Don't rescue that snake!

In Per-Columbian times, North American caves were seldom visited by humans, especially those with vertical pit entrances. Animals that require cave habitats for survival (troglobites) pretty much had the caves to themselves. Some epigean (living above ground) critters occasionally fell into pit entrances and couldn’t climb out, and so died and became food for cave animals. (Photo of Procambarus pallidus in Deathtrap Cave, Florida, by Danny Brinton).

Likewise, rainwater was clean and unpolluted, and either streamed in bringing epigean invertebrates and detritus that served as food to troglobites, or percolated down through porous soils to provide the mechanism to create rock formations like stalactites, stalagmites and gours.

But now the streams bring in trash and dissolved pollutants, often forcing aquatic troglobites to live further from cave entrances and their critical food sources. Humans also draw down aquifers, which can dry up subterranean pools altogether, eliminating both habitat and species. We build gates on cave entrances that all too often prevent animals and detritus from entering the caves, and vandals now roam the nethermost corners of caves in order to deliberately kill troglobites.

The result is that many caves no longer harbor the bats and cave-adapted blind, albino fishes and crayfishes that they once did. In some instances, troglobites are even going extinct. Such losses of biotic diversity is not only of concern in itself, but the “library” scientific information contained within troglobitic populations being destroyed is non-renewable.

But there is hope! Cavers are increasingly successful at convincing governments to legislate protection for cave resources. Cavers conduct trash cleanups within the cave and outside of it. Society is slowly cleaning pollutants from industrial effluents. We are learning how to construct bat- and detritus-friendly entrance gates. We are buying caves and stewarding them. We are establishing trails in the more popular caves to keep floor damage to a minimum. We are making a difference on many speleo-fronts.

But we still have more stewardship to develop. For instance, on caving forums we read that well-meaning cave explorers are rescuing epigean animals from caves. This is largely a mistake that should concern all cave resource conservationists. Epigean animals trapped in caves are among the most important food sources of many troglobites. Stream-borne detritus provides an episodic infusion of small invertebrates, but this food source is generally small, unpredictable, and typically of low caloric value.

A fox or snake that falls into and then dies in a cave, however, can provide high energy meals to numerous troglobites over a several-week period. This nutriment is stored in fatty tissue and can sustain them for months or even years, along with the more frequent detritus and invertebrates, until another vertebrate windfall comes along. Some troblobites may not reproduce unless and until a large animal drops in and dies. Denying troglobites this critical food source thus represents one more significant stress on cave animal populations.

Troglobitic crustaceans (crayfishes, isopods and amphipods) have thus evolved relatively slow metabolic rates and long lives. Although epigean crayfishes live only 3 to 5 years, some troglobitic crayfishes are known to live for decades and suspected to live in excess of a century! It's one thing to splat a bug on the windshield of a car, but a hundred year old decapod is a being that we should respect. So, when we rescue an animal that Darwin would have written off as stupid or unlucky, we are taking food from the mouths of cave organisms.

Now, I am the first person to say that we should give imperiled species every second chance that we can. If I find a short-tailed snake (Stilosoma extenuatum) or a Barbour's map turtle (Graptemys barbouri) below a cave pit entrance, I'm certainly going to try to rescue it. But the species that I read about cavers rescuing are almost always common species like garter snakes, bullfrogs or dogs. I maintain that we have plenty of those common critters and that we don’t need to save any of them. It’s the cave animals that we need to save.

So please, the next time you see an animal that is too stupid to watch out for a pit underfoot, leave it in the cave. Your epigean wildlife populations will be more fit. Your cave ecosystem will be healthier. Your cave crayfishes will thank you and your cave millipedes will be ever so grateful, and your biospeleologists will wonder why there are more troglobites in that cave than they ever saw there before.

Dave Maehr is gone

I am so sorry to note that Dave Maehr was killed in an airplane crash last Friday while looking for bears near Lake Placid when the plane's engine stalled (photo of Dave by Carlton Ward, Jr.).

http://tinyurl.com/3qnkaa

I met Dave Maehr for the first time back in, I think, the mid-1980s. He had found a large, hollow cypress tree in the Mormon Branch floodplain of the Ocala National Forest. Because the tree had bear claw marks on it, he wanted to learn whether it was a winter bear den. A positive finding would have been interesting because no other bear den had ever been found in a tree in Florida. The only way to settle the question was to climb the tree, because the only entry into the hollow was through its broken crown.

Bob Simons, Florida naturalist extraordinaire and the friend who taught me how to id and nominate champion trees, told Dave that I had developed a safe technology to climb such forest giants. Dave contacted me and the next thing I knew we were standing in front of that marvelous vegetable. The three of us studied the situation for a few minutes and then the conversation suddenly transitioned into an expectant quiet. I was on.

I cleared out a small area below the tree so a long monofilament line could be laid out without becoming entangled in the greenbriar, and using a bowfishing rig shot an arrow attached to it over a crown limb. An eighth-inch line was then pulled over the limb with the monofilament, and then a static 11mm caving rope was pulled over the limb using the eighth-inch line. I put on my harness and ascending gear, and climbed the tree.

It's a good thing there was no bear inside that tree, as it most certainly would have climbed back out of the tree before I could have changed over from ascending to rappelling gear. Dave assured me that if there had been a bear in there, it would have zoomed past me and down the tree and into the swamp quicker than greased lightning. I guess I trusted Dave lot at that point.

Dave and I had a few more encounters over the years, the last one being an email thread a couple of months ago. When Bob first introduced us, I expected Dave to be like so many other Florida state biologists I had met – that is, rather supercilious toward me, an environmental consultant. I guess I was initially a little offish toward him, which he instantly sensed, but rather than take it on the chin or reflect my attitude back, he used his natural charm to totally disarm me. Within a few minutes we were buddies, so I really appreciate the statement that “[h]e wore out his welcome at the commission.” Certainly, mine is worn out, too.

In our last email communications, Dave allowed me to invite myself on one of his South Florida bear hunting research expeditions. Had I known about his last flight, I just might have been allowed to invite myself along for that ride, too. Scary, that Fate. I wish I could be given the honor to finish the bear book that he was working on. I am retired and have the time, am a fair writer and am confident that Dave left the copious notes it would take for me to do so. It would be the best way that I could honor his memory, his perseverance, his life.

Floridians have lost the man who possibly was the best friend that Florida bears and Florida panthers have ever had. The rest of us have merely lost a loved relative and a great friend.

Red Pit Cave

In planning for the 2009 Florida Cave Cavort, a group of cavers from the Florida Speleological Society met today at Jerry and Shirl's farm a few miles outside of Williston, FL to review the property's characteristics. Jerry had told us that an adjacent property held what might be a cave unknown to cavers, so after we reviewed the property, Shirl walked us over to a clump of hardwoods in a hayfield to show us the situation. Exploring the little hardwood hammock, we turned up a dig site and a hole in the ground.

The hole looked like a solution pipe but was lined almost entirely with red clay. This is most unusual for the caves in that area (known as the “Archer Caves”), as nearly all others have entrances through rock. Most probably, this vertical entrance is a solution pipe through limestone that had filled with red clay (geological detritus from decomposition of the limestone) long ago, and then recently had fallen down into the cave below to create the entrance. The gang felt that vertical gear was needed for the pit, so everyone but me walked back to their vehicles to retrieve their SRT gear.

I felt confident that I could chimney down and back up the pipe, so instead I went to work digging at the other potential cave entrance. It was a small sinkhole that had been filled over the years by rocks and farm trash by former landowners, probably to keep their cattle from falling in. Most of the rocks were cobble sized and easy to dig out, but they were interlaced with tough roots which had to be removed first. The roots were mostly small, but all of them were as tough as wire and had to be cut with my pocketknife. I was unable to rip any of them out by hand, so the going was relatively slow. By the time the others returned, I was drenched with sweat, and Kitty's offer of water was gladly accepted. I just can't believe I went out there without water! Gobble, gobble.

While I was drinking water and catching my breath, Kitty jumped into the hole and continued removing rocks and soil, and was able to get down almost her height (5ft 2in) into the dig. She stuck her leg down through a small hole and reported she felt a void below her feet. Mike and Danny set a rope and lowered it into the nearby pit and Mike descended first. Danny followed him, and then Annette and Kitty. All of them used SRT. I descended last and basically slid down the narrow pipe, holding onto the rope for insurance.

A room appx 65ft long averaging 8ft wide by 7ft tall exists at the bottom of the pit. The floor of this room is mostly covered with breakdown boulders, but here and there are several fissures in the floor leading down to clear and blue Floridan Aquifer water. Mike explored a bit of this lower level, but determined that it didn't go. I studied the water for signs of life, but saw no bullheads or troglobitic crayfish. We surveyed this room and the pit, and Annette took a number of photographs. Danny announced that this cave was definitely virgin, and confessed that this was his first virgin cave exploration.

At floor level near the back of the room, on the right-hand side (facing into the cave) is a low bedding plane “room” approximately 1-2ft high and perhaps 50ft x 50ft or more in extent. Mike, Danny and I explored part of it but did not survey it. It has numerous partitions, speleogens hanging from the ceiling and rocks, which make it look like a maze, but I think it should be mapped a a single room with “obstructions.” This room will take most of a day to survey, and we were running out of time, so we left it for another day.

