To Rattle Or Not To Rattle

Snakes rattle their tails as a warning, but not all snakes exhibiting this behavior are rattlesnakes.

Here an Eastern Cottonmouth rattles its tail to warn of its presence and desire to be left alone.

Rattlesnakes have evolved an amplification method for their tail twitching. Some dry skin remains at the end of their tail each time they shed skin, which allows for a rattle louder than a tail simply moving in dry leaves. Tail twitching is a method of announcing a snake's presence and the rattle is a highly effective design. However, rattling the tail is generally an action of last resort, so many snakes will not rattle even if a human is close.

There are stories suggesting that rattlesnakes are evolving back to quieter snakes without rattles, because non-rattling snakes go undetected and survive. However, there are not any studies that show snakes are rattling less frequently than in the past. Snakes obviously do not want to reveal their location to prey they are trying to eat and unnecessarily revealing their location to non-prey animals may result in death or injury (see the Internet for numerous images of snakes shot or chopped before they could do any "harm"). Remaining motionless and allowing camouflage to work likely allows  snakes to go unnoticed and unharmed. Conversely, if a snake feels that death or injury is imminent, rattling the tail may cause the source of potential danger to move away. It always works with me.

Besides the encounter shown in the video above, other Eastern Cottonmouth snakes have alerted me to their presence when they felt I was too close. While patrolling in the swamp, I saw snake tracks in the mud, but could not find the snake. I did not want to step any farther without knowing exactly what was sharing my close surroundings. The polite cottonmouth, a few feet to my right, rattled its tail against the dead log atop which it rested to let me know its location and that it preferred to be left alone. I obliged and safely moved away. It was possessive of space, but not aggressive.

Eastern Cottonmouth - Mark Musselman

After the great rain of October 2015, I was patrolling the edge of the swamp near the nature center for signs of wild pigs. I hoped that the high water would have them bunched at the edge of the swamp and vulnerable to elimination. I looked up long enough to identify a vehicle moving down the driveway, which was exactly the amount of time needed to step squarely on the back of a Timber Rattlesnake. Sensing the textural difference from my previous thousands of steps, I lifted my foot. The snake moved off a safe distance, coiled and then rattled its disapproval. I took an image, thanked it for its subdued reaction to my "attack" and moved safely away.

Timber Rattlesnake - Mark Musselman

Though the event listed below has become history, we do offer speaker presentations, including one on our friends the snakes. We can all benefit from a better understanding of these reptiles.

Boardwalk Construction Continues

The construction of the new boardwalk at the Audubon Center at Francis Beidler Forest continues with workers reaching the high ground between the nature center and the boardwalk fork. The lack of rain over the last week has allowed the construction bypass trail to dry out, so the boardwalk is open again except for individuals with certain mobility limitations. Once construction reaches the fork, there will be no need for the off-boardwalk bypass trail and access will be regained for all individuals. You can keep track of the construction progress by visiting the boardwalk map here.

Boardwalk Construction - Mark Musselman

Boardwalk Handrails - Mark Musselman

While checking the boardwalk for fallen limbs and damage, we noted some birds in migration and other wildlife on or near the boardwalk. American Redstarts have been seen recently and we spied both a Northern Waterthrush (also calling) and a Louisiana Waterthrush along the edge of the swamp between #174 and #179.

Near the Meeting Tree at #120, we observed a juvenile Yellow-crowned Night Heron on the boardwalk handrail and later spotted it picking at crayfish-filled raccoon scat near the hollow tree at #179.

Yellow-crowned Night Heron - Mark Musselman

It posed nicely for some additional shots, which we can add to our library.

Yellow-crowned Night Heron - Mark Musselman

On the second platform out at Goodson Lake, we found a large, non-venomous, fish-eating Brown Water Snake taking advantage of the sunlight and the low visitor count.

Brown Water Snake - Mark Musselman

How can anyone be frightened by this mug?

Brown Water Snake - Mark Musselman

Master Naturalists Visit

Yesterday, the master naturalist class from the Lowcountry Institute on Spring Island visited the Audubon Center at Francis Beidler Forest.  What a difference a day makes!  A visit today, after the passing of the cold front, would not have produced the variety of wildlife sightings described below.

