EFFECTS OF VESSELS ON BEHAVIOR OF SOUTHERN RESIDENT KILLER WHALES (ORCINUS SPP.)

摘要: ABSTRACT Vessel traffic may have contributed to Southern Resident Killer Whales becoming endangered. To determine the importance of this threat, we measured behavior Residents in presence and absence vessels 2003 2004 at two different sites along San Juan Island. Data collected include: theodolite tracks focal individuals, with observations their behavior; scan sampling activity states subgroups, counts various distances from each subgroup. Theodolite were summarized terms directness deviation indices, travel speed. Rates respiration display behaviors also determined for sample. number distance used as candidate explanatory variables differences track indices other behavior, natural factors such sex, age, pod membership, time day, year, geographic location, etc. As Northern Residents, index decreased significantly vessels. This increase traveled would result increased energy expenditure relative whales who can rest while waiting affected catch up. nearest vessel decreased. Transitions between by traffic, indicating a reduction spent foraging was observed Residents. If reduced effort results prey capture, acquisition. Each subgroup within 400m most during daylight hours May through September.