Rain, Rain, Save the Day

It was beginning to look like there would not be any canoe trips at the Audubon Center at Francis Beidler Forest due to the minimal rain since August 2012.  With yesterday's rain on top of the rain last week, that is no longer an issue.  In fact, two groups were on the canoe trail yesterday.  The morning group beat the rain and the drop in the temperature, but the afternoon group did not fair as well.  It was still a beautiful paddle, but hot beverages and maybe a warm fire were on most of the post-paddle schedules.

Last Tuesday, we took advantage of the "eye of the storm" to make a quick walk around the 1.75-mile boardwalk.  We quickly spied a Spotted Turtle (Clemmys guttata) and a Common Snapping Turtle (Chelydra serpentina), both likely in search of mates.

A shower of Red Maple debris greeted us early along the boardwalk.  Gray Squirrels (Sciurus carolinensis) are messy eaters.

Red Maple seeds on boardwalk - Mark Musselman

Depressions in the upland areas created by Hurricane Hugo-felled trees filled with water.  Amphibians will use these ephemeral, fish-free pools for breeding.  You may have heard the chorus of frog calls in your neighborhood too.

Upland forest - Mark Musselman

Elsewhere, water has reached even the elevations where the Dwarf Palmetto grows.

Swamp - Mark Musselman

Water flowing by knees - Mark Musselman

If you stand near the fork (#115) on the boardwalk, you will likely hear what appears to be the roar of a mountain stream.  Obviously, that is not the case here in the nearly level coastal plain. What you will be hearing is the cumulative noise of water flowing over the quarter mile of beaver dam.  The log near #154 that skims debris floating on the water's surface is also close to being overtopped.

Log across channel - Mark Musselman

We saw plenty of birds that were also taking advantage of the break in the rain.

Francis Beidler Forest Audubon Center & Sanctuary, Dorchester, US-SC
Feb 12, 2013 1:55 PM - 3:55 PM
Protocol: Traveling
1.75 mile(s)
Comments:     Mostly cloudy, 60Fs
25 species

Wood Duck (Aix sponsa)  2
Great Blue Heron (Ardea herodias)  1
Turkey Vulture (Cathartes aura)  1
Red-shouldered Hawk (Buteo lineatus)  2
Barred Owl (Strix varia)  3
Red-bellied Woodpecker (Melanerpes carolinus)  9
Yellow-bellied Sapsucker (Sphyrapicus varius)  4
Downy Woodpecker (Picoides pubescens)  5
Northern Flicker (Colaptes auratus)  3
Pileated Woodpecker (Dryocopus pileatus)  4
Eastern Phoebe (Sayornis phoebe)  1
American Crow (Corvus brachyrhynchos)  11
Carolina Chickadee (Poecile carolinensis)  10
Tufted Titmouse (Baeolophus bicolor)  12
Brown Creeper (Certhia americana)  1
Winter Wren (Troglodytes hiemalis)  2
Carolina Wren (Thryothorus ludovicianus)  7
Blue-gray Gnatcatcher (Polioptila caerulea)  1
Golden-crowned Kinglet (Regulus satrapa)  6
Ruby-crowned Kinglet (Regulus calendula)  9
Hermit Thrush (Catharus guttatus)  3
Black-and-white Warbler (Mniotilta varia)  1
Pine Warbler (Setophaga pinus)  1
Yellow-rumped Warbler (Setophaga coronata)  20
American Goldfinch (Spinus tristis)  6

At #7, an Eastern Cottonmouth (Agkistrodon piscivorus piscivorus) took the opportunity to catch some sun atop the log it uses for its winter den.

Eastern Cottonmouth - Mark Musselman

Beaver gnawing on Sweet Gum - Mark Musselman

Approaching Goodson Lake, evidence of fresh beaver (Castor canadensis) foraging could be seen on numerous trees and knees.  Like many of us, we're sure the beavers are looking forward to the warmer, sunnier weather of spring.  However, unlike the beavers, we do not need to worry that the warming temperatures allow the alligator (Alligator mississippiensis) to feed once more.

