Photo Caption: Like a lacy glove that’s been cast aside, the shed skin of a tiger salamander floats in a dish of water. Note the keratinized tips of the toes, which aid in digging and gripping.
March 17, 2017
If you’ve ever visited Hickory Knolls, you probably noticed that we have a lot of snakes. Snakes in the lobby, snakes in the exhibit room, snakes in the classroom. If we had a plane, we’d probably have snakes there too, albeit without Samuel L. Jackson and Julianna Margulies along for the ride.
All our squiggly friends are captive-bred donations, and as such portray an important part of our education mission, which is to remind people that wild things need to stay in the wild; conversely, pet animals need to remain as pets, and not be released or “given their freedom.”
Yet, education mission aside, the fact remains that we’ve got a building full of snakes. Such a backdrop usually prompts visitors to ask lots of snake-related questions. No. 1 among them has been, and likely always will be, “Are they poisonous?”
The answer to that query is twofold. The first part is, “No,” and the second part weaves in a little explanation on the difference between poisonous and venomous. (Short answer: Poisons are either ingested, inhales or touched, while venoms are injected. Picture poison ivy and poison dart frogs, vs. bee stings, spider bites and snake bites.)
The No. 2 question usually addresses the topic of snakes shedding their skin. How often, how long does it take, do they eat their sheds? The respective answers are, “It depends on their age and growth rate, and whether they are trying to heal a wound;” “about a half hour;” and “no.”
The people asking the questions typically are happy with our answers and take away some newfound knowledge. But every once in a while, we like to ramp up our interpretive message with an extra statement along the lines of, “You know, snakes aren’t the only animals that shed their skins…”
From there we might launch into a discussion of exoskeletons, and how virtually everything with a hard outer shell – critters like insects, spiders and crayfish, to name a few – shed their skins, or cuticle layers, too. A molt from one of our tarantulas is often used to illustrate this point, and if someone wants to see more we’ve got a whole box of assorted shed “parts”—cicada shells, butterfly chrysalises, dragonfly exuviae (from the Latin for “things stripped from the body”)—that we can dip into and provide, if not hours, at least several minutes of entertainment and education.
However, every once in a while, if a visitor is really lucky, he or she might be treated to the pièce de résistance among molts…the cast skin of a tiger salamander.
I suppose I should mention that in addition to the 13 snakes that call Hickory Knolls home, we have an assortment of Ambystoma tigrinum that have come to us through various means. People are often quite curious because, although common throughout our area, tiger salamanders tend to stay underground for much of the year (they are part of a family known as the mole salamanders) and hence are rarely seen.
But what’s even more unusual than seeing a salamander is finding their cast skin. The outer epidermal layer comes off in its entirety, like a snake, but instead of being dry and scaly it is soft and very fragile.
Some amphibians actually eat their cast skins. I remember once watching a captive green frog shed its skin. When I first walked into the room, I thought something was dreadfully wrong. The frog was puffed up, like he’d just swallowed a golf ball, and he appeared to be breathing heavily and in distress.
I next noticed a translucent material about his mouth. Good heavens, I thought, what could this slimy discharge be?
As I continued watching, though, I noticed that the frog wasn’t expelling the slime, he was consuming it. Using his little froggy feet, he was methodically pushing the gooey strands into his mouth and swallowing them. Slowly—ever so slowly—the dim lightbulb in my brain began to brighten. The frog was molting and, not wanting to let good protein go to waste, was eating the cast skin.
I’ve heard that salamanders will consume their molts too but I’ve yet to observe that activity. The captive animals I’ve watched instead crawl out, like a sausage exiting its casing, and leave the semitransparent skin behind.
Our salamanders don’t seem to be interested in their sheds, but we certainly are. In fact, we added one to our collection just the other day. We certainly wouldn’t want to let a perfectly good molt go to waste.Amphibian, Good Natured
Photo Caption: Woodpecker species in our area have begun drumming, an annual sign that their breeding season has begun. The loud, staccato pounding is used to declare territory; it is distinctly different from the softer pecking sounds the birds create when excavating a nest cavity or foraging for food. Photo credit: Robert Burton, US Fish & Wildlife Service
Signs of Spring
March 10, 2017
How good are you at reading signs? Admittedly, some are easier to pick up on than others. Big red stop signs, for example, are pretty unmistakable (for most people, anyway.) Flashing neon can be hard to miss, too.
But other signs are more subtle, even though they’re all around. And right now, we’re surrounded by a bunch; they’re nature’s undeniable signs of spring. Here, in handy checklist form, are 10 of our naturalist department favorites:
- Woodpeckers, both male and female, are drumming. Listen for the rapid-fire rat-a-tat of our local species as they pound on hollow trees (and gutters) to declare territories.
- Daylight is lasting longer. Hard to believe, but we’ve added more than 100 minutes to our day length since the winter solstice back in December. Plus, we’re less than two weeks away from the spring equinox, March 20, when day and night will equal each other at 12 hours apiece.
- Canada geese are pairing off. They still prefer the safety of the flock at night, but these ever-present members of our suburban landscape have started “dating” during the day. Look for pairs feeding just ever-so-slightly away from each other in areas where that longer-lasting sun has melted the snow off the grass.
- Love is in the air. Have you smelled it? Thiols, the “active ingredient” in skunk spray, have permeated most of our neighborhoods at one time or another this season as Mephitis mephitis (Latin for Stinky stinky) goes about its courtship and mating rituals.
- Skunks aren’t the only mammals in reproductive mode. Squirrels, raccoons, opossums, foxes, coyotes…all have nearly completed their breeding activities and will soon be prepping nests and dens for the arrival of offspring.
