The View from Here

Three hundred million years ago, before the Appalachian Mountains were pushed up by continental collision, the first land dwelling vertebrates were living in vast swamp forests. These were quadraped vertebrates, amphibians recently evolved from fish that had adapted to life in the shallows. Salamanders, essentially. Some were giants, several feet long. These creatures continued to evolve and radiate into many new species over many millions of years. Some would develop the ability to lay eggs on land and would become reptiles, eventually radiating into  dinosaurs, birds and mammals. Some would continue to enjoy life at the water’s edge.  Now, 300 million years later, the Appalachian Mountains are the center of salamander diversity, with over 60 species.  They range from tiny species like the Red-Backed Salamander a couple of inches long, to the stream-dwelling giants like the  two-foot long Hellbender and the Mudpuppy. The Asian relatives of the Hellbender approach the size of the ancient giants, at 3 to 4 feet long. Some of these species occupy a single mountain, others range over much of the country.

A Red-Backed Salamander in my ancient stairwell

My backyard in urban Cincinnati doesn’t seem like such a likely place for these primitive creatures. Still, salamanders are abundant in the local woodlands, so it shouldn’t be too surprising that they occupy a niche in my little oasis of wilderness. Some of our neighborhood preserves have what appear to be “original” trees (200+ years old), implying that parts of the woods are virgin. Salamanders from these undisturbed habitats can refill the areas where amphibians were extirpated by agriculture or development, when suitable habitat reappears in backyards across the neighborhood.
The stairwell leading down to my basement is a damp, mossy place. I suppose I should clean out the moss, but I really kind of like it, and now I find that it is a habitat for some of my favorite creatures. The other day I happened upon a tiny Red-Backed Salamander (Plethodon cinereus), sitting on a step, contemplating an isopod that might make a good breakfast. It struck me that the little microhabitat he was in resembled those swamp forests of yore. Mosses and ferns were the predominant plant types in the coal swamps along with giant horsetails. A tiny descendent of those Carboniferous horsetails lives in my garden pond. I could picture the giant “salamanders” slithering about in the swampy waters, with giant dragonflies overhead. The dragonflies are still present as well. My pond and koi tub attract the winged predators, one the of the great benefits of having water in the garden. Of course, they don’t approach the 3ft wing span of the dragonflies of the Carboniferous swamps, but they are colorful and interesting nonetheless.

A Blue Dragonfly suns itself above my garden pond.

Redbacks are not the biggest or the most colorful salamanders in our area, but they might be among the most important. This is simply because of their abundance. They can account for a biomass equal to the mass of all the mammals in a given forest. This fact makes them among the most important actors in the woodland drama. It shouldn’t surprise any biologist that such a tiny, delicate creature has such a dominant role in an ecosystem. After all, the smallest creatures on earth, the bacteria, are the dominate life form. We like to think of ourselves as dominant, but we have only learned to dominate large creatures. We are still at the mercy of bacteria, who account for the most biomass of all living things on earth.

The Red-Backed Salamander strikes me as the Joe-Six Pack of the salamander world. Pedestrian in every way, they are widespread, are common, and have a dominant role in the economy of the forest floor. They are not particularly colorful or striking in any way. They are somewhat unusual in the salamander world because they skip the aquatic stage of life. They lay their eggs on land, guarding them until they hatch. The young pass through the larval stage while still in the egg, and hatch as fully formed, but tiny, salamanders. This might account for their relative abundance compared to other species. By skipping the need to return to water for reproduction, they can colonize wide areas of suitable habitat.

Other species in our neighborhood have more restricted habitats.  The Longtailed Salamander and the Cave salamander both inhabit the deep recesses of wet rock outcrops.

The Long-Tailed Salamander (Eurycea longicauda)

The Cave Salamander prefers limestone outcrops, and the deep caves of limestone areas. Spring Salamanders take after their name, and can also be seen in deep caves as larva.  Some of my favorites are the Red-Spotted newt and the whole Ambystoma genus. This includes the beautiful Marbled and Spotted Salamanders, along with the Tiger, The Jefferson’s and Narrow-Mouthed Salamanders.  These mostly occur in undisturbed woodlands, so they aren’t seen in or near Cincinnati except, perhaps, as isolated relict populations. Woodland streams in the area can host Two-Lined Salamanders or Dusky Salamanders, but both prefer clean water, something not see very often in streams around the city.

The Cave Salamander (Eurycea lucifuga)

Being colorful and somewhat anthropomorphic, they make great subjects for paintings.  I’ve done a few over the years:

"Cave Salamander" 20 x 30 acrylic on canvas. A Cave salamander on the scalloped limestone of a cave wall.

"A Walk Across Time" 32 x 48 Acrylic on canvas. A Red Eft walks across fossils from the swamps of the Carboniferous, where salamanders first evolved.

"The Slimy Salamander" 10 x 8 Acrylic on panel.

"Spotted Salamander" 8 x 10 Acrylic on panel

We’re well into froggy season now, and we’ve seen our second batch of bullfrog eggs. For some reason, both the Bulls and the Greens seem to prefer to breed in the 2 x 4 x 2 koi tub instead of the big pond. There are fish in both the pond and the tub, so go figure. What really puzzles me is how the frogs find the tub. The water is not visible from ground level (the tub is 2 ft high) and there is no water noise of any kind. It doesn’t seem like instinct would lead one UP to water. They must either be able to sense the water, or they just explore a lot and found it by accident.

The frogs have been especially noisy this year, which hasn’t bothered the neighbors as far as I know. The bullfrogs can be quite loud at times.  When the males are singing, they puff themselves up with air like a balloon so that they float high on the water. When they call, the air transfers from their inflated lungs into the ballooning throat as if an invisible hand was squeezing him like a balloon. While in this inflated condition they seem to be especially agitated, charging and barking at other frogs. Ahhrummm!

An inflated male Bullfrog. This is a stereo photo. Cross your eyes slowly and merge the images to see it in 3D!

The eggs develop very quickly, hatching tiny black tadpoles in about 3 days, but it takes two years to get from egg to frog. Right now, I have tadpoles morphing into frogs in the big pond, survivors of eggs laid in 2007. There are several dozen little frogs visible at any time, and big tadpoles frequently rise to the surface. The big bullfrogs are getting fat by eating little frogs, but every year I see a few that survive to sub-adulthood. Out of the thousands of eggs laid each year, only a couple will survive to produce the next generation. In a larger pond, the tadpoles would have slightly better odds, but the percentage of survivors in nature is always low. This selection for survival keeps the frogs healthy and the population at a sustainable level.

New Green Frog eggs

Developing into tadpoles...