Thursday, April 30, 2015

An Inventory of Osprey's Nests on the Tuolumne and Merced Rivers

We can't resist the urge to check the Mother Lode Osprey nests each week when we get a chance to go outdoors. There are at least four of them along the lower reaches of the Tuolumne and Merced Rivers that we've found so far, and a fifth hidden in the forest near Table Mountain in the drainage of the Stanislaus River.
The birds themselves are spectacular to watch, if they are out and about. They have a huge wingspan, and are graceful flyers.
Activity at the nests is pretty muted, as we have yet to see any chicks. They may very well be there, but the nests are huge and deep. They are used year after year, and each year brings new sticks and other nest materials. The largest nests can be thirteen feet deep and six or seven feet wide. They have been encouraged to use artificial poles and platforms in our region.
There is a nest at the south end of Roberts Ferry Bridge on the Tuolumne River east of Waterford.
There is another nest on an old telephone pole almost hidden in the trees just south of the Merced River near McSwain Dam. One of the biggest nests is on a pole at the junction of Merced Falls Road and Hornitos Road at Merced Falls (below).
The nearest nest to us is on Lake Road just east of Turlock Lake State Recreation Area. The Ospreys there have both the reservoir and the Tuolumne River to utilize as a source of fish.
Under the category of "what did they ever do before telephone poles?", here is an Osprey nest in the top of a conifer tree near Table Mountain and Jamestown that I saw on a hike last week.
I wonder how often such nests collapse under their own weight?
We'll keep an eye out for young Ospreys and let you know when we get some pictures!

Wednesday, April 29, 2015

The Other Bird in the Bush: Ash-throated Flycatcher at Merced Falls

As I mentioned in my last blog post, I saw and got pictures of two new birds for my life list in a matter of a few moments from the same bush out by Merced Falls on the Merced River in the Sierra Nevada foothills. The first was hard to miss, being a bright orange-yellow Bullock's Oriole. After it flew off, I noticed another bird had landed, a little less brightly colored, but unfamiliar. I saw a slight crest so I guessed it might be a Say's Phoebe, but the wing color was all wrong.
It was difficult to tell at first because the bird was being bashful. The pictures here are out of order, with the first picture being the last one I actually took. The first pictures I got were of a bird well-hidden among the branches, as you can see above and below.
It finally popped out into the open, and a little research quickly showed it to be an Ash-throated Flycatcher (Myiarchus cinerascens). It's a common species of the southwestern United States, but you wouldn't know it from my observational powers. They winter far to the south, in southernmost California and Mexico. I noticed in the pictures that this individual is banded.
Lots of birds coming up! There were the nesting Ospreys near the river, and some Flickers competing for the ladies on campus yesterday.

Monday, April 27, 2015

Surprise! Two birds in the Bush are Worth More Than One in the Hand: Bullock's Oriole at Merced Falls

Photo by Mrs. Geotripper
I'm new enough at birding that this kind of thing can still happen. Mrs. Geotripper and I were in the car at Merced Falls trying to get a better look at the Osprey nest on the south side of the Merced River. I happened to look next to me for some reason and to my intense surprise there was a flaming orange bird right next to me, just across the street. I was trying to get a photograph, but the camera kept focusing in the branches in front (yeah, I know, manual focus, but I was fumbling too much). I signaled quietly to Mrs. Geotripper, who was at a better angle, and she got the best set of photos.

Photo by Mrs. Geotripper
It turned out to be a Bullock's Oriole (Icterus bullockii), and it was only the second time I've ever seen one, and the first time we got any kind of decent pictures. The Bullock's Oriole is a close relative to the Baltimore Oriole, but the Baltimore is a pretty much eastern species, while the Bullock's is a denizen of the western states. In the summer anyway. In the winter, the Bullock's lives in Mexico while the Baltimore winters in Central America and the northernmost part of South America. The birds were once thought to be the same species (they sometimes interbreed where their ranges overlap a bit), but they are genetically distinct. 
Photo by Mrs. Geotripper
The Orioles are said to be common, which shows how observant I am in the wild, having seen so few. But I'll be ready for the next one! But the funny thing about the moment was that the Oriole flew away after a few moments, so I watched the Ospreys again, and then I saw movement in the same bush, and it was another bird, and it was another species, and a first sighting for me. And thus the strange title for today's post. More on the other bird in the next post.
And here are my two fuzzy shots through the branches
In the meantime, enjoy these photos of one of the most intensely colored birds I've ever seen around here!

Sunday, April 26, 2015

Small Dinosaurs in the Backyard: Northern Mockingbirds Guard Their Territory

There's a saying amongst field geologists, that when you finish a field project and review your samples, you'll find you've failed to collect the single most common rock in the entire field area. I, of course, have been the same way with my bird project. I've documented all manner of birds that I've seen in my travels around California and elsewhere, and I see that I have failed to include any of the most common birds that visit my backyard. 
And so here is one of those every-day species, the Northern Mockingbird (Mimus polyglottos). They make their presence known in our neighborhood day and night, with singing, of course, but also in their territorial defense. Our cat has been at war with them for a dozen years. They've fought to a draw; she's nailed one or two of the birds, but the birds keep the cat hiding in the planters during the height of the breeding season.

