Thursday, October 29, 2015

Cave Salamander

An old springhouse seems to merge with the forest that surrounds it. This isn't any old springhouse, though. Sited in the hills near western Cincinnati, the 166 year old structure is bank vault solid, its thick limestone walls probably destined to last another century and a half, or more. In a minute we'll go through the creaky wooden door at the bottom right, and meet the building's special inhabitants.

FOOTNOTE: Springhouses are usually simple structures, typically made of rock, that were built over springs. Their main purpose was to protect the emergent spring water from debris or contaminants, and exclude animals. As the cool water also keeps the interior of the springhouse at a consistently low temperature, at least when compared to outside air during warm periods, they also served as a mild form of refrigeration for perishables.

I recently received an irresistible invite from herpetologist Jeff Davis, one of the authors of the new Amphibians of Ohio book. Would I like to join him on a visit to see a population of one of the rarer of Ohio's 25 salamander species? Of course! So last Sunday, I met Jeff and off we went to document Cave Salamanders, Eurycea lucifuga.

Immediately upon entering the dank gloom of the springhouse's interior, we were greeted by Cave Salamanders. A few dozen clung to the moist limestone walls of the building, regarding us with inscrutable smoky eyes. The animals were not put off by our appearance in the least, and we were able to obtain a careful count, and make documentary photos.

Cave Salamanders are at the extreme northeastern limits of their range in Ohio, and nearly all of the relatively few populations in the state are in Hamilton County. There are also a few in neighboring Butler County, and one in Adams County.

These sleek amphibians are well adapted to a world of tight cracks and fissures. This one later disappeared into the slight gap surrounding the wooden dowel that it's perched by. While Cave Salamanders do indeed inhabit the perennial gloom of cave openings in much of their range, that's not the case in Ohio. They are found along small streams incised into fractured limestone bedrock, with an abundance of subterranean groundwater. These sorts of haunts are really not that different than a proper cave - there are plenty of fissures and crevices in the rock that the salamanders can occupy.

A Cave Salamander is an amphibian of great beauty, by almost any standard. Bright orange-red skin is stippled with ebony dots and dashes, and the animal possesses a graceful elongate shape. It would be interesting to better understand their long-term evolutionary history. Why would an animal that seems to live nearly its entire life in habitats so dark that eyes can't see, be possessed of such bright color? Many true troglodytean animals have devolved coloration, and are white or very pale. It would seem that Cave Salamanders, up until very recently (on an evolutionary scale), were much more of an above-ground inhabitant.

Jeff holds a ruler to document a big 'un. Pulled straight and taut, this Cave Salamander probably would have taped out at seven inches. That's about as big as they get.

Give a Cave Salamander enough time - years, for sure - and they can get as large as the one in the preceding photo. But life begins as one of 75 or so eggs, and when the larvae hatch, they look like this. A tiny whitened grublike object that most of us probably wouldn't notice, or if we did wouldn't recognize it for what it is. Jeff found several of these hatchlings in pooled water on the floor of the springhouse, and fortunately I had Canon's MP-E 65mm mega-macro lens in my bag, and could make some images. I think this one was about 7 mm in length.

Before long the white grublike larva loses its pale coloration, develops patterned pigmenting, and begins to look much more like a salamander. If memory serves, this one was about 17 mm or so in length.

After we finished documenting the animals in the springhouse's interior, we moved outside to some nearby cisterns. These are just small subterranean tanks for storing water, and in this case the cement cisterns were five feet or so deep, with a chamber at the bottom.

As soon as Jeff popped the lid off the first cistern, there were salamanders. In all, we counted a few dozen in the two cisterns. This photo shows only 15 of the 74 animals that we saw this day. It is still more Cave Salamanders, by a long shot, than the vast majority of humans will ever see.

We gently netted all of the cistern-dwellers, and in assembly line fashion made documentary photos of each animal's dorsal surface and face, then quickly returned them to the cistern. Every salamander has a unique pattern of spotting, and by amassing sharp digital images Jeff can document and identify the individuals in the population. Thus far, he has found at least 1,390 animals at this site.

We also took a mug shot of each - an image that shows the face well enough to determine the sex. If it is a male, as this one is, it will have a pair of tiny toothlike appendages known as cirri (singular: cirrus) projecting downward from the upper lip. They are small but easy enough to see in this photo. Note also the flattened head, which is a good adaptation for an animal that habitually travels through tiny crevices.

I appreciate Jeff taking me along on this expedition, and letting me help with the work. And great gratitude goes to the owners of the property, who are proud of their rare salamanders and want them protected. I wish everyone had their attitude - the world would be a far better place.


Anonymous said...

Hi Jim. This is a very special read and pictures. Often, some of us never in our life would not see something like this. Thank you for sharing. Gary Wayne

Ryan Lange said...

Incredibly jealous. I've never made it down to lucifuga country to dip any herping, and despite travels all over the Ohio range for long-tailed I haven't been able to find any of those yet either. This is a really fantastic blog, Ohio is a real hidden gem for the outdoorsperson.