Factors affecting life and death in Serengeti cheetahs: environment, age, and sociality

Abstract

We examined environmental and social factors affecting reproductive success across a 20-year data set of individually known cheetahs on the Serengeti Plains of Tanzania. Because cheetahs are seen infrequently and are not amenable to mark-recapture techniques, we devised a model to estimate time of death for individuals that disappeared from our records. We found that males had markedly lower survival than females. Recruitment was negatively affected by rainfall but positively affected by numbers of Thomson's gazelles, the cheetahs' chief prey. There was a negative association between recruitment and numbers of lions, demonstrating that the high rates of predation observed in previous studies have implications for the dynamics of cheetah populations. Recruitment was related to mother's age, peaking when she reached 6-7 years. Sociality affected survival in two ways. First, adolescents living in temporary sibling groups had higher survival than singletons, particularly males with sisters. Second, adult males living in coalitions had higher survival than singletons in periods when other coalitions were numerous, yet they had lower survival when other coalitions were rare. These results corroborate observations of enhanced prey capture by female adolescents and antipredator benefits for adolescents in groups, as well as competitive advantages for adult males in groups. Furthermore, our findings stress the importance of interactions between environmental and social factors in affecting reproductive success in mammals.

Home Range Use of Free-Ranging Cheetah on Farm and Conservation Land in Botswana

“…This difference may be explained by their need to defend their territory in order to obtain females, or the males may have travelled further to occupy territory vacancies or been forced to move to avoid human conflict or competition with other cheetahs or predators. Often single males are pushed out of an area by coalitions or other territorial single males, forcing them to take on a more wandering form of life style (Durant et al 2004). This may have been the case with M5 who occupied a home range of 663 km 2 for 87 days, then travelled 40 km north to set up a 422 km 2 range.…”

“…Collar malfunction and dispersal of cheetah out of monitoring range (Durant et al 2004) had a negligible effect, however cheetah-farmer conflict resulted in at least 55% of losses (some of the cheetah lost to unknown factors were most likely killed). These killings were not due to actual livestock loss, but appear to be due to the perceived threat of loss and an overall intolerance to predators, this problem was also recorded in Namibian farmlands (Marker et al 2003b).…”

Natural and anthropogenic drivers of cub recruitment in a large carnivore

“…Therefore, it is possible that in the Serengeti‐Mara ecosystem, the viability of the cheetah population depends on cub recruitment in other, more densely vegetated, areas. This source–sink dynamic could also explain why, in the Serengeti, overall lion numbers do not have a negative effect on the cheetah population as whole (Swanson et al., 2014), despite the fact that lion abundance is negatively correlated with the survival and recruitment of cheetah cubs (Durant et al., 2004). In the present study, lion nor spotted hyaena abundance had a negative effect on cheetah cub recruitment despite other studies showing that cheetah cubs are often killed by these predators (Laurenson, 1994) and that a larger number of cubs per litter are recruited in areas without lions compared to areas with lions (Bissett & Bernard, 2011).…”

“…Cheetah cubs can succumb to various factors including abandonment, poor health, and fires. However, it is predation by other predators, especially lions ( P. leo ) and spotted hyaenas ( Crocuta crocuta ), that is the predominant cause of cub mortality across sites (Laurenson, 1994; Mills & Mills, 2017) and lion abundance has been shown to be negatively correlated to the recruitment of cheetah cubs (Durant, Kelly, & Caro, 2004). However, the occurrence of predator‐induced mortality could be influenced by factors, such as vegetative cover, that provide concealment and minimizes detection by other predators (Broekhuis, Cozzi, Valeix, McNutt, & Macdonald, 2013; Rostro‐García, Kamler, & Hunter, 2015).…”

Sociality in cats: A comparative review

“…As adolescents, cheetahs are more likely to survive in groups than as singletons, chiefly due to reduced predation by lions, but also because they are able to offset some of the costs of group-living by capturing larger prey (Durant et al, 2004). Once they become adult, male cheetahs living in sibling groups are better able to establish territories and thereby monopolize females (Caro and Kelly, 2001).…”