- Male redwing blackbirds have returned. Competition is stiff among these marsh denizens, which happen to be polygynous (one male, many females) and the early birds definitely claim the better territories. They’ll defend them fiercely throughout the breeding season. (Remember this come June, when the news will no doubt include reports of redwing “attacks” on unsuspecting folks strolling too close to a well-hidden nest. Want to ward off a strike? Stare down the little stinker. RWBBs won’t fly towards eyes.)
- Spiders! Next time the sun is out, find a patch of ground where the snow has melted and leaf litter is plentiful. Bet you’ll find spiders there, tiny little guys stalking even tinier insect prey.
- Male American goldfinches are brightening. Throughout the winter months, these guys have flitted about in drab olive-yellow. But with spring just around the corner, their plumages are beginning to change. Soon they’ll be bright yellow, just as their nickname “wild canary” implies..
- Maple buds are swelling. Live near a silver maple? Those giant blobs on the ends of the branches are this year’s leaves, coiled up in buds awaiting the first rush of sap. A few more warm days and cool nights and things should really start popping.
- Skunk cabbage is up. Our earliest blooming wildflower, Symplocarpus foetidus, has popped up in wetlands throughout the TriCities. Chemical reactions allow this plant to generate temperatures 15 to 35 degrees warmer than the surrounding air. In years where we actually have snow, this reaction would help melt any flakes covering the plant. But it also serves another purpose, helping skunk cabbage spread its stinky (or fetid, as referenced in the Latin name) aroma and attract the carrion-feeding insects it requires for pollination.
I suppose I could go on and on, for more signs of spring are just around the corner. Early breeding frogs and salamanders already have made their way to breeding ponds. And soon comma, question mark and morning cloak butterflies will emerge from diapause, the insect version of hibernation.
But now my phone is ringing. And that’s a sign that it’s time to stop with this talk about signs…at least for now.Bird, Good Natured, Spring
Photo Caption: This time of year, Chinese mantid egg cases are pretty easy to find. Look for squarish forms, about the size, shape and color, of a toasted marshmallow, attached to plant stems in gardens and natural areas.
March 3, 2017
I suppose we all have different ways of coping with winter doldrums. Even though this winter has been far from dull—or wintery, for that matter—it’s still nice to have a few traditions that remind us that when winter comes, spring isn’t far behind.
My mom, for example, grows an amaryllis every January. In fact, this year she’s supplementing that giant bloom with another indoor bulb-growing venture, a lovely purple hyacinth.
Meanwhile, at Hickory Knolls, we are cultivating new life of a different sort: a fresh batch of Chinese mantids.
Our latest foray into mantid-raising (we’ve had several, what, clutches? Litters? over the years) began somewhat unexpectedly about three weeks ago. I wasn’t in the office at the time but received a text from my amazingly tolerant coworkers that read, in part, “You’ve hatched! Baby praying mantis all over!!!!”
Yes, those four exclamation points were part of the text. For added emphasis, I guess.
At any rate, when I arrived at work I found an aquarium sealed up tight with paper and packing tape, all the better to contain the 200 or so little buggers that were popping out of their egg case like puppies scrambling through an open gate.
Hundreds and hundreds of puppies, that is, furless and six-legged, but otherwise just as cute as any baby dog.
Their former home, an ootheca, or egg case, was one of several collected by our coworker, restoration ecologist Jill Voegtle, a month or so ago. At first it might seem odd that we’d want to remove the cases because, after all, they’ve been touted for decades as an effective means of biological insect control. With these guys on duty, we in theory would have less need for pesticides. And fewer chemicals mean a healthier environment, right?
The only problems are that: a) Chinese mantids eat plenty of beneficial insects too; b) large females also consume vertebrate prey, including hummingbirds and small snakes; and c) they’re not native and, as such, have the potential to outcompete our native arthropod predators like spiders, assassin bugs and ambush bugs.
So Chinese mantids aren’t welcome outside. But they make for a really compelling display inside.
Shortly after that first egg case hatched, we dismantled the packing tape-sealed aquarium and set up our 200 bundles of joy in a fine-meshed insect rearing container called a Praying Mantis Pagoda.
Since then we’ve seen quite a bit of attrition, which at first might seem like our little habitat is failing. But such loss actually is a praying mantis rite of passage. In the wild as well as in captivity, stronger individuals consume their weaker brethren.
As of this writing we’re down to about a half dozen young mantids. Each survivor has staked out a territory within the enclosure and guards it carefully. Now that the little guys are a bit bigger, they’re less inclined to feed on each other, and more apt to pursue other prey, which we’ve provided in the form of flightless fruit flies—the mantid equivalent of puppy chow.
It’s been pretty awesome watching the little guys grow—and the fun doesn’t show any signs of slowing down. We have six more egg cases that have yet to hatch, and that’s assuming Jill doesn’t come across any more as she trims and prunes the vegetation outside the nature center.
You know what’s also neat? We don’t have a monopoly on mantids. You too can raise one, or some, as indoor pets. All you need are some egg cases—which you can collect freely, as they are not native—and a small container. Before we received our pagoda, we used to use a gallon-size plastic pretzel jar, rubber-banding a square of screen in place of the lid. You can buy flightless fruit flies at pretty much any pet store, or you can raise your own flighted flies by letting some bananas age past their prime.
By the time the mantids need larger prey, our local insects should be starting to show themselves. Small grasshoppers are good options, as are cockroaches. In a pinch you can also buy pet store crickets.
Chinese mantids aren’t quite as showy as amaryllis blooms, nor as fragrant as hyacinths. But there’s something very fulfilling about raising one to adulthood. Plus, they’re darn cute, like furless, six-legged puppies…Good Natured, Insect