Tuesday, October 30, 2012

American Hover Fly

Yesterday, an American Hover Fly (Metasyrphus americanus) came into our office at the Audubon Center at Francis Beidler Forest.

The American Hover Fly is a very good wasp mimic (note only one pair of wings versus a wasp's two pairs).  If you doubt this is true, watch the histrionics of anyone along the boardwalk or picnic area when one of these insects makes its noisy appearance.  It's only a fly, but you would have an impossible time convincing anyone of that fact.

You can learn more about hover flies (specifically, in Europe) here.  In the meantime, you need to worry about something other than these aphid-eaters.

Friday, October 26, 2012

Hurricane Sandy

It's not a Wilson Pickett song, but there are plenty of people along the East Coast who would like to see Sandy slow down (at least in wind speed).

National Weather Service and Google Earth
For the Audubon Center at Francis Beidler Forest, it looks like the hurricane will stay well east of South Carolina and north of us should it turn northwest as shown by the National Weather Service's cone of uncertainty in the above image.  However, the swamp is fairly dry and we would not mind some rain.  Based on the NWS graphic below, we will be at the outer edge of the rainfall generated by the storm.

Although rain would be welcomed in the swamp, it will not be welcomed by those who have signed up for tomorrow evening's nightwalk.  Like many on the East Coast, we will be watching the weather for the next day or two!

Wednesday, October 17, 2012

Busy Beavers Expand Operation

The beavers (Castor canadensis) at Audubon's Francis Beidler Forest have been busy again!  Previously, none of the beaver construction (shown in orange) could be easily seen from the boardwalk.

However, beavers have recently constructed a 20+-foot section damming the creek channel that runs under the boardwalk at #5.

The image below shows the view back toward the boardwalk (look closely).

Only a portion of this short dam can be seen from the boardwalk, but it slows water that has found its way through or under the main dam, which is another 50 meters north at the power line right-of-way/tree line interface.  A few meters behind the main dam and hidden by a thick screen of cattails, is the beaver's lodge.

Although some trees may not survive the gnawing of the beavers or the near-permanent presence of water behind the dam, other species are benefiting from the beavers' work.  As noted above, cattails are growing in a dense block from tree line to tree line in the sunny, pond-like conditions in the power line right-of-way.  A small Banded Water Snake (Nerodia fasciata fasciata) sought refuge the dam shown above and an Eastern Mud Turtle (Kinosternon subrubrum subrubrum) was foraging in the shallow water on the downstream side.  Wood Ducks (Aix sponsa) and Belted Kingfishers (Ceryle alcyon) can be heard calling behind the dam and big fish can be heard pursuing smaller prey through the deeper water.

While beavers may be providing improved habitat and a bounty for other species, they may have improved the habitat sufficiently to entice an American Alligator (Alligator mississippiensis) to take up residence in the deeper water and sunshine within the power line corridor.  If that occurs, beavers will likely become meals and the maintenance-intensive dam system will fall into disrepair.

Friday, October 12, 2012

Bird Friendly Coffee Growing

With yesterday's focus on songbird wintering habitat, it is appropriate to think about how we can help make a difference.  "Shade grown" coffee does not necessarily mean "bird friendly" grown coffee.  The Cornell Lab of Ornithology explains in their blog.  However, whatever the reason for deforestation, the loss of habitat has an effect.
Stutchbury recapped recent research on Wood Thrushes, sweet-singing birds of Eastern forests whose numbers have dropped by half since the 1960s. Yet, with regenerating forests in the Northeast, Wood Thrushes now have more breeding habitat than they did decades ago. “What does that tell you?” Stutchbury asked her audience. “Must be a problem on their wintering grounds.” (Although some researchers point out that the quality rather than quantity of forest in North America might still be limiting this species.)
And indeed, when Stutchbury tracked individual Wood Thrushes from the U.S. to Nicaragua and back, she found that regional Wood Thrush population declines matched deforestation trends in Nicaragua, where forest cover has dropped 30 percent in just the past two decades.
This deforestation likely affects other wintering songbirds, too, such as Baltimore Orioles and Chestnut-sided and Kentucky warblers, which have also declined in the last half-century, according to the North American Breeding Bird Survey.

Wood Thrush - Mark Musselman

Wood Thrush - Mark Musselman
 As a consumer, you have the power of choice and your spending decisions affect the market.  If you are interested in protecting bird friendly habitat, spend your dollars in support of coffee growers whose efforts will help ensure songbirds return to your yard in the spring.  Look for the Smithsonian Migratory Bird Center certification:

Thursday, October 11, 2012

Mangrove Swamps

The latest edition of the National Geographic Magazine contains an article regarding the Mesoamerican Reef.  Mangrove swamps are a critical component of the reef ecosystem as they prevent sediment and other pollutants from reaching the coral reef, break wave energy thereby protecting sea grass pastures, and provide shelter and nursery space for a variety of marine organisms.

From the article:
Mangroves are not just a convenience for [parrotfish] Scarus guacamaia. They are a necessity. When mangroves are carved away, to make room for tourist venues, for example, the species tends to go locally extinct, with repercussions in all directions. Coevolution has brought the coral reef and its parrotfish into balance; when the horny-beaked herbivores are fished out or otherwise eliminated, the reef declines, its corals overgrown by carpets of the algae the parrotfish normally eat.

John Muir told us what we can expect when humans with their habits begin to unravel a sound ecosystem. “When we try to pick out anything by itself, we find it hitched to everything else in the universe,” he wrote. The parrotfish are a case in point. The Mesoamerican Reef is one section of the universe where the hitches are particularly tight.
Prothonotary Warbler - Mark Musselman

You may have been wondering why this blog's subject is a reef system thousands of miles away from Four Holes Swamp.  Note the John Muir wrote "universe."  Depending on when one starts to pick, those hitched to an ecosystem may not even be present.  Prothonotary Warblers (Protonotaria citrea) breed at the Francis Beidler Forest and the eastern United States, but they spend the winter in mangrove swamps in Central America and the northern coast of South America.  Therefore, the clearing of mangrove swamp for development and tourism is not simply a local issue affecting the reef ecosystem, but it is a hemispheric issue affecting birds we expect to return north in the spring.

Picking at the mangrove swamps reduces the number of Prothonotary Warblers surviving their winter, which in turn means few birds eating insects or feeding insects to their chicks on their breeding territories in the United States, which means fewer eggs or chicks to feed raccoons or rat snakes, which...leads us to discover that it's "hitched to everything in the universe."