Variability in activity definitions and categories among studies

Variability in activity definitions and categories among studies makes comparative analysis difficult. Comparison of the Port River dolphin’s activity budget with other inshore populations indicated the former spent more time feeding and resting, and less time traveling. The greater feeding time seemed to be due to small prey size rather than reduced abundance or unpredictable distribution. The reduced traveling time, possibly the result of low predation pressure and/or evenly distributed selleck chemicals llc prey, gave them more time to rest. They traveled mostly at 2.5

kn or less, consistent with studies from other shallow areas. Most feeding was individual, probably on demersal species. Surface feeding incorporated physical barriers rather than cooperative behavior. Activity durations ranged from 2 s to 2.9 h, with mean durations varying from 7.8 to 22.9 min. “
“This study assessed the short-term responses of humpback whales to whale-watching GSK2126458 in vitro vessels during their southward migration along the south coast of New South Wales (NSW), Australia. The behavior of pods was recorded from commercial whale-watching vessels during tours and compared to pods observed in the absence of vessels from the shore in the same area. While some individuals showed obvious signs of horizontal avoidance, others approached vessels, initiating interactions. Calf pods were more sensitive

to the presence of vessels than non-calf pods. Dive times and the overall percentage of time whales spent selleck products submerged were higher in the presence of vessels, but respiration intervals did not differ. Some surface behaviors occurred less often in the presence of vessels. Whales’ responses differed according to whether vessels were operating in accordance with regulations or not. Whales were more likely to avoid a vessel moving within the permitted 100 m

approach limit than vessels outside the limit. Whales showed some behavioral changes when vessels operated in accordance with whale-watching regulations, compared with whales in the absence of vessels. Pods that showed no obvious horizontal responses to vessels changed their diving and surface activity when compared with pods in the absence of vessels. Because the long-term impacts of effects of vessels are unknown, management of the humpback whale-watching industry should adopt a conservative approach. Improved knowledge of long-term impacts of multiple exposures to vessels is required to inform management of the effects of whale-watching. “
“Although there are several isolated references to the olfactory anatomy of mysticetes, it is usually thought that olfaction is rudimentary in this group. We investigated the olfactory anatomy of bowhead whales and found that these whales have a cribriform plate and small, but histologically complex olfactory bulb. The olfactory bulb makes up approximately 0.13% of brain weight, unlike odontocetes where this structure is absent.

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