Follow by Email

Saturday, February 18, 2012

"That hawk doesn't look tired to me"

Swainson's Hawk
Swainson's Hawk

Spring migration is underway. So Swainson's Hawks will be here soon, arriving from their annual migration. Thousands and thousands of hawks of all species, from all over North America, have spent the winter in a small area in northern Argentina that's about the size of Arizona. That means a round-trip migration of around 12,000 miles.

A reader reported that a flock of Pelicans has settled in at the Southlake Park Lake, near McMath Middle School. Nobody can remember them landing in Denton before, although flocks have been seen on Lake Lewisville in the past.

These are the species "White Pelicans", not the Brown Pelicans that dive underwater for food. White Pelicans, as they swim, strain the water with their large bills, catching fish. Several of them will swim in a line or an arc to trap small fish.

Wednesday, February 15, 2012

Most birds aren't faithful at all

Ruddy Ducks
Carolina Wrens

It may come as a surprise, but very few birds are monogamous. There's a lot of hanky-panky going on in the trees, wetlands and shrubs of north Texas.  Recent DNA research shines a light on the "playing around".

Of course, birds' primary concerm when mating is passing on good genes; those that enable better flying, more endurance, better hunting for food etc. In a typical nest of four nestlings, only about two have the genes of the parents raising them.  The other two have a different mother or father or both (usually it's the father that's different - for logistical reasons).

In other words, it's not uncommon at all for a bird to copulate with a bird that's not its mate; sometimes birds will even incubate an egg laid by another bird. It's all for the sake of the genes!

Passenger Pigeon (extinct)
Early in the last century, Passenger Pigeons were found in great numbers - in most parts of the country. Millions and millions of them - flying wild in their rural habitat.  Now the bird is extinct.

It was hunted to death, and its natural habitat (and food sources) was going away. The last one died in a zoo in 1914.

Which reminds us, especially during a cold spell like north Texas is having now, to make sure your birdfeeders are full, and (when the weather's better) to plant more "birdscape" plants to provide fresh food for our birds.

Sunday, February 12, 2012

Go ahead; pick up that baby bird if you must

Carolina Wren

Momma can't "smell" if someone has handled it.  That's just a silly myth. In truth, birds have no sense of smell (although Vultures can smell somewhat, to locate food). But the songbirds we see in north Texas (Bluebirds, Wrens, Cardinals, Robins, Titmice etc) just can't smell at all.

So pick up the bird if it's absolutely necessary. But don't "kidnap" it. Keep in mind that the vast majority of the time, a "fledgling" bird  is being monitored carefully by a parent in a nearby tree. Most young birds spend around a week on the ground, still unable to fly, after emerging from the egg and growing larger and stronger.

If a human frequently goes and looks at it though, the human will leave a scent trail that a hungry predator (raccoon, snake??) can follow.

Ninety-five percent of Texas' Santa Ana National Wildlife Refuge (in the lower Rio Grande valley) was obtained through the purchase of "Duck Stamps", which are used not only for Duck habitat, but for acquiring habitat for all kinds of birds.