It was just a Sunday afternoon jazz concert at the local high school and birds were the furthest thing from my mind, but when we drove into the parking lot I immediately noticed the flock of Least Terns greeting us jazz aficionados from the roof, singing their own raucous, high-pitched medley of zzreep and kvick-kvick. Mental note: Come back soon with binoculars and camera.
The Least Tern is our smallest tern and a summertime resident along the coast. It has a distinct white forehead patch. They are endangered due to competition for nesting sites on the sandy beaches from sunbathers and developers. As a remarkable behavioral adaptation the terns have moved their nesting colonies to flat gravel roofs, including our local school and Acme Supermarket. The sunbathers have not yet followed them there.
I did return to observe the terns on a hot, sunny morning, timed so the sun would be behind and photography ideal. Birds in flight, and especially these terns, present many challenges. My best advice is to take hundreds of shots to get a few “keepers”. You’ll need to keep exposure time faster than 1/1000 sec. and may find multiple exposure bursts helpful. A white bird on a bright background is easily over-exposed so tend to your exposure compensation adjustments and check your results frequently.
The sleek Least Terns do not do straight line flight but rather display a full acrobatic repertoire of twists, turns, barrel rolls, and hovering. They almost seemed to relish confounding the earthbound photographer with the funny hat and large lens.
According to Frank Gill in his textbook, “Ornithology”, “flight is the central avian adaptation”. The ability to hover, dive, soar, fly upside-down and backwards, all require constant wing and tail adjustments, and set Aves apart from other classes of animals. They’ve mastered the physics of lift, buoyancy, thrust, and drag. Think of their refined brain and nervous system sending and receiving messages from specially designed bones, muscles, and feathers, all making this possible. Flight, after all is the most energy efficient way of getting from point A to point B; more so than walking, running or swimming.
In addition to the Least Terns there are other avian acrobats that highlight my summer birding. The Osprey is the dominant bird-of-prey along our shoreline. When its soaring flight changes to a hover you know it has spotted a fish and you need to be camera ready for a high speed dive. Just before impact the feet and lethal talons come out and enter the water first. I’m still trying to capture that perfect splashing shot of impact.
I’ve described our swallows and their acrobatic feeding frenzy over the lawn in a prior post on 8/1/2016 called “Where Have All the Swallows Gone?”. At our location the “Barnies” seem to fly low, just over the lawn, while the feeding Tree Swallows seek insects at higher elevations. Add an occasional Purple Martin and Chimney Swift and you have quite a show. I find these birds the most difficult acrobats to photograph due to their rapid and erratic changes of direction.
Let me add two more colorful performers to the list, the American Goldfinch and Ruby-throated Hummingbird. My mother first pointed out to me the characteristic undulating flight of the goldfinch some 60 years ago. I have yet to figure out the reason for this roller coaster ride and have concluded that perhaps the bird is doing it for pure pleasure. In any case this allows the ID of the bird from great distances, without even seeing the striking yellow and black coloration.
The “Hummers” are the world’s smallest birds and the flight of these iridescent gems is truly remarkable. Slow motion analysis has shown a figure eight rotation of the wing allowing both the upper and lower surfaces of the wing to face downward and supply buoyancy and lift with each of the 80 beats per second.
Last week Suzanne and I sat down to a sunset dinner of crab cakes, steak, watermelon salad and chilled white wine on the screened, waterside porch. The air was still and the evening quiet following the recent heavy rain. I’m innocent; birds and birding were not on my mind when suddenly a mixed flock of 40 or 50 Laughing, Herring, and Ring-billed Gulls invaded our airspace and put on a captivating display.
This was not a short flyover but rather a sustained airshow of erratic, criss-crossed flight, rapid turns, and many near-misses with other gulls. They were unusually quiet for gulls, only squawking to ward off a collision. Seeing them periodically open their beaks and bend their necks we concluded they were feeding on an invisible-to-us swarm of insects arising from the moist lawn. The spectacle ended as suddenly as it had begun, leaving both of us happy to have witnessed another show of the avian acrobats of summer.