Data from: Disentangling the effects of temperature and rainfall on the population dynamics of Kalahari meerkats

In arid habitats, recent increases in summer temperatures associated with
global warming are adversely affecting many animal populations. However,
annual rainfall also varies widely in many of these areas, and we do not
yet fully understand the relative impact of variation in temperature and
rainfall on the demography of arid-zone species. Here, we examine the
effects of temperature and rainfall variation on the demography of
meerkats (Suricata suricatta) in the southern Kalahari over the last 25
years. During this period, average maximum monthly air temperatures at our
study site increased by around 1.5ºC to 3.2ºC, while annual rainfall
fluctuated without a consistent trend. We show that annual changes in
female fecundity and recruitment were more closely correlated with
variation in rainfall. Increasing air temperatures were associated with
reductions in the recruitment of pups and the survival of some age classes
but, in most cases, the demographic consequences of high temperatures were
modest compared to the effects of low rainfall, which in some years led to
the near cessation of successful reproduction and the extinction of many
smaller groups. For instance, exceptionally low rainfall in 2012-2013 was
associated with low recruitment and with declines in group size and
population density, which fell by over 50%. Unusually hot years did not
have similar consequences. Following the 2012-2013 drought, intermittent
years of low rainfall and frequent droughts continued to suppress
recruitment and slowed the population’s recovery. Future changes in
temperature may affect the dynamics and size of the meerkat population,
but our work suggests that over the last 25 years, annual changes in
rainfall have exerted a stronger influence on meerkat demography. Our
study demonstrates the importance of long-term, individual-based data for
determining how changes in climate affect the dynamics of animal
populations, especially in arid environments where bottom-up processes
often dominate.