Monday, June 23, 2014

Adirondack Birds: The Common Yellowthroat

799px-Common_Yellowthroat_by_Dan_PancamoThe overwhelming abundance of pesky insects in and around aquatic areas in the Adirondacks from late spring through mid summer can discourage travel to these picturesque settings, however, the hordes of bothersome bugs that thrive in wetlands help support the rich diversity of life that occurs around these places.

Among the birds that seek out mosquito, black fly, and deer fly infested streams, swamps and shrubby lake shores is a common and vocal warbler whose voice regularly echoes across these watery habitats. Despite its small size and effective protective coloration, the common yellowthroat (Geothlypis trichas) can be seen by anyone passing through its domain as it bellows out its characteristic song from a perch that temporarily makes this Adirondack resident fairly conspicuous.

The yellowthroat gets its name from the yellow patch that covers the entire front of its neck down to its upper breast. Its back, wings, and tail are a uniform olive-green, which causes this small bird to blend into a background of broad leaves, especially in places exposed to direct sunlight. As is the case with most birds at this time of year, the plumage of the male is brighter in color than that of the female. This makes the female harder to spot, especially since she spends nearly all of her time in places of dense vegetation.

Unlike many of the other warblers that abound in the Park, the common yellowthroat does not seek out mature stands of timber, or forests of tall trees. Rather, this bird strongly prefers thick patches of shrubs and small trees, especially those that grow close to water. Alder thickets that spread outward from the banks of slow-moving streams, shallow wetlands covered with willows, quaking aspen and white birch saplings, and the shores of ponds that have become overgrown with choke cherry, nannyberry, and wild-raisin are all places likely to support a healthy concentration of yellowthroats.

694px-Common_Yellowthroat,_femaleLike the ovenbird, the female yellowthroat spends most of her time very close to the ground hidden in the tangled maze of herbaceous plants, the stems of shrubs, and fallen twigs. In this labyrinth of vegetation, she forages for food, constructs her nest, and incubates her eggs, as her pale coloration causes her to blend well into this background. In most cases, the male remains a dozen feet or more away from her, as his brighter appearance could attract the attention of predators.

Along with his brighter colored plumage, the male yellowthroat also possesses a conspicuous black band or “mask” across his face. Researchers have recently discovered that the larger the size of this black patch, the more sought after the male is by receptive females. Even though most yellowthroats remain faithful to one another during their reproductive period, ornithologists have noted that just prior to laying eggs, a female can be enticed into having a brief encounter with a male supporting a larger than normal black facial mask should this individual be successful in infiltrating his neighbor’s territory.

Under most circumstances, a male seldom strays far from the area in which his mate is readying her nest for eggs. A careful watch over the immediate area prevents any intruder from coming into contact with his mate, which ensures that only his genetic material will go into fertilizing her eggs, and producing offspring. His vigilance is regularly announced when he bellows out his familiar “witchity-witchity-witchity” song from a spot that affords the opportunity to carefully scan the area below.

Occasionally, a male may venture from his post to find food, to chase away a rival male, or lead a predator away from the general vicinity. Should a nearby male happen to notice the absence of the territory’s sentinel, he may try to find the female in an attempt to seduce her. As a general rule, most females shun the advances of other males they happen to encounter; however, should the male be supporting an enlarged black patch on its face, it is likely that she will cave to the temptation and permit the brief reproductive encounter necessary for him to introduce sperm into her system.

The yellowthroat resides in the Adirondacks only during the time of year when most insect populations are near or at their peak. While this bird can be seen flying out from a perch a foot or two to quickly snag a bug as it flies by, it is also well known for devouring spiders, caterpillars, millipedes, and other invertebrates that occur on leaves or twigs. As soon as the numbers of these creatures begin to dwindle, the yellowthroat begins to vacate the region in order to travel to areas where bugs are still abundant.

For the present, there is an especially high concentration of bugs in many of our wetlands that support deciduous trees and shrubs. This bounty of insects is the prime factor that brings many birds to our region, as acquiring the protein enriched food needed for forming babies and nourishing developing young is much easier here than in many other locations.
When visiting a wetland over the next several weeks, especially early in the morning, the clear and medium tempo “witchity-witchity-witchity” call of the yellowthroat is one that is routinely heard and typifies these settings. So too is the high-pitched whining sound of mosquitoes, and the buzzing of deer flies.

Photos: Above, the male yellowthroat (courtesy Wikimedia user Dan Pancamo); and below, the female (courtesy Wikimedia users D. Gordon and E. Robertson.


Tom Kalinowski

Tom Kalinowski is an avid outdoor enthusiast who taught field biology and ecology at Saranac Lake High School for 33 years. He has written numerous articles on natural history for Adirondack Life, The Conservationist, and Adirondack Explorer magazines and a weekly nature column for the Lake Placid News. In addition, Tom’s books, An Adirondack Almanac, and his most recent work entitled Adirondack Nature Notes, focuses on various events that occur among the region’s flora and fauna during very specific times of the calendar year. He also spends time photographing wildlife. Tom’s pictures have appeared in various publications across the New York State.




One Response

  1. Dan Crane Dan Crane says:

    One of my favorite Adirondack warblers!

    Their highly inquisitive nature seems to compel them to come in for a look when I stop near the shore of a wetland for my lunch break while on many a bushwhacking adventure.

    The yellowthroat and the white-throated sparrow are the quintessential Adirondack wetland birds as far as their songs go. I look forward to hearing it again all winter long!