Tuesday, July 18, 2006

Birds of the Mid-Atlantic #16: Indigo Bunting

As the summer enters its peak season, bird-watching becomes a matter of endurance. The temperatures are high (close to 100°F in Washington this week), humidity is high, and cool breezes are rare events. Biting insects and ticks are a constant nuisance. Most birds have reduced their singing and hunker down out of the heat. It is enough to make a birder want to stay indoors and long for late September.

Even so, there are a few birds that stay active through the middle of summer. These species help keep our parks lively and our birding interesting during the typical midsummer lull. One such bird is the lovely indigo bunting.

Indigo Bunting / Photo by Dave Menke (USFWS)

To find your own indigo bunting, listen around meadows and field edges for a prominent song with doubled phrases, like this. (The song is sometimes represented by a mnemonic as follows: Fire, fire! Where, where? Here, Here! Put-it-out, put-it-out!) Typically the singer will be perched on top of a tall shrub. The blue feathers will shine boldly in direct sunlight, but may appear subdued when backlit or on cloudy days.

Indigo buntings are intensely blue and black. The blue is so bright and so intense as look almost artificial, as if the bunting were a midsummer Christmas ornament. The only bird that one might mistake for a male indigo bunting is a male blue grosbeak. The latter tends to be a darker, richer blue and has chestnut-brown epaulettes. In bad lighting, the heavier bill of the grosbeak should distinguish the two.

Blue Grosbeaks (top) and Indigo Buntings (bottom) / Painting by Louis Agassiz Fuertes (via WikiMedia)

Blue grosbeaks share similar habitat preferences with indigo buntings. Both birds prefer fields in the early stages of succession. In Maryland, blue grosbeaks are somewhat more likely to be found on the coastal plain or piedmont; blue finch-like birds in the western mountains are more likely to be indigo buntings.

If you plan to be out birding this week, make sure to bring along an extra supply of water and protect your skin from the sun. Heat exhaustion is a real threat during weather like this, even during light and moderate exercise. See the CDC's tips on preventing heat illness.

Crossposted at Blue Ridge Gazette.