Higher temperature extremes exacerbate negative disease effects in a social mammal

Abstract

One important but understudied way in which climate change may impact the fitness of individuals and populations is by altering the prevalence of infectious disease outbreaks. This is especially true in social species where endemic diseases are widespread. Here we use 22 years of demographic data from wild meerkats (Suricata suricatta) in the Kalahari, where temperatures have risen steadily, to project group persistence under interactions between weather extremes and fatal tuberculosis outbreaks caused by infection with Mycobacterium suricattae. We show that higher temperature extremes increase the risk of outbreaks within groups by increasing physiological stress as well as the dispersal of males, which are important carriers of tuberculosis. Explicitly accounting for negative effects of tuberculosis outbreaks on survival and reproduction in groups more than doubles group extinction risk in 12 years under projected temperature increases. Synergistic climate-disease effects on demographic rates may therefore rapidly intensify climate-change impacts in natural populations.

Climate change and tuberculosis drive non-adaptive shifts in the faecal microbiota of wild meerkats

“…No other microbial cluster predicted survival, with non-microbial factors (TB status, social status, age, season and body condition) all having stronger associations with survival (Table S2). Effects of these non-microbial factors on survival are in line with ndings from previous studies on this population 14,28,32,42 .…”

“…The link between climate change and infectious disease was recognised over two decades ago [5][6][7][8] , and their combined impacts are felt across marine and terrestrial ecosystems [9][10][11] . To date, studies on these twin pressures have focused on their effect on host and parasite demography and population viability [12][13][14] , yet little is known about their long term impacts on host-associated microbial communities. Recent evidence suggests that gut microbiotas are affected by both warming 15,16 and changes to host ecology driven by climate change 17 , but long-term studies documenting shifts in gut microbial communities within a population are absent.…”

“…Recently, high maximum temperatures have also been associated with increased risk of TB outbreaks within social groups 14 . TB is caused by the bacterial pathogen Mycobacterium suricattae, a member of the M. tuberculosis species complex, and is characterised by lengthy latent infections that progress to clinical signs in about 25% of cases 30,33,34 .…”

“…Meerkats (Suricata suricatta) inhabiting the South African Kalahari have experienced both climate change and an increase in tuberculosis (TB) prevalence over the past two decades 14,[27][28][29][30] . Maximum temperatures have increased over the study period (Fig.…”

Climate-driven dynamics of pathogenic microbial taxa in birds and bats

“…Also, wildlife diseases are one of the top ve causes of biodiversity loss 5 . The changing climate may alter the prevalence of pathogenic microbes, parasites, and their vectors in wildlife, directly by altering environmental conditions necessary for their survival and virulence, or indirectly by shifting host community composition, abundance, distribution, phenology, or physiological traits [6][7][8][9][10] . Yet the consequences of changing climate, including both temperature and rainfall, on zoonotic and wildlife diseases remains equivocal 6 and contradictory 11 .Birds and bats are highly mobile vertebrates, often contributing to the large-scale transportation of pathogens 2,3,12 .…”