Upon entering the swamp, a Winter Wren (Troglodytes hiemalis) greeted us with a call as it flew inches off the ground between its inspections of decaying logs.  With the water level remaining low due to the lack of rain, we concentrated our wildlife searches around the few shallow creek channels.  Either the wildlife lives in the water or it eats something in the water.  We had our first hit along the channel near #5.  As we pointed out a frequently used deer trail, free of leaves and with fresh tracks embedded in the mud, a member of the group spotted an Eastern Cottonmouth (Agkistrodon piscivorus piscivorus) wedged low between two trees.

Eastern Cottonmouth - Mark Musselman

As photos were being taken, another member of the group spotted a second cottonmouth nearly obscured by a log off the other side of the boardwalk.  A brief walk to #8 and another cottonmouth was discovered basking on a log.

All was relatively quiet at Goodson Lake and around to #14, which is halfway back on the return loop.  Beyond #14, a Barred Owl (Strix varia) was spotted low on a branch a few meters left of the boardwalk.  For several minutes, the owl tolerated the group of twenty-five adults along with the "aahs" and clicking camera shutters.  Eventually, it flew to a slightly more distant perch and gave a brief hoot to let us know it was time to move along.

Barred Owl - Mark Musselman

As we turned, we spotted the owl's mate ahead of us on the hand rail.  The second owl attempted to catch something on the ground to the left of the boardwalk and then flew to a low perch next to the hand rail.  Again, the cameras came up as the model posed patiently for the art gallery shots.

Barred Owl - Mark Musselman

Barred Owl - Mark Musselman

Having not yet finishing discussing the fortuitous close encounters with the owls, we came upon a large Banded Water Snake (Nerodia fasciata fasciata) that appears to have sensed the cooling weather and has established a den near the fallen water hickory.

Collis Boyd repairing boardwalk - Mark Musselman

We continued on to the nature center for lunch and then made the short drive to the marl bluff along the southern edge of Mallard Lake.  The Six-lined Racerunners (Cnemidophorus sexlineatus) were absent this trip, but we did capture a young Southern Fence Lizard (Sceloporus undulatus) in the dry, sandy upland habitat.  A short walk down the steep slope, approximately 20' change in elevation, brought us to a seep.  Seeps form when rain peculates vertically through the soil until it reaches the impermeable layer of marl.  Water then travels laterally until emerging from the base of the slope in a narrow (5'-6') and short (20'-25') wetland.  The cool, permanent and fish-free water is prime amphibian, especially salamander, habitat.  We quickly located a Slimy Salamander (Plethodon glutinosus) and a Southern Two-lined Salamander (Eurycea cirrigera) before being distracted by a small, beautifully colored Eastern Cottonmouth.  The snake quickly retreated to its likely den in an exposed root mass and we moved away from the bluff to explore the dry swamp.

An immediate and somewhat satisfying find was the skull of a wild pig (Sus scrofa), a scourge we have discussed previously in this blog.  Note the gnawing by other wildlife, mainly rodents, as they seek to meet their calcium needs.  Stirring leaves and rolling a few logs produced a variety of frogs, including a Southern Cricket Frog (Acris gryllus), a Green Treefrog (Hyla cinerea) , and a Pine Woods Treefrog (Hyla femoralis) as well as a beautiful Marbled Salamander (Ambystoma opacum)!

Wild pig skull - Mark Musselman

Marbled Salamander - Mark Musselman

Marbled Salamander - Mark Musselman

Pine Woods Treefrog - Mark Musselman

Finally, before heading back up the bluff to the vehicles, Kelley Luikey snapped a photo of a richly colored Marbled Orbweaver (Araneus marmoreus).  With today's cool, breezy weather portending overnight freezes, these spiders will not be around much longer.

Marbled Orbweaver - Kelley Luikey

Snake in a Tree

No, it's not the latest Hollywood movie title and snakes in trees are not unusual occurrences, but a Timber Rattlesnake (Crotalus horridus) in a tree was a surprise.

On Friday, the Audubon Center at Francis Beidler Forest hosted two students from Ashley Ridge High School's workplace shadow program. In the morning, we walked the 1.75-mile boardwalk through the old-growth, cypress-tupelo swamp and discuss the varied aspects of work at the center.  After lunch, since the young men came wearing snake boots, we walked out to see the beaver dam and generally explored the off-boardwalk areas. We headed back to the center along the south side of the boardwalk in order to explore the area where we had earlier seen two fawns.

