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Friday, July 24, 2009

Weekly Species Highlights

Here are the weekly species highlights for the last week of July:

Bird: Short-billed Dowitcher (Limnodromus griseus) - The Short-billed Dowitcher is very similar in appearance to the Long-billed Dowitcher, however, their common names are misleading, as there is much overlap in their bill lengths. The short-billed was considered one species with the Long-billed Dowitcher until 1950. Range, habitat, and vocalizations can be used to help distinguish between these two species. The call is a sharp, low, two-syllable whistle, easily distinguished from the high peeping of the Long-billed.

A medium-sized, stocky, long-billed shorebird in the family Scolopacidae, it is an inhabitant of North America, Middle America, and northern South America. The body of adults is dark brown on top and reddish underneath. The tail has a black and white barred pattern. In flight, they show a pale trailing edge on their wings and a distinctive white blaze up their backs, which easily identifies them as dowitchers. The legs are a yellowish color. Winter birds are gray overall, with pale eyebrow and white lower back and rump.

Their breeding habitat includes bogs, tidal marshes, mudflats or forest clearings south of the tree line in northern North America. It is strongly migratory. They migrate to the southern United States and as far south as Brazil. This bird is more likely to be seen near ocean coasts during migration than the Long-billed Dowitcher. It feeds on invertebrates often by rapidly probing its bill into mud in a sewing machine fashion. They mainly eat insects, mollusks, crustaceans and marine worms, but also eat some plant material. These are among the first shorebirds to migrate south. Adults leave the breeding grounds as early as July and the young following in August.

Insect: Swamp Cicada (Tibicen tibicen formerly chloromera) - Every year in late-July to early-August the mating calls of male cicadas can be heard ringing through the air in New York City. I'd always been told that it was the sound of the "Dog-day Cicada". I never questioned that until I began researching this week's highlights. I discovered two confusing issues. First, the term "Dog-day Cicada" can refer to more than one species of cicada. It wasn't until I listened to the recordings on the "Songs of Insects" website that I learned that it is actually the annual song of the "Swamp Cicada" that I just began hearing again this week. Second, I learned that what used to be called "Tibicen chloromera" has been renamed "Tibicen tibicen". Anyway, here are some general facts.

Cicadas belong to the family Cicadidae in the order Hemiptera. They are a group of very large insects with clear wings that are held over their abdomen. Most cicadas spend their time high in the trees and are more often heard than seen. Long life cycles involve multiple years spent underground, followed by a brief above ground, adult life. As juveniles and adults, they feed on the xylem fluid of woody plants using piercing and sucking mouthparts. Males produce a loud, mate-attracting songs using specialized organs called called "timbals" located on the sides of the abdominal base. These sounds are among the loudest produced by any insects. However, some small species have songs so high in pitch that the noise is inaudible to humans. "Dog days" refer to the late summer when this species is heard singing. In the northern hemisphere, this is the time of year when the Dog Star, Sirius, becomes visible above the horizon. It is part of the constellation Canis Major.

Wildflower: Jerusalem Artichoke (Helianthus tuberosus) - Neither from Jerusalem nor an artichoke (the thistle family), this wildflower is actually a member of the sunflower family. It is surmised that the common name is a corruption of the Italian "girasole", meaning "turning to the sun". A large, robust yellow sunflower with broad, thick leaves and rough, hairy stems, this perennial grows from 6-10 ft. Native to North America, it is found in fields and thickets. Native Americans called them sun roots and introduced these perennial tubers to the pilgrims who adopted them as a staple food. The edible tuber is highly nutritious and, unlike potatoes, contains no starch, but rather carbohydrate in a form that is metabolized into natural sugar.

Tree: Japanese Pagoda Tree aka Chinese Scholar Tree (Sophora japonica) - This medium-size tree is a native species of China and Korea, growing to an average of 65 feet. Landscapers have planted it in many parts of the United States, especially in the South. People often plant it as a shade tree and as an ornamental. It has become a common urban street tree due to its rapid growth rate, tolerance to city conditions, heat, and drought. It is in the same family of trees as our native Yellowwood. A yellow dye is made from its wood. The Pagoda Tree blooms during the "Dog days" of summer, sprouting 10-15 inch upright panicles of mildly fragrant, creamy-white, pea-like flowers. The fruit are ornamental pale green seed pods, 6 to 8 inches long, which persist into winter and resemble strings of beads.

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