Diet Breadth Research Articles

Foraging ecology of the bird Eupsittula canicularis (Psittaciformes: Psittacidae) in a modified Mexican landscape

Introduction: Seasonal phenological variations in tropical forests cause changes in food resource availability. Animals use foraging strategies to follow the food supply in these settings. The Orange-fronted Parakeet (Eupsittula canicularis) mainly inhabits the tropical dry forest of the Mexican Pacific to Northwest Costa Rica, although little is known about its diet and foraging strategies. Objective: To assess spatial variability in food resource abundance, diet, and foraging behavior of the Orange-fronted Parakeet in a modified landscape in Oaxaca Coast, Mexico. Methods: 30 phenology transects (200 × 6 m) were established during the dry season (February-June 2019) to measure food resource availability in primary deciduous, semi-deciduous, and secondary forests. The Orange-fronted Parakeets diet was determined by focal foraging observations, and dietary niche breadth and resource selection were considered to determine feeding strategies. Results: Orange-fronted Parakeets fed on fruits (42.3 %), seeds (29.3 %), and flowers (28.4 %) of 13 plant species and presented a broad dietary niche breadth with a higher frequency of foraging in primary forest. The Orange-fronted Parakeets select resources and adapt their foraging strategies based on food resource availability in each habitat. Conclusions: The study findings highlights the need to maintain the complete forest structure in a modified landscape to ensure food resources availability for Orange-fronted Parakeets during the breeding season.

Comparative diets and prey resource competition between early-juvenile common snook Centropomus undecimalis and non-native pike killifish Belonesox belizanus.

Pike killifish Belonesox belizanusis an established non-native fish species in Florida, USA, that was first documented in south Florida in 1957 and then in Tampa Bay tributaries in 1994. Decreases in small-bodied fish abundances have been linked to the introduction of B. belizanus in both of these regions. Increases in the range and abundance of B. belizanusin the Tampa Bay area and overlap in habitat usage have led to concerns about potential competition with, and predation on, early-juvenile common snook Centropomus undecimalis [≤100 mm standard length (SL)]. Stomach contents of B. belizanus (N = 422; 14-127 mm SL) and early-juvenile C. undecimalis (N = 1132; 5-119 mm SL) were collected to examine the dietary overlap of these two species and potential differences in the diet of early-juvenile C. undecimalis from locations with and without B. belizanus co-occurring. Prey resources were collected by seine to assess prey resource limitation and prey selectivity. Stomach content analysis indicated that there was low overlap in the diet of early-juvenile C. undecimalis and B. belizanus (C ≤ 0.40). Early-juvenile C. undecimalis had a wider diet breadth, consuming many organisms that are not consumed by B. belizanus and which make up a large portion of the early-juvenile C. undecimalis diet. Analysis of prey resources indicated that some prey groups may have lower abundances in locations where B. belizanus are present, with some of these differences reflected in the diet of early-juvenile C. undecimalis. Despite these differences, there was minimal difference in the diet overlap of early-juvenile C. undecimalis from locations with and without B. belizanus co-occurring. Currently B. belizanus appear to be competing minimally with early-juvenile C. undecimalis for prey resources, with no substantial impacts being detected.

Attributes of host-specificity better explain the diversified wood-boring longhorn beetles in tropical SW China than plant species diversity

A long-debated question in ecology is whether the hyper-diversity of tropical plant-feeding insects is a direct consequence of high tropical plant diversity or should be attributed to increases in host plant specialization. In this study, we used Cerambycidae (the wood-boring longhorn beetles whose larval stages feed on the xylems of trees and lianas) and plants as study materials to explore which hypothesis is more favoured. Multiple analyses were used to show the differences in host specificity of Cerambycidae in tropical and subtropical forests. From these analyses, we found that the alpha diversity of beetles in tropical forests was significantly higher than that in subtropical forests but not in plants. The relationship between plants and beetles was also closer in tropical areas than in subtropical areas. Our results imply that the wood-boring longhorn beetles show higher degrees of niche conservatism and host-specificity in tropical forests than in subtropical forests. The high diversity of wood-boring longhorn beetles in tropical forests might be explained to a large extent by their more finely partitioned diet breadth.

