- Meerkat (Suricata suricatta) pups are gaining less body mass and surviving in fewer numbers as the daily maximum air temperature has risen in the Kalahari, according to a new study.
- When exposed to hot air and soil, the pups may be losing water from their bodies faster than they can replenish it.
- Researchers guessed that the cooperative child-rearing strategy of meerkat groups could buffer the effects of high temperatures, but pup growth and survival declined independently of group size.
The meerkat mobs of the Kalahari Desert fend off snakes and feast on scorpions, but a new foe is wearing them down: the slowly creeping heat of the day.
Over the past few decades, the daily maximum air temperature has risen in the Kalahari. According to a new study, meerkat (Suricata suricatta) pups are gaining less body mass and surviving in fewer numbers as the climate changes.
“Globally, there is evidence of declining body sizes of multiple species in response to the environment getting warmer,” Tanja Van de Ven, lead author of the study, told Mongabay.
“Our results confirmed that meerkats too are declining in body size over the past 22 years.”
So why are these high temperatures affecting the pups? Meerkats get most of their water from the food they eat and regulate their body temperature by evaporative cooling. When exposed to hot air and soil, the pups may be losing water from their bodies faster than they can replenish it. The resulting dehydration causes the breakdown of muscle and reduces growth.
Van de Ven had noticed high air temperatures affecting the growth and survival of a bird species (the southern yellow-billed hornbill, Tockus leucomelas) in the Kalahari and wondered if the same would be true of a small mammal living in this arid environment. Meerkats, however, have an advantage hornbills do not: a little help from their friends.
In arid and unpredictable environments, some animals work together as a community to raise their young, a system known as cooperative breeding. The researchers guessed that this community effort, found in meerkat populations, might buffer the adverse effects of climate change on the pups, with more helpers around to forage and feed the young.
“I did presume that the cooperative strategy of the meerkats could prevent the pups from being affected, because of the family members looking after the pups,” said Van de Ven. But independent of group size, high temperatures still affected pup growth and survival, even though the overall feeding rate increased on hotter days.
“In arid environments, decreases in reproduction and survival [of animals] are typically associated with droughts — that is, the focus is largely on rainfall,” said Maria Paniw, an ecologist at the University of Zurich who has studied the effects of climate on meerkats. “Here, we see that rainfall is only one part of the picture.”
This study draws upon long-term monitoring of meerkats in the southern Kalahari by volunteers at the Kalahari Meerkat Project. The meerkat populations studied, though wild, have been habituated to humans. They are trained to climb on a scale for measurements in exchange for a tiny crumb of boiled egg.
“This paper demonstrates the great value of long-term studies in global-change ecology,” Paniw said. “More than 20 years of detailed observations of meerkats allowed the authors to assess robustly some of the complex mechanisms through which climate change affects natural populations.”
The past decade was the hottest on record, and 2019 the second-hottest year globally. Warming is predicted to continue, meaning the future is uncertain for the meerkats of the Kalahari.
Banner image of a meerkat in the Southern Kalahari by Tanja Van de Ven.Citation: Van de Ven, T. M. F. N., Fuller, A., & Clutton‐Brock, T. H. (2020). Effects of climate change on pup growth and survival in a cooperative mammal, the meerkat. Functional Ecology, 34(1),194-202. doi:10.1111/1365-2435.13468
Liz Kimbrough is a staff writer for Mongabay. Find her on Twitter @lizkimbrough_
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