Friday, March 12, 2010

The run of the salamanders

Up from the primordial ooze, a Spotted Salamander, Ambystoma maculatum, unerringly hones in on its ancestral breeding pool where it will mate, deposit eggs, and then return to its subterranean lifestyle.

Perhaps no passage of spring is more fleeting than the overland migrations of mole salamanders to their woodland breeding pools. Mole salamanders are large species in the genus Ambystoma, and for all but a few days they live out of sight under the earth. Each year with the first warm evening rains, these underground dwellers rise up from the earth and make fantastic voyages to pools where they will complete their life cycle, and do their best to ensure that their kind remains. I suspect few people know about this phenomenon, which is truly one of Nature's most interesting events.

I knew last night would be good, and it was. Dave Hughes, Laura Stalder, and Skip Trask met up with me and off we went into the wet rainy night to some hotspots near Bellefontaine. Following are some photos from that adventure.

The phrase Nature Deficit Disorder is everywhere. I just wish we could get all kids out on a night like this, and maybe more of them would become interested in our natural world. Nocturnal exploits are always full of surprises and interesting stuff; way better than sitting around the tube. This was one of two Virginia Opossums that we encountered; this individual allowing for close approach. Looks like the tip of his bare tail got frostbitten and dropped off; not an uncommon malady for opossums.

While cruising the roads, I saw a flash of movement along the verge, stopped, and leapt out to discover a Meadow Vole. These are nature's french fries for raptors, and this little dude ran onto the roadway where, disoriented, it proceeded to race madly in circles. We placed him back in the grasses and off he tunneled into the vegetation.

Star of the amphibious show are the Spotted Salamanders with their brilliant yellow dots. This is still a common species, and we saw lots of them. This one, like most of the other shots, was taken on the road, and such crossings are incredibly perilous for salamanders. The routes that salamanders take to their breeding pools are ancient and etched into their DNA. Slap a road or other obstruction in the path and they'll do their best to cross it.

Unfortunately, this is all too often the result. Mortality can be extreme; amphibians are just no match for cars. Every spring when I make these trips, I see lots of smashed salamanders. This one almost made it, just getting clipped; most are utterly flattened.

This is the other big threat to the salamanders and other denizens of vernal pools - outright destruction of their habitat. We were dismayed to find that a logging operation had just been established in one of the best swamp woods in the area. Prior to European settlement, wooded swamps abounded; an enormous percentage of them have been destroyed.

A bizarre "unisexual" salamander crosses the road. At this site, there are many, and there is still much mystery about their life history. The unisexuals at this site seem to be a mixture of Jefferson, Smallmouth, and perhaps Blue-spotted salamanders. All are female, and they have extra sets of chromosomes and often display features of several species.

This is a Smallmouth Salamander, Ambystoma texanum, which is still common over much of the state. They can have beautiful bluish-porcelain flecking along the sides, as this individual does.

Like a tiny Kimodo Dragon, a unisexual salamander rears up to inspect me. Compare this photo with the next.

Smallmouth Salamanders are similar in their lead-gray ground color, but have a tiny rounded face because of the short nose projection.

Misfortune befell the only Redback Salamander, Plethodon cinereus, that we encountered. Part of its tail was neatly severed, illustrating the myriad dangers that salamanders face when they leave their element. Redbacks are abundant; often the most common woodland salamander, and can often be found by turning logs. They don't stage the incredible en masse migrations of the mole salamanders, though.

That Redback Salamander may have lost its appendage to one of these, a Rusty Crayfish, Orconectes rusticus (at least I think that's the species). It's common to find crayfish moving overland on wet nights, too. Their pinchers are powerful, and this one got me good as we transferred it for photo ops. They make quick work of salamander tails.

We observed many Red-spotted Newts, Notophthalmus viridescens, one of our most interesting salamanders. Gimlet-eyed and unafraid, newts casually swagger along, confident in their ability to thoroughly poison anybody stupid enough to eat one. This is our only salamander species that thrives in ponds with fish, as their toxins are powerful enough to dissuade the fish from wolfing them down. Newts are excellent swimmers; note the laterally compressed muskrat-like tail, an adaption for aquatic life.

This is a Red Eft, the larval stage of the newt. We didn't see any of these; I just threw it in to show the contrast between the life stages of the adult and immature. Efts are completely terrestrial, roaming the forest floor for up to three years before transforming into the somber olive hued adult and slipping into the water for the remainder of their lives. I took this photo in the highlands of West Virginia; it seems that the higher the elevation, the brighter the eft.

The evening soundtrack was punctuated with the loud voices of frogs. This is a tiny Western chorus Frog, Pseudacris triseriata. Thier song sounds like someone running a finger down the teeth of a comb, albeit highly amplified.

Spring Peeper, Pseudacris crucifer. Peepers are abundant and they were everywhere, their astonishingly loud birdlike notes ringing out from any and all wet spots. So loud are these miniscule frogs that if you get yourself in the middle of a calling assemblage, it will literally hurt your ears.

We can see the elfin scale of a peeper; an amphibious David in the hand of a Goliath. When you hear the peepers and chorus frogs, you can be sure that winter has passed.

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5 comments:

Joan said...

Wonderful photos....

The night air here (N Georgia) is finallyh full of Spring Peeper and Southeastern (formerly Upland) Chorus frog calls.... It'd be time to put the ear plugs in but the calls so welcome after the silent winter

Russell Reynolds said...

You have captured my interest in these neat little critters. Love the photographs . Man , what personality they have. Awesome stuff Jim. You are right , youngsters are missing out on some really cool stuff.

Jared said...

Among my favorite natural events in the world!! I'm trying to get my friend to bring her kids out tonight if it rains to view the salamander migration...they'd love it!!

Cathy said...

Terrific.

Everything. Photos and interesting facts.

Dang. I'm 63 and I've never have seen these critters (salamanders) - plenty of frogs and possum.

Gotta get crackn'.

OpposableChums said...

Excellent post and pix. Thanks.