Animal of the Week April 29, 2014 -- Birds on the EDGE

The EDGE (Evolutionarily Distinct, Globally Endangered) initiative has done a lot to highlight the plight of some of the world's most interesting and most threatened species. Scientists identify the most threatened species with few close relatives—the extinction of which would mean the loss of unique evolutionary history.

http://www.arkive.org/giant-ibis/thaumatibis-gigantea/

A couple of weeks ago, the EDGE team identified 100 bird species that are conservation priorities. One or two of the species high on the list are familiar AOTWs: the kakapo and the spoonbilled sandpiper for example. But number one on the list Thaumatibis gigantea (giant ibis) deserves an its own entry.

Everyone loves an ibis. This prehistoric-looking family can be found on every continent in a various different sizes and colours, but their overall shape leggy and long-necked with a lengthy downcurved bill changes little. But while they may have an unmistakable look, the evolutionary divisions in the group are deep, and many species, such as the giant ibis, represent the only species in monotypic genera.

The giant ibis is the largest member of the family: over a metre in length and weighing 4 kg. The 200 or so remaining birds are found in remote Cambodia, having been driven to the brink of extinction by habitat loss and disturbance, climate change, and hunting. Sparsely distributed, they have possibly never been particularly numerous, but their range did once extend into Laos, Thaland, and Vietnam. And their restricted range means that the remaining birds are vulnerable to local disturbances.

Whereas various other ibis species live in close proximity to people (Herodotus wrote of streets in Alexandria crowded with the birds that would have the benefit of snaffling up pests and discarded waste, but counteracted this by fouling everywhere), the giant ibis avoids human contact, preferring to feed on earthworms, eels, crustaceans, and small amphibians far from human habitation.

Tawny bellied seedeater
http://www.flickr.com/photos/dariosanches/

The reason it has taken 2 weeks for me to get around to the AOTW is that the considerate EDGE people provided a list of nearly 9993 species with their positions on the list...which took me some time to wade through. The bird at the bottom of the list, the least EDGEy species? The rather dainty Sporophila hypoxantha (tawny bellied seedeater), a finch from south Africa with a wide range and many closely related species (30 species in the genus Sporophila compared with just one in the genus Thaumatibis).