California's Endemic: Yellow-billed Magpie on the West Campus, Back from the Brink, Maybe? (from Geotripper's CA Birds)

Note: Occasionally the subject matter of posts that I put on Geotripper's California Birds spills over into areas that may be of interest to those interested in the geology I cover at Geotripper. This is one of them, so I've re-posted it here:

California has precious few endemic species of birds. In one sense, this fact seems odd, given the many ecological "islands" in California, isolated environments where evolutionary pressures are the greatest. There are high alpine environments, desert mountain ranges with relict conifer forests, and valleys isolated by high mountain ranges, for instance. I have a feeling that the geology of the state has something to do with it the distribution of birds. There are many environments, but the orientation of the geological provinces is mostly north-south, and routes exist for birds to spread far and wide, crossing political borders into Baja and the Pacific Northwest. There are low exit points from places like the Great Valley and low passes over the margins of the Sierra Nevada. Other vertebrates can't surmount these boundaries the way flying birds can, so the trapped reptiles, amphibians and mammals show a great deal more species variation and endemism (is that a word?).

Endemic species are also vulnerable. Highly specialized species living in a single environment are subject to population disruptions when that environment is altered by the appearance of an invasive species or new disease. We've seen that on a human scale in our state. The indigenous people of the state were almost completely wiped out in the early 1800s by malaria and other diseases, with mortality rates estimated in the range of 90%. Our endemic Yellow-billed Magpies (Pica nuttalli) almost met a similar fate, and only a few years ago.

In 2004, West Nile Virus reached California and the effect on the Yellow-billed Magpie was nothing less than catastrophic. They had almost no resistance to the virus (95% mortality), and their tendency to gather in large flocks made transfer of the virus inevitable. Within two years the population crashed, dropping from an estimated 180,000 birds to 90,000. By 2007, some research suggested that the population had been halved again. Only 5% of the living birds tested displayed any kind of antibody response to the virus. That's an extinction threat.

I have memories of big flocks of the Magpies in our region, and I've not seen anything like them in my travels of the last few years. I was so very pleased to come upon a small flock when I was walking the perimeter of our West Campus on Tuesday. There were a dozen or so birds, and that is probably the largest group I've seen in some time. I saw more of them this evening in my neighborhood as well. I hope it is a good sign. They are gorgeous spectacular birds, and it would be such a shame to lose them.

I can't find any more recent data on their populations. If you know anything, please feel free to contribute to the comments!

A Scarred and Beaten Ecosystem Persists: The Native Species of the Great Valley

I live in an extraordinary place! In my last post on the Great Valley I was discussing our use and abuse of our most precious resource, one of the richest soils on the planet. Some 95% of the original ecosystem has been manipulated by humans to achieve the highest biomass production possible. Our burgeoning population has to eat after all, and the amount of arable lands is declining worldwide, not expanding. I also posted a number of photographs that intimated what the Great Valley might have looked like prior to 200 or so years ago when European colonists began twisting the landscape to their desires. The valley must have been a fascinating sight in all seasons!

Cedar Waxwing (Bombycilla cedrorum). For more pictures of these beautiful birds, check out my post at Geotripper's California Birds.

Since arriving home after nearly two weeks of extensive travels, I finally had a chance to get out and check my walking routes, around the pasture near my home, and out by the "mini-wilderness" on the west campus of Modesto Junior College. We also stole a moment from our errands today and watched the sun set at the Beckwith unit of the San Joaquin National Wildlife Refuge, which has a viewing platform just eight miles west of town. There had been a lot of changes in the two weeks as a number of migrant species had arrived, including especially the Cedar Waxwings (above).

Nuttall's Woodpecker (Picoides nuttallii), a California endemic species.

Walking through my normal haunts, I was struck once more with a realization about the scarred and embattled ecosystem I live in. There are survivors of the apocalypse still living among us. Like a war zone, there are vast areas of destruction, and little enclaves where the native species still hang on. Sometimes it is in stretches of woodland along rivers where the ground was too uneven to plow. In other instances, the alien invaders happened to plant ornamental trees that produce just enough berries or fruits that the natives can thrive. In a few precious localities, the alien invaders set aside larger environments from abandoned farmlands (partly so they could hunt the natives species, but that's the Faustian bargain that had to be made). In any case, the walks and observations this week for some reason included no Pigeons, Starlings, or House Sparrows, all of whom are opportunistic alien species. The birds I saw were the native species that had found a way to survive in this new alien world. There was a Nuttall's Woodpecker, a California endemic (when one includes a portion of Baja California, anyway). It was hunting for insects on fenceposts instead of trees.

