Bristle-thighed curlew  (Numenius tahitiensis)

The fairly small population of bristle-thighed curlews is believed to be declining, primarily due to the impacts of introduced predators on their wintering grounds (1). The flightless period during the moult would have evolved during a time when there were no mammalian predators on the South Pacific islands where it spends the winter. Today, with the establishment of humans on these islands, and the subsequent introduction of mammals, moulting leaves the curlew in an extremely vulnerable position. Introduced cats, dogs and possibly pigs, prey heavily on the flightless curlews, causing a significant decline in numbers (4) (6).

Hunting was a threat to this species in the past; on the Tuamotu islands it was traditionally caught for food. However, the possession and use of firearms is now restricted on these islands and therefore hunting no longer poses a significant threat (2). On their breeding grounds the curlew suffers predation by Arctic skuas, common ravens and foxes, and the expanding development of gold mines and mining roads on the Seward Peninsula is an increasing threat that could have a significant impact on this bird, due to its reliance on this small area for breeding (2) (6).

The bristle-thighed curlew occurs in a number of protected areas. Both the Yukon Delta and some of the remote Hawaiian Islands, are designated National Wildlife Refuges, which protects breeding grounds and several stop-over and wintering sites (4) (6). Wildlife and habitat is monitored in the Yukon Delta, but further specific monitoring of the curlew is recommended (4). Hawaii's Comprehensive Wildlife Conservation Strategy proposes a number of conservation actions for the bristle-thighed curlew including protecting the current habitat of the curlew in Hawaii, and protecting and restoring additional wetland habitat, especially where it can be reclaimed from abandoned urban or agricultural uses (7). However, to protect this species from further declines, it is important to tackle the primary threat of introduced mammals across its wintering range.