Niche breadth explains the range size of European-centred butterflies, but dispersal ability does not.

The breadth of ecological niches and dispersal abilities have long been discussed as important determinants of species' range sizes. However, studies directly comparing the relative effects of both factors are rare, taxonomically biased and revealed inconsistent results. Europe. Cenozoic. Butterflies, Lepidoptera. We relate climate, diet and habitat niche breadth and two indicators of dispersal ability, wingspan and a dispersal tendency index, to the global range size of 369 European-centred butterfly species. The relative effects of these five predictors and their variation across the butterfly phylogeny were assessed by means of phylogenetic generalized least squares models and phylogenetically weighted regressions respectively. Climate niche breadth was the most important single predictor, followed by habitat and diet niche breadth, while dispersal tendency and wingspan showed no relation to species' range size. All predictors together explained 59% of the variation in butterfly range size. However, the effects of each predictor varied considerably across families and genera. Range sizes of European-centred butterflies are strongly correlated with ecological niche breadth but apparently independent of dispersal ability. The magnitude of range size-niche breadth relationships is not stationary across the phylogeny and is often negatively correlated across the different dimensions of the ecological niche. This variation limits the generalizability of range size-trait relationships across broad taxonomic groups.

Body size predicts prey preference but not diet breadth in pythons

AbstractFor gape‐limited predators like snakes that swallow their prey whole, large‐bodied species with wide gapes should theoretically be able to consume a more diverse range of prey than smaller species with narrow gapes and, therefore, may have broader diets. However, in cases where large‐bodied species exclude small prey, their diets may not necessarily be more taxonomically diverse compared to smaller species. Thus, while body size can potentially predict broad dietary preferences, it cannot always predict diet breadth. We explored the relationship between body size and diet within the Pythonidae—a morphologically diverse clade of dwarf and giant snakes. We gathered ecological data of pythons and tested if python body lengths correlated with diet breadth and diet preferences respectively within a phylogenetic framework. Next, we reconstructed ancestral diets (as proportional use of ectothermic prey in their diets) and body lengths across a phylogeny of 36 species of pythons to explore the evolutionary relationship between these traits. We demonstrate that among extant pythons, body size is not linearly associated with diet breadth but linearly correlates with proportional use of ectothermic (and inversely endothermic) prey. Small‐bodied pythons more often have specialized diets dominated by the use of ectotherm prey whereas large‐bodied pythons tend to have diets dominated by the use of endotherm prey. We further show that the most recent common ancestor of pythons was likely large‐bodied and fed on a diet comprised mostly of endothermic prey. Shifts in diet towards greater proportional use of endothermic prey coincided with increases in body size. Conversely, shifts in diet towards greater proportional use of ectothermic prey coincided with decreases in body size. Our findings contribute to the growing body of work investigating the ecomorphological determinants of snake diets and thus provide further insight into our understanding of these animals' ecology and evolution.

Metabolic consequences of various fruit-based diets in a generalist insect species.

Most phytophagous insect species exhibit a limited diet breadth and specialize on a few or a single host plant. In contrast, some species display a remarkably large diet breadth, with host plants spanning several families and many species. It is unclear, however, whether this phylogenetic generalism is supported by a generic metabolic use of common host chemical compounds ('metabolic generalism') or alternatively by distinct uses of diet-specific compounds ('multi-host metabolic specialism')? Here, we simultaneously investigated the metabolomes of fruit diets and of individuals of a generalist phytophagous species, Drosophila suzukii, that developed on them. The direct comparison of metabolomes of diets and consumers enabled us to disentangle the metabolic fate of common and rarer dietary compounds. We showed that the consumption of biochemically dissimilar diets resulted in a canalized, generic response from generalist individuals, consistent with the metabolic generalism hypothesis. We also showed that many diet-specific metabolites, such as those related to the particular color, odor, or taste of diets, were not metabolized, and rather accumulated in consumer individuals, even when probably detrimental to fitness. As a result, while individuals were mostly similar across diets, the detection of their particular diet was straightforward. Our study thus supports the view that dietary generalism may emerge from a passive, opportunistic use of various resources, contrary to more widespread views of an active role of adaptation in this process. Such a passive stance towards dietary chemicals, probably costly in the short term, might favor the later evolution of new diet specializations.

