15 August 2009

bird eat bird world

It's a bird eat bird world, but we don't have conclusive evidence in this post.

Earlier in the week, we adventured over to the Waco Wetlands for a bit of birding and bugging.

There's always something of interest, this time was no exception: the boardwalk gave us a blog feast!

The "feast."

Eeew, dead bird. Well, yes, but that's the food web for you. And it's been a while since a dead bird was featured in the blog! Looking around, it was plain to see that a lot of roosting time was spent on the railings. Whitewash... everywhere.

The featured feast (likely devoured by a Great-Horned Owl or other such raptor) was a hapless Cattle Egret (Bubulcus ibis). ID is based on smallish white wings.

Wingspans, per National Geographic's Birds of North America:
Great Egret - 51 inches
Snowy Egret - 41 inches
Little Blue Heron* - 40 inches
Cattle Egret wingspan - 36 inches

*Little Blue Herons are white until their first molt (when their adult feathers grow in)

Next to the scene of the feast was a pile of floating feathers. And maybe 20' away from the wings, I found conclusive "not-a-Snowy" evidence.

For those of you who are not birders but want to identify small, white heron/egret type birds, look at the beak and the feet. If it's the middle of summer, Cattle Egrets will usually have a wash of orange on the breast and back - eliminating Snowy Egret from your ID options.

Snowy has a long, thin, black beak
Cattle has a short, thick, yellowy orange beak

Snowy has black legs and BRIGHT yellow feet
Cattle has all dark legs and feet

Yep, dark feet. And the longest toe (middle of the front-facing toes) has a handy-dandy preening modification! Preening is how birds groom themselves. Unlike the lickings of cats and dogs, birds have to use their beaks and feet to keep their feathers in good condition.

There's a larger picture of the claw modification. It's just a slightly serrated edge/comb that helps the bird scratch at places it can't reach with its beak. So the head, neck, face and chin get a good kicking to knock the dust out... with a mini-comb.

Now, I'd hate to just leave this post alone, with just a "Cattle Egret is victim" theme, we might as well give it credit for what could have been its last meal. Call it a crayfish, crawfish, or crawdad, it probably tasted pretty good.

So now we've covered that the North American pygmy lobster was a delicious snack, and the Cattle Egret found itself a fluffy banquet for something more feisty. Which would lead us to the natural conclusion that it's a food web out there, so be careful!

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