Understanding the effects of seasonal variation in prey availability on prey switching by large carnivores

Abstract

Optimal foraging theory predicts that carnivores select prey species based on intrinsic factors, such as body size, vulnerability, and abundance. Prey abundance can vary significantly, especially when prey species move in and out of an area en masse in search of food. However, little is known about how these resource pulses influence the prey profiles of large carnivores. Using data on lion (Panthera leo) and cheetah (Acinonyx jubatus) kills in the Maasai Mara in Kenya, we investigate whether changes in prey abundance, as a result of a mass annual migration of herbivores, influence the prey profiles of these two carnivore species. Furthermore, for cheetah we investigate whether there are sex-specific differences in prey profiles in response to changes in prey abundance. Using data from 387 lion kills and 220 cheetah kills (160 female and 60 male), we found that changes in prey abundance had a strong influence on prey profiles, but that for cheetahs this varied by sex and social grouping. More specifically, during the migration, when there is an influx of wildebeest (Connochaetes taurinus), lions and male cheetah (particularly those in coalitions) were more likely to feed on wildebeest than out of the migration. In addition, when wildebeest were less abundant, lions switched to buffalo (Syncerus caffer). Overall, the breadth of the prey profiles was narrower during the migration compared to out of the migration but this was most significant for lions and coalitions of male cheetahs. These changes in prey profiles could have an impact on herbivore dynamics, human-wildlife conflict and ecological interactions more broadly. Through the detailed characterisation of prey profiles, we contribute to the understanding of predator-prey dynamics and trophic interactions in complex, multi-species ecosystems and illustrate the importance of taking into account inter-and intraspecific variations in predators when modelling predator-prey dynamics.

Animal behavior informed by history: Was the Asiatic cheetah an obligate gazelle hunter?

“…We could not find any evidence of the effect of social structure, season, or protected area on the prey choice in Asiatic cheetahs, contrary to our second hypothesis [ 29 , 30 ]. Bezoar goats are the largest medium-sized ungulates in Iran, often found in rugged, precipitous terrains [ 74 ] which are less suitable as habitats of cheetahs [ 75 – 77 ].…”

“…Bezoar goats are the largest medium-sized ungulates in Iran, often found in rugged, precipitous terrains [ 74 ] which are less suitable as habitats of cheetahs [ 75 – 77 ]. We expected that bezoar goats would be preyed upon by cheetah coalitions, which corroborate those of studies done in Africa which found that male coalitions killed larger prey species [ 30 , 78 ]. More than half of the kills made by coalitions in Iran were bezoar goats; however, our sample size for kills that were made by coalitions was too small to test its significance.…”

“…Cheetah populations are known to show some degree of specialization in their choice of prey [ 30 , 78 ] or hunting habitat [ 31 , 79 ]. Our work revealed selective hunting of adult male (> 4 years) urials and bezoar goats, which is in accordance with previous observations of prey sex selectivity by cheetahs in central Iran [ 80 ] as well as Africa [ 63 , 81 ] Antipredator vigilance, which is more common in females and their young among mountain wild sheep and goats [ 37 , 82 ], is a possible explanation for apparent male-selective predation by Asiatic cheetahs.…”

“…Second, we questioned the determinants of recent prey choice made by Asiatic cheetahs given that their prey species is currently scarcer than historical times. We thus hypothesized that the prey choice is affected by cheetah social structure [ 29 ] and season [ 30 , 31 ].…”

Season, prey availability, sex, and age explain prey size selection in a large solitary carnivore

“…Individual prey selection among solitary carnivores likely impacts predator–prey dynamics in multi‐prey systems (e.g., prey switching, Vettorazzi et al., 2022 ), such as the population viability of rare prey (Festa‐Bianchet et al., 2006 ; Ross et al., 1997 ; Wittmer et al., 2014 ). It may also provide insights into the ecology of different life stages of a species (Elbroch, Feltner, & Quigley, 2017a ), as well as social tolerance for (Treves & Karanth, 2003 ) and management of (Linnell et al., 1999 ) carnivores in general.…”