Skip to content

Picky Eater

December 30, 2009

Every morning I have coffee. The meal varies from day to day. Sometimes it’s a bagel. Other times cereal. Occasionally an egg. But I have the good fortune of being an omnivore and can basically have whatever I wish to start my day.

Snail Kites (Rostrhamus sociabilis) don’t have the luxury of choice when it comes to meals. They have evolved over time to survive on an extremely specific diet of Apple Snails. While I can’t relate to a palate that prefers gooey gastropods, it’s quite evident that natural selection has favored a bird that is expert at extracting invertebrates from deep inside their homemade calcium carbonate abode. Snail Kites have an extremely curved beak that makes plucking their preferred prey a simple task but finding said prey has been anything but simple in recent years.

Snail Kites are found throughout the Americas but in the United States they are considered endangered and only found in south Florida. As wetlands have been drained over the last half century and water management practices based mainly on the needs of humans, Apple Snails (Pomacea paludosa) have suffered severe population declines. Consequently, as their prey goes, so goes the Snail Kite. Less than 500 breeding pairs survive but when snail populations soar, Kites breed prolifically. When prey disappear, Kite populations crash.

Snail Kites are sexually dimorphic with males having a grey-black plumage with distinct red legs and a curved, orange beak. Females are brown with flecks of white and the same wildly curved bill.

As I drove to work the other morning I passed this female Kite perched on a wire and recognized the beak immediately. Had anyone doubted my bird identification skills, I would have been redeemed soon after as she plunged into a canal below, grabbed an apple snail and returned to the wire where she proceeded to enjoy the same breakfast of snail she surely has enjoyed time and time again. Amazingly the snail thrashed about in futile protest before being dragged from its shell, had its antennae yanked off and was eventually devoured. I think I’ll have a bagel for breakfast tomorrow.

Channeled Apple Snails

While native apple snail populations have risen and fallen, the invasive Channeled Apple Snail (Pomacea canaliculata) has surged throughout Florida’s wetlands. The baseball-sized gastropod most likely got a foothold in Florida from an aquarium dump. They lay long strings of Barbie-pink eggs which contrast with the light pink to white, pea-sized eggs of the Florida Apple Snail

Advertisements
No comments yet

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s

%d bloggers like this: