Only the largest terrestrial carnivores increase their dietary breadth with increasing prey richness

Abstract

1. Animals should adapt their foraging habits, changing their dietary breadth in response to variation in the richness and availability of food resources. Understanding how species modify their dietary breadth according to variation in resource richness would support predictions of their responses to environmental changes that alter prey communities. 2. We evaluated relationships between the dietary breadth of large terrestrial carnivores and the local richness of large prey (defined as the number of species). We tested alternative predictions suggested by ecological and evolutionary theories: with increasing prey richness, species would (1) show a more diverse diet, thus broadening their dietary breadth, or (2) narrow their dietary breadth, indicating specialisation on a smaller number of prey. 3. We collated data from 505 studies of the diets of 12 species of large terrestrial mammalian carnivores to model relationships between two indices of dietary breadth and local prey richness. 4. For the majority of species, we found no evidence for narrowing dietary breadth (i.e. increased specialisation) with increasing prey richness. Although the snow leopard and the dhole appeared to use a lower number of large prey species with increasing prey richness, larger sample sizes are needed to support this result. 5. With increasing prey richness, the five largest carnivores (puma Puma concolor, spotted hyaena Crocuta crocuta, jaguar Panthera onca, lion Panthera leo, and tiger Panthera tigris), plus the Eurasian lynx Lynx lynx and the grey wolf Canis lupus (which are usually top predators in the areas from which data were obtained), showed greater dietary breadth and/or used a greater number of large prey species (i.e. increased generalism). 6. We suggest that dominant large carnivores encounter little competition in expanding their dietary breadth with increasing prey richness; conversely, the dietary niche of subordinate large carnivores is limited by competition with larger, dominant predators. We suggest that, over evolutionary time, resource Mammal Review

Dietary similarity among jaguars (Panthera onca) in a high-density population

“…Across their distributional range, jaguars have been documented to take at least 111 wild species [ 19 ]. They are widely considered to be opportunistic predators, displaying greater dietary breadth (increased generalism) with increasing prey richness [ 20 ]. However, generalist feeding behaviour at the distributional level may reflect specialisations at the population level (e.g.…”

CarniDIET 1.0: A database of terrestrial carnivorous mammal diets

“…Such studies have been combined to address conservation questions about individual carnivore prey preferences (Hayward & Kerley, 2008) and diet variation across abiotic gradients (Bojarska & Selva, 2012; Virgos et al., 1999), and to conduct multispecies macroecological and macroevolutionary analyses. However, such analyses are often taxonomically and morphologically limited, such as vulnerability of felids to prey loss (Sandom et al., 2017) or dietary breadths of large (>14.5 kg) Carnivora (Ferretti et al., 2020). Collating and making openly accessible diet data across taxonomic groups of carnivorous mammals across wider body mass ranges would allow further conservation questions to be answered, and open up research avenues in macroevolution and macroecology.…”

Forest cover mediates large and medium-sized mammal occurrence in a critical link of the Mesoamerican Biological Corridor

“…Jaguars, alongside pumas ( Puma concolor ; IUCN: least concern; [ 53 ]), are the largest predators in the region and their presence elsewhere has been associated with prey biomass and availability [ 22 , 54 – 56 ]. However, some studies have also found that prey richness can be related to large carnivore richness [ 57 ], occupancy [ 15 ], or dietary niche breadth [ 58 ].…”