Raw Material Surveys and Their Behavioral Implications in Highland Lesotho

Archaeologists have long considered climate change a primary mechanism behind human behavioral adaptations. The Lesotho highlands’ Afromontane and climatically extreme environments offer a unique opportunity to examine proposed correlations between topography, climate, and human behavior. Previous studies suggest that warmer temperatures allowed humans to expand their diet breadth and foraging range, whereas colder temperatures restricted humans to resources in riverine corridors. These studies used faunal and floral change as proxies to track changes in forager mobility but did not consider how differential access to stone resources affected human behaviors. To account for this gap, we conducted a survey for knappable rocks around the Sehonghong rock shelter in eastern Lesotho, recording the materials present and their size and shape in the modern environment. We compared the survey results to later Pleistocene (~ 22–11 ka cal. BP) lithic assemblages at Sehonghong to better understand whether archaeological patterns match modern knappable rock availability. Contrary to previous hypotheses, we find that past peoples at Sehonghong were not limited to exclusively riverine resources during colder conditions. We then used flake-to-core and noncortical-to-cortical flake ratios to track changes in mobility and knappable rock procurement patterns. The ratios remain constant up until the Late Glacial, ca. 14 ka cal. BP, when we see an increase in both flake-to-core and noncortical-to-cortical ratios, suggesting increased movement of stone out of Sehonghong. These conclusions show that resource procurement and mobility patterns are not solely dependent on climate change but may be driven by more complicated causal mechanisms such as increased interaction and the formation of social networks across the Lesotho highlands and beyond.

Bee diversity decreases rapidly with time since harvest in intensively managed conifer forests.

Despite widespread concerns about the anthropogenic drivers of global pollinator declines, little information is available about the impacts of land management practices on wild bees outside of agricultural systems, including in forests managed intensively for wood production. We assessed changes in wild bee communities with time since harvest in 60 intensively managed Douglas-fir (Pseudotsuga menziesii) stands across a gradient in stand ages spanning a typical harvest rotation. We measured bee abundance, species richness, and alpha and beta diversity, as well as habitat characteristics (i.e., floral resources, nesting substrates, understory vegetation, and early seral forest in the surrounding landscape) during the spring and summer of 2018 and 2019. We found that bee abundance and species richness declined rapidly with stand age, decreasing by 61% and 48%, respectively, for every 5 years since timber harvest. Asymptotic estimates of Shannon and Simpson diversity were highest in stands 6-10 years post-harvest and lowest after the forest canopy had closed, ~11 years post-harvest. Bee communities in older stands were nested subsets of bee communities found in younger stands, indicating that changes were due to species loss rather than turnover as the stands aged. Bee abundance-but not species richness-was positively associated with floral resource density, and neither metric was associated with floral richness. The amount of early seral forest in the surrounding landscape seemed to enhance bee species richness in older, closed-canopy stands, but otherwise had little effect. Changes in the relative abundance of bee species did not relate to bee functional characteristics such as sociality, diet breadth, or nesting substrate. Our study demonstrates that Douglas-fir plantations develop diverse communities of wild bees shortly after harvest, but those communities erode rapidly over time as forest canopies close. Therefore, stand-scale management activities that prolong the precanopy closure period and enhance floral resources during the initial stage of stand regeneration will provide the greatest opportunity to enhance bee diversity in landscapes dominated by intensively managed conifer forests.

