Monday, March 21, 2011

Skunk Cabbage Flowers February 2011

Amidst patches of ice in a marshy area of Greenbrier State Park, the Skunk Cabbage (Symplocarpus foetidis) is flowering when I visit on February 16, 2011.  This is one of my favorite plants because it is so unique.
Emerging so early in spring means the plant needs a way to withstand the lingering cold and potential snows. The plant stores carbohydrates in its large root system. The increased respiration that occurs during new growth enables it to burn these carbs and produce heat--at times enough to melt the snow and ice that may be surrounding it!
Skunk Cabbage blossoms before its large leaves show their tips.  A mottled ear-like form called a spathe emerges. Its color ranges from green to purple. Within the spathe is a globular spadix, where the tiny flowers extend like pins on a pin cushion. The temperature within the spathe may be as much as to 27 degrees (F) above the outside air.
Skunk Cabbage emits a foetid odor. Plants that smell disagreeable to us are usually pollinated by insects that are drawn to the scent of decomposing material.  Small gnats and flies emerge around the same time as the Skunk Cabbage and frequent the same habitat. They buzz from spathe to spathe to sip the nectar on the tiny flowers, thereby spreading pollen and enabling the plant's reproductive cycle. Larger insects may be able to squeeze their way into the spathe but then can find themselves too large to exit the opening, and become trapped.

 The leaves of the Skunk Cabbage push out of the ground in a tightly wrapped cone, and grow quickly, each plant soon covering more ground than can be encircled with your arms. By June this site will be thick with Skunk Cabbage and waist high with arching fronds of Cinnamon Fern.

Monday, January 10, 2011

Gobbler Wild

On December 31, 2010, not far from the entrance to Greenbrier State Park, I spied a small flock of wild turkeys wandering through the woods.   Meleagris gallopavo is not the prettiest of North America's native birds.   
Mounted bird at Smithsonian Naturalist Center

Both males and females have featherless heads.  Adult males develop a fleshy appendage beneath the jaw called a wattle, and growths on their necks called caruncles.  They also sport a triangular protrusion from the top of their head called a snood.  When a male turkey is distressed or in breeding mode, the wattle, caruncles, and snood become engorged with blood, turn red and enlarge. The snood may extend until it resembles a long fat juicy worm draped over the male's beak. 
This feature may detract from his appearance to humans, but likely makes him irresistible to female turkeys.   

Even to humans, however, wild turkey plumage can be quite beautiful. A male's feathers are glossy, glittering in shades of bronze, green, gold, red and purple.  Females have more muted plumage in browns and greys.  Males are frequently depicted in the iconic "display" posture, body feathers ruffled and puffed, barred wings outstretched and trailing seductively, with tail erect and fanned like a peacock.  Termed gobblers or toms, males have a diverse repertoire beyond the eponymous gobble, including grunts, purrs, whines, cackles, yelps, and a rapid drumming. In breeding season, like many birds, they use both display and vocalizing to lure females and establish territory. 

For habitat, wild turkeys like open woodland and grassland where they can fly close to the ground, and easily find perches. Turkeys prefer to eat hard mast (seeds of forest trees such as acorns and nuts). They also forage other types of seeds, berries, roots and grasses, and may devour insects, small amphibians or reptiles.  South Mountain's oak trees produced an unusual bounty of acorns this year. Not surprisingly, these turkeys looked well-fed even in the midst of winter.

Midsummer in 2010, I had an even closer encounter. It was a warm afternoon and I was absent-mindedly picking and eating wine berries growing along the trail. I threaded my way deeper and deeper into the bramles, tempted by the sight of more ripe berries. Suddenly there was an explosive sound at my feet, and a huge whirring shape shot high into the air.  Just as suddenly, the turkey (for what else could it be?) dropped and disappeared into the brush beyond.  Heart thumping, I glanced down and saw about a dozen gleaming eggs directly in front of me. It was like finding a treasure. 
I took just a moment to admire the perfect ovoids. Each one seemed about twice the size of a grocer's extra- large. Cinnamon-brown dusted the smooth creamy shells..  The clutch rested directly on layers of last autumn's leaves, which were matted into a shallow depression the shape of the hen's body.   Some scattered twigs were the only other components of the nest. Berry canes arched overhead to form a protective bower.  The hen had chosen her setting place well--she need only extend her neck to nibble wine berries. Feeling like an intruder, which I certainly was, I quietly retreated.
Wild turkey hens usually lay 10 to 12 eggs over a two week period.  They carefully tend and turn the eggs during incubation.  In about 28 days the poults (chicks) hatch and must leave the nest within 24 hours to feed.  At first the poults are unable to fly and very vulnerable.  The hen and her brood must roost at night on the ground.  A hungry raccoon, skunk, opossum or snake would love to find a cache of turkey eggs or newly- hatched poults!   

