Friday, September 28, 2012

Around #104

You do not need to walk far out the back door of the nature center at Audubon's Francis Beidler Forest to see migration in action as there is plenty happening around #104.

Although only the male Hooded Warbler (Setophaga citrina) below stayed close enough for a picture, he was joined by a Black-throated Blue Warbler (Setophaga caerulescens), a Worm-eating Warbler (Helmitheros vermivorus), a Veery (Catharus fuscescens), both sexes of American Redstart (Setophaga ruticilla), a Northern Parula (Setophaga americana), and a Black-and-white Warbler (Mniotilta varia).

Hooded Warbler - Mark Musselman

Hooded Warbler - Mark Musselman

Nearby some color was added by a Purple Lobelia (Lobelia elongata)...

Purple Lobelia - Mark Musselman

and a fruiting Jack-in-the-Pulpit (Arisaema triphyllum).

Jack-in-the-Pulpit - Mark Musselman

Tuesday, September 25, 2012

River Sweep 2012

On Saturday, September 15th, staff from the Audubon Center at Francis Beidler Forest and eight volunteers participated in the annual Beach Sweep/River Sweep and cleaned 0.6 miles of US Hwy 78 east of Bridge Lake where the road crosses Four Holes Swamp.

Google Earth - River Sweep 2012

That mileage again was 0.6, not 6.0 or 60.0.  We concentrated on the litter at the base of the highway embankment as that is the trash most likely to be picked up by high water and delivered downstream to the Edisto River.  Therefore, the 122 bags of collected trash shown in the image below does not account for all of the trash along the 0.6 miles of highway.  Additionally, there were items too bulky to handle (a log from a passing truck complete with red flag and reflector) or not permissible for disposal at the landfill (multiple tires).

Collected trash - Mike Dawson
The overwhelming majority of litter collected consisted of beverage containers (plastic, foam, aluminum, or glass).  It was obvious, due to the weight of the beverage containers alone or the weight of the partially-filled containers, that the items had been consciously ejected from passing vehicles and had not blown away from an absent-minded driver.

As the guys on ESPN's NFL show are fond of saying, "C'mon man!"

Thursday, September 13, 2012

How Are We Supposed to Work?

Having inside work to do when working at an old-growth swamp is always tough!  However, at the Audubon Center at Francis Beidler Forest it is especially tough during the periods of bird migration.  Nature is right out every window of the nature center and we all have unobstructed views from our desks.  Here is a small sample of what distracted us today:

Black-and-white Warbler - Mark Musselman
Black-and-white Warbler - Mark Musselman 

White-eyed Vireo - Mark Musselman

Acadian Flycatcher - Mark Musselman

American Redstart - Mark Musselman

American Redstart - Mark Musselman

Hooded Warbler - Mark Musselman

Hooded Warbler - Mark Musselman

Wednesday, September 12, 2012

Unintended Habitat Enhancement

If you have ever been a property owner outside of town or know someone who is, you have likely seen surveyor's blazes and boundary line painting.  The blazes, surveyor chops in the tree trunk forming a distinctive scar, point to the boundary line or a corner (change of direction) and are painted by us to make them visual apparent.

Boundary marker - Mark Musselman
Audubon's Francis Beidler Forest has over 100 miles of exterior boundary lines in addition to internal boundary lines and all of them need to be painted to ensure that there is no confusion as to their location.  For example, a logger working a neighboring property needs to know when to stop cutting or hunters need to know when they are about to cross into the sanctuary.

Yesterday, while doing some boundary line painting, we discovered that the surveyor's blazes have enhanced the habitat for some of the forest creatures.  The vast majority of the blazes were covered with spider webbing, but several held resting amphibians.  The first to be discovered was a small Green Treefrog (Hyla cinerea) that was nearly skewered with a web-clearing machete.

Green Treefrog - Ricky Covey

Green Treefrog - Ricky Covey
The next treefrog, possibly a Squirrel Treefrog (Hyla squirella), got a dab of white paint before it was discovered.  A quick rinse from a bottle of water got it back to its natural color and on its way.  After two treefrogs in blazes, we were alert to the possibility and spotted the Gray Treefrog (Hyla versicolor) before it was in danger of being cut or painted.

Gray Treefrog - Ricky Covey
We also encountered some species that needed no habitat enhancement, but that caused us to enhance our own attire.  Although snake boots can get uncomfortable after a day of stomping through the forest, stepping on a Southern Copperhead (Agkistrodon contortrix contortrix) could certainly ruin a beautiful walk in woods!

Southern Copperhead - Ricky Covey

Southern Copperhead - Ricky Covey

Wednesday, September 05, 2012

Boardwalk Assassins Strike Again!

At the Audubon Center at Francis Beidler Forest, the Barred Owls (Strix varia) patrolling the backside of the boardwalk between #155 and #177 have struck again.  A visitor returning from the boardwalk reported seeing an owl eating a turtle on the handrail.  Previously, we have reported owls in the same area unsuccessfully trying to eat an adult Eastern Mud Turtle (Kinosternon subrubrum subrubrum) and hunting a variety of other prey..."Wood Duck ducklings, Yellow-bellied Sapsuckers, and crayfish."

