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Flight of the tern at Lake Murray

By David D. Cooksy | Mission Trails Regional Park

Despite the dismal rainy season of 2017-18 and the corresponding dearth of food across the ecological spectrum (was there a wild flower season and I missed it?), somehow Kumeyaay Lake has survived. Actually, it has thrived. You would not think this true by looking at it now, but my regular rounds have discovered white-tailed kites, hummingbirds, nesting hawks, nest boxes with ash-throated flycatchers and house wrens. Within the lake itself, the population of tadpoles, minnows, dragon- and damselflies are seemingly unaffected by desperately low water levels.

A Caspian tern takes flight over Lake Murray. (Photo by David Cooksy)

In fact, over the past several months, one visitor has captured my attention on a daily basis: a Caspian tern (Hydroprogne caspia). Just one mind you, but just one Caspian tern is enough to witness the acrobatic aeronautical fleet-winged skill of this premier flyer.

The Caspian tern is grouped with gulls and skimmers in the family Laridae. There are 42 species of tern worldwide, 14 in North America, and 12 recorded in San Diego County. The Caspian tern is the largest species of tern in North America. It is primarily brilliant white, with a black cap, black legs, and brilliant red beak; it can be confused in flight with gulls. Primarily a spring and summer visitor to San Diego County, perhaps no other bird can claim the unique breeding distribution of the Caspian tern: Pacific coast region to British Columbia, Utah, Wyoming and east to the Great Lakes and Newfoundland.

While spotting the Caspian tern at Kumeyaay Lake is not rare, it is more likely at Santee Lakes or Lindo Lake. Greater numbers, including mating pairs, are often spotted along Mission Bay and the salt flats of South County.

My photographic fascination of flight is easily satisfied by this creative flier. The Caspian tern has a long, thin body, long wings tapered to a fine tip and a distinctive sharply wedged tail; a design perfect for high-speed gliding or lazy spinning turns when searching the water below for prey.

The most impressive aeronautical maneuver is a pinpoint turn that pulls into a momentary full stop, allowing gravity to take over for a straight-down, high-speed dive. The result is a spectacular headfirst explosive splash to a fully immersed grab for food. Although not always successful, the tern does not often miss.

—David. D. Cooksy is a trail guide at Mission Trails Regional Park.

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