operations, however, contributed large amounts of living mussels and shell material to the seabed. Acoustic telemetry revealed that H.gammarus remained within the farm for between 2 and 283 days using both the farm anchors and areas of seabed dominated by fallen mussels for refuge. In contrast, C. pagurus movements showed no affinity to either the farm infrastructure or benthic habitat under the farm. Stable isotope analysis indicated a high dietary niche overlap in C. pagurus and H. gammarus (67.8 and 84.6 %) between the mussel farm (mixed muddy sediment) and nearby rocky reef. Our mixed-methods suggest that the mussel farm augments structural complexity on the seabed providing refuge and similar feeding opportunities for lobster and crab as their typical habitat on rocky reefs. Longline mussel farms can deliver profound biodiversity-positive effects through biogenic augmentation of degraded habitat for commercial species and potential for co-benefits to local fisheries.

Interspecific Dietary Overlap Between Two Sympatric Wild Canids in Hirpora Wildlife Sanctuary, Northwestern Himalayas, India

Interspecific Dietary Overlap Between Two Sympatric Wild Canids in Hirpora Wildlife Sanctuary, Northwestern Himalayas, India

Intraspecific and interspecific resource partitioning between bumblebee workers and males related to nectar quantity and quality.

Bumblebees are important pollinators for many natural and agricultural systems in temperate regions. Interspecific and intraspecific variation in floral resource preferences have been proposed to influence bumblebee community structure. In particular, sexual dimorphism is a major source of intraspecific niche variation. Although interspecific resource partitioning is well studied, few studies have explored the intraspecific dynamics between workers and males. Here, we report a study on a total of 11528 workers and 2220 males of 14 bumblebee species recorded over 5years in the Hengduan Mountains of Southwest China. We first compared the potential for interspecific and intraspecific competition between workers and males using visitation records and resource partitioning indices (overlap index). We then evaluated the influence of nectar traits on flower preference, including nectar volume and the levels of hexose, sucrose and 10 essential amino acids (EAAs). We found that the niche overlap between intraspecific workers and males was higher than that between different species, and temporal overlap alone did not strongly determine diet overlap. Males of most species preferred flowers with high levels of EAAs and hexose, whereas workers of some species preferred flowers with high nectar volume and sucrose levels. This study suggests that there is floral resource partitioning among bumblebee species, and between workers and males, which may play a key role in alleviating interspecific and intraspecific competition. These findings also provide a useful guide for which kinds of plants might be most valuable for bumblebees, especially the understudied males, in this biodiversity hotspot.

Shared use of a mass‐flowering crop drives dietary niche overlap between managed honeybees and bumblebees

Abstract Resource competition between wild pollinators and managed honeybees (Apis mellifera) has the potential to detrimentally impact insect biodiversity as well as wild plant and crop pollination. As honeybees are central place foragers, their competitive impact on wild bees is expected to be structured by hive proximity, in conjunction with foraging decisions related to landscape‐level resource availability. Yet, how these factors structure dietary niche overlap between wild bees and managed honeybees remains unclear. We conducted a field experiment in seminatural grasslands, where honeybee foraging densities and niche overlap with buff‐tailed bumblebees (Bombus terrestris) were measured at four distances (<100, 500, 1000 and 2000 m) from experimentally placed apiaries, during and after the blooming period of mass‐flowering oilseed rape (Brassica napus). We measured honeybee foraging densities using standardized transect surveys, and quantified species diet composition and dietary niche overlap from pollen samples collected from both bee species. Honeybee foraging densities were highest near apiaries and declined sharply beyond 500 m from the apiaries. However, niche overlap was unrelated to hive proximity but positively related to the availability of oilseed rape. Furthermore, there were significant inter‐ and intraspecific differences in pollen diet composition and breadth throughout the season. Synthesis and applications: Niche overlap between honeybees and bumblebees in agricultural environments was due to resource sharing of mass‐flowering oilseed rape. When both honeybees and bumblebees predominantly forage on wild plants, they maintain distinct pollen diets, suggesting there is a low risk of resource competition between these generalist taxa. Conservation actions that promote floral resource availability and diversity in agricultural landscapes are crucial to maintain niche differentiation between managed honeybees and wild bees.

Understanding the seasonal dietary patterns of the golden jackal (Canis aureus) for conservation implications in the Hirpora Wildlife Sanctuary, Western Himalayas

BackgroundWild canids form an important component of the ecosystem but are generally less studied and least prioritized for conservation. Diet is fundamental for effective management and exhibits the role of a species in an ecosystem. Golden jackal (Canis aureus, Linnaeus, 1758), a medium-sized canid species is known for opportunistic and omnivorous foraging behavior. MethodsThis research investigates the feeding ecology of golden jackals within the Hirpora Wildlife Sanctuary, Western Himalayas. From August 2020 to July 2022, trails (n = 9; 1.5–5.5 km) were walked seasonally (once per month) to collect fecal samples (n = 128) for investigation of seasonal diet composition and dietary niche breadth and biomass consumption of prey items by golden jackal. The association between the coefficient of digestibility value and food items was assessed using the Pearson correlation. We also conducted PCA to understand contribution of major dietary items. ResultsScat analysis revealed that jackals feed on both animal and plant matter. Animal matter constituted most of the diet, encompassing small mammals and domestic livestock, insects, and birds. Rodents emerge as the dominant dietary item, maintaining consistent prevalence year-round. Livestock carrion, notably domestic sheep formed a significant component across all seasons, with maximal consumption observed in summer. Notably absent from the jackals' diet were traces of threatened mountain ungulates. Domestic sheep emerged as the primary contributor (33.4 %) to the overall biomass consumed, highlighting the jackals' interaction with human-associated food resources. The research unveils an overall dietary niche breadth of 0.38, indicating a low degree of dietary diversity. Seasonal analysis indicates heightened dietary overlap in the autumn-summer transition, with rodents, domestic sheep, and birds being major contributors to this overlap. ConclusionThe findings underscore the adaptability of golden jackals to diverse food resources in a seasonal environment. This study provides foundational insights into the dietary ecology of jackal crucial for its conservation and management strategies in the ecologically fragile ecosystem. The finding gives a hint at the role jackals can play in regulating rodent populations and contributing to environmental cleanliness by scavenging.