Dan Gribbin’s blog for May 28, 2021

One of nature’s most arresting phenomena occurs every spring along the South Shore of Bermuda (and at certain points elsewhere around the island’s coast) as the Longtails—aka White-tailed Tropicbirds—carry out their courtship and nesting rituals. The nests are actually holes in the limestone cliffs where these pelagic birds can find refuge and dutifully care for the one chick that is born to them each year. Artificial nests now exist (they call them igloos), and, in season—roughly late April through late August—a Google search for the live camera in an igloo on Nonesuch Island will provide a look at a chick under the care of its parents.

Longtails spend much of the year gliding over the Sargasso Sea. Lacking thetoed feet of perching birds, they are ill-suited for anything other than flying or paddling along the surface of the water with their tiny black feet. That’s why nesting in holes in the cliffsides is preferable, but that doesn’t mean it’s easy. After a foray out over the ocean to catch fish or squid for its young, the adult bird must measure the wind and time the approach to the nest holeperfectly in order to crash-land on the nest’s sandy portal. Waddling into thelimestone mini-cave, then, the adult bird feeds the chick, a cuddly ball of feathers with a formidable beak which will eventually rival its parents in size as spring gives way to summer.

I have had the privilege of handling adults and chicks alike, birds that were brought to the Bermuda Aquarium, Museum, and Zoo (BAMZ) for rehab. The adult bird weighs about two pounds, while the chick may weigh much more than that during its development toward maturity. The chick I held in my hands was a fat little thing which would be put on a diet by the BAMZ staff asthe time for release into the wild approached. For a fledgling in the nest, theparents simply cut off the food supply when the time comes to slim it down for that fateful moment when it abandons the nest and forages for food on its own.

My main interest is in photographing the birds, of course, and the great challenge with White-tailed Tropicbirds is to capture a pair of them as they glide out over the water, sometimes circling back toward me but often drifting high and out of photographic range.  To close the gap, I typically perch on the relatively flat surface at the top of a cliff about fifty feet above the rocky shoreline. The automatic focus on my handheld Nikon D750 (80x400 Zoom with 1.5x teleconverter) works overtime trying to sharpen my view of a pair of birds.  I fire off multiple shots of the pair in desperate hope that, at some point, one or two will be in focus.

It all happens so quickly because the birds themselves seem never to know when they will achieve a close pairing as they arc into the orbits of each other. When they do pair up, the upper bird (presumably the male) is often
seen with mouth open, giving instructions to the lower bird (the female) about their precarious pas-de-deux. The sounds that they make during thesemaneuvers are a unique kind of rapid clicking. Ultimately, the female veers off and makes her next choice about whom to pair up with, the whole delicate operation as a pair lasting perhaps only eight or ten seconds.

This pairing off of Longtails is such a difficult piece of work to capture with a camera that I have taken the precaution of separating the focus function from the shutter release function, a common trick of the photographer’s trade. By assigning the focus function to the button that my thumb can easily reach on the back of the camera, I increase my chances of latching onto a pair of birds clearly once I locate them in the view finder. I typically shoot in “S” (shutter priority) mode set somewhere in the range of 1/2500thto 1/4000th of a second to be sure that the wings will be in focus in the final product.

My preference is not to use the most rapid-fire triggering sequence, but rather a middle-of-the-road setting, since I prefer to come back to our lodgings with 500 frames rather than 1000 frames to process. I limit myself to two hours of shooting. By that time, the weight of the camera rig has my back and arm muscles shouting for relief. During our two-week vacation, as one might expect, the process of viewing the shots after a session out on thecliffs is always a high point. Background is everything, and a perfectly focused shot of a Longtail pair in brilliant morning sunlight against the rich background of azure waters or deep blue sky—well, that’s what passes for priceless treasure in my experience of “the far Bermudes.”