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Inelegant Elegant Terns Arrive as Winter Shorebirds Prepare to Leave

by Marjorie Powell On In Nature | Comments Disabled
Alameda Post - A mostly white bird with black markings and an orange beak flies across the water. [1]
Elegant terns certainly do look elegant when they are flying, with their white wings edged in black. Photo by Rick Lewis.

The shorebirds that have enlivened our coastline all winter, in their white and gray or pale brown and white outfits, are suddenly changing into new more vibrant browns, blacks, and golds, and are fattening up to make their long flights north to breed. I will miss them over the next months.

Alameda Post - A collection of brown and black shorebirds sit on the beach. [2]
Shorebirds that have spent the winter here are growing their more vibrant breeding feathers and resting in preparation for their flights north to breed. They will return in the fall. Photo by Rick Lewis.

But they have recently been joined by a pale, swift-flying bird with a long yellow bill, a scruffy black head patch, and a raucous call. It’s misnamed, in my opinion, as an elegant tern. I think the black feathers sticking out at the back of their heads make them look like they are ready for an inelegant confrontation.

Alameda Post - Two white and black terns sit together on the beach. They have distinctive spiky feathers on their heads. [3]
These two elegant terns show off their spiky head feathers as they sit at attention on the beach. Photo by Rick Lewis.
Alameda Post - Dozens of terns stand in shallow water along the shoreline with other shorebirds. [4]
Their jumbled black head feathers make elegant terns look ready for a confrontation, as they gather in large flocks along the Alameda shorelines. Photo by Rick Lewis.

For years we saw them in the fall, when the adults and newly fledged juveniles followed the small fish north [5] from their breeding locations in Mexico and southern California. But now, they are sometimes found nested at the Veterans Administration (VA) property [6] at Alameda Point, and we are hoping they do so this year.

Alameda Post - A flying white bird with black markings and a black and orange beak. [7]
Of the three species of terns that can be seen now in Alameda, the Forster’s terns are the smallest, with a black bill that has yellow near the head in the summer. They dive for very small fish. Photo by Rick Lewis.

There are actually three species of terns here now. The smaller ones with black bills that are starting to get yellow near their heads are Forster’s terns; they will leave shortly for Canada and the upper Midwest to breed and will return in the fall. The larger ones with a fatter red bill are Caspian terns, which also sometimes nest at Alameda Point. Larger than the elegant terns, the Caspian terns also more aggressively drive predators away from their nests, so the elegant terns like to nest nearby, taking advantage of the protection. Gulls and peregrine falcons are the primary predators of tern eggs, chicks, and fledglings. Mammals such as foxes and raccoons also take eggs and chicks; the outer fence at the VA property provides some protection from them.

Alameda Post - A group of white and black birds sit on the shoreline. [8]
Caspian terns are larger than elegant terns, with a fatter darker reddish bill; in this photo the tern in the back right is a Caspian and all the others are elegant terns. Photo by Rick Lewis.

All terns nest in small depressions in sand, close to other nests. While beaches are their traditional nesting spots, our beaches are too full of people throughout their spring-summer nesting season, so they have found other locations. The sand between the runways at the former Alameda Naval Air Station is one such location. The California least terns, which usually arrive in early to mid-May, still nest there but the elegant and Caspian terns found another sandy area a little distance from the least terns.

Alameda Post - Two least terns stand in the watery sand. They are mostly white with black markings and yellow beaks, and somewhat small. One holds a minnow or other small fish in its beak. [9]
California least terns, which usually arrive in Alameda in early to mid-May, are the smallest terns that visit Alameda, and can be identified by their yellow bill and white forehead before their black head feathers. They nest at Alameda Point. Photo by Rick Lewis.

All terns eat fish, which they catch by plunge-diving as they fly over the water looking down. Without a hook on their beak, terns can’t break up their fish, so they swallow them whole; the smaller terns need to catch smaller fish. And the adults need to catch even smaller fish for the very small young chicks. Young chicks do well in years when there are lots of small fish. The waters of San Francisco Bay usually produce lots of small fish, but a warmer year, pollution, or less fresh water that results in saltier Bay water, can kill the small fish, so the tern chicks starve.

Alameda Post - One elegant tern holds a fish towards another elegant tern. Around them are other shorebirds. [10]
A male elegant tern offers a fish to a female as part of the courtship as they select mates in the spring. Photo by Rick Lewis.

In the spring, as elegant terns are selecting mates for the year, a male may offer a fish to a female, and a female will beg for and accept a fish from a male. You might see a tern offering or begging for a fish if you watch the terns from the platform at the Elsie B Roemer Bird Sanctuary on Shoreline Drive or the rocks past the Visitor Center at Crab Cove just before or after a high tide.

Alameda Post - Two flying terns that look like copies of on another, raising their wings in a V shape. [11]
Elegant terns fly in parallel with their wings lifted into a V as part of their courtship. They glide, flap, glide, flap, and glide together. Photo by Rick Lewis.
Alameda Post - Two flying terns that look like copies of on another, raising their wings in a V shape. [12]
They earn their name, elegant tern, in this courtship display of fine flying. Photo by Rick Lewis.

Another step in the courtship process, after a fish transfer, is called a V-flight. One elegant tern flies up, followed by the second bird, which positions itself below the first. The two terns lift their wings into a V and glide in parallel, then flap for a short distance before gliding again, followed by a flap and third glide. The pair may swoop down then fly up and repeat the V-flight flap-and-glide pattern. These courtship behaviors occur shortly after they arrive, as they select mates. They start breeding in late April, so this is the time to look for courtship behaviors.

Alameda Post - A large flock of birds flying just above the water. [13]
Large flocks of elegant terns may be seen in the Bay and estuary around Alameda now, although sometimes I see only one or two at a time. I often hear them before I see them flying over the water fishing. Photo by Rick Lewis.

Cornell University’s Birds of the World reports that elegant terns nest on the coast of Mexico and the Sea of Cortez, as well as San Diego, but that before 1950 they nested in the San Francisco Bay. We birders who have been excited to have them nesting the past few years are hopeful that they will continue to nest at Alameda Point and that the scientists will catch up with our new summer birds.

Marjorie Powell moved to Alameda from the East Coast in 2014. A member of Golden Gate Bird Alliance [14], she serves on its Alameda Conservation Committee, the Friends of the Alameda Wildlife Reserve [15], and tries to go birding frequently.

This article is part of a series from the Friends of the Alameda Wildlife Reserve [15] (FAWR), a Conservation Committee of the Golden Gate Bird Alliance [14] (GGBA). Learn more about FAWR at www.goldengatebirds.org [16].