Signs of the Season: Feathered fall migrants

by on November 12, 2013

 
Black-throated blue warbler, male. Photo by Cuatrok77/Flickr.
 

 

As the days shorten and valley oak leaves fall, hundreds of birds are flocking to the Bay Area.

Many of these birds come from the distant shores of Alaska and Canada to escape freezing temperatures and to forage in the many microclimates they find here. Others use the Bay Area as a resting ground for a few days on their long journeys across the Americas.

The San Francisco Bay is the largest estuary on the Pacific Coast, making it an ideal refuge for a variety of winged creatures including shorebirds, raptors, and songbirds. Every fall more than 250 species of migratory birds visit the region, so whether you’re on the sandy shores of Ocean Beach, or hiking the steep slopes of Mt. Diablo, or just sitting on your backyard patio, you’re already on the perfect viewing platform.

Keep an eye out for these prominent species, and do tell us about your sightings!

Varied thrush. Photo by Roger Golub.

Varied thrush. Photo by Roger Golub.

Varied thrush
During fall and winter months you can find the varied thrush hopping around in the understories of both temperate coniferous and deciduous forests.This majestic songbird is similar in appearance to an Oriole with a robust orange breast, and black and gray bands along its wings. Twentieth-century bird artist Louis Agassiz Fuertes described the varied thrush’s song “as perfectly the voice of the cool, dark peaceful solitude which the bird chooses for its home as could be imagined.”

Ferruginous hawk. Photo by Jöshua Barnett/Flickr.

Ferruginous hawk. Photo by Jöshua Barnett/Flickr.

Ferruginous hawk
The ferruginous hawk is the largest hawk found in North America. With a wingspan of up to 56 inches (roughly 4.5 feet) this hawk soars over open grasslands hunting small rodents and mammals. The ferruginous hawk breeds in the Northern Great Plains and eastern slopes of the Rockies during summer months, and makes its way west to California and south to Mexico for the winter. While the majority of ferruginous hawks migrate, permanent populations can be found in the arid regions of northern Arizona, Nevada, New Mexico, Utah and Colorado. The Ferruginous Hawk is one of only three raptors found in North America with feathered legs all the way to the toes.

Whimbrel. Photo by Muchaxo/Flickr.

Whimbrel. Photo by Muchaxo/Flickr.

Whimbrel
If you happen to find yourself at the beautiful California coast over the next few weeks be sure to look for the whimbrel. This shorebird has a unique long and slightly curved bill that allows it to dig into the sand in search of invertebrates. You can find the whimbrel on nearly every continent. These birds have been known to fly up to 2,500 miles non stop as they make their way down from Alaska and Northern Canada.

Golden-crowned sparrow. Photo by Alexandra MacKenzie/Flickr.

Golden-crowned sparrow. Photo by Alexandra MacKenzie/Flickr.

Golden-crowned sparrow
After migrating from the thick coniferous forests of western Canada and Alaska, the golden-crowned sparrow spends its winters hopping around in shrubs, coastal chaparral and backyards throughout the Bay Area and California coast. In fact, it spends more of its time in its California wintering grounds than almost any other species. Interestingly enough the sparrow’s golden crown becomes less prominent during winter months. And its song is so woeful that Yukon miners of yesteryear referred to it as the “no gold here” bird, which it apparently sounds like it’s saying.

Black-throated blue warbler, male. Photo by Cuatrok77/Flickr.

Black-throated blue warbler, male. Photo by Cuatrok77/Flickr.

Black-throated blue warbler
Although the black-throated blue warbler generally does not inhabit or migrate to the California coast, individual birds can be spotted throughout the Bay Area. The black-throated blue warbler breeds in the northern deciduous forests of the Northeastern U.S. and Canada, and in winter migrates to Caribbean Islands and Eastern Latin America. Cool fact about them: the sexes look so different that they were originally described as two species, and they even hang out in different areas, the males preferring lower elevation forests and the females liking shrubby habitat at higher elevations. Apparently they make some compromise during mating season. And its name, as you can see, definitely refers to the male’s markings.

Black-throated blue warbler, female. Photo by Outdoors2magic/Flickr.

Black-throated blue warbler, female. Photo by Outdoors2magic/Flickr.

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6 comments:

Cindy on October 17th, 2012 at 7:58 pm

I had no idea the guy and gal brb warblers looked so different. Now I’m gonna look for them. The golden-crowns just arrived in my yard for the winter. I so enjoy waking up to their beautiful song.

cady on October 18th, 2012 at 8:03 am

backyard patio? if you’re lucky. try fire escape!

Kris on October 19th, 2012 at 8:43 pm

I did not know that about the Golden Crown Sparrow…no gold here. I know its Fall when I hear their mournful song! Thank you Jackson.

Allen Fish on October 25th, 2012 at 3:52 pm

I wish to respectfully disagree with the note that the Ferruginous Hawk is easily identifiable. Though on average Ferrugs are bigger than Redtails, the wingspans, and most body measures overlap extensively depending on gender and individuals. Further, juvenile Ferruginous are very much like a pale juvenile redtail in their body coloring. To tell them apart, it helps to know the tell-tale patagial mark on the underwing of all Redtails. Also Ferrugs tend to show a richer white in the outer wings than the more barred-wing Redtail. Backs of both juv birds can be similar, but Ferrugs show a richer cleaner white in the dorsal outer wing window, and at the base of the tail. Bottom-line, sizes overlap between the two species, and identification of the two species may not be at all easy.

dr hawk on November 16th, 2013 at 7:00 pm

Black throated blue can be seen”throughout the bay Area”?? Surely you were not serious, as I believe there were only 2/3 reports of this species in the past 2 fall migrations in the greater Bay Area! Was it once more widely seen hereabouts?

Kathy on November 23rd, 2013 at 7:37 am

Spotted a flock of western bluebirds on a suburban street in Berkeley. Truly amazing what you come upon if you are looking.

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