Barred Owl - Mark Musselman
Although we have no images, we have observed Barred Owls in another territory eating a small Yellow-bellied Slider.  In conjunction with the mud turtle attack noted in the previous paragraph, we knew of two turtle species preyed upon by the resident owls.  Therefore, we were interested in seeing what species of turtle was consumed today.  Near #167, we found the remains of a small Musk Turtle (Sternotherus odoratus) shown in the images below.  Musk Turtles have minimal plastron (bottom shell), so fleshy parts, including the head, were exposed to attack by the owl's sharp beak and talons.  Note that the shell appears to have been pried and snapped apart to get at the those regions protected by the plastron.

Musk Turtle Eaten by Barred Owl - Mark Musselman

Musk Turtle Eaten by Barred Owl - Mark Musselman

Musk Turtle Eaten by Barred Owl - Mark Musselman
When you visit, keep your eyes open and maybe you can spot an owl dining on an item not yet on our published menu!

Tuesday, September 04, 2012

Rainy Day Migrants

Rain during the past two weeks has often kept us trapped within the building at the Audubon Center at Francis Beidler Forest.

Another unfortunate side effect of the rain is the presence of mosquitoes.  As long as there is water flowing in the swamp, mosquitoes are seldom an issue as they prefer standing water.  However, a portion of the boardwalk traverses the high, dry forest and later parallels the edge of the swamp.  The high volume of rain has filled depressions, like those caused when trees tip over, throughout the dry forest bordering the swamp and mosquitoes have taken advantage of the situation.

Even if adult mosquitoes were not present to lay eggs in the standing water, mosquito eggs can survive dry periods and hatch once water returns...cue the rain.  Predators in the water, like mosquito fish or dragonfly nymphs, and predators in the air, like Blue-gray Gnatcachers (Polioptila caerulea) have put a dent in the mosquito population.  However, for a time a bloody gauntlet needed to be endured to reach the sanctuary of the swamp.  The aberrant situation has nearly returned to normal.

We cannot do anything to manage mosquitoes in the forest, but you can manage them in your yard.  Eliminating standing water in any containers is the most effective control.  Mosquitoes obtain viruses during feeding on an infected host and then when next feeding they can introduced the virus to humans and pets via the mosquito's salivary glands. Therefore, if mosquitoes are already present, applying insect repellent and wearing clothing that prevents exposed skin are effective defensive strategies.

Poor weather might slow bird migration, but it will not stop migration.  Even with the rain, we saw birds foraging outside the office window that likely were not residents during the breeding season.  Hooded Warblers (Setophaga citrina), Prothonotary Warblers (Protonotaria citrea), and Worm-eating Warblers (Helmitheros vermivorus) were some examples.  A Green Heron (Butorides virescens) spent a few days wading in the shallow water at #104 just behind the nature center.  Green Herons are not normally seen along the boardwalk, so it may be a bird migrating from higher latitudes or a local bird that could not resist the glut of fish gorging themselves on mosquito larvae in the shallow water.

Another bird seen out the office window is definitely a migrant.  The male American Redstart is black and orange overall, so the bird in the images is likely a female or possibly a juvenile male.

American Redstart - Mark Musselman

American Redstart - Mark Musselman

American Redstart - Mark Musselman

 On Friday, we were able to get out on the boardwalk during a break in the weather.  Two steps out the door we encountered a Blue-winged Warbler, a Worm-eating Warbler, a Black-and-white Warbler, a Northern Parula, two Red-eyed Vireos, a Downy Woodpecker, several Carolina Wrens, and a White-eyed Vireo.  Below, you can see the complete list, including a Veery at #113.

Francis Beidler Forest Audubon Center & Sanctuary, Dorchester, US-SC
Aug 31, 2012 2:00 PM - 4:00 PM
Protocol: Traveling
1.75 mile(s)
Comments:    Clear, 80Fs
25 species

Wood Duck (Aix sponsa)  4
Great Egret (Ardea alba)  2
White Ibis (Eudocimus albus)  27
Red-shouldered Hawk (Buteo lineatus)  1
Yellow-billed Cuckoo (Coccyzus americanus)  5
Barred Owl (Strix varia)  2
Red-bellied Woodpecker (Melanerpes carolinus)  6
Downy Woodpecker (Picoides pubescens)  2
Pileated Woodpecker (Dryocopus pileatus)  3
Acadian Flycatcher (Empidonax virescens)  4
Great Crested Flycatcher (Myiarchus crinitus)  1
White-eyed Vireo (Vireo griseus)  10
Red-eyed Vireo (Vireo olivaceus)  2
American Crow (Corvus brachyrhynchos)  4
Carolina Chickadee (Poecile carolinensis)  8
Tufted Titmouse (Baeolophus bicolor)  6
White-breasted Nuthatch (Sitta carolinensis)  2
Carolina Wren (Thryothorus ludovicianus)  9
Blue-gray Gnatcatcher (Polioptila caerulea)  4
Veery (Catharus fuscescens)  1
Worm-eating Warbler (Helmitheros vermivorum)  1
Blue-winged Warbler (Vermivora cyanoptera)  1
Black-and-white Warbler (Mniotilta varia)  1
Northern Parula (Setophaga americana)  7
Northern Cardinal (Cardinalis cardinalis)  2