Yellow-billed Magpie (Pica nuttalli):  More on this California endemic can be seen in this post.

There was a small flock of Yellow-billed Magpies in the pasture. These striking birds are a wholly Californian endemic species, found only in our Great Valley. They were almost wiped out by the West Nile virus, but they are slowly making a comeback.

Western Bluebird (Sialia mexicana)

I see the Western Bluebirds on occasion throughout the winter and spring. I think they migrate up into the Sierra Nevada during the summer. 

Western Scrub Jay (Aphelocoma californica)

The Western Scrub Jay is a perennial visitor to the feeders in my backyard. They've done well in relation to agricultural development, especially with nut trees, as can be seen above. They'll often make noise on our roof as they peck at pecans (and a number have taken root in our yard after pecans being left behind by the jays)

Oak Titmouse (Baeolophus inornatus) on a west campus oak tree.

Another more-or-less California endemic is the Oak Titmouse (Baeolophus inornatus). It ranges a little into Baja California and Oregon. The acre or so of oak trees in the "mini-wilderness" provides them a bit of valley habitat in our area.

Sooty Fox Sparrow (Passerella iliaca unalaschcensis)

Finally, there is a Sooty Fox Sparrow (Passerella iliaca unalaschcensis) that I discovered Tuesday on the west campus of my school. I'm new at this birding business and so was not used to searching the leaf litter for what I always thought were House Sparrows. The Sooty is one of four subspecies of Fox Sparrows. The number and variety of American sparrows is incredible, and is a startling picture of ongoing evolution in action.

It's inspiring to find that some hint or echo of the Great Valley's natural heritage still survives here and there, especially when it is a short walking distance from home or work. More than anywhere else, though, the glory of the ancient days still lives on in the federal bird refuges that line our valley like a string of pearls. Last night we saw a sky filled with migratory birds, thousands of them, who still have a winter home on part of the valley floor (see the video at the top of the post). These are places that should be protected and cherished, and not criticized because they take up some of the water in these hard drought years. Although I understand farmer resentment in such situations, the total water devoted to wildlife survival is no doubt a small percentage of the total utilized, and I'd rather see a healthy population of native birds over an additional field of cabbage or corn.

Geotripper is for the Birds: Life persists in the midst of horrific drought

It was on my morning stroll that I realized that Dry Creek was flowing. The creek has its headwaters in the Sierra Nevada foothills, and drains a region about thirty miles long before joining up with the Tuolumne River in downtown Modesto. It might seem extraordinary to be impressed by such a thing, but Dry Creek in recent decades tends to flow all year, from winter and spring rain runoff, and from irrigation overflow during the rest of the year. We had about two-thirds of an inch of rain yesterday, and in this drought year, that was finally enough to stop just infiltrating into the ground in the headwaters and begin flowing down the channel. In the twenty-five years I've been here, I've never seen such dry conditions. The rain is welcome, giving a last bit of moisture to fuel the growth of vegetation before the long dry season sets in. But it does little to alleviate the drought; we'd need something on the order of a foot of rain in the Great Valley and many feet of snow in the mountains in the next few weeks to fill the reservoirs.

As many of my readers know, I got a new camera a few months ago, and the powerful zoom lens has allowed me to explore a world that has been largely hidden to me until now: birds. Living in the Great Valley is wonderful for the access it provides to the incredible geological wonders of the Sierra Nevada, the Coast Ranges and the Cascades, but during the winter months when most field studies aren't happening the valley can seem a boring place. But not for the birds; for the birds, the valley is life itself. Millions of migratory birds winter on the valley floor, primarily in the federal and state bird refuges that have been established up and down the San Joaquin and Sacramento Valley floors. Over the last few months we have been frequenting some of the wildlife refuges, and the variety and number of bird species has been stunning to me (the neophyte birder). But the lingering drought is going to have an effect on their populations.

