High temperatures and human pressures interact to influence mortality in an African carnivore

Abstract

The impacts of high ambient temperatures on mortality in humans and domestic animals are well‐understood. However much less is known about how hot weather affects mortality in wild animals. High ambient temperatures have been associated with African wild dog Lycaon pictus pup mortality, suggesting that high temperatures might also be linked to high adult mortality. We analyzed mortality patterns in African wild dogs radio‐collared in Kenya (0°N), Botswana (20°S), and Zimbabwe (20°S), to examine whether ambient temperature was associated with adult mortality. We found that high ambient temperatures were associated with increased adult wild dog mortality at the Kenya site, and there was some evidence for temperature associations with mortality at the Botswana and Zimbabwe sites. At the Kenya study site, which had the highest human impact, high ambient temperatures were associated with increased risks of wild dogs being killed by people, and by domestic dog diseases. In contrast, temperature was not associated with the risk of snare‐related mortality at the Zimbabwe site, which had the second‐highest human impact. Causes of death varied markedly between sites. Pack size was positively associated with survival at all three sites. These findings suggest that while climate change may not lead to new causes of mortality, rising temperatures may exacerbate existing anthropogenic threats to this endangered species, with implications for conservation. This evidence suggests that temperature‐related mortality, including interactions between temperature and other anthropogenic threats, should be investigated in a greater number of species to understand and mitigate likely impacts of climate change. ​

Climate change is predicted to cause population collapse in a cooperative breeder

“…While temperature has been found to impact recruitment at all sites where it has been studied (Abrahms et al, 2022; Woodroffe et al, 2017), the age at which these impacts have been found to occur varies both within and between studies (Abrahms et al, 2022; Woodroffe et al, 2017). Temperature impacts on adult survival have not been detected at other sites (Rabaiotti et al, 2021). Unlike the Kenyan site, Southern African sites show strong seasonal variation in temperature and rainfall, and, consequently, seasonal wild dog reproduction (McNutt et al, 2019); these patterns complicate the association between temperature and wild dog demography.…”

“…The interactions modelled explicitly in the model are: adult survival and juvenile survival decrease at higher temperatures, the inter‐birth interval is longer at higher temperatures (Woodroffe et al, 2017), adult survival increases with pack size (Rabaiotti et al, 2021; Woodroffe, O'Neill, & Rabaiotti, 2020), litter size increases with pack size (Woodroffe, Rabaiotti, et al, 2020), dispersal probability increases with pack size (Woodroffe, Rabaiotti, et al, 2020), the inter‐birth interval increases with litter size (Woodroffe et al, 2017), and juvenile survival increases with litter size (Woodroffe et al, 2017). Explicit interactions are shown in Figure 1 and Figure S1.…”

“…The species has a coat pattern that is unique to each individual, meaning that long‐term studies across multiple sites have been able to monitor individuals throughout their lifetime (Creel & Creel, 2002; Woodroffe et al, 2017). Using such data, researchers have been able to estimate rates of recruitment (Abrahms et al, 2022; Woodroffe et al, 2017), survival (Rabaiotti et al, 2021; Woodroffe, 2011a; Woodroffe et al, 2007) and dispersal (Behr et al, 2020; Woodroffe, O'Neill, & Rabaiotti, 2020; Woodroffe, Rabaiotti, et al, 2020). Studies have shown that African wild dog vital rates are impacted by high ambient temperatures across a number of populations, with lower adult survival (Rabaiotti et al, 2021) and recruitment (Abrahms et al, 2022; Woodroffe et al, 2017) at higher temperatures.…”

“…Using such data, researchers have been able to estimate rates of recruitment (Abrahms et al, 2022; Woodroffe et al, 2017), survival (Rabaiotti et al, 2021; Woodroffe, 2011a; Woodroffe et al, 2007) and dispersal (Behr et al, 2020; Woodroffe, O'Neill, & Rabaiotti, 2020; Woodroffe, Rabaiotti, et al, 2020). Studies have shown that African wild dog vital rates are impacted by high ambient temperatures across a number of populations, with lower adult survival (Rabaiotti et al, 2021) and recruitment (Abrahms et al, 2022; Woodroffe et al, 2017) at higher temperatures. The time between one litter and the next (the inter‐birth interval) is also longer at higher ambient temperatures at a site with aseasonal breeding (Woodroffe et al, 2017).…”

Increasing ambient temperatures trigger shifts in activity patterns and temporal partitioning in a large carnivore guild

“…Additionally, the ecology and fitness of species within the African large predator guild are influenced by climate variables; for example, the behaviour, reproductive success and mortality of different species are impacted by temperature (e.g. [39][40][41][42]).…”