Thanks
to Mr. and Mrs. Anderson for their generous donation to Audubon South
Carolina in memory Lloyd and Margaret Cone, we were able to fund a
seasonal internship aimed at increasing our monitor efforts of the
Prothonotary Warbler at three locations across Four Holes Swamp – two areas in
old growth and one area that was logged once. Heather VanTassel, our intern, received her bachelor’s degree in Biology from
Carlow University. She went on to obtain her PhD in Ecology from the University
of California Riverside focusing on understanding wildlife
responses to anthropogenic disturbances in the southwest.
Old-growth Swamp - Heather VanTassel
With Heather's assistance, we have learned that while
Prothonotary Warbler densities may not seem to be as high in the logged
areas as they are in the old-growth swamp, the once-logged areas still maintain healthy densities
of Prothonotary Warblers. These results reinforce our efforts to conserve Four Holes Swamp and allow once-disturbed sites to return to their natural state in
order to support healthy bird communities. We also plan to put out 50
Prothonotary Warbler nest boxes in the logged locations, which will provide additional nesting
cavities and help maintain Prothonotary Warbler densities in the future.
Project PROTHO Nest Box - Heather VanTassel
You can follow what we are doing with Project PROTHO on our webpage.
The rain over the last weeks has produced water levels not seen along the boardwalk at the Audubon Center at Francis Beidler Forest since the spring of 1997. Although feet below the aftereffects of Hurricane David in 1979, when walking on the boardwalk would put one knee deep in water, this has been a significant water event for Four Holes Swamp. We have posted a video at the end of this blog.
Hurricane David High Water Mark - Mark Musselman
A nail about a foot above the base of the Mockernut Hickory tree marks the extent of the water dumped by Hurricane David. The current rain event has pushed water up to the base of the tree.
Marsh Rabbit - Mark Musselman
Although Marsh Rabbits (Sylvilagus palustris) are comfortable swimming, they apparently have their limits. This individual was high in the pine woods directly behind the Loblolly Pine sign.
Water in High Pine Woods - Mark Musselman
Water often pools in the pine woods, mainly in depressions created by tip-ups when Hurricane Hugo knocked down 80% of the canopy. However, during this rain event, the high ground was flooded and the water was running across the pine woods.
Water in High Pine Woods - Mark Musselman
White Ibis in High Pine Woods - Mark Musselman
A trio of White Ibis (Eudocimus albus) were foraging in the high pine woods because everywhere else in the swamp was too deep for wading. We were not sure what they might be finding as the newly submerged habitat is not known for crayfish or fish.
Yellow-crowned Night Heron in High Pine Woods - Mark Musselman
A Yellow-crowned Night Heron (Nyctanassa violacea) was wading in the water on the opposite side of the boardwalk from the White Ibis.
Yellow-crowned Night Heron in High Pine Woods - Mark Musselman
Approaching the fork in the boardwalk, the water could be seen up to the cross supports.
Swamp Edge - Mark Musselman
Although the boardwalk is relatively level, the 1977 construction was mainly accomplished by volunteers not professionally certified in carpentry, so the keyword is relatively. The low spots could be detected by the various depths of water across the deck.
Approaching Fork in Boardwalk - Mark Musselman
In some cases, the water had already receded.
Water Over Boardwalk - Mark Musselman
Fork on Boardwalk - Mark Musselman
The return portion of the boardwalk parallels the edge of the swamp and is often dry under the boardwalk. In the image below, the water can be seen close to the deck.
High Water at #20 - Mark Musselman
At the #3 rest area, the water is up to the deck supports though the reflection off the water gives the impression of space below the boardwalk.
High Water at #3 - Mark Musselman
If any Prothonotary Warblers had nests below the level of the nest boxes on the signs, the nests were submerged and a loss.
Sign at #3 - Mark Musselman
Looking out from the rest area at #3, not a single one of the thousands of cypress knees can be seen due to the high water.
No Knees Visible From #3 - Mark Musselman
The cypress tree felled at #4 by Hurricane Hugo was under water except for a small portion at the root end.
Water Over Fallen Cypress at #4 - Mark Musselman
Looking back at the Meeting Tree, the water can be seen approaching the boardwalk deck.
High Water at Meeting Tree - Mark Musselman
High Water at Meeting Tree - Mark Musselman
The high water limited the above-water options and made it treacherous for emerging aquatic insects. A Dark Fishing Spider (Dolomedes tenebrosus) made a meal of a dragonfly that had selected poorly and emerged on a boardwalk cross support.
Dark Fishing Spider - Mark Musselman
Dark Fishing Spider - Mark Musselman
The large knee at #5, which many state looks like a wave, is barely exposed above the water's surface.
"Wave" Knee at #5 - Mark Musselman
Though the knees in the channel at #5 are quite tall, not a one could be seen above the water.