Everybody but me used SRT to exit the cave, while I just shimmied up the clayey pit, wrapping the rope around an arm for a belay. I exited after Mike, and photographed Kitty, Annette and Danny as they ascended and exited the pit.

We initially decided to call the cave Shirl's Cave, as she showed it to us. Also, the cave on their own property (we thought) was called Jerry's Cave. It turned out that Jerry had named their cave Shirl's Cave, so we needed to come up with another name, which we couldn't decide on. Until we have a better name for it, I am calling it Red Pit Cave.

Flag at half-mast

Sadly, the young red-shouldered hawk didn't make it through the night. It doesn't look like a vertebrate predator did the grim reaping, as the body is whole although infested with fire ants (Solenopsis wagneri = S. invicta). Perhaps the ants did the dirty work. I thought it odd yesterday that the adults weren't strafing me when photographing the young 'un, so perhaps the parents were not caring for it and it starved to death.

Can an owl carry a grudge?

I have often seen songbird nestlings sitting on the ground or in low shrubs, having fallen out of their nest but still being raised by their parents. I leave them alone, as their parents know more than me about rearing their young. In Suburbia, such chicks are often taken at night by neighborhood predators such as cats, dogs, opossums and raccoons. I live in Suburbia.

Today I found an immature red-shouldered hawk (Buteo lineatus) on a levee that runs out into Orange Lake. It was sitting in the grass under a small Chinese elm sapling (Ulmus parvifolia) beside an unoccupied RV. I ran back to my RV for the camera. This was much better than a cardinal (Cardinalis cardinalis) or blue jay (Cyanocitta cristata) waif!

When approached, the bird at first hunkered down, head lower than its tail, possibly trying to remain inconspicuous in the hope that I had not yet seen it. I approached very slowly, and it then raised its shoulder feathers as if trying to look larger and more fearsome.

After I took a few photos, I guess it realized it wasn't in immediate danger, and perked up a bit and I was able to get some better pics. I hope it's there tomorrow morning but, as I have written before, there are barred owls (Strix varia) and great horned owls (Bubo virginianus) in these woods. The red-shouldered hawks hassle the great horned owl every chance they get. Hmmm, can a great horned owl carry a grudge?

I went back a little later and found it under Roger and Jean's RV, with its head tucked firmly under its wings.

Trails in the Dry Marsh

Sunday, June 8, 2008

I have been making paths in the dry marsh beside Orange Lake ever since I moved in last November. They were relatively easy to clear during winter because the flora was dormant, but require more effort now that everything has leafed out. Above is a series of pictures of the main trail located a couple hundred feet from my home. The trail may be a little indistinct in these pics.

The tall, sparse grass is maidencane (Panicum hemitomon), which will grow on dried marsh soil or in standing water several feet deep. When inundated, it is a terrific cover for invertebrates and small fishes and reptiles. With the lake level so low due to the current drought, maidencane is providing cover for mostly grasshoppers, spiders, snakes and rabbits. My favorite spider is the one (Dipluridae?) that made the funnel web amongst the maidencane.

This dry marsh has a relatively high water table supporting the lush vegetation. Several hundred feet north of my trail is a ditch and dike system encompassing a portion of the marsh that once held farmland. It is no wonder early settlers controlled water levels in this and other marshes for food production. Contrasting this with the previous post, I wonder if this marsh will someday again be farmed?

Farming Licenses to Come?

Sunday, June 8, 2008

Back in mid-May, north Florida was under drought conditions (and still is), with lawn watering controls and no-fire rules in place. North Florida normally is in drought every spring (and autumn), but this year's spring drought feels unusually dry. I guess farmers deal with it by either irrigating or not planting at all.

Here's a field in north Florida along CR318 in Putnam County, in sandhills. These deep, nutrient-poor sandy soils naturally support a xeric habitat dominated by longleaf pine (Pinus palustrus), turkey oak (Quercus laevis), rosemary (Ceratiola ericoides) and wiregrass (Aristida stricta). They must be given a lot of fertilizer and irrigation in order to grow food crops. It has been cleared of the original vegetation and was plowed and left fallow over the winter and spring. It looks like a dustbowl.

You can see a rich flora where the soil was not stripped of cover, both on the roadside and in the background. With the human population continuing to rise exponentially in much of the world, farming marginal land like droughty sandhills has even come to the USA, the world's richest country. Can the world continue to allow such poor farmland management? I wonder if farmers will have to get their crop plans approved in the future in order to assure our burgeoning population that farm soils will be sufficiently well-tended to feed us?