Saving the `AlalÃ¢

grrlscientist — Sun, 19 Apr 2009 15:25:58 +0000

Saving the `AlalÃ¢

tags: 'Alala, Hawaiian Crow, Hawaiian Raven, Corvus hawaiiensis, endangered species, conservation

One of the last wild-born `AlalÃ¢ to ever be photographed in the wild.

One of the rarest forest birds in the world, the critically endangered `AlalÃ¢, or Hawaiian Crow, Corvus hawaiiensis, was awarded $14.3 million in conservation funding over the next five years, according to the United States Fish and Wildlife Service (USFWS).

This funding package will focus on expanding captive propagation, establishing new populations in managed habitat, protecting suitable habitat, managing threats to the species, increasing public support and continuing research and adaptive management practices. The expense is primarily due to the high cost of habitat restoration.

The `AlalÃ¢ is a medium-sized brownish-black crow with a large beak, similar to that of a raven. It is the only surviving member of a group of crow species that were found throughout the Hawaiian archipelago before humans arrived (see map, below). Revered by the native Hawaiians, the `AlalÃ¢ is the second largest forest bird in Hawaii after the endangered `Io, Buteo solitarius, also known as the Hawaiian hawk.

Historic range of `AlalÃ¢.

`AlalÃ¢ have only ever been indigenous to the Big Island, but they haven't been seen since 2002. They were first listed as federally endangered species in 1967, but a recovery plan was not published until 1989.

Even though they are extinct in the wild, the last remaining `AlalÃ¢ have been conserved in captivity by a federal captive breeding program. The entire population of `AlalÃ¢, all of which have been captive raised, live at one of two bird conservation centers; one center is on Maui and the other is on the Big Island. Both of these conservation centers are managed by the Zoological Society of San Diego.

In this Tuesday, June 19, 2001 file photo, a newly hatched `AlalÃ¢
receives its first meal of bee larvae and cricket parts at the
Maui Bird Conservation Center, in Maui, Hawaii. Federal wildlife officials
have a revised recovery plan for the endangered Hawaiian crow, which
is only found in captivity on the Big Island and is one of the rarest forest
birds in the world. (AP Photo/Zoological Society of San Diego)
[slightly larger view].

"The point is not to keep them in a box," said biologist Jeff Burgett, who is in charge of `AlalÃ¢ recovery for the Fish and Wildlife Service. "The point is to build the flock up to the point where they're generating enough young that you can put them back out in the wild."

But reintroducing `AlalÃ¢ into the wild is more complicated than simply pushing the birds out of their aviaries: young birds remain with their parents for one year, learning survival skills and proper "raven behaviors" from them. Unfortunately, the "culture" of the wild birds that was passed down through the generations was lost, remarked Alan Lieberman, program director of Hawaii Endangered Bird Conservation Program run by the Zoological Society of San Diego. As a result, the wild birds lack proper survival skills.

At this time, there are 60 living `AlalÃ¢, but mathematical modeling studies indicate that their population must grow to at least 75 individuals to avoid further loss of genetic diversity before attempting to reintroduce them into the wild once more.

"The fact that the species is extinct in the wild means that its former habitat is no longer able to support the population for whatever reason," stated Burgett. "Unless we change it in ways that are better for the bird, it has no suitable habitat."

The reason that the `AlalÃ¢ were driven to extinction is not mysterious. Invasive exotic species that were intentionally introduced by people drove these birds to extinction. The worst culprits are feral and free-roaming housecats, which hunted the birds and also fatally infected them with toxoplasmosis, a common parasite in domestic cats. Other exotic invasive animals that negatively impacted the `AlalÃ¢ include dogs, pigs, cattle, rats and mongoose, which destroyed their habitat and killed the adult birds and their chicks.

"We've let mongoose and cats and rats and all these things out there. They're taking Hawaii away from us, slowly but surely," Burgett said. "If you want to keep Hawaii, then you've got to do something to control those things."

Between 1993 and 1998, 27 captive-bred juvenile `AlalÃ¢ were released. Tragically, 21 died and the remaining birds were recaptured and added to the captive flock. Some of the dead `AlalÃ¢ had toxoplamosis, a disease carried by housecats and pass it on through their poop.

Sources:

USFWS Draft Revised recovery plan for the 'AlalÄ or Hawaiian Crow, Corvus hawaiiensis (free PDF). Interesting background information.

USFWS Initial recovery plan for the 'AlalÄ or Hawaiian Crow, Corvus hawaiiensis (free PDF). Interesting background information.

USFWS publication: Endangered Species in the Pacific Islands: Hawaiian Crow. Interesting background information.

$14M effort announced to save rare bird.

Last pair of wild 'alala feared gone. Interesting background information.

Seeking the Sacred Raven by Mark Jerome Walters. My book review of this fascinating and heartbreaking true story of political in-fighting between conservation groups and their attacks upon private citizens, with the ultimate result being extinction of that which they sought to save.

grrlscientist Sun, 04/19/2009 - 11:25