Dietary diversity, sociality, and the evolution of ant gustation

Ants have remarkably diverse diets and extraordinary species richness, making them an excellent model system to study the evolution of taste. In this entirely eusocial clade, food choice and the mechanisms that regulate feeding have both individual and social dimensions. How taste receptors and sensory processing drive food preferences to generate dietary breadth in ants is poorly understood. It is additionally unclear how elements of colony organization such as division of labor and social food flow impact the mechanistic basis and evolution of taste. Previous work on dipteran, lepidopteran, and hymenopteran gustatory systems, while foundational, provide limited insights into ant dietary specialization. Here we synthesize and analyze research on ant gustation to identify mechanisms, sociobiological correlates, and phylogenetic patterns. We discuss the current state of genomic analyses of taste and future research. We propose that strikingly polymorphic species of Pheidole, Cephalotes, Camponotus, and leafcutter ants (Atta and Acromyrmex) offer compelling social systems to explore adaptive variation in gustation because of their pronounced division of labor in which morphologically, behaviorally, and neurally differentiated workers vary in feeding behavior. Research on ant gustation within and among species will advance our understanding of sensory systems and provide insight into the impact of taste on the evolution of species diversity and how social organization influences gustation.

Climate or diet? The importance of biotic interactions in determining species range size

AbstractAimSpecies geographical range sizes play a crucial role in determining species vulnerability to extinction. Although several mechanisms affect range sizes, the number of biotic interactions and species climatic tolerance are often thought to play discernible roles, defining two dimensions of the Hutchinsonian niche. Yet, the relative importance of the trophic and the climatic niche for determining species range sizes is largely unknown.LocationCentral and northern Europe.Time periodPresent.Major taxa studiedGall‐inducing sawflies and their parasitoids.MethodsWe use data documenting the spatial distributions and biotic interactions of 96 herbivore species, and their 125 parasitoids, across Europe and analyse the relationship between species range size and the climatic and trophic dimensions of the niche. We then compare the observed relationships with null expectations based on species occupancy to understand whether the relationships observed are an inevitable consequence of species range size or if they contain information about the importance of each dimension of the niche on species range size.ResultsWe find that both niche dimensions are positively correlated with species range size, with larger ranges being associated with wider climatic tolerances and larger numbers of interactions. However, diet breadth appears to more strongly limit species range size. Species with larger ranges have more interactions locally and they are also able to interact with a larger diversity of species across sites (i.e. higher β‐diversity), resulting in a larger number of interactions at continental scales.Main conclusionsWe show for the first time how different aspects of species diet niches are related to their range size. Our study offers new insight into the importance of biotic interactions in determining species spatial distributions, which is critical for improving understanding and predictions of species vulnerability to extinction under the current rates of global environmental change.

Head shape predicts isotopic diet in anoles and day geckos

Abstract Trophic morphology affects resource acquisition; therefore, species differences in such traits may be informative for inferring resource use overlap and potential species interactions. In lizards, head size and shape determine the size and hardness of prey that can be consumed. Lizards with large differences in head morphology are expected to overlap less in prey use than lizards with more similar traits. Stable isotopes are increasingly being used to describe diet, yet how traditional functional traits affect isotopic diet is often not clear a priori. We measured head size, head shape, 𝛿15N, and 𝛿13C under controlled resource availability in an enclosure experiment using introduced lizards in Hawaiʻi to test whether functional traits predict isotopic diet. Brown anoles Anolis sagrei had the tallest and narrowest heads, the highest values of 𝛿13C, and the lowest values of 𝛿15N. Gold dust day geckos Phelsuma laticauda had the shortest and widest heads, the lowest values of 𝛿13C, and the highest values of 𝛿15N. Green anoles Anolis carolinensis were intermediate in both diet and morphology. As a result of isotopic diet overlap, green anoles have reduced competitor‐free resource space in the presence of both of the other lizard species. Head shape was the best predictor of diet and the only trait that explained variation within as well as among species. Head size was sexually dimorphic, and therefore the weaker diet correlations with this trait may be explained by sexual selection. Breadth in morphospace did not correlate with isotopic diet breadth, nor did the amount of overlap in morphospace predict the amount of overlap in isotopic diet space. While lizards were able to locally depress prey in experimental enclosures, no shifts in diet were detected in response to the presence of heterospecifics. The generality of head shape in predicting isotopic diet, and whether it does so independent of habitat use, warrants additional study. Head shape provides a potentially fruitful avenue for trait‐based approaches to studying ecology and evolution in lizards. Read the free Plain Language Summary for this article on the Journal blog.

