Chapter Seven—Reptiles & Amphibians—The Crawling Things!
Midway through the 10-month classroom portion of the Maryland Master Naturalist training program, we arrived to the classroom at Adkins Arboretum to find Dr. Scott Smith, a wildlife diversity biologist, but a de facto herpetologist (snake dude), surrounded by all manner of containers, bowls, and cages.
Dr. Smith started his talk with a refrain I am hearing again and again—with such a diversity of geography and geology, the state of Maryland has a wide diversity of habitats, and thus a wide diversity of “herps” (reptiles and amphibians). Herps, from the Greek word herpeton, meaning “crawling animal,” is a short-cut nickname for creatures that are ectothermic—they get their body heat from their environment. We spent some time discussing and considering the impact of this basic physiological fact.
Another early lesson in the class has cleared up for me a confusion I’ve always had—amphibian or reptile? Well, another Greek word contributed to clarity: amphi, meaning “both” and referring to the fact that amphibians live a double life. They are born of water but live primarily on the land. Think frogs, toads, salamanders (whose tadpoles have branching gills to support their early, aquatic days). Amphibians are a good indicator of both forest quality and water quality, so my pleasure at seeing frogs happily using the backyard goldfish pond may be underscored by knowing that I am providing some habitat as well (the local blue heron also seems rather pleased with the situation).
We next spent a few minutes reviewing the importance of SKIN. As in humans, skin is a large organ (as organs go) and another good way to tell amphibians from reptiles. Amphibian skin is scale-less, tends to have lots of mucus, and their toes do not include claws. Reptiles have scales (including a turtle’s shell, whose pieces are called scutes, another new vocabulary word) and their toes, when present, do have claws. The mucus on an amphibian plays at least four roles: escape, toxicity, antibiotic, and respiration.
Before we plunged into identification of specific species, Scott reviewed some ecological issues and introduced us to the idea of species richness maps. There are 69 species of herps on the Eastern Shore, for example. A few more vocabulary words were added to the growing pile: Caudata (salamanders), Anura (frogs), Squamata (lizards and snakes), fossorial (living underground), and hydroperiod (the length of time a vernal pool holds water).
While Maryland has good laws to support wetland area buffers (to help protect the critters), the creatures themselves use “life zones” and are not aware that they will be protected only within certain human-set boundaries. Terrestrial habitats, mostly hardwood forests, are the most important for herps. We reviewed six threats to herps (habitat loss, environmental pollution, disease & parasites, unsustainable use, global climate change, and invasive species), and Scott referred us to Partners in Amphibian and Reptile Conservation for more information on how to get educated and involved.
Next, we got to take a look at all the creatures that were sharing the classroom with us—with tips and ideas as a sort of crash-course in identification. Salamanders came first—known as “walking tails,” they typically have a neck, and you can count their costal grooves (between the front and rear legs). Scott forgot to tell us how to politely ask the salamander to roll over and show us its costal grooves, but we pressed on.
Frogs versus toads came next—frogs have relatively long legs and smooth skin; toads have shorter legs and warty skin.
Turtles brought two more vocabulary words: carapace (top shell) and plastron (bottom shell) and a brief mention that the amount of the bottom shell varies depending on use—for example, snapping turtles don’t need as much protection because they have other means of defense.
On to lizards, with a note that lizards came before snakes, evolutionarily. Snakes can have keeled or smooth scales, and you can tell the difference even from a cast-off snake skin (which is actually inside-out when you find it). Once again, identifying a venomous from a non-venomous snake involves checking out the subcaudal (under the tail) scales—“excuse me, Ms. Snake, would you please show me your subcaudal scales so I can classify you?” We met Scott’s corn snake, Carl, who was a little less colorful than usual because he (Carl, not Scott) was getting ready to molt (ecdysis).
At this point, Scott detoured a bit to encourage us to start keeping a field notebook—he showed us a couple of his—and reminded us to include details, details, details, such as date, weather, exact location, habitat, and even photo and GPS (latitude/longitude) coordinates. I was reminded of my love of Beatrix Potter’s writing and drawing and her lifelong habit of keeping a field journal.
Back to identification strategies, and we learned about (and looked at) a spotted salamander, a red-spotted newt, an eastern red-backed salamander, a four-toed salamander (only the rear foot has 4 toes), an eastern spadefoot, Fowler’s toad versus American toad (count the spots on the warts to differentiate), New Jersey chorus frog, northern spring peeper, Cope’s Grey versus Northern Grey tree frogs, wood frog, southern leopard frog, pickerel grog, northern green frog, bullfrog, eastern fence lizard, skink, northern watersnake, garter snake, ribbon snake, black racer snake, rat snake, and copperhead snake. In addition to looking at these animals, we also listened to many of their vocalizations. Whew!
After our lunch break, we came back into the classroom to find four stations set up, each with 5 or 6 questions on cards, propped in front of a creature or some part thereof. We broke into four groups (I was the secretary for the Lizards) and spent 10 minutes at each table, trying to identify what we were seeing—we had our notes and some field guides to help us, plus the excellent “four brains are better than one” approach. After each group had a chance to work at each table, we compared notes and scored our efforts. Scott had thrown in a couple of very tough examples, but the idea of this “quiz” helped us to really approach the process of identification as much as actually getting an answer.
I found myself glad, once again, that our class only meets once a month because there is so much material to incorporate into my thinking; I am exploiting the opportunity to go home, review my notes, try to identify the creatures I find in the backyard, do some online readings, etc. Even in 10 full days of training, there is a LOT of information to cover. We were so pleased to spend the day with Scott Smith and all his herps!
by Beth Lawton
Maryland Master Naturalist-in-Training
Photos courtesy of Beth Lawton; lizard drawing by Beatrix Potter.