African wild dogs (Lycaon pictus), photographed at the Bronx Zoo.
African wild dogs (Lycaon pictus) don’t have it easy. Their taste for large mammalian prey puts them in competition with lions and spotted hyenas for both prey and living space, meaning that wild dogs regularly have their kills stolen or are even killed by other predators. In fact, the dogs may even be unintentionally attracting the attention of these other hunters.
Like other social carnivores, African wild dogs communicate with each other through body language and olfactory cues, but they also employ a variety of high-pitched vocalizations. Despite their social benefits, however, the chirps and twitterings of these canids also come with costs. Eavesdroppers can use the information gained through what they overhear to their own advantage, and this can be especially dangerous in the case of lions. They kill wild dogs if they can catch them, and by vocalizing wild dogs run the risk of calling attention to their dens, their kills, or even themselves.
That lions do hone in on African wild dog calls is supported by a recent paper by scientists Hugh Webster, John McNutt, and Karen McComb published in the journal Ethology. Over the course of several years the team ran a series of playback experiments in Botswana’s Okavango Delta in which African wild dog calls (“twitters”) were played in the vicinity of lions and spotted hyenas (as well as bird calls similar to the wild dog vocalizations as a control and spotted hyena whoops to see if there was a difference in reactions). In all the researchers observed the reactions of 51 lions from a minimum of six prides and 11 spotted hyenas from three clans, with one month between each experiment.
The results of the experiments showed a very clear pattern. In almost every case lions approached the direction of the speaker as soon as they heard an African wild dog call. They ignored the bird calls, and lions belonging to groups containing adult males were more likely to approach the speaker when they heard hyena whoops than those in groups without males, but almost every time the researchers played a wild dog call the lions approached regardless of their own group dynamics. The hyenas, on the other hand, showed clear signs that they heard the vocalizations, but they did not regularly approach. In fact, the researchers report that they sometimes observed hyenas resting in the vicinity of wild dogs, showing the dogs no nearly no attention until they set off to hunt.
Given these results, it would appear that (in the Okavango Delta, at least) African wild dogs vocalize at their own risk – if a lion hears a wild dog it will almost certainly approach. In one playback experiment not included in the final dataset, for example, a group of lions temporarily abandoned a buffalo kill when they heard the wild dog call, suggesting that their antagonism is driven more by competition and less by the desire to steal kills from the dogs. As the researchers note, the aggressive attitudes of the lions may explain why African wild dogs are rare in areas with denser lion populations, and it appears that hyenas are not as much of a threat to the canids as previously thought.
Given these risks it might be expected that African wild dogs would be less vocal or at least develop more cryptic vocalizations, but this does not appear to be the case. It would seem that the social benefits that come from their vocalizations outweigh the risk of detection by lions, and since African wild dogs are highly mobile predators they probably try to avoid areas frequented by lions as much as possible. As suitable habits for these predators shrink, however, lions and African wild dogs may be brought into closer contact, and understanding the interactions between these predators will be important for conservation efforts aimed at helping these predators.
Webster, H., McNutt, J., & McComb, K. (2010). Eavesdropping and Risk Assessment Between Lions, Spotted Hyenas and African Wild Dogs Ethology, 116 (3), 233-239 DOI: 10.1111/j.1439-0310.2009.01729.x