It's Hot in the Swamp!

It's been hot in the swamp this week.  The rain that fell Tuesday at the Audubon Center at Francis Beidler Forest did little more than fill some low spots in the swamp, but water has yet to begin flowing downstream toward the Edisto River.  In some areas, only the cracks in the mud collected water.

In lower areas, the water is more than an inch deep, but the cracks can still be seen below the film-covered water.

Though the heat and humidity have been high and the water level low, but the business of producing life has continued.  A Great-crested Flycatcher (Myiarchus crinitus) was spotted sitting on a nest across Goodson Lake from the observation tower.  The nesting bird is half rolled on its side with its mouth agape in an effort to dissipate heat.

On the boardwalk stretch back to the nature center, we were able to capture something we had previously observed regarding Golden Silk Orbweaver (Nephila clavipes) behavior.  The male spider is much smaller than the female and she continues to grow throughout the summer.  Males are often observed on the web with the female, but  males maintain above and behind the female.  This positioning appears to be an attempt to remain off the female's dinner menu.  However, the male is there for a reason and how is mating to occur if such a safe distance is maintained?  The male's strategy seems to be one of patiently waiting until the growing female must shed her too-small exoskeleton and, like a soft-shell crab, is too flaccid to fend off or devour an amorous suitor.

The female's shed exoskeleton can be seen above the pair of spiders.

Images by Mark Musselman

Advanced Camp - Day 3

The heat and humidity have returned to the swamp!  Day 3 of advanced summer camp at the Audubon Center at Francis Beidler Forest had campers soaking wet even though the swamp is nearly dry.

The plan for the day was to hunt for reptiles and amphibians during the morning and then insects within the sunny power line corridor after lunch.  Heat index values approaching 112F caused some modifications to the plan, including an early afternoon retreat to the air-conditioned nature center.

Here are some of the images captured during the day:

Very young Carolina Anole

Eastern Cottonmouth (only snake seen)

Early in the herp hunt

Appeared to be a young Bronze Frog

After some swamp stomping

Non-target spider species

 Dragonflies

Images by Mark Musselman

Dry Swamp

The old-growth swamp at the Audubon Center at Francis Beidler Forest is dry except for water trapped in the various holes like Goodson Lake.  No significant rain has fallen in the last two months and any water that did not drain into the Edisto River has evaporated or been drawn into the thirsty vegetation.  Muddy remnants of the numerous creek channels have cracked open as moisture continues to escape.

Aquatic organisms in ever-diminishing pools of water become easy prey or they become stranded on the mud.  As the summer campers made their way to Goodson Lake, we saw an Eastern Cottonmouth (Agkistrodon piscivorus piscivorus) scavenging pieces of a large fish left behind by another predator.

Although the American Alligator in Goodson Lake is not in danger of losing its watery habitat, the lower levels have altered its basking sites.  Though normally not seen close to the observation tower, the summer campers caught the alligator basking directly across from the tower on a partially-submerged log.

Elsewhere in the swamp, wildlife are doing what they can to survive the dry, hot (100+F) conditions.

 Green Treefrog (Hyla cinerea)

Southern Black Racer

 White-tailed Deer

Eventually, the rains will return and Four Holes Swamp will look more like a swamp.

Images by Mark Musselman

Whiskers in the Swamp

Though they were not true whiskers on the animals, that's what they looked like to the summer campers at the Audubon Center at Francis Beidler Forest.  While exploring the forest and swamp near the nature center, we discovered a mere puddle of water in a depression at the base of a hollow tree.  This was all that was left of the water pooled behind the beaver dam and will likely disappear by the end of the day tomorrow.  Elsewhere, water cannot be seen from the boardwalk until the approach to Goodson Lake at the end of the boardwalk.  Naturally, the hole that is Goodson Lake continues to hold ample water to support the American Alligator (Alligator mississippiensis), Longnose Gar (Lepisosteus osseus), Bowfin (Amia calva), Yellow-bellied Sliders (Trachemys scripta scripta) and other aquatic or semi-aquatic organisms.

