دانلود رایگان مقاله انتخاب گونه چتر برای حفاظت برای پرندگان ساحل تودرتو

ABSTRACT

Umbrella species are rarely selected systematically from a range of candidate species. On sandy beaches, birds that nest on the upper beach or in dunes are threatened globally and hence are prime candidates for conservation intervention and putative umbrella species status. Here we use a maximum-likelihood, multi-species distribution modeling approach to select an appropriate conservation umbrella from a group of candidate species occupying similar habitats. We identify overlap in spatial extent and niche characteristics among four beach-nesting bird species of conservation concern, American oystercatchers (Haematopus palliatus), black skimmers (Rynchops niger), least terns (Sterna antillarum) and piping plovers (Charadrius melodus), across their entire breeding range in New Jersey, USA. We quantify the benefit and efficiency of using each species as a candidate umbrella on the remaining group. Piping plover nesting habitat encompassed 86% of the least tern habitat but only 15% and 13% of the black skimmer and American oystercatcher habitat, respectively. However, plovers co-occur with all three species across 66% of their total nesting habitat extent (~649 ha), suggesting their value as an umbrella at the local scale. American oystercatcher nesting habitat covers 100%, 99% and 47% of piping plover, least tern and black skimmer habitat, making this species more appropriate conservation umbrellas at a regional scale. Our results demonstrate that the choice of umbrella species requires explicit consideration of spatial scale and an understanding of the habitat attributes that an umbrella species represents and to which extent it encompasses other species of conservation interest. Notwithstanding the attractiveness of the umbrella species concept, local conservation interventions especially for breeding individuals in small populations may still be needed.

4.2. Conclusions

Because the use of the umbrella species concept is very likely to remain prominent in conservation, it is important to systematically select umbrella species so that they are effective and efficient. Here, we show that substantial investments in piping plover protection are very likely to have benefits for other beach-nesting species at the local scale, chiefly because habitat requirements of plovers are a subset of the niche of other species. At the local scale, protecting plover nesting habitat will encompass potential breeding sites of other beach-nesting birds,supporting the status of piping plovers as umbrella species. In a complementary fashion, at the regional scale the greater breadth of breeding habitat used by American oystercatchers is likely to encompass a larger component of other species' suitable nesting habitats. Complete protection of oystercatchers will also protect species with more restricted breeding site requirements. Large-scale protection is, however, more costly or less politically palatable, and hence may complement local efforts and be used primarily in the wider context of land-use planning. We suggest that even with systematic selection approaches such as those employed here, there is unlikely to be a single “clearly best” umbrella species candidate identified, particularly in more complex systems with a target species that span several taxonomic groups. The final choice is dependent on the spatial ambit of conservation interventions (local vs. regional), the cost and political feasibility (large vs. small areas), and the conservation status of the species of interest, which dictates the degree of legislative protection offered by the umbrella.