Monday, April 20, 2020

The Babies of Spring: Great Horned Owls and Red-tailed Hawks

One of the wonderful pleasures of spring bird-watching is the possibilities of catching sight of the new chicks. The birds of course go to great lengths to keep their children hidden from predators, but once in awhile one gets lucky and gets a peek at some of the young ones. Today I stopped by the covered bridge a few miles up the Tuolumne River and found that the Great Horned Owls (Bubo virginianus) had hatched and there were at least two chicks in the nest. No matter what stage of life they are in, I find the stare of an owl unsettling.
I haven't been allowed back to work at my campus, but there are no rules against walking around the grounds, so I stopped there last week to see if the Red-tailed Hawks had laid eggs or not. The pair have been around for weeks, but I didn't see them on the nest they used last year, but as I looked carefully I saw something move up there.
Zooming in, one can see there is at least one baby present. I couldn't tell if there were others. They fledged two young ones last year.

Spring rolls on! I'll be watching for the Ospry babies next. There are at least four active nests up the river.

Saturday, April 18, 2020

More Color for Drab Days: The Bullock's Orioles on the Tuolumne River

I admit it. I can't resist the Orioles. They are one of the flashiest colorful birds out there right now, and I'm seeing them a tiny bit more often these days. There are at least three individuals on the trail at the moment, and I am getting used to where they like to feed. The picture above shows that they might be getting tired of me taking their picture, though...
The black eye strip and black crown identifies this one as a male Bullock's Oriole (icterus bullockii). I'm on the lookout now for some sign of their unique nests. They build a hanging affair out of palm fibers, and there are several promising palms along the trail.
The females are not as flashy as the males, but I have seen one or two so far. These birds are tropical migrants with a winter home in Mexico or Central America. I always enjoy their summer sojourn on the river, and I look forward to more sightings in the weeks to come.

Thursday, April 16, 2020

Another Migrant Passing Through: Nashville Warbler on the Tuolumne River

Sometimes it just boils down to sheer luck. I am not very good at spying and/or identifying Warblers. Somewhere around sixty of them are listed in Sibley's Guide West, referring to the American western states. Of these, I've seen eight, but I only find one or two in any regular fashion, the Orange-crowned Warbler, and the wonderfully named Yellow-rumped Warbler, otherwise known as Yellow-butt. The Yellow-butts are so common that I get sort of impatient about identifying little yellow birds high above me in the oak canopy. I'll try and try to get a clear shot of these very active birds and finally find after craning my neck for thirty minutes that it's yet another Yellow-butt.
But yesterday something strange happened. The bird I was tracking turned out not to be a Yellow-rumped Warbler. The breast was bright yellow, it had a grayish-olive colored back, and it had a complete eye-ring. It took me a moment before I realized it was a Nashville Warbler (Oreothlypis ruficapilla), only the second one I've ever seen. The pictures are not great, although the first shows the reddish color sometimes seen on the head of the males (I didn't even see that until the pics were loaded onto the computer). But these three pictures were the only usable ones out of the forty pictures that I took. This was a challenging individual.

As I've noted before, this warbler clan shows the effect of isolation on the evolution. The western population of the Nashville Warbler is a brighter yellow than those found in the eastern United States, and it was once considered a separate species called the Calaveras Warbler, a name I find much more interesting. We can still call it by that name, since it is officially a subspecies called Oreothlypis ruficapilla ridgwayi. Oh, and by the way, the bird has little to do with Nashville. It breeds in Canada and the Pacific Northwest and migrates in winter to the tropics. The ones seen in Nashville that gave the species its name were simply migrants passing through.

Sunday, April 5, 2020

There's No Place Like Home: The Rufous Hummingbirds Arrive on the Tuolumne

So here's the thing. I've been on a quest to find a Rufous Hummingbird (Selasphorus rufus). At this time they are in the middle of a truly epic migration. They are traveling from Mexico and Central America all the way to Canada and Alaska. They travel farther north than any other hummingbird, and for their size compared to miles traveled, they have the greatest migration of any bird (others travel farther, but they are bigger and are able to store more fat reserves for the long journey). What that means to us here in Stanislaus County is that we have a window of just a few weeks to see them as they pass through during the spring.
I have been scouring the Wild Tobacco shrubs that have proliferated along the Tuolumne River Parkway Trail for a couple of weeks now, and was thrilled to read that fellow nature blogger Siera Nystrom spied one on the trail on March 27 (check out her great blog here). It was only the second sighting in the entire county this year. On April first my quest continued and I was walking past one of the shrubs they love so much. I saw movement, and thought I saw a flash of gold, so I got the camera ready and got off a single shot before the bird flew off. I got home and downloaded the picture, enlarged it, played around with Photoshop, and finally decided that I might have seen the elusive bird.

Then Mrs. Geotripper called me off the computer, letting me know I promised to work in the garden in the backyard. And of course you know what happened...
The bird buzzed right past my ear, took a drink at the hummingbird feeder, buzzed past my ear again, and landed in the Crepe Myrtle tree not ten feet from where I was standing. And it sat there for another five or ten minutes while I went indoors for the camera and came back to start snapping pictures. Of course it was a female Rufous Hummingbird. The only limitation was that the sun had set and it was a bit dark for photography.
Like most birds, the female is the least-adorned. I was still hoping to catch a male somewhere, so the search continued at home and along the river. And today it happened.

Somehow Mrs. Geotripper has been my good luck bird charm. She called me while I was hiking so I stopped and was staring off in the distance while talking, and my attention was drawn to movement in the tobacco plant across from me. And there it was, a male feeding in the flowers. Even better, it was slowly hovering enough to get some pleasing shots, including the one at the top of the post.

The Rufous Hummingbirds can live for as long as a decade, and they have an excellent memory for the locations of the kinds of shrubs and flowers they prefer. Even though they are not overly common in our area, they have shown in up in the same area in the four years that I've been watching.