Wednesday, June 27, 2018

Cute Downy Baby Bird Alert! Turkey Vultures on the Tuolumne River

You know what? I wasn't always the handsome dashing geologist/naturalist that you see before you now. Let's face it: I was an ugly baby. But you also know what? All babies deserve some love and tenderness, so put aside your prejudices about rotting meat and dead carcasses and give these two baby Turkey Vultures (Cathartes aura) some well-deserved love and tenderness. The scavengers of our ecosystems have a dirty job, and the world would be a much worse place if they weren't around to clean it up for us.

It's not always a pleasant experience to realize there is something really big in the brush off to your side when walking alone on a trail. The Tuolumne River Parkway Trail is not exactly a wilderness with bears and mountain lions or other menacing creatures, but there is still a moment of uncertainty and doubt when some large animal makes that first detectable motion. I quickly looked around and could see that it was actually a pair of juvenile turkey vultures warming themselves on a fallen log. I've seen an adult in the immediate vicinity in the last couple of days, but I have no idea where their next was located.

So....hold your nose and politely say to the proud parents what lovely babies they are raising. It's the polite thing to do.

Monday, June 25, 2018

Even Parasites Need Some Love? Brown-headed Cowbirds at the Mojave National Preserve

Brood parasite is such an ugly pair of words. Birds who practice this form of raising their young are almost universally hated. That one bird species would survive by killing another seems so unfair, even though that is what predators do by definition. But it is what it is, and I finally got some pictures of a Brown-headed Cowbird (Molothrus ater) so we 'll be mentioning it today.
If you haven't heard of it before, brood parasitism is the reproductive strategy by which a species of bird lays its eggs in the nest of another species, forcing the victim species to raise the nestlings as one of their own. The Cowbird eggs tend to hatch earlier than their victims and the chicks grow faster. As such they can destroy the other eggs, or push the other nestlings out. The Cowbirds have laid eggs in the nests of some 220 other species.

Brown-headed Cowbirds are certainly a native species, long a part of the ecosystems of North America, but they have increased their range with the expansion of agriculture. This has happened because they prefer open fields where grazing animals disturb insects that can then be captured and eaten.

I finally got my first clear look at a Cowbird in an unlikely place, in the middle of the Mojave Desert at Hole in the Wall Campground. They are far more common back home in the Central Valley, but I've always managed to miss them in the large flocks of blackbirds with whom they tend to hang out.

I dunno, do you think people would like them better if we thought of them as unfortunate children who were abandoned by their parents, and they just need our understanding?

Sunday, June 24, 2018

Black-tailed Gnatcatcher at Hole in the Wall, Mojave National Preserve

Here's a bird I never get to see on the home turf. Black-tailed Gnatcatchers (Polioptila melanura) are creatures of the desert southwest. We were on the second day of our Colorado Plateau field studies journey and had camped the previous night at Black Canyon in the Mojave National Preserve in eastern California. We were wandering around the visitor information center seeing what birds might be around.
The bird chases down insects and generally gets the moisture it needs from the food it consumes. They are true wilderness birds, rarely venturing into urbanized areas, but their numbers have suffered from habitat loss in desert regions of the southwest United States.

Friday, June 22, 2018

Mountain Bluebirds at Mesa Verde National Park (with bonus babies!)

I love the color blue, and I really can't resist that color in birds. Scrub Jays, Great Blue Herons, Western Bluebirds, Stellar's Jays, I love them all. There's one that is common enough, but I'm not in the right place to see them often, so it feels special when I get the chance. It's the Mountain Bluebird (Sialia currucoides). They've been seen tantalizingly close to my stretch of the Tuolumne River, but I've only seen them up in the mountains, specifically in Tuolumne Meadows.

These birds were hanging out two weeks ago in our campsite at Morefield Village in Mesa Verde National Park. I recognized them as fledgling bluebirds but I was not sure of which kind until I saw them chasing poppa around the campsite (the females are far less colorful). I didn't get a shot of their faces, but I did get this one shot of parent and baby together.

Mesa Verde National Park is famous for the ruins of the Ancestral Puebloan people that are common in the alcoves and mesa tops. The protection of the archaeological resources actually provides for the protection of the bird life and other animals as well, since people are not allowed to roam freely around the park. They are allowed only in specific areas leaving large parts of the ecosystem intact and undisturbed (aside from the all-too-often wildfires).

