Distribution and frequencies of shark-inflicted injuries to the endangered Hawaiian monk seal (Monachus schauinslandi)


Petra Bertilsson-Friedman. Current address: GPS Department, St Joseph's College of Maine, 278 Whites Bridge Road, Standish, ME 04084-9978, USA.
Email: pfriedman@sjcme.edu


I analyzed the frequencies of wounds inflicted by sharks to the endangered Hawaiian monk seal Monachus schauinslandi at three colonies in the Northwestern Hawaiian Islands between 1990 and 2000. I applied specific criteria typical of shark bites to all injuries to avoid bias. Pooling data from all years and the three colonies revealed several patterns. Sharks injured more pups (nursing and weaned) and juveniles (1–2 years old) than adults and subadults. More female pups and male juveniles than any other size classes were injured by sharks. Almost all (97%) of the injured pups were from French Frigate Shoals. More juveniles than expected were wounded at Laysan Island and Lisianski Island. Most shark wounds were between the diaphragm and the pelvic girdle, but pups were bitten most often just behind the pelvis compared with adults who were bitten more often near the head and neck.