Since mating season for wild turkeys is February to April, the nest I almost stumbled over was probably the hen's second brood for the season.  Perhaps the group of turkeys I saw on the last day in December included some of the siblings from the eggs I saw in July. Young turkeys typically flock with their mother through the remainder of the year, dispersing the following spring.
In my research, I learned that there are five subspecies of Meleagris gallopavo native to North America. The turkeys inhabiting South Mountain are M. gallopavo silvestris, also referred to as the Eastern Wild Turkey.  It is the most common of all the subspecies, ranging over the entire eastern half of the U.S.  Our largest game bird, it can grow up to four feet tall and weigh some thirty pounds.
Coyotes, great horned owls, and foxes prey on adult wild turkeys, but for centuries the species' most voracious predator has been Homo sapiens.  By the 1940s, the once plentiful bird was almost extinct in the U.S. and Canada. Since then, conservation efforts have succeeded in restoring respectable numbers of M. gallopavo.  Let's give thanks that the Wild Turkey Federation estimates the current population at 7 million!  

Bittersweet Story

This brightly-berried vine is thriving near a grove of pines on the Big Red trail in Greenbrier State Park.  As I made my rounds on the last day of 2010, I first noticed tiny yellow petal-like clusters littering the pine needle carpet beneath my feet. Delicate flowers at this time of year? I soon realized they were protective coverings that had burst and fallen from the red-orange berries on the vine. The festive hue was a welcome sight on this overcast day.  But something about the way the plant contrasted so vividly with its surroundings gave me an uneasy feeling.

A little research identified the vine as Oriental or Japanese Bittersweet, Celastrus orbiculatus, a species brought here from Asia as a garden ornamental around the time of the Civil War.  It became popular because of the profusion of color that persists through the dreary winter months, and perhaps cheered a nation weary of war.   

Alas, as with so many imported plant species, it has outcompeted our native American Bittersweet, Celatrus scandens, which has many of the same decorative qualities.

The Name Game: Other common names for our native Bittersweet are Climbing Bittersweet, Jacob’s Ladder and Fever Twig! Celastrus derives from kelastros, an ancient Greek name for an evergreen tree. The word
scandens is Greek for trailing or climbing. Orbiculatus refers to the circular shape of the leaf.

C. orbiculatus is a persona non grata for those of us who wish to preserve our native ecosystem. It grows more vigorously and produces more berries than C. scandens. It likes disturbed habitats and can tolerate many different kinds of soil.  It chokes out other native vegetation, breaking plants by its excessive weight or shading them out.  The older plants of C. orbiculatus can have stems up to 4 inches in diameter. The vine aggressively crawls to the tops of the tallest trees, contributing to uprooting from wind and snow.  It can strangle a tree’s roots, cutting off water and nutrients.

C. orbiculatus also has cross-bred with C. scandens, and as a result our native vine has become increasingly rare.  Jil M. Swearingen, writing for the National Park Service in 2005, said that C. orbiculatus had been reported as invasive in 21 states and in 14 eastern national parks.  With such a negative profile, I find it surprising that Celastrus orbiculatus is still sold and used in the landscaping trade. Especially since there are many native plants that can be easily substituted.

Celastrus orbiculatus is categorized as a woody perennial, and grows both as a climbing vine and a trailing shrub.  You will often find it in natural areas near old homesteads. It likes open sun so favors fields and edge habitat, but is shade tolerant so can readily creep into woodlands.  The vine can grow by sucker roots, but reproduces and primarily spreads by its seeds. Birds and other wildlife gorge on the berries and carry the seeds far and wide.

Here are the most obvious ways to tell the two plants apart, (assuming one is not examining a hybrid):

Oriental Bittersweet, C. orbiculatus:
Leaf shape: round, about as long as wide
Flowers and fruit: short clusters growing in leaf axils (the upper part of the angle created where the leaf grows out from a stem) many clusters along the stem, clusters are shorter in length than the leaves. Berries more brightly colored than C. scandens.

American Bittersweet, C. scandens:
Leaf shape: About twice as long as wide, tapered at both ends
Flowers and fruit: Single clusters at the tips of stems, clusters about as long as the leaves.  Fewer, larger clusters than C. orbiculatus

I will now keep an eye out for American Bittersweet in the South Mountain environs, including Greenbrier State Park. Here is a public domain image of C. scandens from the U.S. Fish and Wildlife Service taken at a different season from the photos above that I snapped of C. orbiculatus. The plant is still green-leaved and the protective coverings on the berries remain. However, one gets a good idea of the leaf shape and the larger, longer arrangement of berries in comparison to the nonnative species.