Change in Southern right whale breathing behavior in response to gull attacks

A. FAZIO; M. BERTELLOTTI; M.B. ARGÜELLES

Puerto Madryn

Workshop; Southern right whale die-off Workshops; 2014

Organizado por la Comisión Ballenera Internacional (IWC) y Cancillería

Animals possess behavioral responses to avoid discomforting situations. In particular, pain can result in learned avoidance behaviors. We report such a case in Southern right whales (Eubalaena australis) that have been the target of attacks by kelp gulls (Larus dominicanus) that feed on their skin and blubber in Península Valdés, Chubut (Argentina) since the 1980?s. Becoming more common every year, whales have developed alternative postures to keep their backs protected from the pain inflicted by gulls. Recently, a particular avoidance skill has been observed, the ?oblique breathing?, in which whales breathe keeping only the head out of the water. The main goal of this work is to describe the emergence of oblique breathing in two coastal areas of Golfo Nuevo (P. Valdés), during the whale reproductive seasons in 2010, 2012 and 2013. Results suggest that all age and sex classes of whales can breathe obliquely. Emergence of the oblique breathing seems to have proceeded in three stages: 1) the origin, with rare observations, 2) the spread, when the behavior was registered only during gull attacks, and 3) the establishment, when whales performed it in a preventive manner, even when attacks were not occurring. Oblique breathing is likely to have extra energy costs, which could be detrimental to whales, especially for recently born calves that need to gain weight for undertaking their first long trip to the feeding grounds. However, given the increasing prevalence of this behavior, it seems to be a useful strategy to prevent pain caused by gulls.