Sunday, January 23, 2011

Pump Station Trail, Eno River (Durham, NC)

This morning, before the sun thawed the crisp morning air, we hiked along the Eno River on the Pump Station Trail in Durham, North Carolina. Thirty feet off the trail, past the crumbling remains of a towering stone dam, sits a small pond carved out of the Carolina mud by spillover from the old dam.

In spring, this pond ripples with the sporadic jolting of tiny gilled salamander larvae. In summer, the pond provides home for mayfly and stonefly larvae. In autumn, birds dip their beaks into the shallow water for a quick drink. But in winter, the pond reveals a mysterious, and perhaps sinister, side.

As we arrived to stand at the edge of the little pond, the cold winter sun angled through the trees highlighting a strange, motionless shape beneath an inch-thick layer of hard ice. The disparate images of a thick, dark head with small dark eyes, clawed feet, and a dark brown, slightly ridged shell reluctantly congealed into a medium, adult common snapping turtle (Chelydra serpentina) in suspended animation. Nearby the image was replicated in miniature: a young snapper, with a shell not even two inches across, frozen in place amongst unmoving air bubbles.

We stood stunned, as motionless as the anomalous objects that had captured our attention. Were the turtles hibernating? Were they dead? I stopped one of the members of our group, bent on arming himself with a stick to prod the static specimen, with a sharp comment. We gawked, and then ran for the camera.

In the end, I don’t know if those two turtles – looking like taxidermic models in a habitat recreation at a natural history museum – were dead or hibernating. According to Brown and Brooks (1994), snapping turtles occupy three types of hibernacula. Usually they are wedged beneath logs or sticks along steams banks or they burrow into the deep mud in marshy areas, but sometimes they remain unburied and visible through the ice. The two snappers may be awaiting the spring thaw, ever-ready for reanimation. I like to think of them this way. Yet, in this state they sit vulnerable to the predations of hungry foxes and raccoons. Is this any better then being air-starved or damaged from deep freezing, never to stir again?

I often hear people wax poetic about returning to a state of nature, as if Nature equates to gentleness, justice and harmony, but Nature is as cruel as it is kind. As humans, we would be remiss to forget that we are a part of Nature, whether we like it or not.








Photos from Pump Station Trail, Eno River State Park, Durham NC (by Nicolette L. Cagle, 23 January 2011)


References:

Brown, G. P. and R. J. Brooks. 1994. Characteristics of and fidelity to hibernacula in northern population of snapping turtles, Chelydra serpentina. Copeia 1994(1): 222-226.

Costanzo, J. P., P. J. Baker and R. E. Lee Jr. 2006. Physiological responses to freezing in hatchlings of freeze-tolerant and -intolerant turtles. Journal of Comparative Physiological Biology 176: 697-707.

Tuesday, January 4, 2011

GREAT EXPECTATIONS: January in the Piedmont

Birds.− In the depth of winter, as you walk through the quiet woods, you may come across a lone thrush standing at attention with its delicately speckled throat exposed. Although the hermit thrush is a gifted songster, its song is muted until arriving at its breeding territory to the Canada and the western United States in spring. As the hermit thrush leaves the Piedmont, the wood thrush -- with its rufous wings and boldly spotted breast – arrives to mesmerize North Carolinians with its haunting call.

In January, many people are afflicted by winter birding doldrums. Yet, winter is a great time to watch busy birds from the comfort of your own home. Many species visit well-stocked feeders, including Carolina wrens, brown-headed nuthatches, white-breasted nuthatches, Carolina chickadees, northern cardinals, white-throated and white-crowned sparrows, and finches. Woodpeckers often frequent feeders, especially downy woodpeckers and flickers.

Butterflies.− A few butterflies manage to sneak out in January, especially sulphurs and whites (family: Pieridae), but sightings are rare.

Reptiles & Amphibians.− Expect to hear chorus frogs and spring peepers on warm, wet January days. The calls of southeastern chorus frogs resemble the noise of someone running their thumb over a plastic comb, while spring peepers charm with distinctive “peeping”.

Spotted salamanders will appear in breeding ponds towards the end of the month on warm rainy nights with plenty of moonlight. Found in the Piedmont’s deciduous and mixed forests home, spotted salamanders spend most of summer and winter below ground. However, in late January and early February, they emerge to begin their magnificent courtships in ponds and slow streams.

In Bloom this Month.− The bright red berries of our native hollies (North Carolina is home to at least ten species), including the deciduous holly (also known as possumhaw, Ilex decidua) and American holly (Ilex opaca) still cling to frosted branches. The brilliant berries, technically referred to as drupes, provide food for red foxes, gray squirrels, white-tailed deer, raccoons, eastern box turtles and many bird species, including wild turkeys, mourning doves, cedar waxwings, American goldfinches, and northern cardinals. Although wildlife devours these fruits, holly berries can make humans quite sick.

The remnants of the spiny, ball-like sweetgum fruit can also be seen still holding fast to lower branches. Each of these distinctive balls is actually composed of many beaked capsules, which each contain two tiny, black seeds.

In Bloom (in some years):
ROUND-LOBED HEPATICA – Anemone americana
BLUETS – Houstonia sp.

In Fruit:
BEAUTY BERRY – Callicarpa americana
SUGAR BERRY - Celtis laevigata
HEARTS-A-BUSTIN’ – Euonymus americanus
AMERICAN HOLLY - Ilex opaca

References:
Harrison, H. 1975. Peterson Field Guides Eastern Birds’ Nests. New York, New York: Houghton Mifflin Company.

Daniels, J. C. 2003. Butterflies of the Carolinas. Cambridge, MN: Adventure Publications, Inc.

Cook, D. 2001. The Piedmont Almanac. Chapel Hill, NC: Mystic Crow Publishing.

Peattie, D. C. 1948. A Natural History of Trees of Eastern and Central North America. Boston: Houghton-Mifflin Company.