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Wednesday, January 2, 2013

Where are north Texas' owls going?

Great-horned Owl
North Texans are often surprised to learn that they have owls as neighbors. It's true, but there are fewer owls around than a decade ago. That's worrisome!

Our common owls range from the ±10” Screech Owl, through the mid-sized Barn Owl and Barred Owl, to the large Great-horned Owl. All four kinds of owls hunt at night, feeding on animals that are also active at night. These include large insects (favored by Screech Owls), many kinds of rodents, up to skunks (a favorite of Great-horned Owls).

Barn Owls
      An owl is one of the best rodent-control creatures on earth. For example, one adult Barn Owl eats about 90g. of food a night – the equivalent of two rats.  A breeding pair and their chicks can eat about 3000 rats per year. Where rodents have been displaced by recent construction, owls (particularly Barn Owls) eat well.

     Unfortunately, the large, dead trees they like to nest in are frequently cut down and natural tree cavities are filled in, so good nesting sites can be hard to find.  Man-made nest boxes can help alleviate the problem, although not all owls use boxes. Boxes can be put almost anywhere – even on the wall of a house. It should be in shade most of the day and, especially in Texas, shouldn’t face the hot, west sun.

Screech Owls
Barred Owl
 Since owls fly quietly at night, you may never know that they’re around. During the day, they often sleep in the open, undetected, since they are so well-camoflaged. Hence they’re very good neighbors. With the leaves gone from most trees, now is an excellent time to look for them resting in trees.


Sunday, December 30, 2012

Why do birds puff up in cold weather?

Carolina Chickadee, puffed up
In cold weather they can look like tennis balls with wings sometimes! It just means they’re trying to keep warm. When a bird puffs up, or plumps up, he’s actually conserving warmth by raising up his feathers, fluffing and separating them, then bringing them back into place - except with lots of tiny air pockets between the feathers and the bird’s body.  This trapped air increases insulation for extra warmth, and the trapped air is is kept warm by the bird's body heat.

If you have a birdbath, remember that only clean feathers fluff up properly. If a bird has dirty feathers, inclement weather affects him greatly. So, even in winter, birds need a clean, handy birdbath. In very cold weather, the actual bath only takes only a second or two.

Lots of birds, however, hang around a birdbath a lot, to get multiple baths and sips of water. In freezing weather I'll pour hot water in ours to keep it from icing over.



Fox Sparrow
Double-scratching birds     In the winter, many birds forage for food by scratching through the leaf litter on the ground. In north Texas, you’ll see Juncos, Towhees, most blackbirds, many kinds of native Sparrows, and others doing this. Watch closely; actually the birds hop forward by moving both legs forward at the same time, then backwards a little if there’s snow covering the ground. This double-scratching does an excellent job of locating food.