As regular CFZ-watchers will know, for some time Corinna has been doing a column for Animals & Men and a regular segment on On The Track... particularly about out-of-place birds and rare vagrants. There seem to be more and more bird stories from all over the world hitting the news these days so, to make room for them all - and to give them all equal and worthy coverage - she has set up this new blog to cover all things feathery and Fortean.

Thursday, 19 May 2016

Deadly Brain Disease Is Driving Swamp Birds Insane

A mysterious disease has been killing ducks and eagles in Florida’s wetlands, and endangered snail kites may be its next victims.

By Hannah Waters

It’s not easy to make a living as a bird of prey, especially if you’re a Florida snail kite. Once at risk of starvation due to declines in its favored prey, the endangered bird is now facing a terrifying threat: a deadly disease that drives birds insane.

True to its name, the foot-long snail kite eats only snails—its hooked beak is the ideal shape for plucking muscular morsels from whorled shells. But an adult raptor must find and eat dozens of snails every day to survive, more if it’s feeding babies.

Unfortunately for the birds, Florida’s native apple snails aren’t doing well. Half of the Everglades wetlands are now developed and riddled with canals and levees, leaving water unpredictable in their habitat. Droughts alternate with floods to desiccate eggs and drown adult snails.

Since ecologist Phil Darby from the University of West Florida began monitoring the snails in the mid-1990s, their population has declined tenfold. “The native snails are just gone,” he says. The kites started following suit, hitting a population low of 800 birds in 2008.

Then an unlikely savior arrived: exotic apple snails from South America. The golf ball-size invasive snails, dumped into Florida’s waterways from home aquariums, are bigger than their native relatives. They can survive drought and flooding, they lay more eggs, and they live longer.

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