Wednesday, August 29, 2007

Blakeman on Barn Owls and a Photo of the Day

Barn Owl hissing with feeling.
Being nocturnal, he isn't all that happy about being awake perhaps?

John Blakeman, comments on the severely reduced numbers of Barn Owls in Wisconsin and in his state, Ohio, and presents another theory as to why.

I noted our comment about the depressed state of barn owls in Wisconsin. There are only a few left here in Ohio, too.

But the best ecological evidence is that in pre-settlement days, before either Ohio or Wisconsin were converted primarily to rural agricultural landscapes, barn owls did not reside in either state. The birds almost surely moved into the northern tier of states upon European settlement.

Consequently, the bird (in geological or biological time frames) is only a recent invader, from the south.

To presume that the barn owl is a legitimate, continuing resident of either the Badger or Buckeye states would be to also presume that the typical agricultural landscapes that the bird thrived in, those of the late 19th and first half of the 20th centuries were the real, "natural" state of our respective landscapes.

In fact, barn owls can't survive in the forested or prairie areas that covered the northern tier of states in presettlement times. The barn owl is a recent invader here, having adapted to the rodent-filled meadows of livestock farming. Now, with the abundance of both human residences and the conversion of most agriculture to row-crop farming (where voles and other rodents can't survive), the days of the barn owl are limited. (Possibly, at least in these areas currently. D.B.)

The decline or loss of the barn owl merely reflects continuing changes in human uses of landscapes. Many biologists would claim that the barn owl isn't a real native; merely a recent opportunistic invader, one whose days are now limited because of modern landscape changes.

Nice, while it lasted.

--John Blakeman
Fascinating, so Barn Owls are autochthonous. They originated somewhere else and may have only been here only briefly in the big scheme of things. Which brings up the questions of what did they use in their range of origination for roosting and nesting as they used barns for here, and just where exactly did they come from before they were here?
Turns out it's not all that easy to find out in an hour. But I did find out where they roosted and nested, at least 94,000 years ago in Israel--caves. Actually makes perfect sense that they used barns in the Midwest instead. Most of the Midwest is pretty short on caves.
I wasn't having that much luck in finding out what their cavity of chose was until I ran across a tangential mention in a Harvard University Gazette article from 2003 on, which caves were inhabited when by which precursors of man. The answer: If there were Barn Owl pellet fossils in a given time frame, there were no pre-human inhabitants in residence.
Barn Owls don't like that much company.
Though I still don't know where the midwestern Barn Owls that took up residence here, came from yet, I did read that they are making a come back in Iowa.
Why Iowa? They were extirpated there far before they were even close to it in Ohio and Wisconsin.
Therefore if the surmise that the diminishment in rodent population is the big factor in the disappearance of Barn Owls in the Midwest, what are Iowans doing now, they weren't 50 years ago that hosts rodents?
Wait a second, in the Midwest many Red-tails survive on rodents,--voles, and what have you, and there are currently many many Red-tails here. Why haven't their populations been as severely diminished as the Barn Owls have been? Mr. Blakeman?

Remember Karen Anne Kolling, who wrote in and told us about the Gulls dropping sea creatures on her roof, to crack them so they could be readily eaten? Here is a photo of one of her recent visitors. Nice backyard for waterbird watching, don't you think?
Donegal Browne

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