Archivos de diario de julio 2023

16 de julio de 2023

In Aoteroa: half a native avifauna

Aotearoa ("Land of the long white cloud") is the traditional Maori name for the North Island of what is now Aotearoa New Zealand. For the naturalist, it is a fascinating but frustrating place. Like Hawaii, it is fascinating because the isolation of the islands has given rise to a wealth of endemic species; and frustrating because so many of these are reduced to a marginal existence. Also like Hawaii, Aotearoa has gone through two waves of extinction: one following Polynesian settlement of the islands, and another following European colonization. The extinctions brought about by these two waves amount to around half the native land birds, from the flightless moas and the eagles which preyed upon them to the iconic huia and piopio. The gaps have been filled by introduced species. Especially bizarre is the suite of British birds, half a world away from home -- Eurasian Starling and Blackbird, Song Thrush, Chaffinch, Goldfinch and Yellowhammer -- juxtaposed with Australian species like Eastern Rosella, Common Myna and Australian Magpie.
Of the surviving endemic species, a few are widely distributed around the main islands. These include the Grey Gerygone, New Zealand Fantail, Tui, New Zealand Scaup and Red-breasted (New Zealand) Dotterel. The New Zealand Pigeon and Bellbird have a patchy distribution on the mainland. The remaining endemic land birds have been extirpated from most of the mainland, surviving only in sanctuaries -- offshore islands like Tiritiri Matangi, or enclosed areas of the mainland from which predatory mammals have been eradicated, like Shakespear Regional Park. In creating these sanctuaries Aotearoa has acted more swiftly and decisively than Hawaii. The sanctuaries have proved so successful that surplus birds can be translocated to new sanctuaries. The success has prompted a bold "moonshot" project: to eradicate predators from the whole of the country by 2050. Local efforts towards this goal are already bearing fruit, with native birdsong returning to more and more areas of the country.
Aotearoa has another claim to ornithological fame -- as the seabird capital of the world. Thousands of shearwaters congregate in the fish-rich waters of the Hauraki Gulf north of Auckland, and can be viewed from ferries or from the shore, including Auckland's North Shore and the Whangaparaoa peninsula. Although few breeding colonies of shearwaters and petrels remain on the main North and South islands, offshore island colonies have benefited from eradication of rats and other predators.

Publicado el 16 de julio de 2023 por stephenmatthews stephenmatthews | 28 observaciones | 0 comentarios | Deja un comentario