Friday, March 11, 2011

GREAT EXPECTIONATIONS: March in the Piedmont

Birds.− As spring arrives in the Piedmont this month, we begin to see some profound changes in the composition of our avifauna. Wood-ducks, blue-winged teals (local breeders), double-crested cormorants and ospreys become more abundant. Also expect to begin seeing vireos, ruby-throated hummingbirds, purple martins and other swallow species this month. Lucky observers may even catch sight of a snowy egret, little blue heron, Mississippi kite, blue grosbeak, indigo bunting or some sandpiper species and early warblers (e.g., black-and-white, prothonotary, yellow-throated, blue-winged, Tennessee). However, don’t expect to catch any more rare sightings of snow geese or mute swans.

In March, many bird species begin breeding and building nests. By the end of the month, they may even be sitting on eggs. This month, you may see both male and female woodpeckers excavating their nests (although the males often do most of the work). Woodpeckers usually excavate a new nest cavity each year, and empty cavities are quickly taken by starlings, sparrows and titmice. Although the trees that they excavate may look alive, research has revealed that most woodpecker species chose to excavate trees with dead heartwood. One exception, found in the North Carolina sandhills, is the red-cockaded woodpecker, which prefers to dig into live pine trees.

Later this month, you may observe a few ruby-throated hummingbirds arriving from the forests and scrublands of Central America at your Piedmont feeder, although sightings typically pick up by the second week of April. In the Piedmont, female hummingbirds construct small nests of soft thistle and dandelion down, placed in a shell of lichen and bud scales held together by spider webs, ten to twenty feet off the ground. These nests may even be reused the next season, following repairs.

Butterflies.− This month, butterfly watchers may begin to find hairstreaks (including the red-banded, gray, juniper, and great purple) and swallowtails (e.g., black and eastern tiger). If you want to find zebra swallowtails, be sure to look in the right sort of habitat: breeding takes place in rich, moist woodlands often near rivers and swamplands. In fact, zebra swallowtail larvae will only feed on paw-paw (Asimina spp.), although adults may fly out to the forest edge to enjoy nectar from a variety of sources including milkweeds (Asclepias spp.) and the eastern redbud (Cercis canadensis).

Lucky observers may find Henry’s elfins and eastern pine elfins, while definitely spotting a lot more cabbage whites, sulphurs, spring azures, question marks, eastern commas and mourning cloaks. Towards the end of the month, keep your eyes open for sleeper, Juvenal’s and Horace’s duskywings, adults of which are often seen perched on bare ground, including dirt roads and trails, where they glean minerals.

Did you know that butterflies have neither lungs nor blood? Both butterflies and caterpillars breathe through small openings along the sides of their bodies, called spiracles. From each spiracle, a tube (i.e., the trachea) carries oxygen into the body. Since the trachea bring oxygen directly to the tissue, butterflies don’t need blood to transport oxygen. Butterflies do rely on a green-colored fluid, called hemolymph, to carry other nutrients (but not oxygen) throughout their body.

Reptiles & Amphibians.− Throughout March, expect to continue hearing southeastern chorus frogs, spring peepers, northern cricket frogs, American toads, pickerel frogs and eastern spadefoots. Fowler’s toads, bullfrogs and green frogs will start calling this month, but don’t expect large choruses until April. March frog call guide:

southeastern chorus frog: raspy, rising call like someone dragging their thumb over the teeth of a comb

spring peepers: a loud, medium pitched “peeep”

northern cricket frogs: clinking like two small metal balls being tapped together

American toads: long, musical trill

pickerel frogs: drawn out snore

eastern spadefoot toads: a crabby, deep “eeeerrrr”

Continue to look for breeding salamanders. This month you may also observe basking yellow-bellied sliders and the occasional black-rat snake or racer warming up in dappled sunlight.

In Bloom this Month.− March is a great month to brush-up on your herbaceous plant identification, starting with the spring ephemerals – fragile wildflowers that disappear after a brief vernal resurgence. One of the first flowers to bloom in March is round-lobed hepatica (Hepatica americana). Other March ephemerals include the spring beauty (Claytonia virginica) and trout lilies (Erythronium americanum) with their yellow nodding flowers emerging from a pair of dark green, spotted leaves. If you’re exploring richer woods, you might find red trillium (Trillium cuneatum), may-apples (Podophyllum peltatum), a few species of wild ginger or heart leaf (Hexastylus spp.) and bloodroot (Sanguinaria canadensis).

Bloodroots are fascinating plants with clasping, multi-lobed dark green leaves from which emerge a delicate 8-12 petaled white flower. Its flowers are pollinated by small bees and flies, and its seeds are dispersed by ants in a process known as myrmecochory. The ants are attracted to a fleshy, edible organ on the seed known as an elaiosome. They bring the seed back to their nest, where they eat the elaiosome, and then deposit the seed in their fertile nest debris!

Soil Series of the Month.− The United States contains over 19,000 different soils series, i.e., the most specific grouping of soils based on shared history, chemistry, and physical properties.

The most general classification of soil is the soil order. Worldwide, there are only 12 soil orders. North Carolina is home to seven: Entisols, Inceptisols, Alfisols, Ultisols, Mollisols, and Spodosols.

Ultisols, the quintessential deep red, clayey soil of the Piedmont, are the most common soil order in North Carolina. Found in humid areas, like the Southeastern United States and Southeast Asia, Ultisols tend to be weathered, low in native fertility, and clayey in the deeper horizons.

North Carolina’s state soil, the Cecil soil series is an Ultisol. Cecil soil, deep red and clayey, develops over igneous and metamorphic rock, with granitic qualities. Virgin Cecil soil support mixed hardwood and pine forest, and usually has a rich, dark colored topsoil. Most Cecil soil isn’t in its virgin state, and this layer of rich soil has been eroded away, exposing the dark red, less fertile subsoil.

References: Cook, D. 2001. The Piedmont Almanac. Chapel Hill, NC: Mystic Crow Publishing. LeGrand, H. E. Jr. 2009. Notes on the Butterflies of North Carolina. Available at: Martof, B. S., W. M. Palmer, J. R. Bailey, and J. R. Harrison. 1980. Amphibians and Reptiles of the Carolinas and Virginia. The University of North Carolina Press: Chapel Hill, NC.

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