Innovation across 13 ungulate species: problem solvers are less integrated in the social group and less neophobic.

Innovation is the ability to solve new problems or find novel solutions to familiar problems, and it is known to provide animals with crucial fitness benefits. Although this ability has been extensively studied in some taxa, the factors that predict innovation within and across species are still largely unclear. In this study, we used a novel foraging task to test 111 individuals belonging to 13 ungulate species-a still understudied taxon. To solve the task, individuals had to open transparent and opaque cups with food rewards, by removing their cover. We assessed whether individual factors (neophobia, social integration, sex, age, rank) and socio-ecological factors (dietary breadth, fission-fusion dynamics, domestication, group size) predicted participation and performance in the task. Using a phylogenetic approach, we showed that success was higher for less neophobic and socially less integrated individuals. Moreover, less neophobic individuals, individuals of domesticated species and having higher fission-fusion dynamics were more likely to participate in the task. These results are in line with recent literature suggesting a central role of sociality and personality traits to successfully deal with novel challenges, and confirm ungulates as a promising taxon to test evolutionary theories with a comparative approach.

Traits shaping urban tolerance in birds differ around the world

As human density increases, biodiversity must increasingly co-exist with urbanization or face local extinction. Tolerance of urban areas has been linked to numerous functional traits, yet few globally consistent patterns have emerged to explain variation in urban tolerance, which stymies attempts at a generalizable predictive framework. Here, we calculate an Urban Association Index (UAI) for 3,768 bird species in 137 cities across all permanently inhabited continents. We then assess how this UAI varies as a function of ten species-specific traits and further test whether the strength of trait relationships vary as a function of three city-specific variables. Of the ten species traits, nine were significantly associated with urban tolerance. Urban-associated species tend to be smaller, less territorial, have greater dispersal ability, broader dietary and habitat niches, larger clutch sizes, greater longevity, and lower elevational limits. Only bill shape showed no global association with urban tolerance. Additionally, the strength of several trait relationships varied across cities as a function of latitude and/or human population density. For example, the associations of body mass and diet breadth were more pronounced at higher latitudes, while the associations of territoriality and longevity were reduced in cities with higher population density. Thus, the importance of trait filters in birds varies predictably across cities, indicating biogeographic variation in selection for urban tolerance that could explain prior challenges in the search for global patterns. A globally informed framework that predicts urban tolerance will be integral to conservation as increasing proportions of the world's biodiversity are impacted by urbanization.

Bee functional traits and their relationship to pollination services depend on many factors: A meta‐regression analysis

Abstract Understanding relationships between organisms and the ecosystem services they provide is crucial for predicting the impacts of continued biodiversity changes. Functional traits of organisms can affect ecosystem properties and are thus increasingly used to predict long‐term ecosystem functioning. Bees are ideal taxa for using functional approaches given their role in pollination for many plant species and wide diversity of traits. Although distributions of bee functional traits are being documented in the literature, there is a clear lack of understanding of how they relate to ecosystem functioning (i.e. pollination). To address this knowledge gap, we conducted a meta‐regression analysis with the following objectives: (1) quantify the effects of bee functional traits on pollination and (2) assess sources of heterogeneity to identify variables that might explain variation across studies. Seventeen studies met our criteria for inclusion, yielding 45 individual effect sizes for six traits (body size, tongue length, diet breadth, nesting, parasitism, and sociality). Overall, bee functional traits had a significant effect on pollination; however, effect sizes were weak with high variability across studies. Sources of heterogeneity included the metrics used to quantify pollination, the number of bee genera analysed in a study, and whether traits were measured categorically or continuously. These results indicate a need for more research to improve understanding of trait–pollination relationships. For some bee traits, effects on pollination may be dependent on other factors like bee abundance, environmental context, and the plant species evaluated in studies.

