Articles & Resources

ATTENTION: WARBLERS MIGRATING
By ornithologist, Maria Stockmal of the New Haven Bird Club

The spring migration of wood-warblers is very short. In fact, I sometimes think that if I blink it will be over before I even get to see any warblers. This fear is the case with many birders and ornithologists and so we pack our month of May with as many field trips as possible and will always be on the lookout for new "hot" birding spots. The wood-warbler spring migration can take place from as early as the last week of April until about the first week of June. There may be some late arrivals but activity will significantly wind down by early June. Of course, weather plays a significant role on when the birds arrive. The weather needs to be warm enough so that the birds can find their food which mostly consists of insects.

It's great for birding if tree foliage does not peak until mid-May but that is usually not the case. If weather is unusually warm and the trees are leafy in April, it can be very hard to find and see these small to medium-sized colorful birds.

The dilemma therefore becomes: warm weather is needed for the insects to become food for the arriving warblers but the weather can not be too warm so that the trees are in full bloom. If we are lucky we will have something in between. All avid birders and ornithologists would like to see the longest season possible because many of the migrating warblers leave the State of Connecticut and migrate further north to their breeding grounds. Some do remain behind and there is a good chance to see two specific species of warblers both during spring migration and during the summer because they breed in Connecticut. They are the Yellow Warbler (Dendroica petechia) and the Common Yellow-throat (Geothlypis trichas). All wood warblers are from the family Parulidae.

The Yellow Warbler (Dendroica petechia) is just as its name states. It is an all yellow bird with yellow tail spots, prominent dark eyes, and is generally plump looking. The male Yellow Warbler will have dark red streaks on its breast whereas the female's streaks will be fainter or non-existent. They are small birds of about 5 inches.

These birds can be found in shrubby areas especially near water such as yards, orchards, gardens, or any type of wet habitat. They eat insects as caterpillars, gypsy moths, beetles, and aphids.

When looking for Yellow Warblers listen for their song. It is a distinct "sweet sweet sweet I'm so sweet" song and they are found low in the trees. The Common Yellow-throat (Geothlypis trichas) male also looks different than the female. In fact, this is the case with many wood-warblers with the male being more colorful than the female. The Common Yellow-throat male has a yellow throat and upper breast. It supports a black mask (it has been affectionately suggested that the warbler supports a black mask so that it cannot be identified in the field) with a grayish-white border. The female also has a yellow throat and breast but it has an olive-brown face and upper parts, a whitish eye-ring, a suggestion of an eyebrow, and brown wash on its forehead. Their size can range from 4 ½ to 5 ½ inches.

The Common Yellow-throat favors habitat that is dense and brushy near wet areas. It can also be found in drier dense understory, grassy fields, and marshes. Their diet consists of insects, spiders, and seeds that they gather from the ground or shrubs. The Common Yellow-throat also has a distinct song in "witchity witchity witchity" and will be found in brush that is lower to the ground.

The anticipation of the wood-warblers is just as exciting as their arrival. We (birders and ornithologists) brush up on identification field marks pouring over field guides and listening to bird songs at home and in the car using CDs. There are many good field guides. The best is to find one that is good for you, but, I would suggest the Peterson Field Guides series Birding by Ear, the eastern/central edition, as the first introduction to bird songs. The bird songs are grouped into similar songs and the differences strongly noted. It makes identification much easier and you will probably recognize several of the songs. Most bird lovers would agree that seeing a bird sing is the best way to learn its song. I know this is true for me too.

The Peterson Field Guides series Birding by Ear is available in the Nature Shop at the New Canaan Nature Center. You can visit the Nature Gift Shop Monday - Saturday from 9 a.m. to 4 p.m.