In the puddle of water behind the beaver dam, we found numerous small fish and a meatier 3-inch long fish.  All were too muddy from their struggles in the shallow puddle to be identified, but we grabbed a few to show the campers waiting a the swamp's drier edge.  While showing the campers the larger fish, we discovered, via a fin jab in the hand, it was a species of catfish.  As the catfish would likely be dead by morning from either the disappearing water or the return of the herons, ibis and raccoon whose tracks were still in the mud from the night before, we put the catfish in a jar of water and hauled it out to Goodson Lake to give it a fighting chance.

As we moved along the treeline at the edge of the power line corridor, campers were able to spot a variety of native insects feasting on an abundance of native plants.  There were pollinators like butterflies, bees, beetles as well as an assortment of other flying insects, including several species of insect-hunting dragonflies.  Native fauna and native flora have evolved together and therefore maintain a system of checks and balances within the ecosystem.  The introduction of non-native flora or fauna can throw the system out of balance as predators may not exist for the non-native fauna or the native fauna may not be able or willing to eat non-native flora, which in turn may crowd or eliminate native flora.  One of the native species the campers found was a Pipevine Swallowtail caterpillar in search of pipevine on which to dine.  It is apparently unpalatable and therefore has little fear of becoming a meal itself.  The whisker-like, fleshly projections give the caterpillar a fearsome look and might give a predator a scare.

Images by Mark Musselman

Wood Ducks Still on the Menu

There has not been a significant rain at the Audubon Center at the Francis Beidler Forest in quite some time.  A trip around the 1.75-mile boardwalk provides few opportunities to see water beyond the deep hole called Goodson Lake and the adjacent main creek channel.  However, behind the beaver dam there is still water, so that's where all the action is happening.  On Monday, we heard what sounded like trees rubbing against each other as a warm breeze blew over the swamp, but the sound at times appeared to originate from a wading bird of some sort or possibly an animal in distress.  We decided to investigate.

As it turned out, the sound was a combination of wind-generated tree rubbing and birds going about their business.  Once under the rubbing trees, the sound was distinctly tree-on-tree.  As the wind shifted directions, the sound generated by the trees changed pitch and volume, which caused some of the confusion at our listening post higher up at the nature center.  However, the water impounded under the power line by the beaver dam had attracted a host of bird species and their unique calls.

Several generations of Wood Ducks (Aix sponsa) were moving in and out of the tall grasses growing in the shin-deep water.  Adults seemed content to snooze, while juveniles and ducklings paddled about.  What sounded like children idly dropping stones into the water turned out to be ducklings returning to the water after launching themselves at drooping  grass seed heads.  In a classic mistake oft noted in the movies, we brought a knife to a gunfight.  Our mission was simply to scout sites for activities to be conducted during the upcoming summer camp sessions.   A camera was brought along to document the sites and anything of interest regarding camp.  The 21st-century camera with the lens capable of reaching out a greater distance would have been perfect for the 10-meter distance we were able to close on the Wood Ducks.

The Wood Ducks were not alone in taking advantage of the diminishing water resource.  Wading birds including Great Blue Heron (Ardea herodias), Great Egrets (Ardea albus), and a half dozen or more White Ibis Eudocimus albus) squawked and honked as they stalked prey and foraged in the shallow water.  Also calling along the treeline were Pileated Woodpeckers (Dryocopus pileatus), Red-bellied Woodpeckers (Melanerpes carolinus), Acadian Flycatchers (Empidonax virescens), Great Crested Flycatchers (Myiarchus crinitus), and several species of frogs.
 
As we watched and listened, a mass dropped from a nearby tree into the tall grasses that create a mini-marsh in the "pond" produced by the beavers.  At first we thought a squirrel had missed a step and fallen from the tree canopy as we have observed these accidents in the past.  However, the thrashing in the tall grass was caused by something considerably larger than a squirrel.  As the flapping increased, we determined the animal was a bird and by the size it had to be a raptor.  Based on our surrounding habitat, the prime suspect was a Red-shouldered Hawk (Buteo lineatus), which was confirmed as it cleared the tall grasses and headed to the treeline on the north side of the power line.  In its talons was a Wood Duck duckling destined to be the meal of one of the Red-shouldered Hawks recently fledged from the parking area nest.

