Endangered songbird returns to old habitat after 60 years

[pmbryant]

Cross posted at my blog: pmbryant.typepad.com

Some good news for the weekend. In California's central valley, an endangered songbird is making a comeback and showing up in places it hasn't been seen in decades, thanks to efforts at land restoration:

FRESNO, Calif. -- A chatty songbird thought to have disappeared from the Central Valley 60 years ago has been spotted nesting in a patch of restored habitat along the San Joaquin River.

The least Bell's vireo, a little gray songbird that fits in a closed fist, was once widespread in the Central Valley. It disappeared from the area as the riparian habitat it favors was ripped up to make way for development and agriculture. About 90 percent of the valley's historic riverside vegetation has been lost, said Al Donner, spokesman for the U.S. Fish and Wildlife Service.

The bird was put on the federal endangered species list in 1986, when there were only about 300 pairs left in the low-lying shrubbery along creeks and streams in southern California.

...

Dropping her equipment, Lina focused her binoculars on the bird -- a male perched on a branch about 30 feet away, singing and shaking his tail feathers. As she called her supervisor about the discovery, a female joined him and did a copulation dance.

Further investigation showed the nesting pair was feeding two baby birds, which were just learning to fly, said Lina, who does bird counts and observation for the Point Reyes Bird Observatory Conservation Science.

...

The area where they were found had been a ranch, which was bought in 1998 and restored over the last three years by Fish and Wildlife with help from the state of California.

It must be immensely satisfying for these biologists to see the fruits of the efforts of years of hard restoration work.

A blog called Toad in the Hole has an email from a couple days ago from within the federal Fish & Wildlife Service announcing this discovery. Also, Hedwig has a pointer to this story in her current edition of Birds in the News.

As a result of the destruction of much of their riparian habitat over the latter half of the twentieth century, least Bell's vireos had been confined to southern California—in particular the Camp Pendleton area in San Diego County. Habitat loss and also nest-parasitism by brown-headed cowbirds reduced the vireos numbers into the hundreds by the mid-1980s.

Fortunately, efforts to control cowbirds and preserve and restore habitat have increased the numbers of least Bell's vireos to around 3000 these days. And with that increase, they have been expanding back north into their former range. So perhaps this exciting discovery in the central valley should not be all that surprising.

For those who aren't familiar with cowbirds, here is a description of their parasitic behavior from the Audubon Society:

Instead of building their own nests, incubating their own eggs and raising their own nestlings, Brown-headed Cowbirds have a different breeding strategy. Cowbird females use other bird species as hosts -- laying their eggs in the nests of other bird species and relying on these hosts to incubate and raise their chicks.

...

Brown-headed Cowbirds occupy most of North America south of the Arctic, but this large range has occurred only recently and is the result of human-induced factors. Prior to the arrival of Europeans in North America, cowbirds were nomadic, following the large herds of bison that roamed across the Great Plains.

When their nests are parasitized, tiny vireos and other songbird parents end up feeding chicks bigger than they are.

Unfortunately, cowbirds are a major problem for far more bird species than just the least Bell's vireo. For instance, here in central Texas, they are a major reason why the black-capped vireo is an endangered species.

But for today at least, we can celebrate the least Bell's vireo return to its old home in California's central valley.

--Peter

[doodadem]

1. Well, well--will have to keep an eye out

for those on the bird feeders. Can you post a picture? (on edit--nevermind, just found them in my "Field Guide to Calif.")

I'm wondering where all of my little goldfinches are this year. They are my absolute favorites--every one is uniquely colored, they are very friendly (I've had them come right up to me in the garden)and they have big rowdy parties in the birdbaths. I've counted up to 20 at a time in there splashing around. I've seen one or two this spring, but nothing like the big groups we've had previously.

[oldtime dfl_er]

2. Is it possibly still a little early?

Goldfinches don't generally nest until late, like July, I think.

http://www.cafepress.com/scarebaby/665903

[doodadem]

3. Hmmm....I thought I remembered them being here by now

But maybe you're right. Everything else is here! We have a family of Redtail Hawks, that nested in one of the big oak trees here. We always have a bunch around, but I've never seen them nesting before. They are just starting to get the 2 babies out to fly now, and they are pretty noisy early in the a.m.
We have tons of Western Jays, woodpeckers, mourning doves, nuthatches, grosbeaks, hummingbirds, bluebirds, and titmouses. At night, there are the owls. I never will forget taking the garbage out one night, flipping on the light in the garage, and having an owl with a wingspan like a 747 go swooping out over my head!

[XemaSab]

4. The goldfinches

should be where you are year-round. Dunno why they're missing.

Also, vireos don't come to feeders. They eat little insects off trees and bushes, like warblers.

Where do you live?

[Xithras]

5. A couple of minor errors:

The first quote says that 90% of the original riverside habitat has been lost. Sadly, the real number is much higher...98% of the Central Valley riparian forests have been destroyed, leaving only 2% of their original range intact (I only live a few miles from one of the few remaining pockets). While there are trees along most of the rivers inside of the levees, almost none of it qualifies as "riparian", and the vast majority isn't even forest...it's just a thin line of trees wedged between the water and the levee. For comparison, most of these forests extended for several miles on each side of the river 100 years ago.

Second, the forests weren't wiped out in the second half of the twentieth century. Most of the forests were lost due to farmland conversion shortly after irrigation showed up. That process started about 1900, and by the 1950's there were almost no riparian forests left.

Unfortunatly, these forests will never come back. Much of the land originally cleared for farming is today being developed and urbanized. Since restoring the riparian forests requires removing the levees holding back the rivers, there is very little land in Northern California that can be restored without putting homes in danger. Because of that, the remaining riparian forests will remain as "museums" of what once was for the predictable future.