Opposite companion effect on flight initiation distance in sympatric species: plateau pika (Ochotona curzoniae) and White-rumped Snowfinch (Onychostruthus taczanowskii)

Abstract

There are many factors influencing prey’s risk perception and escape decision during predator–prey encounters. The distance at which animals move away from perceived danger (often quantified as flight initiation distance or FID) has been used by behavioral ecologists to understand the economics of antipredator behavior. Using general linear models, we investigated escape decision-making processes in plateau pika (Ochotona curzoniae (Hodgson, 1858)) and White-rumped Snowfinch (Onychostruthus taczanowskii (Prjevalsky, 1876), formerly known as Montifringilla taczanowskii Przewalski, 1876) together and we found that (i) there are significant positive correlations between starting distance and FID in both species; (ii) pika escapes at a longer distance from an approaching intruder when it is far from its burrow; (iii) foraging animals tolerate closer distances than watching ones, both in pikas and in Snowfinches; (iv) conspecifics seem to have no effect on pikas’ escaping behavior, while the appearance of Snowfinches dramatically decreases the FID of pikas. On the contrary, conspecifics significantly decrease the FID of Snowfinches, while the presence of pikas has no effects. These findings provide new evidence, which are consistent with optimal escape theory. These novel results in multispecies interactions prompt us to pay attention to the potential relationship between pikas and Snowfinches, as well as the “bird–pika in one hole” phenomenon.