Chicago Nature Blog: Vernals & vitality

Before I left for my first trip to Pennsylvania on business, I agreed to an outing with Matt Ignoffo to look for spotted salamanders (Ambystoma maculatum) at one of the few places they are still found in Cook County. However, once I realized I was stuck at the airport in Allentown due to bad weather, I wasn't sure when I'd be home, or if I'd even want to go out in search of these introverted caudates right off a plane. Informing him of my situation, he assured me we'd get out soon enough, even suggesting that the original plan may be too early anyway.

True to his word, he soon offered an alternative date - April 4th. I was excited about the prospect of seeing spotteds again, but actually any amphibian would be great. Until this point in the year, I saw a few snakes, but no amphibians yet. And herping with Matt Ignoffo is like batting against Cy Young. He's done his homework and put his time in the field to become as knowledgeable as he is. He is the one who inspired me to improve my photographic skills. Whether or not I succeeded in doing that is debatable, but it's got me trying anyway.

Matt, his two young kids, and I spent a few hours around a couple vernal ponds in search of spotted salamanders, but to no avail, even though spotteds have been recorded here and are found rather frequently - IF you know how and when to look. We just weren't there at the right time. However, we did find blue-spotted salamanders (Ambystoma laterale) and "Tremblay's" salamanders (Ambystoma "tremblayi"), the latter of which are a polyploid hybrid (specifically, a triploid). Basically (well, as basic as I can put it), the Tremblay's salamander is a cross between the blue-spotted salamander and the Jefferson's salamander (Ambystoma jeffersonianum). But it's not simply one species breeding with another species - those pairings don't typically produce a new species. The Tremblay's salamander is unique is that is contains three sets of chromosomes, two from the blue-spotted salamander and one from the Jefferson's (these hybrid species are often referred to as "JLL", or jeffersonianum/laterale/laterale). A female JLL salamander (the only sex they come in, as if this wasn't weird enough) has to breed with a male blue-spotted salamander in order to produce young, BUT the male's sperm does NOT fertilize the eggs of the JLL female. She basically steals his sperm to stimulate egg development. No genetic information is passed on to the male. This process, called kleptogenesis (klepto as in kleptomaniac), is only known from a few species. Tremblay's salamanders are effectively "sexual parasites", since they are taking sperm of blue-spotted salamanders, which a female blue-spotted salamander needs in order to produce eggs, just like the rest of the civilized world. Another hybrid species, the silvery salamander (Ambystoma platineum, aka JJL), is similar in that it is a triploid, but it contains two sets of chromosomes from the Jefferson's salamander and one from the blue-spotted. Whew! This is like the Maury Povich Show of salamanders.

So, how did these crazy hybrid-species-things get here? Well, they do occur in nature and are widespread. However, the population in Cook County was introduced from its core range all because of a science project gone wrong. Back in the 1970s, a professor studying these salamanders ended up releasing some of them into one pond, and over the last forty or so years, the salamanders have spread and now breed in several nearby vernal ponds. You can still find pure blue-spotted salamanders here, but there are probably more JLL animals here due to their reproductive strategy. I'm not sure what the future holds for these JLL animals, but for now, at least, they are here, and they are in good number.

Also heard and seen on this outing were lots of spring peepers (Pseudacris crucifer) and a few Western chorus frogs (Pseudacris triseriata). And of course, in any open woodland during April in the region you're sure to find amorous Chicago garters (Thamnophis sirtalis "semifasciatus") on the prowl.

A Tremblay's (JLL) salamander

The first garter snake we observed was this massive beast female. She was the recipient of all kinds of battle scars from years past. The full extent of her size isn't realized until another adult garter snake is placed next to her.

Oh what do we have here? As I was photographing the female, this adult male enters the frame with love (or maybe lust) in his eyes.

He quickly traces the outline of her body with his head until he is able to line up his cloaca with hers.

In this shot, the male has commenced copulation. This, folks, is how magic happens with garter snake.

Matt introduces his kids to a spring peeper.

One of several spring peepers found hopping alongside a vernal pond. This particular one inadvertently jumped right into Matt's hand as he knelt down.