The team could not have come to its unexpected conclusions without those decades of detailed field observations led by Botswana Predator Conservation, Abrahms said. Over the same time frame, annual maximum temperatures spiked by 3.8 degrees Celsius - just over 6 degrees Fahrenheit. They discovered a correlation between temperatures during the denning period and survival: Warmer denning periods led to fewer pups recruiting to packs at the end of winter, which indicated that fewer pups survived the denning period.Īverage daily maximum temperatures in the study period rose by about 1.6 degrees Celsius, or 2.9 degrees Fahrenheit, over 30 years. The team used long-term demographic data to calculate how many pups survived the denning period each year. Such a large shift is likely due to the rapid pace of warming in the region, and because African wild dogs have evolved to breed within a narrow “thermal window,” according to Abrahms. “Although most animal species are advancing their life history events earlier in the year with climate change, this finding represents a rare instance of a species delaying its life history, and at a rate twice as high as the average rate of change observed across animal species”, said Jeremy Cohen, a researcher at Yale University and the Center for Biodiversity and Global Change, who was not involved in the study.
Krystyna GolabekĪbrahms and her colleagues analyzed the dates that African wild dog mothers gave birth to their litters each year, which is how they determined that adults gradually delayed breeding by about one week per decade over the 30-year study period. After birth, pups spend about 3 months with their mother at the den before beginning to travel and hunt with the pack.Īn African wild dog mother and pups. This species breeds annually each winter. Abrahms and her colleagues show that large predators can indeed exhibit strong responses to long-term climate change, even though predators are “farther removed” up the food chain.įor this study, the team analyzed more than three decades of data that they and collaborators collected on 60 packs of African wild dogs that live across a more than 1,000 square-mile region of northern Botswana. But, until now, scientists had never documented a climate-driven phenological shift in a large mammalian carnivore. Other research has shown that long-term warming can trigger phenological shifts, or shifts in the timing of major life events, in “primary producer” species like plants and “primary consumers” that feed on plants, including many birds and insects. The study demonstrates that species on high “trophic levels” in ecosystems - like large predators - can be just as sensitive to climate change as other species, something that scientists were uncertain about. “African wild dogs shifted birthing dates later in order to keep pace with optimal cool temperatures, but this led to hotter temperatures during the denning period once those pups were born, which ultimately lowered survival.”Īn African wild dog mother and pup. “It is an unfortunate ‘out of the frying pan, into the fire’ situation,” said Abrahms.
In a phenological trap, a species changes the timing of a major life event in response to an environmental cue - but, that shift proves maladaptive due to unprecedented environmental conditions like climate change. This study shows that African wild dogs, which are distantly related to wolves and raise young cooperatively in packs, may be caught in a “phenological trap,” according to lead author Briana Abrahms, a UW assistant professor of biology and researcher with the Center for Ecosystem Sentinels. But as a result of this significant shift, fewer pups survived their most vulnerable period because temperatures during their critical post-birth “denning period” increased over the same time period, threatening the population of this already endangered species.
They discovered that, over a 30-year period, the animals shifted their average birthing dates later by 22 days, an adaptation that allowed them to match the birth of new litters with the coolest temperatures in early winter. A team led by researchers at the University of Washington, in collaboration with Botswana Predator Conservation, a local NGO, analyzed field observations and demographic data from 1989 to 2020 for populations of the African wild dog - Lycaon pictus.
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