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Naomi E.LANGMORE 《中国鸟类》2013,4(1):86-92
长期以来,人们一直对寄生性繁殖的杜鹃所采用的种种计谋惊叹不已。本文对澳大利亚的寄生杜鹃如何增加寄生巢的可获得性、如何寻找和接近巢以及如何让宿主接受它们的寄生卵与雏鸟进行了综述。这些杜鹃所采用的对策,有一些是世界上其他杜鹃种类也采用的,但有一些对策,如产隐蔽的卵和模拟的雏鸟,却似乎仅见于澳大利亚的杜鹃。泛性寄生的杜鹃因为要应对较多种类的宿主,难度自然远大于专一性寄生的杜鹃种类,这同时也解释了为什么不同种类的杜鹃进化出不同的寄生策略,以避免不同宿主的识别。 相似文献
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The application of blue-dye to fishing baits is a seabird bycatch mitigation technique used in some pelagic longline fisheries that is thought to make the baits less visible and hence less attractive to seabirds. We tested this assumption in two ways. First, by measuring the spectral profiles of blue-dyed baits (fish and squid) and modelling the spectral profiles of the ocean under set conditions, we assessed how well wedge-tailed shearwaters (Puffinus pacificus) can distinguish dyed baits based on the known visual characteristics of this species. Results showed that no baits were perfectly cryptic against the background ocean, and only blue-dyed squid were relatively cryptic both in terms of chromatic and achromatic contrasts. Second, during at-sea trials blue-dyed and non-dyed baits that were simultaneously presented submerged on a longline or as surface presentations. During 26 longline sets which presented squid only, a 68% reduction in interactions with blue-dyed squid was observed compared to non-dyed squid. During surface presentations only 3-8% of blue-dyed squid baits were struck over the duration of the study compared with 75-98% of non-dyed squid bait. When using fish baits, however, approximately 48% of all blue-dyed baits presented in the first two days of trials received strikes from seabirds but this increased to 90% over the last three days. These results suggest the use of blue-dyed squid bait could decrease seabird bycatch in pelagic longline fisheries whereas blue-dyed fish baits are less likely to have a mitigatory effect. 相似文献
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