The Northern Mockingbird is an American species. It's northern limit coincides with the Canadian border for the most part. They also range into Mexico, but they are found in all of the lower 48 states. It was part of the title of one of our country's greatest novels (and movie), and Mockingbirds were once kept as pets in the eastern United States, almost to the point of removing them entirely from the wild.
I'm not entirely sure why, but Mockingbirds remind me of the dinosaur connection more than most birds. The birds descended from small theropod dinosaurs like the Velociraptors. As such, birds are more closely related to dinosaurs than dinosaurs are related to reptiles inhabiting our world today (the present-day snakes, lizards, turtles and alligators split from the dinosaur line in the Permian Period millions of years before the dinosaurs themselves evolved.

Thursday, April 23, 2015

Red-tailed Hawk and Raptor Real Estate: Room With a View

The Great Valley is a great place for raptors. Despite the intense disruption of the natural landscape, they've benefited in some ways. For one, they have received the gift of thousands of potential nesting sites in the form of telephone/electricity transmission lines. I spotted a couple of Red-tailed Hawks (Buteo jamaicensis) on Claribel Road east of Modesto this week, but even more, I spotted lots of nests in the power transmission lines. As nest after nest passed by, I couldn't help but wonder about the sales pitch from a Raptor real estate can perhaps even imagine the kind of look they give one of their potential customers. Like that look in the picture above...

"Claribel Road is a fine neighborhood for raising a raptor family! We have housing available for every kind of need! And every one has a great view! We've got lots of single family dwellings like the one below..."
"Oh, not quite in your budget? Maybe we can save you a few bucks (or does) with a duplex. As an aside, though, can I suggest you go for the top one? It gets a little messy below sometimes..."
"Still not in your budget? Well...we do have a condominium complex at this tower. I've gotta warn you about those lower floors again. The bottom floor...yuck!"
"Not interested in sharing space with neighbors? May you should consider a do-it-yourselfer, like that family down there. You get to choose your own decor!"
"And there's also that fixer-upper down there. They sure let that place go. It's gonna take a lot of work..."
"Wait! You've been holding out on me! You can afford any place you want? Well, here we go, the mansion! The biggest place on the block! You might have some trouble convincing the current owners to leave, though..."
Next time, maybe we'll take a look at the Osprey nests that have popped up all around here.

Sunday, April 19, 2015

A Violet-Green Swallow near Table Mountain in the Sierra Nevada

I took a hike to the top of Table Mountain in the Sierra Nevada Mother Lode today. It wasn't a birding trip, but there were a few of them about, including some swallows that were moving very fast over the grassy meadows. One of them finally sat still long enough for a couple of pictures, and I was able to see the green coloring of the Violet-green Swallow (Tachycineta thalassina). I've seen them before in the Mono Lake area, but this was the first I've identified on this side of the mountain (due more to my lack of attention than any kind of rarity on their part). These birds, like their cousins the Tree Swallows, are residents of western North America, ranging from Central America and Mexico to northern Alaska, depending on the time of year. They prefer open woodlands, which is just where I found them.

Table Mountain is a unique geologic and biologic environment. You can read more about this strange place over at Geotripper (click here).

Saturday, April 18, 2015

White-headed Woodpecker: A Western American Endemic

The White-headed Woodpecker (Picoides albolarvatus) is endemic to western North America, found in conifer forests from the Canadian border almost to the Mexican border. I read that it is not particularly common, which probably explains why I've only seen it three times (then again, I'm not that observant either). And each time the pictures turned out somewhat fuzzy. But they get a little bit better each time. My latest catch was in Yosemite Valley in Cooks Meadow by Sentinel Bridge.
It was late in the evening and I wasn't really on the lookout for birds because of the poor lighting conditions, but once I saw this female, it was unmistakeable.  I had to at least try for the photographs, and while not perfect, they are the best I've taken so far.
A beautiful bird!

Source: Audubon Society

Thursday, April 16, 2015

Red-tailed Hawk on the Tuolumne River (And Yosemite, too)

There is a dead snag above the Tuolumne River near the bluffs of the future river walk park. I have to give it a look every time I wander by because there seems to be a different bird perched there every time. Sometimes a Starling, or a Magpie, and once a Turkey Vulture. On Monday it was a Red-tailed Hawk.

Red-tailed Hawks (Buteo jamaicensis) are sometimes described as the "default" choice when trying to identify an unknown raptor. They are common all across North America, and are often the most common raptor species in a given area. Just to make things confusing, they come in a variety of colors, or morphs. One variation is leucistic, almost pure white!

I only got  the one picture that day, but I decided to check the archives for a few other shots, and I was reminded of an extraordinary day in 2010 in Yosemite National Park. It was before my official birding days, but I was always paying attention if they happened to be close by. There was a rockfall off of El Capitan that day that I witnessed, and there was a Red-tailed Hawk in a tree near Sentinel Dome that didn't mind at all our efforts at photography.
I rarely ever think of hawks as slightly comical looking, but cross-eyed does it for me...

