Stranger Danger: Differential response to strangers and neighbors by a social carnivore, the Asiatic wild dog (Cuon alpinus)

Abstract

The function of holding territories is primarily to have access to resources like food and mates. However, it is costly in terms of energy and time investment. Solitary-living, territorial species are known to reduce these costs by being more aggressive towards unfamiliar strangers and less aggressive towards neighbors. However, in social, territorial species, neighbors can impose a greater threat than strangers. We tested whether the highly social Asiatic wild dogs/dholes (Cuon alpinus) exhibit the “nasty neighbor” or the “dear enemy” phenomena in Tadoba Andhari Tiger Reserve (TATR), Maharashtra, India. We conducted scat translocation experiments where we presented fresh scats collected from unique donor groups to a resident dhole group and tested the type and the intensity of behavioral response (duration) to the stimulus. Dholes responded differentially to the two treatments suggesting they exhibit neighbor-stranger discrimination. Overall, strangers elicited a stronger response with longer duration and larger packs were less likely to respond to the stimulus than smaller packs. Differences found between categories of dhole scent marks establish the importance of olfactory communication, especially “counter-marking” in the species. Within recipient packs, individual status affected the response to trials wherein the alpha pair reacted more intensively to strangers than others. Our study provides experimental evidence to demonstrate that dholes exhibit the “dear enemy” phenomenon.

Significance statement

Animals defend territories from other members of their own species, but intrusions are commonplace in the wild. Different intruders may pose different levels of threats, and hence, intruders are treated differentially to minimize the energetic costs of territorial defense. In some animals, neighbors with well-established territories may become less aggressive towards each other. This is known as the dear enemy effect. By contrast, at times neighbors may represent a greater threat than strangers which is known as the “nasty neighbor” effect. We experimentally show that dholes exhibit the dear enemy phenomenon by responding more intensively to strangers than familiar neighbors. We show how response varied based on hierarchy in a pack as well as the pack sizes. Furthermore, we found that, both in core as well as buffer areas of their own territory, this relationship was consistent.