Wednesday, April 18, 2007

How to tell Orville from Scout

Incubation continues on track, however, yesterday during a mate change it looked like there were only 3 eggs. I was pretty sure that it was simply a matter of 2 eggs being close together and the angle of view made it look like it was just 1 egg. Another look later confirmed there are still 4 eggs!
Now, how to tell Orville from Scout?! I think of all the different peregrines we've had in Columbus over the years, Scout and Orville look alike the most! And so, it can be pretty tricky to tell which bird is on the eggs. It seems that Orville has actually been doing a fair amount of incubation duty! I haven't kept specific notes, but more times than not, when I look, he's there. Here are a couple of picture of the 2 birds for comparison (saved for me by Juanita Woods). Juanita did a GREAT job of catching the 2 birds in the same position and the same light:

The top photo is Scout and the bottom photo is Orville. The best fieldmark is basic overall size. Scout is larger than Orville. Her body appears more massive and she takes up more room in the nest box. This is something that you have to get a feel for in order to recognize it. For those of you who also watch other birds, think of the difference between a downy woodpecker and a hairy woodpecker. Both woodpeckers are similar in appearance, but a hairy woodpecker is larger than the downy. It takes a trained eye to tell the difference with a quick glance. The same is true of looking at the peregrines. For me personally, I notice Scout's mass more than Orville being smaller. So, when I initially look I go by the rule, if it isn't obvious that the bird is large, then it's probably Orville.

More pictures:

If you look close in the bottom picture you might also notice that Orville's beak is more yellow than Scout's. Her beak has a small amount of yellow but overall it is darker. His breast is also more white, while hers is more off-white. These traits definitely acquire a trained eye to notice and the tones can and will vary with current lighting inside the nest box. With a couple of more weeks left of incubation, we'll all have plenty of time to continue honing our skills of telling the 2 birds apart!