Tracking the isotopic changes of d13C, d15N d18O and d2H of African Wild Dogs (Lycaon pictus) over a 12 year period in Laikipia, Kenya
African wild dogs (Lycaon pictus) are social coursing predators that hunt in packs and rely on mammalian prey and water intake from bodies of water. They are also listed on the IUCN list of endangered species. The role of prey-derived water in their survival, especially during drought, though seemingly important, is largely unknown. Our goal in this study was to address changes in the behavior of African wild dogs by analyzing d13C, d15N, d18O and d2H of hair collected from 22 individuals over a period of twelve years (2001-2013). Special interest was paid to the years when the area experienced a severe drought. We expect changes in feeding behavior and movement patterns during drought years. Both the specific isotopic variation of each element and the co-variation among them was used to gain insight into the changing behavior of the wild dogs during these times.
The average values for δ15N, δ13C, and δ18O were +12.8 ± 1.0‰, −16.6 ± 1.9‰, and +15.5 ± 0.9‰ respectively. Our results show large variability between packs, most notably, from the Lebai dispersal pack, but the comparison among individuals from the same packs showed that they are very similar in their isotopic compositions. The latter is a strong indication of the cooperative nature of their hunting and eating habits. The δ18O composition of the hair keratin increased by ~1 ‰ and δ13C ~2 ‰ during the drought. We see a positive excursion going from C3 (browser) towards C4-plant based animals (grazers) such as impala and wildebeest, indicating that dogs likely switch from feeding over their preferred prey (dik dik) and start following larger prey. This is supported by the co-variation between high δ18O values and high δ13C and δ15N values. In conclusion our preliminary data suggest that wild dogs may increase the amount of grazers in their diet during drought, possibly taking advantage of their congregation at watering holes.