Wednesday, March 15, 2006

Blakeman answers question about Charlotte and Lola's eggs

Another good exchange between web-site correspondent Mai Stewart and John Blakeman:

Note: the program that transfers photos to my website doesn't seem to be working these days. To see the photo with the egg and newspaper discussed below, please check out Lincoln's website at .
Once there, click on Hawks 2006 and then March 14, 2006.

Hi John,

I've been very interested in the photos on the websites lately -- in particular, I was wondering about what we've seen the last couple days in PMJ's nest -- here are my questions:

* The pix show Charlotte standing, looking at the egg, or around the nest -- I know these birds know what to do, but I get worried that the egg/s is exposed too much -- I'm under the (possibly false) impression that the eggs need to be kept covered, for warmth, so they can develop properly, virtually all the time -- am I wrong?

* Also, it was so interesting to see that sheet of newspaper on Charlotte's nest -- do you think one of the RTs actually picked it up + brought it to the nest, or perhaps it just wandered in on a gust of wind (of which there have been many this past week) -- i.e., would it be natural for the RTs to use newspaper, and esp. such a large piece, for their nests? Could it be a kind of protection, or windbreaker, for the egg/s?

* It appears from what I've been reading about PM/Lola's behavior that Lola, too, has at least one egg in her nest -- is this the same conclusion you draw from their behavior as well?

Well, thank you again -- hope these questions aren't too mundane (I'm not at all a trained scientist).
Mai Stewart


Everyone who closely studies red-tail nests is initially alarmed -- as you are -- about the birds' nonchalance and inattention in keeping the first egg warm.

But it's not a problem. Actually, it's perfect. So that all eyasses hatch at the same time, it's important that serious incubation start simultaneously for all eventual eggs. Therefore, the female will not sit hard on the eggs until the last one (Three this year?) is laid. Until then, she will dance around the exposed eggs. She will not sit down and put her brood patch against the egg for any period of time. She wants only to keep the egg from freezing.
In raptor breeding experiments, scientists frequently remove newly-laid eggs and store them for a week or longer in a refrigerator. This keeps them healthy, alive, and undeveloped until incubation proper begins.

So take no concern here. The female will sit when she's good and ready, and that will be when no more eggs are descending down her single fallopian tube. Her inattentive attitude reveals that at least another egg is on the way. If we see this after the laying of the second egg (which will be today or tomorrow), then we will know that this year a third egg will be laid.
For all of us, keep watching.

The piece of newspaper up there? This shows that like so many New York mothers, she wants only the best education for her offspring. She wants her eyasses to be reading before the others. Out here in the rural wilds, our eyasses are rather illiterate, unable to keep up with the daily offerings of the NYT or lessor rags. Our birds only get to read an occasional McDonald's hamburger wrapper. Charlotte is a modern NYC mother. Her kids are going to be able to compete and get accepted to one of the better kindergartens.
But no, it's not a windbreaker or protection of any kind. It just looked "interesting" when the parent picked it up and brought it to the ledge. Yes, it may have been flying around int he air when picked up. A good rain will resolve (Dissolve?) the matter. It was probably perceived to be good lining material. Out here, our red-tails commonly use corn stalk leaves, which are about the thickness and texture (but not the size) of newspaper.

And yes, from what I can see, Lola, too, has an egg and is waiting for the descent of a second one.

For interest, let me recall an observation I made last year. After I made this comment, you or some other woman observer came back with a rather pointed retort -- which was much deserved. In some masculine language that apparently masked the gravity of the matter, I mentioned that I recalled a profound look of "discomfort" (or something else rather dismissive) on the hen's face for a few hours before she laid each egg. For some time she stood on the edge of her nest with this strange look, after which she sat down and laid the egg. As a male unfamiliar with either egg laying or birthing experiences, I will respectfully defer on the matter to those who have. The bird also moves about on the nest with a certain awkwardness for a time. Things to watch for, as they presage the laying of another egg.

And your questions are quite proper and appropriate. There never should be a scientist/non-scientist dichotomy in the search for explanations. That problem usually is the fault of scientists who don't invite or receive such questions. I do, and it's a pleasure to convey my explanations to people as curious and interested as yourself.

Once again, ain't this fun?

--John Blakeman