Play by Peary caribou calves before, during, and after helicopter harassment

• Published in: Canadian Journal of Zoology
• Main Authors: Miller, Frank L., Gunn, Anne
• Format: Article in Journal/Newspaper
• Language: English
• Published: Canadian Science Publishing 1981
• Subjects: Animal Science and Zoology; Ecology, Evolution, Behavior and Systematics; Northwest Territories; Peary; Prince of Wales Island; caribou; Rangifer tarandus
• Online Access: http://dx.doi.org/10.1139/z81-118; http://www.nrcresearchpress.com/doi/pdf/10.1139/z81-118

We observed 93 bouts of play behaviour by Peary caribou (Rangifer tarandus pearyi) calves on northeastern Prince of Wales Island, Northwest Territories (N.W.T.), between 23 June and 16 August 1977. Play consisted of 58 contagious, 20 exploratory, 13 agonistic, and 2 sexual bouts. Calves engaged in 30 bouts of play during the undisturbed phase, 30 bouts during the harassed phase, and 33 bouts during the recovery phase of the observations. Play was proportionately most frequent during the harassed phase, least frequent during the undisturbed phase, and occurred slightly less than expected during the recovery phase (P < 0.005). We speculate that (1) Peary caribou calves were more excited than adult companions by helicopter; (2) this higher excitement led to a general readiness to be active; and (3) when adults did not overtly respond, the readiness of the calves to be active was released as play. Therefore, play by Peary caribou should not be used as an indication of a total lack of stress during or shortly after periods of harassment.