Dietary niche breadth and overlap of four sympatric southern African myrmecophagous mammal species, as inferred from the literature

Five myrmecophagous mammal species occur sympatrically over large parts of southern Africa. Of these, the diets of four species have been studied in sufficient detail to facilitate interspecific comparisons. The diets of the aardvark Orycteropus afer, aardwolf Proteles cristatus, bat-eared fox Otocyon megalotis and Temminck’s pangolin Smutsia temminckii were compared based on the overall prey categories utilised and the proportion of each prey category in their diets, while Meller’s mongoose Rhynchogale melleri had too few data to be assessed. Bat-eared fox fed on the greatest number of prey categories (n = 116) and had the greatest dietary niche breadth (4.71), while aardwolf utilised the fewest prey categories (n = 28) and had the lowest dietary niche breadth (1.19) when analysing the proportion of each prey category in the diet at the genus level. Temminck’s pangolin was the only species that was observed to feed exclusively on ants and termites. The diets of Temminck’s pangolin and aardvark showed a moderate degree of overlap (dietary niche breadth 0.49–0.57), but overlap was low between all other species pairs (0.01–0.26) when analysing the proportion of each prey item in the diet at the genus level. The results suggest that these myrmecophages have low to moderate dietary overlap, which combined with the high abundance of ants and termites and differences in their feeding ecologies, likely reduces interspecific competition.

Environmental context and herbivore traits mediate the strength of associational effects in a meta‐analysis of crop diversity

Abstract Crop diversification offers a promising solution to meet expanding global food demands while maintaining ecosystem services. Diversification strategies that use mixed planting to reduce pest damage (e.g. intercropping), termed ‘associational effects’ (AE) in the ecological literature, can decrease (associational resistance) or increase (associational susceptibility) herbivore abundance on a focal plant. While application of AE to agroecosystems typically reduces pest abundance, the range of outcomes varies widely. We conducted a meta‐analysis using 272 estimates of insect herbivore abundance on crops neighbored by a conspecific or heterospecific from 44 studies undertaken on six continents. We focus on four agricultural crops well represented from sites across the globe to test hypotheses related to understanding how herbivore traits (diet breadth, feeding guild, origin), plant traits (crop type, phylogenetic distance to neighbour) and environmental context (climate, experimental design) contribute to variation in the outcomes of AE. Overall, bicultures provided a strong reduction of insect abundance on the focal crop. Climate and interactions between herbivore traits, particularly diet breadth and origin, and plant traits or environmental context mediated the strength of AE. Bicultures provided the strongest reductions in insect abundance at low latitudes, and this effect decreased at higher latitudes but only for insects with certain traits. Abundance of generalist herbivores and globally distributed pests tended to be most strongly negatively affected by bicultures, under certain contexts, whereas specialist herbivores and native pests were less affected by neighbours. Synthesis and application. This meta‐analysis highlights that crop diversification schemes have an overall strongly beneficial effect of reducing pest abundance. However, there was also variability in the outcomes that is determined in part by the interactive effects of herbivore traits and environmental context. The results provide guidance for incorporating beneficial ecological interactions into integrated pest management strategies.

Ancient and modern scats record broken ecological interactions and a decline in dietary breadth of the critically endangered kākāpō parrot (Strigops habroptilus)

