THE TURUCHAN PIKA (OCHOTONA TURUCHANENSIS NAUMOV 1934, OCHOTONIDAE, LAGOMORPHA) PLAYING IN THE WILD

The adaptive functions and evolution of animal play remain unclear despite the great interest of researchers to these topics. One reason for this is thought to lie the deficiency of data on animal play in the wild, as well as on certain taxa. The latter include lagomorphs, as there is no information at all about the play in pikas (family Ochotonidae). This report describes some cases of play in the local population of the Turuchan pika on the Primorsky Mountain Ridge in the Irkutsky District of the Irkutsk Region (52.07 N, 105.16 E). During two vegetation seasons (May–September 2020–2021), we observed 14 individually marked pikas (6 males, 6 females, 2 subadults) for more than 150 hours by the ad libitum scoring of the focal animal behavior in the morning and in the evening. All behaviors were continuously recorded with a voice recorder. A total of 15 game episodes were registered in seven animals, of which 8 episodes were video recorded (32 frames per second). A subsequent frame-by-frame analysis of the videos allowed us to describe play behaviors more accurately and to evaluate their time parameters. Following Burghardt, we defined play behaviors as repetitive, but non-stereotypic activities that differed from the common activities and failed to contribute to current survival, initiated spontaneously by non-distressed animals. We found one element that was present in all episodes of an individual play, one we termed “jerk-uplifting”. A “jerk-uplifted” animal rose sharply on outstretched hind legs (sometimes jumps), while the head was thrown back, and the front legs were extended forward. Such a movement took an average of 0.54 ± 0.34 seconds. “Jerk-uplifting " could be accompanied by body twisted around the vertical axis. We analyzed 30 cases of “jerk-uplifting” of seven animals. In six cases, it was a single act; in the other 24 cases, “jerk-uplifting” occurred in a series of 2–4 acts, separated by intervals of several seconds. Of the seven playing pikas, four were adult males, two were adult females, and two were young animals. In 22 cases (73.3%), a “jerk-uplifted” animal had some object in its mouth: most often a bunch of lichens, but sometimes a bunch of grass or a dry stick. Only once after playing did the pika begin to eat lichens with which it was “jerk-uplifted”. “Jerk-uplifting” could alternate or end with sudden jumps and runs. Some motor activity preceded “jerk-uplifting” in all cases. Another form of individual play was noted twice: the animal jumped several times, breaking off the ground with all four paws and bending in the air, then, grabbing a dry branch with its teeth, fell on its back and rolled from side to side. Then, the pika dropped the branch and abruptly jumped up on four paws. Two episodes of social play were recorded. Once, an adult female and a young sexually mature male alternately scampered after each other, then the female hid behind a stone and jumped out at a running male. These actions were repeated several times with a change of the initiator, following which the animals parted in different directions. The second time, the same pikas followed each other with one jumping at the partner. Thus, for the first time, all three types of play (locomotor, object and social) were recorded for Lagomorpha in the wild. This was the first documented evidence of playing pikas that involved different sexes and ages. The play in pikas included elements (jumping, spinning, falling on the back) that were associated with a temporary loss of control.