Thursday, December 9, 2010

GREAT EXPECTATIONS: December in the Piedmont

Birds.− By December, the fall migration has decidedly ended, and the celebration following the arrival of winter juncos, kinglets and creepers has dissipated. The woods and brush are eerily quiet, except for the sharp warning calls of cardinals and the flitting of sparrows. The most common sparrows that visit the Piedmont in the winter months, often extending into early spring, include the fox, swamp, savanna, white-throated and white-crowned sparrows.

The fox sparrow, with its rusty tail, is often seen kicking and scratching beneath winter feeders. The shy swamp sparrow, identified by its gray cheeks, unadorned gray chest and russet wings, may be observed dunking its head into shallow water in search of macroinvertebrates (e.g., the larvae of insects like stoneflies and dragonflies). Savanna sparrows sporting heavily streaked breasts and yellow marks between their eyes and beak cavort in open habitats and are known to return to their specific birthplace somewhere in Canada or the northern United States each summer, a phenomenon termed “natal philopatry.” The quite common white-throated sparrow also dons yellow marks near the beak, but its clear breast, white throat, and black-and-white striped head easily distinguishes it from the savanna sparrow. White-throated sparrows often flock in winter and will continue to croon “oh sweet Canada” on crisp winter days. The heads of the white-crowned sparrow are also black-and-white striped, but they lack the yellow markings of the white-throated sparrow and their throat and chest are a consistent medium gray. They also tend to flock and will scatter into the shrubs as hikers approach.

Butterflies.− Even in December, the rare butterfly is sometimes observed. In the Piedmont, the following species have been observed in December: black swallowtail, spicebush swallowtail, checkered white, American lady and a number of sulphurs.

Reptiles & Amphibians.− Red-backed salamanders can be found in large numbers on Piedmont roads in December. Chorus frogs are often heard calling in the middle of the month.

Other Insects.− This month, large American bird grasshoppers spring to life on warm days. Sensitive to the heat of North Carolina summers, American bird grasshoppers often migrate north in summer. They prefer grassland habitat and forest edges, feeding on grass, leaves and other herbaceous plants. This species lays eggs in a mass in the soil, where the nymphs gradually work their way to the surface.

Meteor Showers.- Three meteor showers occur in December: the Phoenicids (Dec. 5; with an average of 25 meteors per hour), the Geminids (Dec. 13-14; 60/hr) and the Ursids (Dec. 23; 20/hr). Conditions are favorable for the Geminids this year, which can be viewed starting at around 10 pm on December 13 and will peak around 2 am on the 14th.

In Bloom this Month.− Be on the lookout for these December fruits and flowers:

In Bloom:
WITCH HAZEL - Hamamelis virginiana
FROST ASTER(S) - Symphyotrichum spp.

In Fruit:
PERSIMMON – Diospyros virginiana
BEAUTY BERRY – Callicarpa americana
HEARTS-A-BUSTIN’ – Euonymus americanus
AMERICAN HOLLY - Ilex opaca
PASSION FLOWER – Passiflora spp.


References:
Cook, Dave. 2001. The Piedmont Almanac. Chapel Hill, North Carolina: Mystic Crow Publishing.
Discover Life “Lynx rufus”. Available at http://www.discoverlife.org/mp/20q?search=Lynx+rufus [accessed 5 Dec 2010].

LeGrand, H. E. Jr. 2009. Notes on the Butterflies of North Carolina. Available at: http://149.168.1.196/nbnc/

Wheelwright, N. H., and J. D. Rising. 1993. Savannah Sparrow (Passerculus sandwichensis). In The Birds of North America, No. 45 (A. Poole and F. Gill, eds.). The Academy of Natural Sciences, Philadelphia, and The American Ornithologists' Union, Washington, D.C.

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