Increased Wounding of Southern Right Whale (Eubalaena australis) Calves by Kelp Gulls (Larus dominicanus) at Península Valdés, Argentina

A dramatic increase in the wounding of southern right whale (Eubalaena australis) calves by Kelp Gulls (Larus dominicanus) at Península Valdés, Argentina, has been documented over the past four decades. The study found that while only 2% of mother-calf pairs showed gull lesions in the 1970s, this figure rose to 99% by the 2000s. Calves, particularly those older during the calving season, suffered more extensive and numerous lesions compared to their mothers, with some bearing nine or more wounds covering a significant area of their backs. The research analyzed aerial survey photographs of living pairs (1974-2011) and stranding photographs of dead calves (2003-2011), revealing that intensified gull harassment could potentially compromise calf health by leading to dehydration, impaired thermoregulation, and energy loss due to wound healing. However, this trend does not fully explain the large year-to-year variance in calf mortality rates observed since 2000.

Marón, C. F., Beltramino, L., Di Martino, M., Chirife, A., Seger, J., Uhart, M., Sironi, M., & Rowntree, V. J. (2015). Increased Wounding of Southern Right Whale (Eubalaena australis) Calves by Kelp Gulls (Larus dominicanus) at Península Valdés, Argentina. Plos One, 10(10), e0139291. https://doi.org/10.1371/journal.pone.0139291