Black Skimmers of Foster City

Reminiscent of a large, bizarre-looking tern, Black Skimmers (Rynchops niger) are one of those really neat, must-see species any birder should have on his or her list.  Their black-white-and-red coloring is as striking and attention-grabbing as their uniquely-formed bill.


Skimmers are in the same family as terns and gulls (Laridae), and last weekend, the flock we saw along the San Francisco Bay in Foster City was happily sharing its sand spit with numerous Ring-billed Gulls and Forsters Terns (not to mention hundreds of sandpipers and plovers, among others).


The laterally compressed bill of the Black Skimmer appears thick and bulky from the side, but is knife-thin when viewed from the front.  The lower mandible protrudes farther than the upper, giving the birds the appearance of an under bite.  This special design allows skimmers to literally plough through the water as the bird flies low over the surface, its bill open, lower mandible slicing through the water.  As the bird skims along the top of the water, contact with prey causes the upper bill to snap shut when a fish has been caught. 


In addition to possessing bills with unusual proportions, Black Skimmers are recognized at a glance in flight by their extremely long, thin wings, and on land by their short red legs.  Flocks of Black Skimmers often fly in formation, turning and maneuvering through the air in unison, even beating their wings in synchronization.


Black Skimmers prefer sheltered coastal waters, such as sheltered bays, lagoons and estuaries, but may also be found inland at the Salton Sea in Southern California.  Flocks are often seen resting on sandbars, as well as gravel or shell bars, and open beaches with little vegetation.  Along the central coast of California, Black Skimmers are regularly seen in the shell bar area of Foster City, along the western side of the San Francisco Bay, and occasionally farther south in the area of the Moss Landing harbor. 

Black Skimmers nest in large colonies, often mixed with species of terns and gulls.  Nesting sites include sandy islands, shell bars and beaches, and nests are little more than shallow depressions in the ground.  Because Black Skimmers nest very close to the water's edge and feed along the surface, they are one of the species that is the most negatively effected by oil spills.

Watch the video below, from the Cornell Lab of Ornithology, to see the interactions between Black Skimmer parents and chicks!


Comments

Post a Comment

You Might Also Like:

Birds of the Desert: Residents & Spring Migrants

Image
Nearly everyone knows the desert as a barren, desolate land of extremes: high heat, low precipitation; little available food and water; prickly, spiny, unfriendly plants growing in a sea of rocks and sand as far as the eye can see.  But for those who stop and look closer, the desert reveals itself as the beautiful, incredible, mesmerizing place it truly is, teeming with unexpected life. Juvenile male Costa's Hummingbird visiting chuparosa blooms next to our campsite in Anza-Borrego Desert State Park. I particularly love the desert in the spring, when the annual wildflowers, cacti, flowering trees and shrubs are all in bloom.  (I've experienced the desert in the searing 120 degree heat of summer, and the rainy, even snowy cold of winter... and spring wins every time!)  Eric and I just returned from a week in the Colorado desert, exploring the imperiled, accidental Salton Sea (more on that coming soon), the vital wetlands of the Sonny Bono Salton ...
Read more

Joshua Tree Woodlands: A Tale of Sloths, Moths and the Trees that Need Them

Image
In 1844, early California explorer John C. Fremont gave a somewhat scathing review of Joshua trees when he wrote, "...their stiff and ungraceful form makes them to the traveler the most repulsive tree in the vegetable kingdom."  Rather unkind, don't you think?  But when Joshua trees were formally described by scientist William Trelease in the 1890's, he noted that Joshua Trees are "the most attractive of all the Yuccas."  I am inclined to agree with this sentiment, and must disagree most heartily with Lieutenant Fremont! I, for one, adore Joshua Trees, with their whimsical shapes and great ecological significance!  If you struggle with plant identification, the iconic Joshua tree, hallmark of the Mojave Desert, is a good place to start.  With densely spiked tufts protruding from the ends of gangly arms stretched towards the heavens, this looks like a plant straight from a Dr. Seuss book....
Read more

A Shorebird Primer: Godwits, Curlews, Willets and Whimbrels

Image
For those of us living in the Great Central Valley, autumn is the time to head to the coast.  Of course, there is no bad time to visit California's magnificent coastline.  But as the heat and haze of summer drag on in the Valley, the sea becomes increasingly tantalizing: September and the onset of autumn bring sunny weather and an abundance of migratory seabirds and shorebirds to our coast. A new birder visiting California's Central Coast will undoubtedly be met with a splendid array of very confusing birds.  Among these are small shorebirds like  "peeps" (sandpipers), Sanderlings and various  plovers .  But the larger birds can be just as confusing, until you learn a few distinguishing features.  Four large shorebirds that are commonly seen (and commonly confused) along California's Central Coast are Godwits, Curlews, Willets and Whimbrels. Marbled Godwit (upper left), Whimbrel (upper right), Long-billed Cu...
Read more

All The Ducks!

Image
On a recent birding trip to Merced National Wildlife Refuge, I tallied up a list of sixteen different species of ducks.  Only a few more species, around twenty in total, are expected in the Central Valley of California's freshwater marshes during the winter, so I consider that to be an excellent day for ducks! North American ducks are broadly separated into two categories, largely based on their methods of foraging for food.   Dabbling ducks , also known as "puddle ducks," tend to frequent shallow water, where they are commonly seen tipping bottoms-up to feed on plant matter and invertebrates in the water and on the muddy bottom.  They are most at home in water, but walk easily on land as well, as their legs are positioned near the center of their bodies.  The wings of dabbling ducks are relatively large, which allows them to take off from the surface of the water, straight up into their air.  Dabbling ducks almost all nest on the ground, near water....
Read more

Birding in Adverse Weather Conditions: Wind and Rain

Image
Though I often extol the virtues and merits of winter in the Central Valley , especially when it comes to birding, the whole truth is that we experience "bad" weather also, just like anywhere else.  But even when the winter weather rolls in, the birds are still out there!  And sometimes, despite our best planning efforts, a birding day happens to coincide with crummy weather.   In that case, what's a birder to do?  Usually, we go birding anyway!   Birders far more intrepid than I regularly brave the ice and snow of northern winters to see their favorite birds, so perhaps you should look to them for real tips on winter birding!  For those of us in the valleys of California, the worst weather we see - wind and rain - is really comparatively mild.  Birding on an extremely windy day! I don't know of anyone who actually likes birding in the rain.  But I would argue that birding in the wind is just as aggravating as trying to bird in the rai...
Read more

Winter Gulls: The Great I.D. Challenge

Image
Gulls are a fun challenge for birders, from beginners to experts.  A few things make gulls an interesting study: they are large and conspicuous in their open habitats, so they are easy to see, easy to put a scope on, and easy to watch and study for long periods of time.  Furthermore, gulls are almost always identifiable as gulls; none of this confusing warbler/vireo/kinglet nonsense! And yet, gulls are almost impossibly difficult!  (Though perhaps not nearly as difficult as Empidonax flycatchers!) An intimidating scene to many a birder: a mixed flock of gulls.  I see five different species of gull here. Oh, and one American Coot in the background. One of the reasons they are so complicated is most gull species take two or three years to achieve adult plumage, and go through multiple molts in a year.  So, you may be looking at three or four gulls together that look like four completely different species, when they are actually just different ages (...
Read more