(Alex Dale; Photo: Andreas Trepte; 7 march 2017)
New research suggests that the Numeniini – a tribe of large waders including Curlews and Godwits – could be the most endangered birds you’ve never heard about. Indeed, two species may already be extinct
To the layman, the curlews are a shy, unassuming family of birds. Their mottled-brown plumage makes for effective camouflage against their marshland and mudflat feeding grounds, meaning they can go about their business unnoticed, prying out invertebrates such as ragworms with their purpose-built curved bills. But if, like the curlews, you take time to dig beneath the surface, you’ll discover that they are beautiful and remarkable birds.
The Numeniini are a tribe of large waders consisting of the curlews, whimbrels, godwits and Upland Sandpiper Bartramia longicauda. They are some of the most widespread and far-travelling of all birds, migrating back and forth from their upland and grassland northern hemisphere breeding habitats to their wetland, often coastal, non-breeding habitats to the southern extremities of all continents except for Antarctica.
Indeed, one such member, the Bar-tailed Godwit Limosa lapponica is holder of the world record for the longest non-stop journey without feeding of any animal – satellite tagging has shown that birds from one population take eight days to fly from breeding grounds in Alaska 11,000 km to New Zealand every year.
Perhaps it’s their wide range that means they have been a little overlooked by birders until now. Or maybe it’s that their camouflage is a little too effective. Whatever the reason, it’s time for the curlew to be counted, because an eye-opening new study reveals that they could be one of, if not THE, most threatened group of birds on our planet.
The paper, produced in collaboration with the RSPB (BirdLife in the UK), British Trust for Ornithology (BTO) and the International Wader Study Group, and published in the journal Bird Conservation International, collated the views of over 100 wader experts from around the world, who assessed the threats faced by these species across their migratory flyways. Their conclusion: seven of 13 species – or over half – are now threatened with extinction.
Indeed, two species of curlew may already be extinct; the Slender-billed Curlew Numenius tenuirostris, last spotted with confidence in 1995, which once migrated between the Mediterranean Basin and its breeding grounds in Siberia; and the Eskimo Curlew Numenius borealis, which once travelled between Canada and South America, and is almost certainly a goner, having not been seen with certainty since 1963 (and not in South America since 1939).
The plight of the Eskimo Curlew has strong parallels with the far-wider publicised extinction of the Passenger Pigeon Ectopistes migratorius. The shorebird once numbers in its millions, but widescale hunting and habitat loss in its spring staging areas in the Rocky Mountains has led to, if not the total eradication of the species, then at least its decimation to the point where if it still exists, it does so as a tiny population in some uncharted corner of the Canadian wilderness.
While the hunt goes on for traces of these Critically Endangered species, the paper highlights that attention too should urgently be given to the threats faced by the species we know for sure are still among us.
The study discovers that overall probably the most serious threats to the future of curlews and their allies, is the habitat loss or degradation of the coastal wetlands they depend upon to roost and feed across their non-breeding range, including as refuel stopovers during their epic migrations.