As we were walking 25 feet from the boardwalk, one student said, "Snake."  We stopped. We had been watching the ground carefully, so we were somewhat surprised that we had missed it.  Camouflage is what makes some snakes difficult to see (bad news for prey), so missing a snake was not impossible.  We were still looking ahead when the student said, "No, back here."  We looked back where we had walked and saw nothing.  The student again gave direction, "No, up here."  The Timber Rattlesnake (1-1/2' to 2') in the images was above the ground between a vine and a sapling.  We only had the iPod Touch camera and the snake had moved elsewhere by the time we returned with a better camera.

We were also able to capture a brief video.



No matter how many times we walk out along the boardwalk, we invariably see something new or something old doing something new or in a different place.  Never a dull moment!

Images and video 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

The King of Snakes

Yesterday, as we were finishing our Project PROHTO survey around the boardwalk at the Audubon Center at Francis Beidler Forest, we caught site of an Eastern Kingsnake (Lampropeltis getula getula) near the edge of the swamp.  The Eastern Kingsnake, which includes the subspecies L. g. getula, L. g. nigra, and L. g. holbrooki, has one of the largest geographic ranges of any North American snake.  They are at home in a wide variety of habitats and though strongly terrestrial, they can often be found near aquatic habitats.

The Eastern Kingsnake is quite secretive even though it is active during the day.  Although this snake's overall population is sufficient to not warrant protection, isolated populations have been diminishing or have disappeared.  As with many flora and fauna species, habitat loss is likely a factor.  Introduced species such as fire ants or disease may also be taking a toll on the Eastern Kingsnake population.

Although Eastern Kingsnakes will eat lizards, rodents, and turtle eggs, they also eat other species of snakes.  Kingsnakes are immune to the venom of pit vipers, so they have no issues with eating copperheads, cottonmouths, or rattlesnakes.  If you are not a fan of snakes in general, you should be a fan of the snake-eating Eastern Kingsnake!



Video by Mark Musselman

Action in the Swamp

The swamp at the Audubon Center at Francis Beidler Forest is alive with our spring residents – almost everyone has returned at this point. The morning bird chorus around the boardwalk now includes Northern Parulas, Black-and-White Warblers, Hooded Warblers, Yellow-throated Warblers, Summer Tanagers, Blue-Gray Gnatcatchers, Great-crested Flycatchers, Acadian Flycatchers, Red-eyed Vireos, White-eyed Vireos and of course Prothonotary Warblers! In the upland, Ovenbirds, Kentucky Warblers, Pine Warblers & Swainson’s Warblers can also be heard merrily singing along. We’ve also had some great migrant sightings – a Black-throated Blue Warbler singing over the building this morning and a Scarlet Tanager sighted around the boardwalk last week by the staff.

Project PROTHO is fully underway. We have 23 banded Prothonotary Warblers that have returned to Beidler Forest so far this year. Of those 23 Prothonotary Warblers, 12 are visible from the boardwalk. We are sure there are still more banded birds that have returned and are waiting to be rediscovered during an off-boardwalk trek. There are several tracts of land, where we've put up nest boxes, left to investigate for more banded returns. On an interesting note, every banded bird that has returned has been male. It is curious that no banded females have yet been observed. The females are more subdued in color, sound and behavior, so we'll keep our hopes high for seeing one when we check nest boxes later in the season.

We have been very fortunate to secure the assistance of Dr. Chris Snook, a licensed bird bander from the Charleston area. He is doing the Prothonotary Warbler banding this season and working on training Denise Ecker to be an independent bander as well. We have banded six new Prothonotary Warblers this season, all of which are visible from the boardwalk.

We have been receiving a tremendous amount of data sheets from visitors participating in this citizen-science project. Combining those data sheets with staff observations, we have had early success on identifying Prothonotary Warbler nest sites around the boardwalk. As of last night, we have three active nests, each with five eggs. There are also three other nest sites that will most likely have eggs in them within the week. All nests have (at least) the male Prothonotary Warbler banded, so it is easier to keep an eye on the action.

On a very interesting note, we (along with the Master Naturalist group from the Lowcountry Institute on Spring Island)  watched a Greenish Rat Snake check out a possible Prothonotary Warbler cavity on the way to the lake. Later in the afternoon – we saw a pair of Prothonotary Warblers continuing to build in that same nest site! Apparently, the fact that a snake had stopped by was not enough to deter their nest construction.

