This study assessed the short‐term responses of humpback whales to whale‐watching 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 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.
Many people support whale watching on the basis that it enhances people's appreciation and awareness of the whales they are viewing and can lead to the protection of the species and of the environment generally. Because whale watching can directly impact on whales' behavior it is important that whale watching is beneficial for people's understanding of whales and for the conservation of whales. This article examines the educational and conservation value of the whale-watching experiences currently offered in New South Wales, Australia. The current education provided lacks structure, there are no clear conservation objectives, and there is limited addition to knowledge and conservation behaviors of whale watchers in the long term. Through improvement of the education provided during whale-watching experiences, it is argued that the whale-watching industry can become a more sustainable form of wildlife tourism and provide conservation benefits for whales and other forms of biodiversity.
Biological invasions by large herbivores involve the establishment of novel interactions with the receiving mammalian carnivore community, but understanding these interactions is difficult due to the large spatiotemporal scales at which such dynamics would occur. We quantified the functional responses of a native apex predator (the dingo (Canis familiaris), which includes wild dogs and their hybrids) and a non-native mesopredator (red fox; Vulpes vulpes) to an invading non-native ungulate (sambar deer; Cervus unicolor) in Australia. We predicted that the apex predator would exhibit a stronger functional response to increasing sambar deer abundance than the mesopredator. We used a state-space model to link two 30-year time series: (i) sambar deer abundance (hunter catch-per-unit-effort); and (ii) percentages of sambar deer in dingo (N = 4531) and fox (N = 5002) scats. Sambar deer abundance increased over fourfold during 1984À2013. The percentages of sambar deer in dingo and fox scats increased during this 30-year period, from nil in both species in 1984 to 8.2% in dingoes and 0.5% in foxes in 2013. Dingoes exhibited a much stronger functional response to increasing sambar deer abundance than foxes. The prediction that invading deer would be utilized more by the apex predator than by the mesopredator was therefore supported. The increasing abundance of sambar deer during the period 1984À2013 provided an increasingly important food source for dingoes. In contrast, the smaller red fox utilized sambar deer much less. Our study demonstrates that prey enrichment can be an important consequence of large herbivore invasions and that the effect varies predictably with the trophic position of the mammalian carnivores in the receiving community.
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