Black Skimmer - Rhynchops niger

The Black Skimmer is a gregarious species, nesting in colonies that can exceed 1,000 birds. On the west coast they are seldom seen often north of the Oakland Bay Bridge, but they are regular at Radio Road in Redwood City. On my Jan 18 visit I noted 4 of them loafing on a close mud bar in the main pond.

The white nape will be gone with the advent of alternate plumage. Huge bill favors a male. No doubt you've seen videos of these long-winged tern-like birds flying low over the water with the lower mandible cutting a swath through the water, ready to snap shut when a prey item is encountered. Since they feed by touch they often are foraging at night, and most often spend the day resting with their buddies. You'd think that there would be serious drag from the large beak cutting through the water, but in fact the bill is so greatly compressed laterally that it meets with minimal resistance. Old shot from Florida shows the bill face on:

Many taxonomists currently place the Skimmers in a subfamily Rhynchopinae, within in the family Laridae (Gulls, Terns and Skimmers). Some think skimmers are more closely related to terns than to the gulls. In the North America the Black Skimmer is a coastal bird, whereas the other 2 Skimmer species (African Skimmer and Indian Skimmer) are found on the banks of rivers. Along our East Coast the birds head south to Florida for the winter, while those seen in California are largely sedentary. They are a species of concern, as reproductive success if quite variable (most years only 50% of pairs fledge chicks, and 2 chicks is about average (BNA #108, Gochfeld and Burger). Nesting failure more common in small colonies.

Black Skimmer - Rhynchos niger

We occasionally see the Black Skimmer in the North Bay, but they are more reliably found in the South Bay, where they breed. In Florida the Black Skimmer is seen regularly along the coast, often roosting on a beach with terns, shorebirds and gulls.

This one was at Fred Howard Park, Tarpon Springs, hanging out with Royal Terns and Laughing Gulls. Note how the camera focused on the Laughing Gull and the Royal Tern, so the Skimmer is a bit blurred.

​I walked a little closer and after waiting a bit the Skimmer could be seen more by itself, allowing better focus. The Skimmer may look a bit grotesque on land, but it is a marvelous long-winged aerialist, foraging by flying low over the water with the over-sized lower mandible skimmer the surface for small fish.

We used the see Black Skimmers in good numbers at Fred Howard Park, but heavy use of the area by beachgoers and kayakers seem to have caused them to roost elsewhere.
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Black Skimmer - Rhynchops niger

These photos from Florida trip in February, Fred Howard Park, Tarpon Springs. I think they show a male Skimmer, because of the gap in the bill. The deep black suggests alternate plumage. The frontal shot show the laterally compressed bill, which enables it to slice through the water with minimal resistance. 

Side view shows the long wings (span 44") and short red-orange legs, and of course that amazing underbite:

Last shot gives us a closer look at the bill. Skimmers fly very close to the water, dipping the lower mandible into the water's surface and snapping it shut when they contact a fish. Fun to watch.

Skimmers are seen on both coasts. In California their northern range limit is the SF Bay Area. Once year we had one loafing at Shorebird Marsh in Corte Madera, Marin County. They are seen regularly at preserves in the south bay, and are known to breed there.

The Black Skimmer, Rhynchops niger, displays great size differences between male and female, with the larger male fully 10% bigger or more in all measurements, and fully 30% heavier (365 gm. vs 265 gm., or 12.9 oz. vs 9.3 oz.). The male has a bowed or "open" bill (BNA account).

Skimmer taxonomy tends to vary with the source, and remains unresolved. What follows is the mostly widely accepted understanding, and to me the most sensible.

Order: Charadriiformes - Huge and diverse order, including shorebirds, gulls, auks, etc.

Family: Laridae - Gulls, Terns, and Skimmers. (Skuas and Jaegers now have their own family)

Subfamily: Rhynchopinae - The Skimmers. Only one genus here. The other sub-families in Laridae are Larinae (Gulls and Kittiwakes) and Sterninae (Terns and Noddies). Skimmers thought to be closer to the terns, but really not very close.

Genus: Rhynchops - Skimmers. 3 species world-wide. Other two are the African Skimmer (yellow tip on bill, and not dimorphic) and the  Indian Skimmer (always with white collar, and orange-yellow on bill).

Species: Rhyncops niger - Black Skimmer. 3 subspecies, all in the New World. Ours in North America is the nominate subspecies, R. n. niger, which is mostly coastal, but seen inland in Florida and California (especially at the Salton Sea). Subspecies further south are more riverine in their nesting and foraging.

Skimmer population in NA is fairly stable, but nesting success in not high (less than 50%), with disruption by flooding, predation and human disturbance. Caution advised in banding or observing nesting colonies (duh).