Coming up, we will begin checking some of the sites away from the center for nest box activity. Stay tuned for more great Prothonotary Warbler action!

Images by Mark Musselman

"Horse Sugar!"

No, "Horse Sugar!" is not something one exclaims when seeing a snake from the safety of the 1.75-mile, elevated boardwalk while touring the old-growth, cypress-tupelo swamp at the Audubon Center at Francis Beidler Forest.  Horse Sugar (Symplocos tinctoria) or Sweet Leaf is a shrub or small tree with dense clusters of fragrant flowers. The name is derived from the fact that horses (and cows and deer) readily consume the leaves.  Horse Sugar blooms between March and May and began blooming outside the office this past weekend.

Yesterday, we walked around the boardwalk in anticipation of the Prothonotary Warblers' return.  Although we did not find any Prothonotary Warblers, we did complete the Swamp Snake Slam!  Actually, one more Red-bellied Water Snake (Nerodia erythrogaster erythrogaster) and we would have completed a double slam.  There are five species of snakes that are likely to be seen in the swamp from the boardwalk.  Although spotting four of the five species is not unusual during the spring with its warm days and cool nights, seeing all five species during one trip around the boardwalk is a rarity.  The experience is rare enough that we created a certificate awarded to anyone in a guided group or anyone that can show images of all five species.

Here are our documentation photos:

 

Red-bellied Water Snake

 

Eastern Cottonmouth

 

Banded Water Snake

 

Brown Water Snake

 

Greenish Rat Snake

Although we did not find our primary quarry, the Prothonotary Warbler, we will continue to search each day until they return.  The office pool ranges from an early date of today to the slightly tardy date of the 29th.  Stay tuned!

Images by Mark Musselman

Stormy Weather

Yesterday afternoon as we were set to depart the Audubon Center at Francis Beidler Forest, it became as black as night outside and the skies opened to begin dumping over 5.6" of rain!  Winds drove the rain against the building.  Lightning sizzled and thunder added the exclamation point to the storm's dramatic entrance!  Needless to say, we got soaked heading to the car.

Sunday mornings are usually quiet with visitor traffic slowly building as the day progresses.  This morning, however, we were greeted at the end of the driveway by a sodden, ivy-covered pine trunk blocking our path.  Though the log was not so large that it couldn't be moved by hand, it was still securely anchored into the ground and ample poison ivy (Rhus radicans) guarded access to the trunk itself.  Among the Prius' qualities one will not find 4-wheel drive or off-road capabilities.  Unable to pass the log or handle it manually, we were left with no option but to walk the mile to the barn and fire up the old tractor. (Note to self: Get instructions on how to operate a tractor.)

After a quick, over-the-phone class on basic tractor operation, we notice the flat front tire.  After a quick shot of air from the compressor to inflate the tire, we fired up the tractor and backed it out of the barn.  We immediately noted that the tractor's steering is more sensitive than that of the Prius or any other vehicle we've driven.  The small, water-filled ditches on either side of the driveway, which we've previously given little thought beyond, "Wonder if there are any tadpoles in there?", suddenly appeared to be Panama Canal-size hazards.  The tractor, possibly having experienced a previous life as a Stephen King character, seemed determined to steer itself into one watery abyss or the other.

Once at the log, the difference in elevation between the driveway and the sloping road edge made it difficult to use the tractor's bucket to push the log completely to the side.  Eventually, however, the mission was completed without any roll-overs or damage.  For a first-time driver, that is a win.

After driving the tractor back to the barn, there was the mile walk back to the car, which was still marking the spot on the driveway where travel had ended more than an hour earlier.  By now, the neatly ironed Audubon staff shirt was drenched with sweat incapable of evaporating into the already-saturated August air. (Oh, yeah. That's what was missing in Europe...humidity!)  Walking down the maintenance road from the barn, we came upon a Timber Rattlesnake (Crotalus horridus) coiled in the sun at the road's edge.  It was undoubtedly in the same position when we made our walk in to get the tractor and went unnoticed as we contemplated the possible issues associated with first-time tractor operation.  It did not rattle, or strike, or even move...as is usually the case.

Now, for those not paying attention during summer camp or previous blogs...ivy is poisonous and snakes, like the Timber Rattlesnake, are venomous.  It's never to late to learn the difference.  Afterall, it took almost 47 years to drive our first tractor!

Images by Mark Musselman