Birds

Gray squirrel: While attractive and entertaining, not only can these arboreal mammals be pesky at bird feeders, but at this season they routinely eat bird eggs and young. If you hear song birds giving alarm calls from trees, it means that something, hawk, crow, or squirrel, is worrying the owners of nearby nests.

Nesting time

Story & Photo By E. Vernon Laux - June 8, 2006

The most obvious thing going on in the natural world is the activity of breeding birds. The serious business of reproducing the species, essentially passing on the most successful genetic material that belongs to living birds, is what is now going on with almost all birds in the area. The job at hand involves courting, building a nest, laying eggs, incubating, feeding young, and surviving to breed another day - that is what the next couple of months are all about for Island birds.

Despite great changes in human habitation and density on the Vineyard over the past decades, it still retains much protected land and a generally rural character away from the down-Island town centers. This is very good for nesting birds. The Island has prodigious numbers of eastern towhees, gray catbirds, common yellowthroats, ovenbirds, and yellow warblers, to name a few species, that far exceed in density what may be found on neighboring Cape Cod.

A worthwhile experiment for people newly interested in birds and one worth repeating, repeatedly, for those with a lifetime of experience, is to rise at 4:30 am on a morning with little wind, no precipitation, and hopefully a sunrise, and proceed out to the State Forest or a nearby Martha's Vineyard Land Bank property. Upon stopping your car, bicycle, or when finally standing still, regulate your breathing so that it is not a distraction and listen. Concentrate on sound and listening for a good long three minutes. Take another deep breath and be amazed at the numbers of birds and how loud they sing. This dawn chorus is a remarkable event that draws the listener into a deep appreciation of the mysteries of life, living, and the role that birds play in the grand scheme.

For terrestrial-based life forms that get up and go to work every day at a certain time, or observe whatever schedule one observes, it offers a glimpse into an entirely different world. These small, feathered creatures, far and away the most mobile animals on earth, traverse distances unthinkable for a bipedal creature (especially before the advent of modern technology, specifically jet aircraft). They live life at a pace we cannot even imagine.

Foiling the predators

The breeding season is for them a draining, physically demanding, and dangerous time because they are forced to remain in one place, their nest site, giving predators that at other times of year have no chance of capturing such alert, active animals, an almost level playing field, so to speak. Predators have a far greater chance of capturing a bird in or on a nest than at any other time.

This is partially overcome by the sheer numbers of birds breeding and each species' synchronicity. This means that nest building, laying of eggs, hatching of young, etc., happens more or less simultaneously among all members of the same species, essentially overwhelming the predators' ability to get more than a small percentage of the population. The natural predators can eat only so much. The case of domestic cats is something else entirely and makes a devastating, human-inspired impact on native songbirds.

An example of prey species overwhelming predators with an abundance of food is Arctic nesting waterfowl. Take the snow goose. Like most waterfowl, they molt all their flight feathers at the same time. The feathers drop off their wings, rendering them flightless for several weeks, much to the delight of Arctic foxes that share their breeding grounds. Fortunately for the geese, Arctic foxes are quite small and are year-round residents in an area the geese frequent for only a few months. The resident foxes (and the area supports very few during the winter months) are only so many, and they eat their fill of geese quickly. The vast majority of geese survive to migrate south and return the following spring.

An easier example is the exploding population of caterpillars of the winter and gypsy moths. These, heretofore unknown caterpillars have exploded exponentially on the scene, overloading all their various predators' ability to eat them. Every nesting bird I have seen feeding its young this season has had a beak full of little green caterpillars. Both yellow-billed and black-billed cuckoos are more abundant than at any time in decades and still the caterpillars prevail. No matter how many the birds can eat, it is just a drop in the bucket compared to how many caterpillars there are.

Colorful visitors

A few laughing gulls - small dark mantled gulls with black heads at this time of year - have been seen Island-wide. Sooty Shearwaters, pelagic birds that arrive to spend the austral winter in our climes, have been in small numbers in the waters surrounding the Island. They nest during our winter in the Southern Hemisphere, At least two razorbills are once again summering in Menemsha Pond, becoming something of a bizarre New England phenomenon as they are the only two summering anywhere in the region. More on these in a later column.

Scarlet tanagers, Baltimore orioles, and great crested flycatchers were the three most actively reported birds on the bird line this past week. These three species variously thrilled and delighted those fortunate to see and hear them, many for the first time. Once seen and heard, these birds brighten the observers' memories for years to come.

Until next week - keep your eyes to the sky!

To contribute news about birding activities or sightings, call The Times Birdline, 508-693-6100, extension 33, or e-mail birds@mvtimes.com.