Threatened animal taxa are often absent from most of their original habitats, meaning their ecological niche cannot be fully captured by contemporary data alone. Although DNA metabarcoding of scats and coprolites (palaeofaeces) can identify the past and present species interactions of their depositors, the usefulness of coprolites in conservation biology is untested as few endangered taxa have known coprolite records. Here, we perform multilocus metabarcoding sequencing and palynological analysis of dietary plants of >100 coprolites (estimated to date from c. 400–1900 A.D.) and > 100 frozen scats (dating c. 1950 A.D. to present) of the critically endangered, flightless, herbivorous kākāpō (Strigops habroptilus), a species that disappeared from its natural range in Aotearoa-New Zealand (NZ) after the 13th C. A.D. We identify 24 orders, 56 families and 67 native plant genera unrecorded in modern kākāpō diets (increases of 69, 108 and 75% respectively). We found that southern beeches (Nothofagaceae), which are important canopy-forming trees and not an important kākāpō food today, dominated kākāpō diets in upland (c. >900 m elevation) habitats. We also found that kākāpō frequently consumed hemiparasitic mistletoes (Loranthaceae) and the holoparasitic wood rose (Dactylanthus taylorii), taxa which are nutrient rich, and now threatened by mammalian herbivory and a paucity of dispersers and pollinators. No single dataset or gene identified all taxa in our dataset, demonstrating the value of multiproxy or multigene datasets in studies of animal diets. Our results highlight how contemporary data may considerably underestimate the full dietary breadth of threatened species and demonstrate the potential value of coprolite analysis in conservation biology.

How do host plant use and seasonal life cycle relate to insect body size: A case study on European geometrid moths (Lepidoptera: Geometridae).

We used European geometrid moths (>630 species) as a model group to investigate how life history traits linked to larval host plant use (i.e., diet breadth and host-plant growth form) and seasonal life cycle (i.e., voltinism, overwintering stage and caterpillar phenology) are related to adult body size in holometabolous insect herbivores. To do so, we applied phylogenetic comparative methods to account for shared evolutionary history among herbivore species. We further categorized larval diet breadth based on the phylogenetic structure of utilized host plant genera. Our results indicate that species associated with woody plants are, on average, larger than herb feeders and increase in size with increasing diet breadth. Obligatorily univoltine species are larger than multivoltine species, and attain larger sizes when their larvae occur exclusively in the early season. Furthermore, the adult body size is significantly smaller in species that overwinter in the pupal stage compared to those that overwinter as eggs or caterpillars. In summary, our results indicate that the ecological niche of holometabolous insect herbivores is strongly interrelated with body size at maturity.

Feeding Habits of Dentex maroccanus and the Effect of Body Size

The feeding habits of organisms are important elements in their ecological role and are affected by several factors. The present study provides for the first time information on the diet and feeding strategy of Dentex maroccanus (Valenciennes, 1830) and examines the effects of various factors on the species' feeding activity. Various indices (vacuity index, numerical and weight proportion, frequency of occurrence, alimentary coefficient, index of relative importance, diet breadth and overlap, Shannon-Wiener index, and trophic level) were estimated. The diet of the species consisted of 18 different prey taxa. The most important prey taxon was Decapoda. The study of the feeding strategy showed the narrow width of the species. Body size was found to significantly affect the species' feeding habits. Polychaeta and Stomatopoda were found only in individuals with size ≥165 mm, Bivalvia mainly in sizes ≤120 mm, and Decapoda in the intermediate sizes. The largest individuals showed the lowest overlap with all other size groups. The trophic level increased from 3.7 in young individuals to 4.0 in larger sizes, indicating the carnivorous character of the species. The results of the present work contribute to a better knowledge of the species' feeding ecology.

Diet composition of Asiatic lions in protected areas and multi-use land matrix

Comparative studies on the diet of large felids in protected areas (PAs) and surrounding multi-use landscapes are important for their conservation. The Asiatic lion is an endangered felid distributed in Gir PA and the surrounding multi-use land matrix. Based on scat analyses, we assessed the dietary composition of Asiatic lions. The frequency of occurrence (FOO), biomass consumption model, dietary niche breadth and dietary overlap index was used to quantify diet. The Asiatic lion ate more wild prey (74%) than domestic livestock (26%) in the Gir PA. In contrast, lion diets comprised 51% wild prey and 42% domestic livestock in the multi-use land matrix. Sambar contributed most (38%) to the diet in PAs, while blue bull most (29%) in the multi-use land matrix. However, diet diversity and niche breadth were similar between these two areas. The dietary overlap in the lions' diet between these two areas was 0.52. The results suggest that large-size wild ungulates are the main prey species in Gir PA, while in the surrounding multi-use land matrix, both large wild ungulates and domestic livestock are the main prey. The present study may help future lion conservation management decisions.