Saturday, August 29, 2009
Although Danny has been downgraded to a tropical depression and will not affect South Carolina, it will be off the coast of Maine as we fly north. A quick check of the local forecast via a Twitter contact revealed that we'll be leaving hot, humid summer for damp, cool fall.
MaineBirder@TheSwampThing Beautiful week ahead. 60's-70's w/chance rain Tuesday. Nights 30's-40's. Dress fall-like.
This morning, as we enjoyed not having to wake to an alarm clock, we were jolted to full consciousness by a 3.2-earthquake centered 5 kilometers below Summerville. We hope that travel and the conference are not quite as bumpy!
Friday, August 28, 2009
Although schools and businesses are usually closed on International Vulture Awareness Day due to the vital role these birds play in our planet's varied ecosystems, this year September 5th falls on a Saturday. Oh, September 5th is also Labor Day.
Just like the decomposers on the forest's floor, vultures prevent the accumulation of organic material by rapidly and efficiently consuming dead animals. In the case of the Turkey Vulture (Cathartes aura) shown in the images, the genus name Cathartes means purifier. Their keen sense of smell allows them to locate carcasses under the forest canopy. More-aggressive Black Vultures (Coragyps atratus) may follow Turkey Vultures down to the food, so Turkey Vultures tend to specialize one smaller items that can be consumed quickly. Not having feathers on their heads makes it easier for vultures to stay clean while reaching into a carcass. Urinating on their feet helps vultures cool themselves while simultaneously killing dangerous pathogens collected from their last meal. Due to strong stomach acids, vultures are capable of eating carrion in all stages of decay.
Threats to vultures include pesticides, powerline electrocution, aircraft strikes (Turkey Vultures are the main avian species causing damage and fatalities in military aircraft), automobile strikes (while feeding on roadkill), and ingestion of pharmaceuticals or contaminants in carcasses. In fact, the last threat listed was sufficiently devastating to the vulture population in India that the sale of the veterinary drug diclofenac, which was used in cattle, was banned in 2006. The vulture population will be slow to rebound in India as the birds do not reproduce until age five and lay only one egg per year. Although the sale of the drug was banned, stock remained on the shelves and subsequently in the carcasses of dead cattle. Fewer vultures eating dead cattle could also lead to an increase in cattle-borne diseases, including anthrax.
Some information from:
Kirk, David A. and Michael J. Mossman. 1998. Turkey Vulture (Cathartes aura), The Birds of North America Online (A. Poole, Ed.). Ithaca: Cornell Lab of Ornithology; Retrieved from the Birds of North America Online: http://bna.birds.cornell.edu/bna/species/339
Images by Mark Musselman
Thursday, August 27, 2009
Image by Mark Musselman
Wednesday, August 26, 2009
The old-growth, cypress-tupelo swamp is rich in biodiversity, including the largest leech we have ever seen on a turtle! The first two images show leeches (likely Placobdella parasitica) on a Common Snapping Turtle (Chelydra serpentina). Almost any turtle we handle in the swamp has at least one leech on its carapace. The leeches are able to access their meal between the scutes (sections) of the carapace or via the fleshy parts of the legs and neck. The turtle has a chance of scraping the leech off of its legs and neck. However, the turtle has little chance of getting a leech off of its carapace.
Tuesday, August 25, 2009
Near the maintenance trail to the equipment barn, we came across a large fungus at the base of a long-dead tree. The fungus, which is over a foot in diameter, is currently a mystery. Whether we know the name or not, we're glad to have the decomposing abilities of fungus in the forest. Between the annual crop of falling leaves and trees dying from age, disease, insects, or lightning, we would rapidly be buried in organic debris if not for fungus!
Saturday, August 22, 2009
Thursday, August 20, 2009
Tuesday, August 18, 2009
Yesterday, we made a visit to Mepkin Abbey to plan the GPS portion for the upcoming field trip. Below is a SMALL sample of what we saw on the grounds, which are open to the public from 9:00 am to 4:30 pm (closed Monday).
Little Blue Heron
|Golden-winged Skimmer - Mark Musselman|
Images by Mark Musselman