Calves at Play: Neonate Humpback Whale Behavior when Escorts are Present vs. Absent

Abstract

This study examined humpback whale (Megaptera novaeangliae) mother-calf pair behavior when escorts (other accompanying adults) were present vs not present. In the ‘Au’Au Channel, Maui, HI, humpback whale pods were located and their composition determined. Data was collected only for pods that contained a mother and calf. Mother and calf pairs were identified by observation of close behavioral association, size differences and juvenile features of the calf including size, body color and dorsal fin curvature. Calf relative age may be characterized by the degree of unfurling of the dorsal fin. We conducted focal-follows of each pod lasting approximately 15 minutes each, recording behaviors, and collected GPS points where the calf surfaced. We classified the behaviors of the calves including: different rates of travel (resting, slow travel, fast travel) and display behaviors (breaching, fluke/ pectoral fin slapping). Our previous observations have suggested  that calves participate in energetic behaviors such as fast travel, frequent breaching, and swimming on both sides of the mother in the presence of at least one escort, where in the absence of a male escort, calves participate in slow travel and resting. Behavioral observations made in the presence and absence of escorts suggests the possibility of a marked difference in behavior depending on pod composition. This research was conducted under NOAA NMFS permit #22750-01.

Presentation