Tuesday, April 14, 2015

Western Bluebirds at the Tuolumne River Bluffs

Western Bluebirds (Sialia mexicana) run hot and cold on my walks. Sometimes weeks will pass and I won't see any at all, and then I'll see several of them within a day's time, and in multiple locations. In a matter of weeks I expect that most of them will start moving up into the Sierra Nevada foothills and on into the higher forests.
These individuals were lurking around the area I call the Tuolumne River Bluffs, a future park set on the hills overlooking the Tuolumne River in the edge-of-the-foothills town of Waterford. There are some old trees, oak and walnut, lining the bluffs. I also see the birds fairly often on my college campus, but I've had less time these days to look in on them. The end of the semester is looming; lots of work piling up, and then onto delayed projects at home and office.
A less brightly colored female

Monday, April 13, 2015

Tree Swallows on the Tuolumne River: You See What You Know...

In my usual life as a geologist and professor, I often describe to my students the secret of mineral or fossil hunting: once you've seen something, however difficult to see, you'll start seeing it everywhere. I've spent my entire first year and a half as an amateur birder, and in that time I never saw or noticed the Tree Swallows that live in our area. Barn Swallows, yes. Violet-green Swallows, sure, but never the Tree Swallow (Tachycineta bicolor).
But then we took a walk on Friday evening through the Joe Domecq Wilderness Park on the Tuolumne River, and I saw a pair of unfamiliar swallows in an old snag and got a few pictures. A short while later I discovered it was a Tree Swallow. 
So here it is on Monday, and I take a walk down to the Tuolumne River bluffs at the future park in Waterford, and there is another Tree Swallow in an old snag, hunkered down in the heavy winds. It was kind enough to let me get a couple of close-ups before wandering off. 
Tree Swallows range all the way from Central America to northern Alaska, and are more tolerant of cold temperatures than other swallow species (when their preferred food of bugs aren't available, they'll switch to plants). They arrive from their migrations sooner than the others, and with global warming, they have been nesting nine days earlier than they used to. Sibley's guide suggests that they are year-round residents in the Great Valley. So why haven't I seen them until now?

Sunday, April 12, 2015

New Video on the Birds of Stanislaus and Merced Counties (Audubon)

I had a fine afternoon at our local State Theater watching a locally produced movie on the birds of Stanislaus and Merced Counties. It was produced by David and Sharon Froba of the Stanislaus Audubon chapter. If you haven't been following Geotripper's Birds, you might be surprised to find that more than 300 bird species are known from the two county area. There aren't many places in the country with this kind of species diversity!

The richness of the birds follows from the varied habitats in the region: the Coast Ranges, the rivers of the Great Valley, the grasslands, and the Sierra Nevada foothills, including the reservoirs. There was a time when I would have thought the Great Valley a boring place. Since I've lived here, I've found this not to be the case at all. Not just the birds, but the geology! California's first ever dinosaur was discovered here, along with mosasaurs, plesiosaurs, ichthyosaurs, and the ice age mammals like wooly mammoths, mastodons, sabertoothed cats, short-faced bears, and many other strange and wonderful species!

Thursday, April 9, 2015

From the Archives: A Barred Owl from Muir Woods National Monument

I may have picked up the birding hobby in a big way within the last two years or so, but birds have captured my attention for years, even if I was only dimly aware of their names or circumstances. This Barred Owl (Strix varia) was a good example.

I get out to Muir Woods National Monument whenever I can, which isn't often enough. In 2008, we were wandering the trail taking pictures of the Trillium flowers, and enjoying the serene atmosphere when I noticed a small group of people gathering at the edge of the trail. It was soon apparent that they were looking at an owl off in the distance. I immediately thought the rare "Spotted Owl", since I knew how Great Horned Owls looked, and this wasn't one of them. I got these pictures (plus a lot of fuzzy other pictures; the forest was poorly lit for some reason having to do with giant redwoods), and wandered down to the park store to consult a bird book. I realized pretty quickly that the feathers on the back and tail were "barred", and not "spotted", and that it was streaked in front as well. It was a Barred Owl.
I didn't realize it at the time that this was the opening stage of a wildlife drama. The Spotted Owl is a rare and endangered species that has been controversial at times because of its need for old-growth forest habitat for survival. The closure of various regions to logging and other uses has led to court cases over the continued existence of the species.

The Barred Owl, on the other hand is not threatened at all, and indeed has been expanding its habitat. It is primarily a species of the eastern United States, but reforestation and abandonment of farmlands across the midwest has allowed the owl to expand westward and come into direct competition with the Spotted Owls. It tends to win out, being larger and able to survive in a wider range of habitats. The first Barred Owls at Muir Woods appeared there in 2002, and according the Muir Woods Nature Notes, it is the southwesternmost occurrence of the species.
I'll be hoping to catch a glance of a Spotted Owl one of these times, now that I know what to look for...