Wednesday, June 20, 2018

Rock Wren in the Devil's Garden at Arches National Park, Utah

I was in the southwest for the last couple of weeks, so our birds for the next few days will be some of the desert species that I observed during our trip. I didn't have a lot of time for birding, but a few made themselves known. An example would be this Rock Wren (Salpinctes obsoletus) that introduced itself while I was walking along the Landscape Arch Trail in the Devil's Garden area of Arches National Park in Utah.
The wren was hunting for bugs on the sandstone fins that form the framework for the park's many beautiful arches (more than 300, the largest concentrations of arches on the planet). The birds do well in desert environments because they get all the water they need from the insects that they consume.
Pine Tree Arch on the Landscape Arch Trail

Tuesday, June 19, 2018

Return from Back of Beyond: California Condor on the Colorado River

Did you notice something missing from your life lately? Like maybe the posting of bird pictures here on Geotripper's California Birds? Well, it is true: I've been missing in action, as I was co-leading a two-week course on the Geology and Archaeology of the Colorado Plateau. I had barely a moment to myself, and literally no access to the internet from a laptop.

In terms of bird sightings, the trip was a mixed bag. We certainly saw a large number of birds, but there was little time for careful observation. I will be posting some of them in coming days. But we did have some interesting surprises at times. The best is what we saw at Navajo Bridge over the Colorado River in Arizona upstream of the Grand Canyon. It was a pair of California Condors.
The California Condor (Gymnogyps californianus) is a rare bird indeed. It is one of the last remnants of the "Megafauna", the extremely large animals that populated North America during the Ice Ages. The Megafauna included the mammoths and mastodons, rhino-like animals, camels, horses, giant ground sloths and a group of nightmare-inducing predators like the Saber-tooth Cat, the American Lion, Dire Wolves, and the Short-faced Bear. All of these animals went extinct around 12,000 years ago except for the Condor. As a scavenger, these huge birds feasted on the slain bodies of the large grazing animals, and when those animals went extinct, the population of the Condors plummeted. I've read that the total number of these creatures at the time of Spanish contact was no more than a few hundred birds.

As modern civilization encroached on their remaining territory (and left lead buckshot in the carcasses of deer), the Condors lost ground and lost population. By the late 1980s there were fewer than 30 of them left in the wild, and the decision was made to capture them all and begin a program of captive breeding. It has been a great (and unfortunately rare) success story, as there are now 410 living birds, and more than half of them have been released into the wild.
Most of the "repatriated" birds are in the coastal ranges of California, but a number of them were released in the Grand Canyon region as sort of a back-up population in case of catastrophe in California. I've seen them on both the north and south rim of Grand Canyon, and once saw them perched on the Navajo Bridge. That's where our group saw a pair last week, but by the time they told me about them they had taken off and were headed west. I got a pair of fair shots of them in the air.

Friday, June 1, 2018

The Ugly Ducklings are Doing Okay: Watching the Mute Swans Grow on the Tuolumne River

There's a pair of Mute Swans (Cygnus olor) who live in a quarry pond across the river from the west end of the Tuolumne Parkway Trail. They've been there for at least three years, and although they could be domestic, they've been freely raising young ones.
Last year they had four nestlings, but only one of them survived to adulthood. It was kind of heartbreaking to watch them for weeks and seeing fewer cygnets following mom and dad on the pond. It wasn't for lack of effort by the parents. I've seen the parents aggressively driving off Canada Geese and other larger birds from the pond area.
So far this year has been different. There were four cygnets again, but after several months three of them have survived, and seem to be getting large enough to fend for themselves (see the top picture).
As I've pointed out in previous posts, Mute Swans produce ambivalent feelings among birders and ecosystem managers. They are beautiful birds, the subject of myths and legends, especially in European culture. But that is because they are native to Europe. They were brought to America as domestic waterfowl, part of the landscaping for rich estates. But as usually happens some escaped and established feral populations, and as such they have caused a lot of damage by eating up much of the available forage, and displacing other species. There have been many efforts in the eastern United States to control their populations. Permits are needed to own these swans in California because of their potential in damaging natural habitats. For the time being, there are only a few showing up on the EBird reports in the region (Dawson Lake has been another dependable spot for seeing them).