No Knees Visible at #5 - Mark Musselman
Approach to #6 - Mark Musselman
Rest Area at #6 - Mark Musselman
No Knees Visible Beyond 7' Knee - Mark Musselman
High Water at #8 - Mark Musselman
The shadows make it difficult to see, but the water is just below the deck at the #9 rain shelter.
Rain Shelter at #9 - Mark Musselman
High Water at T on Boardwalk - Mark Musselman
High Water at T on Boardwalk - Mark Musselman
Animals of all sorts took advantage of any resting spots out of the water.
Yellow-bellied Slider with Eastern Mud Turtle - Mark Musselman
High Water at #10 - Mark Musselman
Bald Cypress at #10 - Mark Musselman
View of Second Platform From #10 - Mark Musselman
Tower at Goodson Lake - Mark Musselman
Tower at Goodson Lake - Mark Musselman
The average water level at Goodson Lake is 4.0'. The level at the time of the image on Tuesday was 7.53' down from the morning level of 7.6'. The heavy rain yesterday will likely counter some drop in the water level.
Goodson Lake Gauge - Mark Musselman
Looking back from the tower at Goodson Lake to an area that is almost always dry or extremely shallow, the water can be seen covering all the cypress knees, including one that had been used as a nesting site by Prothonotary Warblers earlier in the season.
Boardwalk to Second Platform - Mark Musselman
A Southern Toad (Bufo terrestris) could find no dry ground except for the boardwalk.
Southern Toad at #10 - Mark Musselman
Elsewhere, a small Eastern Cottonmouth (Agkistrodon piscivorus piscivorus) also sought high ground on the boardwalk.
Eastern Cottonmouth - Mark Musselman
The high water has basically eliminated all above-water basking sites except for the boardwalk we installed. Fear not! After taking the first image from a significant distance, the snake quickly retreated as we tried to get a more artistic ground level shot. Dry is nice, but humans are huge and scary and retreat is the best option. Remember, the majority of people have problems with snakes once they begin to mess with the snakes.
Eastern Cottonmouth - Mark Musselman
If you have not seen the swamp with high water, do not wait another 15-20 years for the next event!
If you have never seen a male Wood Duck (Aix sponsa), then you are missing one of nature's works of art! In fact, hunting this bird for its plumage and as food brought the species to the brink of extinction by the early 1900s.
male
Wood Ducks nest in cavities, natural or made by other animals, so they are often found in swamps and bottomland forests. Loss of habitat and some forestry practices eliminated the nesting cavities sought by this species, which is the reason Wood Duck nest boxes became ubiquitous in some areas. While the practice of placing nest boxes helped the species recover, more is not necessarily better as female Wood Ducks increase their habit of dumping eggs into other birds' nests as the density of cavities or nest boxes increases. Clutches of 15-50 eggs can result from 2-10 hens contributing eggs to the nest. Cavities may be quite high in a tree, but 24 hours after hatching, the ducklings will exit the cavity and free fall. Their light weight and landing zones of soft leaves or water results in few injuries.
female behind male
Over the last two weeks, Wood Ducks have gotten our attention at the Audubon Center at Francis Beidler Forest as their noisy courtship has begun. The female's vocalization, heard at the end of this audio, is what can be heard most often from the boardwalk and our offices. Displays will continue into the spring as groups of a dozen birds, more
males than females, gather to court and eventually split into
monogamous pairs. These displays occur mainly on the water. The heavy weight of ducks relative to their wing area requires continuous flapping and makes aerial maneuvers and displays difficult to impossible.
male
The wet area behind a portion of the beaver dam (small portion shown in blue) near #1 along the boardwalk is where the Wood Ducks have been located. As our Wood Duck images consist of distant blurs or the ones above taken inside at the South Carolina Aquarium, we wanted to try and capture some clear images in the swamp. Down the hill from the outdoor classroom, there was a screen of large trees between us and the ducks. We moved slowly and quietly while frequently checking with binoculars the location of our quarry. Occasionally, a duck would swim out from behind the screen of trees and we would freeze until the duck returned to a position out of our view. Quite pleased with our stealth, we arrived at a position close enough for our long lens to provide a quality image. Alas, there were no ducks! Scanning with the binoculars, we located a male watching us from a position 50 meter to the south. Upon further inspection, we saw additional ducks silently swimming south down the channel. As the trees screened us from the ducks, or so we thought, so too was the ducks' exit screened from us. Visitors passing along the boardwalk caused the ducks to flush to flight, which revealed the presence of at least a dozen ducks when we had seen no more than five. Obviously, we were not as stealthy as we thought and had been under careful observation the entire time, which allowed for the ducks' silent withdrawal.
The elusive ducks won again. However, trips into the swamp would be less exciting if we did not have plenty of targets still on our image wish list!
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!
