Spring Migration

What a wonderful Spring I’m having! This birding stuff is opening my eyes, getting me outdoors and leaving me in awe regarding the realization of all that I’ve been missing. It still amazes me that I’ve lived nearly 25 years in Colorado and had no idea the plethora of colors, sizes and shapes of birds we have here. It really is astounding. One evening last week I came home from and added three (!) new birds to my growing list of ‘Yard Birds’ before work the next day. I’m so tickled.

Today another first showed up! I’ve decided I saw an American Redstart at my feeders. Nice dark bird, not unlike a black-bird, but with a creamy belly and distinctly orange ‘epaulets’ and markings on its back. It spent a lot of time trying to scare off other birds; raising the feathers on its head, generally fluffing up and opening its wings some, while fanning its tail. He was definitely trying to look big and ferocious. I missed his flying away, but am confident it was the Redstart. My how smug; feeling confident enough finally to ID a bird all by myself! While I didn’t get a photograph of the pretty little thing, I’ve linked to a good example of what I saw, but what really shows the pugnacious attitude of the little guy is this 1890 drawing by B.H. Warren, M.D. from his book: Birds of Pennsylvania.

One of the ‘new’ birds is the Western Tanager…a beautiful creature which apparently is nesting near here. Odd thing about this bird, unlike other Tanagers and most other birds, the red on its head is manufactured by eating certain insects…not unlike the pink Flamingos exhibit if they’ve been eating shrimp. I wonder why the male has more red? Perhaps when his hormones are raging, he gets a penchant for the bugs. At any rate, this red coloring is called rhodoxanthin and is a rare plumage pigment, according to Cornell.

Speaking of oddities, what is up with that bird's belly? I have no idea, but the photo above reminds me of broody-birds. While in most birds it is usually the female who sits on eggs, some males give it a go as well. To the point that they too, exhibit the brood-patch; the un-feathered belly-skin with which a bird covers and incubates eggs. Woodpeckers and occasionally Nuthatches are two breeds where the male oftentimes develops a brood-patch. You can see pictures of a brood-patch here.

While doing the research on incubation, I discovered yet another bit of superfluous information. When eggs are first laid, the reason cold weather doesn’t bother them so much…and so the female can spend several days laying a full clutch…is because the new eggs are thicker. As the developing bird grows (and who knew it was called an eyass?), it produces Carbon Dioxide which, as it mixes with the fluids within the egg forms a mild carbonic acid…which will slowly react with the shell, thereby thinning it over time and making things much easier for the hatchling to break out. While the egg is new and strong, the adult birds can carefully roll the eggs every hour or so, which keeps everything inside properly suspended. Unturned eggs will not develop properly…and will die. And when actual incubation does start, the 15-20 minutes of time eggs are left uncovered from time to time is not inattention on the parents part…it is necessary to let oxygen diffuse into the eggs. Who knew? I found this fascinating; you can read all about it by John Blakeman here. …and who is John Blakeman? I Googled him too; he’s an expert biologist/birder in Ohio.

I visited the Great Horned Owls the other day…the babies are growing fast! I wish I had a lens that would allow me to take better photographs! Still, these little shots remind me of my visits and how cool it is to see such a site in person.

I’ll include a couple shots of Grosbeaks here, too. I was fascinated to discover the females are not at all dull-looking. The female Black-headed Grosbeak is a beautiful bird with a boldly striped head. Apparently she is quite similar to the female Rose-breasted, but that one has more defined streaking which also continues across the entire breast. Also, the Black-headed female has a two-toned beak, the top mandible is darker; while the Rose-breasted female’s bill is all-over pale. I’m not sure if I’ve seen her, yet; I’ve only seen a male or two and not very often. Course, the fact that they hybridize creates more problems with identification.

The female Evening Grosbeak looks entirely different in her somewhat formal looking black and grey and dramatic white wing-patches. What I find beautiful about the two of them is that both their beaks turn a beautiful teal-color during breeding season. I noticed this once, and have read that this occurs with the males; but obviously it is both sexes which sport this pretty display.

Speaking of females, I had to study up on the difference in the females of Bullock’s Orioles and Western Tanagers. They are somewhat similar…but the Tanagers are smaller and the Orioles’ bills are longer and sharper looking. The female Western Tanager’s back is dusky with an almost olive-yellow head, while the Bullock’s Oriole female’s head and face are quite strongly bright yellow-orange.

I think I’ll include four shots of my feeders to show the incredible number of birds which visit here. This is just some of ‘em! Wow…

Great-tailed Grackle, Western Tanager (m), Black-headed Grosbeak (m+f),
Bullock's Oriole (m+f) Evening Grosbeaks (m)

all changed places...and add a Hairy Woodpecker (f)