It's a swamp out there!  For those of you keeping track on you food web diagrams, draw another line from Wood Ducks as they are now documented to be on the Red-shouldered Hawk's menu.

Images by Mark Musselman

Bowfin Problem Solver

After all the rain in December and January, we did not think we would be discussing low water levels at the Audubon Center at Francis Beidler Forest by the end of April.  Canoe trips are no longer feasible and the swamp looks less and less swamp-like as the water level continues to drop.  The light rain we received yesterday did little to change that situation.  However, the shallow water is a boon for some predators.

The the water level in the swamp drops, some of the shallow channels get cut off from the deeper channels.  Without water flowing in to replenish water lost to evaporation or transporation, the cut off channels become smaller and smaller pools of water.  Any fish or crayfish caught in those shallow pools become easy prey for owls, raccoons, herons, ibis, egrets, otters, snakes, and other fish.  Other fish?

While on the boardwalk observing Prothonotary Warblers (Protonotaria citrea) for Project PROTHO, we saw a Bowfin (Amia calva) moving up a shallow channel.  A third of the fish's body was out of the water when it met an obstacle to its upstream movement.  A log across the channel caused the fish to stop and probe the length of the log in search of upstream access.  We're not sure what the large fish was seeking in the increasingly shallow water, but we have observed Bowfin eating crayfish and there are plenty of crayfish in the diminishing water.  After finding no path through the water, the Bowfin leapt over the log and continued on its way.  The video below consists of a series of still images showing the event.



Images and video by Mark Musselman

Charleston AFB Earth Day

Yesterday, the education department from the Audubon Center at the Francis Beidler Forest took samples of macroinvertebrates from the swamp and headed to the Charleston Air Force Base for the Earth Day celebration.  In 10-minute waves over two hours, 300 5th graders stopped by our tent and picked through the macroinvertebrate samples and learned how the organisms help us determine the quality of the water.













Images by Mark Musselman

No Christmas Miracle

It's not our imagination, this has been one of the wettest Decembers on record! The rain that moved through Four Holes Swamp last week turned to snow in the Upstate and continued with record-breaking snowfall across the border into North Carolina and on into New England. Enough snow dropped in the latitudes to the north that it will likely be a white Christmas in those areas. It doesn't look like we'll be getting any snow at the Audubon Center at Francis Beidler Forest, but the forecast shows one more dose of rain before December comes to a close.

This month has been the wettest December on record since 1941 with records at the North Charleston airport beginning in 1938. The rain forecast for later this week might be enough to push the month's total to the #1 position in the record books.

December rainfall (National Weather Service office at Charleston airport)
1. 1941/11.08"
2. 2009/9.72"
3. 1953/7.09"
4. 1994/6.35"
5. 1977/5.88"

Not only is the month of December on a record-setting pace, the new record daily maximum rainfall for December 18th was set at the NWS office at the Charleston airport where 3.18" fell thus breaking the old record of 0.95" set in 1948.

What does all this rainfall mean to the swamp? Besides making the swamp actually look like a swamp, it means that there will likely be no Christmas miracle for the Loblolly Pine that has sprouted far from the swamp's edge and the safety of higher ground. The Bald Cypress and Tupelo Gums that constitute the majority of trees growing in the swamp are unaffected by the coming and goings of water. However, this Loblolly Pine seedling stands alone on its fallen-log perch because this and other local tree species are not adapted to stand with their roots in saturated soils. Without the extensive evaporation in warmer weather and with photosynthesis shut down in all but a few swamp-residing trees, the higher water level in the swamp will drop more slowly than at other times of the year, which will cause the Loblolly Pine seedling to endure a more extensive period of submergence.

Although it will likely be wet and not white, have a Merry Christmas!

Image by Mark Musselman