It was 11 p.m. on a moonless night. With spring in the air, the chorus of Northern red-legged frogs calling from a nearby pond was intermittent but loud. I was accompanying a researcher who was documenting the location, quantity and variety of frog calls all over Bowen. We drove slowly, stopping frequently so that she could get out of the car and disappear off in the direction of the calls. I always enjoyed these evening forays around the island. For many of us, there’s something mesmerizing about a frog chorus. We notice the sounds of the frogs, and we see the frogs, but what you may not realize, is that frogs are not the only amphibians that share this island home. Nearby are quiet cousins.
With the data collection done for the night, I turned the car back down the dead-end street and crept the car along at a walking pace for any last minute research.
As slow as I’d been going, my sharp-eyed passenger stopped me within a tail length of an almost translucent little creature on the road. We jumped out of the car. While there is protocol regarding the handling of amphibians so as not to spread disease to them, this one was at risk of being run over. It walked gently onto my hand, a perfect match in size between my hand and its full body length. We marvelled at the delicate Oregon ensatina salamander.
Unlike the nearby frogs, this amphibian was not a semi-aquatic species, but a forest-dweller who, like so many creatures that hide in our forests, is rarely seen. They vanish from sight under decaying leaves, bark and fallen trees; venturing out only after the bright daylight has slipped away.
It’s the dampness of the forest floor and decaying plants that allows the lungless ensatina to absorb oxygen through its skin. The damper and rainier, the more likely it is to come out on the surface without risk of its skin drying or freezing. The more extreme the heat or cold, the deeper these soft-skinned animals dig into the depths of the soft forest floor for protection.
Finding an ensatina on the road was a surprise. They prefer cover, and are sensitive to disturbances, like the knocking over of their log, or the raking up of leaves that provide protection. They will venture out from debris, mostly in the evening to munch on a variety of insects and tend not to travel far.
Adapted to dark conditions, their eyes are bulgy and big, while their bark-coloured skin helps them go undetected against leaves and twigs. This one was almost undetected because of the darkness. The animal now looked around at the situation and reached out with long toes and long legs, intending to be on its way.
Seemingly unthreatened, it wasn’t excreting poison, which comes from parotid glands behind its head or from an the area on its tail. Nor was it arching its tail, trying to look threatening to any perceived threat. The tail in this salamander is distinctive, with a constriction at the base of the tail. Another survival strategy to distract predators is to drop the tail. It’s a desperate measure as the tail holds fat reserves to get the salamander through the winter. If the tail drops in the fall, the loss of the fat stores is more harmful but the tail will regrow.
The salamander on the road may have been wandering in search of a mate. Like birds, our ensatinas lay eggs, an average of eight to ten that hatch in spring. The females curl up around their eggs, guarding the pebble-sized spheres through to hatching for three to five months, taking breaks to feed until the young hatch at the end of summer. The offspring are a miniature version of the terrestrial parents.
There is a wide variety of ensatinas along the coast and slightly inland, but only the Ensatina eschscholtzii oregonensis is found on Bowen. It is vulnerable to people moving the logs and leaves and mulch under which they live. They can be squished by heavy feet and hurt by sharp claws of pets that hunt, run through or dig in the forest, and by pesticides, herbicides, and anything that also harms the insects and insect habitat that hosts their prey.
The first time I saw an ensatina was in a partially developed area with small single-lane roads. I peeked under a fallen log and thought that I was looking at some worms. Wonderfully, I realized I was looking at two small salamanders, sleeping together. I quickly covered them back up before they had a chance to awaken. Unfortunately, that habitat has since been blasted with explosives to make room for development. On the west side of the island, where many types of amphibians could be previously heard and found easily, developers are clearing swaths of forest for roads and paths. Densification is taking its toll on species in ways that we may never know. While it’s true that new trees can grow around the edges of house lots and along streets, for the ensatinas curled up around their eggs, sleeping, or hiding under debris, dropping a tail doesn’t protect them from a bulldozer or tires.
What we can do
Find ways to protect habitat. Refrain from using herbicides and pesticides that kill the food required by amphibians. Refrain from using dirt bikes and ATVs, and other things that damage the soft forest floor and mulched trails and instead find recreation on hard-packed gravel paths outside of the forest. Avoid going off-trail in the forest. Don’t let your pets dig after ground-dwelling species and try not to disturb rotting logs in the undergrowth.
Generally do what you can to reduce your footprint. Don’t release non-native animals into the wild and don’t dump fish tanks or tanks from pet-shop amphibians that could contain pathogens into the outdoors.
As a landowner developing one or multiple properties, consider leaving untouched forest as much as possible. Habitat loss is the biggest threat to island biodiversity. Let tree branches, logs and leaves remain in the ecosystem following a cycle of decay and replenishment of the earth.
Though found commonly along the B.C. Coast, Vancouver Island and down to California, for the ensatina on this island, unlike its mainland cousins with more unconstrained territory, there is no genetic inflow to keep our native species replenished.