In some ways, the most surprising aspect of the bird-watching has been the variety of species I've found in my local neighborhood.  I documented some of them back in January in this post, but I have seen some more as the rain has finally come, and a few migrants have arrived back in the valley for the spring and summer. Here is a selection of the birds I have seen in the last week or two.

Cooper's Hawk (Accipiter cooperii)

The nicest discovery from this morning was a pair of Cooper's Hawks near Dry Creek (they could also have been Sharp-shinned Hawks, a closely related species; I invite corrections!). Even with the zoom lens, the raptors have been surprisingly shy about getting photographed. The hawks this morning were paying more attention to each other.

Western Bluebird (Sialia mexicana)

I saw quite a few Western Bluebirds during January and February, but I thought they had migrated higher up into the mountains, having not seen any for weeks. But here was one that was hanging out in the cow pasture a few blocks from my house. I love his colors.

Lesser Goldfinch (Carduelis psaltria)

There has been no lack of Lesser Goldfinches around my house. They are one of the most common visitors at our birdfeeders. This morning was the first time I've caught them foraging in the wild (the wild in this case being the grass along the highway north of my little farm town). The flowers in the background are Fiddlenecks and Purple Vetch.

Black Phoebes (Sayornis nigricans)

I love the little flycatchers in our area called the Black Phoebe. They are a western species, found commonly only in California, Arizona, and New Mexico, and many points south as far as Argentina. The Great Valley seems to be the northernmost end of their range. I'd never noticed them in the past, but I've seen dozens of them in the last three months.

Western Scrub Jay (Aphelocoma californica)

It's hard to miss the Western Scrub Jays around here. They're obnoxious and loud sometimes, and they're always chasing the other birds away from our feeders. On the other hand, they are one of the most colorful birds in our area. I always enjoy getting a close look at one.

Barn Swallow (Hirundo rustica)

One the recent arrivals in our area have been the Barn Swallows. They winter in Central and South America and migrate into our region for the summer. I photographed one for the first time just a few days ago. I'm seeing flocks of them lately building nests under the bridges around our irrigation canals.

Nuttall's Woodpecker (Picoides nuttallii)

I was very surprised to find a species unique to California living in my neighborhood. I thought "rare" endemics are hard to find. The Nuttall's Woodpecker hangs out in oak woodlands of California and nowhere else. I've now seen them several times in the walnut trees next to the cow pasture (and on telephone poles).

Great-tailed Grackle males (Quiscalus mexicanus)

The Great-tailed Grackles just recently arrived on the CSU Stanislaus campus. They arrived raucously, with one of the loudest calls I've heard during my bird travels of late.The males are dark black (above), while the females are brown (and much smaller).

Great-tailed Grackle females (Quiscalus mexicanus)

Yellowlegs Sandpiper (Tringas species); I don't know if it is the Greater or the Lesser.

I found the Yellowlegs Sandpiper in the slowly filling irrigation canal a few blocks from my house. They winter in our area before heading north into Alaska and Canada.

Yellow-rumped Warbler (Setophaga coronata)

I've briefly seen the Yellow-rumped Warbler flitting about in the grass on my campus, and even  chasing insects on my back porch one morning, but I walked out of my classroom on the third floor of our new Science Community Center the other day, and there was this little one right there in front of me. He politely waited until I had taken a few pictures before flying off.

Yellow-billed Magpie (Pica nuttalli), a Central Valley original

The Yellow-billed Magpie is endemic to the Central Valley. I see them all the time, and they are beauties. They are also in grave danger. The West Nile Virus reached our region in 2004, and the Yellow-billed Magpies were particularly vulnerable to the infection, with something like a 95% fatality rate. The population dropped by half in two years when the infection began. According to some web sources, they are rebounding somewhat from the disaster. I hope so; they are one of the prettiest of our local species.

So why all these birds on my geology site? Well, mainly because it's my blog, and I write about whatever interests me at the moment. But in the larger picture, the native species of a region are shaped by the geological forces acting on that area. These birds are adapted to the Mediterranean climate of the Great Valley and the riparian areas (rivers) and grasslands found within. They have survived hundreds of droughts in the past, and presumably are equipped to survive those of the present and the future. They have persisted through the vast floods which sometimes turn our valley into a vast lake. They are products of the geological forces shaping our valley just as surely as the rocks and sediment beneath our feet. And like so many of the wonderful geological sites in our state, they are interesting and often beautiful.