Tuesday, July 17, 2007

AHA! So That's Who Lives In That Burrow! And What About the Feathers Standing Up On Top of Bird's Heads?

Remember the mystery as to what kind of beastie lived inside this burrow?

Well this is the beastie, but it's still possibly a mystery. This is the front of the animal. Not much help is it?
Sorry about the lack of clarity, the animal was oozing/ burrowing through the bottom of the grass stems at some speed towards the burrow entrance, so the grass is moving and the animal was moving and it was dusk. We do what we can.

This is the back end of the animal. Note the short but furred tail. The fur was very smooth, healthy and a shiny black. Let's call him Midnight. Midnight was 3 or so inches long and may have been a youngster out for a foray outside the burrow. As on a number of occasions he froze in that young kind of way...but didn't freeze long enough for a decent photo in the dim light with the equipment I had at hand.

I immediately thought MOLE. But then I read that the Eastern Mole has a mostly naked tail. Then after more research found that shrews have furred tails but the Short-tailed Shrew's tail is longer than this one. A photo popped up of a mole WITH a furred tail, but without any label beyond "mole".

Currently I'm thinking Midnight is an undisclosed (to me) species of mole...maybe, mostly.

Midnight oozed his way across several feet of grass, scurried over the sidewalk and into the mystery burrow. Then of course there is the question, did he really live there or was it just handy? It looked like he knew where he was going so I'm tentatively saying he lives there.
Any one want to take a gander at what Midnight is and help out a woman stranded in Wisconsin without her mammal field guide?

Next up: Eleanor Tauber, a Central Park Photographer who often contributes to the blog, and an avid birdwatcher, came up with a very interesting thought.
Donna, I loved your story and photos of “Little Chip”, but have a question:-
You mention the raised feathers on the top of his head as part of an aggressive display.........Might the head feathers also be displayed as part of a mating ritual?

Here’s two photos of a Swamp Sparrow, singing away [you’ve seen these]. Do you think the raised feathers are because he is claiming his territory or for more romantic reasons? Or both??Eleanor

Photograph by Eleanor Tauber

Eleanor really got my brain going on this one. Did I use the word aggression too lightly? Perhaps strong feeling is a better way of putting it?

But then again, that puts us into the dangerous realm of conceivably using the words for human feelings, as that's what we feel, to label bird "feelings" which we don't feel.
Now that you've brought it up Eleanor it's hard to say either/or when we don't know if he has already snagged a mate. On the face of it, I'd say this Swamp Sparrow is protecting his territory and/or advertising it. which would then enter the edges of the realm of mating behavior. Therefore we'd need a definition of what constitutes mating behavior. But we could say from his posture, intensity, body tension and the standing feathers, that whatever it is he's feeling very strongly about it. Without observation of what the exact circumstances, I'd say we can't know for sure because what erect head feathers mean for some species, Red-tails raise the feathers on the back of their heads in aggression, but Little Chip raises his as it's a display that shows how strongly he feels about getting fed. In fact he fees so strongly about it he gets right in his father's face which we as humans might call aggressive. As in putting oneself forward strongly.
Having said that, mature Chipping Sparrows raise their rufous triangle when another Chippie of the same sex shows up. They then dive bomb each other. They raise the "red flag" when surprised. But that might be an aggressive reaction to being surprised and to tell the truth, it does work on the the other fellow. It is a touch startling.

Earlier in the season I'd come in off the patio to get something quickly I'd forgotten, left the door open, and gone up the hall to get it. After finding what I was looking for, I came back down the hall, and was startled by a Chipping Sparrow flipping his bright head feathers at me. He had been eating the seed off the carpet that I'd tracked in on my shoes. I'd surprised him, the feathers went up, and he startled me. Part of it had to do with his cheek in just coming right in for a snack and my not expecting to see him there so I was surprised too.

Chipping Sparrow mating ritual doesn't seem to involve the rufous triangle, at least in the portion that I witnessed. This is the species in which the female will just be minding her own and the male will appear in the I'm-a-baby-bird-who-is-lost-and-starving mode. Although the female in this case who was being harassed threw up her head feathers and jumped at the suitor, who suddenly recovered from being a "baby bird" in a hurry and flew off.

I'm not at all sure we'd include that part as mating ritual.

Can anyone think of other species in which head feather raising is part of the mating ritual?
(I'm thinking we shouldn't include species in which all the feathers are raised, just those that use the isolated head feathers.)

Donegal Browne

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