|5/23/2017 2:00:00 PM|
Changing bird populations
At my bird-feeder in the front yard of my domicile I have a mystery going on. Without an acceptable reason, house finches and house sparrows have taken a nosedive in populations, along with my white-crowned sparrows.
|White-crowned Sparrow. How many did you see last fall, and this spring? |
photo by Lola Knox
In previous years, white-crowned sparrows have been in good numbers, feeding alongside the juncos and quail (with a now-and-then desert cottontail and at least a chipmunk or two getting in their way).
Even the rufous-sided towhees appear to be among the missing, but the presence of the all-too-obnoxious scrub jays hasn't dropped. In fact, I've gained one more nesting in my back yard; and the unspeakable Eurasian doves have increased three-fold!
Having the jay move in makes all the songbirds nervous as a pregnant fox in a forest fire. Jays make a living by eating baby birds - even bluebirds that jays can snatch out of a nesting box.
Lola Knox, who lives out in Tollgate, is also seeing fewer white-crowned sparrows than she has in past springtimes.
I've been looking for the usual feral (or neighbor's) cat that will cause a great stir upon the behavior of feeder birds, but aside from a very big black one that shows up occasionally, there haven't been any others at my feeder.
Oh, sure, an accipter can also raise holy-cats-let's-get-outta'-here with the feeder birds, but usually when the sharp-shinned or stealthy Cooper's hawk go off to higher forests to nest about now, and song birds settle down and numbers return to normal.
Well, that may be a loose statement. I had one female Cooper's who was really good at what accipiters like to do: kill and eat song birds. This one learned a new strategy when she moved in, or it may have got on to it at its past residence. When it first showed up, about six months ago, it would sneak into the big juniper next to the feeder without putting the Fear of God (literally) into everyone on the feeder and/or ground under it.
But when the birds spotted her, the quail would explode from under the feeder and vanish into the sagebrush and juniper trees like a bunch of F-16s on a stealthy mission. The juncos would scamper under the long walkway I have between the driveway and porch.
At first the juncos thought that was a safe refuge - but not from that ruthless, hungry Cooper's it wasn't. That sneaky little accipiter would watch them run under the walkway and then, giving the juncos time to think they were safe, she'd go after them.
Just about the time her shape appeared the juncos came busting out of the hideaway like feathered rockets. So the Cooper's gave up that strategy. So did the juncos. Then the juncos thought that running for cover in the twisted branches of the bitterbrush was the way to stay safe. Nope, that didn't work either....
That sneaky Cooper's would just fold those short rounded wings in and go right after them, using her velocity to keep going like a bullet, and steering with that long tail. She got about six juncos that way before the survivors caught on.
Now she doesn't bother to chase them. She just comes to the feeders like a rocket, sends everyone scattering and watches for the one that hits my window. Then she makes a beautiful Immelmann fighter plane turn (named after a German World War I ace) and grabs the stunned junco, dove, house finch or house sparrow.
Another that I haven't seen at my feeder in ages are the evening grosbeak families. They'd appear in flocks of 20 or so when we first moved into Sun Mountain, but they, too, have been very scarce over the last few years.
Please send me a note if you have also seen things happening with your bird populations that are somewhat askew: firstname.lastname@example.org.
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