Climate change imposes an urgent need to recognise and conserve the species likely to be worst affected. However, while ecologists have mostly explored indirect effects of rising ambient temperatures on temperate and polar species, physiologists have predicted direct impacts on tropical species.
The African wild dog (Lycaon pictus), a tropical species, exhibits few of the traits typically used to predict climate change vulnerability. Nevertheless, we predicted that wild dog populations might be sensitive to weather conditions, because the species shows strongly seasonal reproduction across most of its geographical range.
We explored associations between weather conditions, reproductive costs, and reproductive success, drawing on long-term wild dog monitoring data from sites in Botswana (20°S, 24 years), Kenya (0°N, 12 years), and Zimbabwe (20°S, 6 years).
High ambient temperatures were associated with reduced foraging time, especially during the energetically costly pup-rearing period. Across all three sites, packs which reared pups at high ambient temperatures produced fewer recruits than did those rearing pups in cooler weather; at the non-seasonal Kenya site such packs also had longer inter-birth intervals. Over time, rising ambient temperatures at the (longest-monitored) Botswana site coincided with falling wild dog recruitment.
Our findings suggest a direct impact of high ambient temperatures on African wild dog demography, indicating that this species, which is already globally endangered, may be highly vulnerable to climate change. This vulnerability would have been missed by simplistic trait-based assessments, highlighting the limitations of such assessments. Seasonal reproduction, which is less common at low latitudes than at higher latitudes, might be a useful indicator of climate change vulnerability among tropical species.
Biomass ratio of wild dog packs in Kenya
The file presents, for each day before, during, and after the denning period, the ratio between the total biomass of wild dogs in each pack, and the biomass of wild dogs able to feed directly from kills (i.e. excluding pups and babysitters confined to the den). Data are from our Kenya study site.
biomass_ratio_Kenya.xlsx
Activity every 24hrs for wild dogs in Kenya
Summed activity over 24hr periods (sunrise-sunrise) from 10 GPS-collared African wild dogs during denning and non-denning periods in Kenya
activity_Kenya.xlsx
Home range size of wild dogs in Kenya before, during, and after denning
Home range size (in sq km) of GPS-collared wild dogs, for 10-day periods before, during, and after denning in Kenya. Home range size was measured using Minimum Convex Polygons. Wild dog WDM123 was tracked through two denning periods.
home_range_size_Kenya.xlsx
Daily distances travelled by wild dogs in Kenya
Daily distances travelled (in m) by GPS-collared African wild dogs before, during, and after denning in Kenya
daily_distance_travelled_Kenya.xlsx
Periods of occupying successive dens in Kenya
The file shows, for each GPS-collared wild dog, the number of days spent using each den and the distance moved to the next den. Dat are from our Kenya study site.
den_moves_Kenya.xlsx
Inter-birth intervals for wild dog packs in Kenya
File shows the period (in days) between successive births for African wild dog packs in Kenya, along with potential covariates
interbirth_interval_Kenya.xlsx
Activity every 5mins for wild dogs in Kenya
File shows, for 10 GPS-collared African wild dogs in Kenya, activity every 5 mins measured relative to the mean activity for that time point smoothed over a 20min period. Concurrent data on temperature measured by the collar are also provided.
relative_5min_activity_Kenya.xlsx
Number of den moves vs ambient temperature in Kenya
The file shows the number of times packs of wild dogs in Kenya shifted den during each denning period, and mean daily maximum ambient temperature during the same period. Data are limited to the GPS-collared wild dogs monitored over an entire denning period. Only data from GPS-collared packs were used because monitoring using VHF collars was necessarily less intensive and may have failed to detect some den moves.
den_shifts_vs_temp_Kenya.xlsx
Annual reproductive success and population density at all 3 sites
The file shows, for each calendar year of monitoring in all three study sites, the estimated density (adults and yearlings per 100 sq km), and mean litter size per pack and mean pup survival to 12 months for the previous year.
reproductive_success_vs_density_all_sites.xlsx
Wild dog reproductive success at our Botswana study site
This file shows, for our Botswana study area, the number of pups raised to three months of age in each breeding attempt, the number that survived to 12 months, and various potential covariates.
reproductive_success_Botswana.xlsx
Wild dog reproductive success at our Zimbabwe study site
This file shows, for our Zimbabwe study area, the number of pups raised to three months of age in each breeding attempt, the number that survived to 12 months, and various potential covariates.
reproductive_success_Zimbabwe.xlsx
Wild dog reproductive success at our Kenya study site
This file shows, for our Kenya study area, the number of pups raised to three months of age in each breeding attempt, the number that survived to 12 months, and various potential covariates.
reproductive_success_Kenya.xlsx
Trend in denning-season ambient temperature at our Botswana site
The files shows, for each year of monitoring at our Botswana site, mean daily maximum ambient temperature for the dates 20 May-10 Sep. The year 1994 was conservatively excluded due to unusually low reported temperature and hence high leverage; including this year strengthened rather than weakened the observed warming trend.
Botswana_temperature_by_year.xlsx