Nelson Tasman Branch Wrybill Watch A noon high tide at Nelson in mid August saw twenty five members of Nelson-Tasman Branch of Forest & Bird braving the cool thigh deep water of the Waimea Estuary. Led by ornithologist Willie Cook, this was no mid-winter fun dip but a necessary wade to gain access to a spit of land from which a group of distant transients might be viewed. The transients in question were some thirty wrybills. This New Zealand endemic bird overwinters on the mudflats of North Island harbours and returns to its nesting grounds of the South Island braided river shingle during late winter. The Waimea estuary provides a good rest point in that migratory journey. The wrybill derives its name from its rightward laterally twisted bill; a feature unique to its species. Current population estimates are between 3,000 and 5,000 individuals and surveys seem to agree that bird numbers are declining. The most likely causes of the decline are loss of habitat through weed encroachment (eg.lupins) and the effects of hydroelectric and irrigation schemes, and predation by mustelids. The wrybill shows a remarkable tolerance to the presence of man, another factor which may not be helpful in its bid to survive but, on the positive side, allowed us to enjoy its visit.
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