Thaindian News

Washington, January 6 (ANI): In a new research, University of Utah biologists have found that birds called finches have developed antibodies against two parasites that moved to the Galapagos Islands, suggesting that the birds can fight the alien invaders.

The study involved two parasites that invaded the Galapagos Islands, off the coast of Ecuador.

One is the pox virus, Poxvirus avium, which according to Jen Koop, a University of Utah doctoral candidate, “creates lesions on non-feathered parts of a bird - around the bill, eyes, legs and feet. Toes and feet can fall off.”

The study’s main focus was the other parasite, the nest fly, Philornis downsi, which was introduced to the Galapagos as early as 1964.

The fly larvae infest finch nests and attack featherless skin, impairing the growth of nestling birds and even killing them.

But, no native birds have yet gone extinct in the Galapagos, a fact that may change with the introduction of nest flies from elsewhere in South America and of mosquitoes that carry the pox virus.

The new study and ongoing work aim to determine whether “the birds are able to fight back, do they have defenses, or have they just been blindsided because they have no evolutionary history with these parasites,” Clayton said.

The researchers collected ground finches in 2008 at two Galapagos islands about 5 miles apart: Isla Daphne Major and at El Garrapatero on Isla Santa Cruz.

Nest flies were found on both islands, but pox virus was found only on Daphne Major.

The birds were captured using nets and baited live-animal traps. Before release, each bird was fitted with leg bands for future identification.

On Daphne Major, the Grants, the researchers captured 30 finches and noted whether the birds had pox sores or signs of prior pox infection, like scarring or lost toes.

On Santa Cruz, they examined finches before and during nesting, which is when the birds are exposed to fly larvae that infest their nests.

They captured 37 birds exposed to nest fly larvae, and 76 that were not. They found 96 percent of nests were infested.

The new study found that finches on Daphne Major had an antibody response to pox virus three times stronger than the response by Santa Cruz finches, which showed no signs of the virus.

It is unlikely the finches already evolved defenses to the pox virus and nest fly, but for yet-unknown reasons, they “have genetic diversity that lets them mount immune responses to parasites, including ones they haven’t seen before,” said Clayton. (ANI)