Star-crossed Lovers of the Amphibian World
By Nils Anderson
Imagine yourself as a tiger salamander. It’s late April and the last of the spring snow is melting. You dig yourself free of the pocket gopher mound in which you spent the winter, snug and cozy, just beneath winter’s icy grip. As you wiggle and strut your way towards a nearby pond, a resounding chorus of wood frogs greets you.
With no fish in the pond, you’re confident and secure in your position as the top predator. At over 20 cm in length you’re too big a mouthful for even a hungry garter snake. It’s late afternoon, the owls aren’t out yet and the grey-green blotches on your back and sides camouflage you from the occasional northern harrier or red-tailed hawk. When you slip into the cold water, it slows your movements. You stick close to the shore, where the shallow water has warmed up a little more compared to the pan of ice still floating in the centre.
An epic breakfast
This warmer shallow water has also attracted the male wood frogs. They are busily advertising their love in the hopes of attracting mates. Your breeding season is just around the corner as well, but until you track down a partner there’s no reason to pass up an easy meal. Having been asleep for six months—and too cold to move—you’re craving a breakfast of epic proportions. A nice frog egg omelet would be a great way to start the day.
The frogs are close now; you’ve passed some of the smaller males hanging on the fringes of the group hoping to intercept females. A few have been successful, but even here there is competition for matesone poor female is in the grasp of three competing males. One male is so eager that he has grabbed another male. The recipient of this misdirected affection gives a short shrill squeak, and the rendezvous is aborted.
As you crawl over a folded blade of cattail, it hits you.
We're all fools in love!
Strong arms with muscular thumbs have you ensnared in an amphibian bear hug. You struggle to no avail. If only you could make a sound, something to tell your assailant that he is mistaken, but you are mute! Salamanders can’t call like frogs and toads. Soon another set of arms encircles you, and then more until your world shrinks to a mass of male wood frogs, hugging, kicking and struggling with each other for the chance to mate with the biggest female in the pond. The only problem is that it’s you!
Now you are being lifted clear of the water—it’s a strange sensation, and a view of the world that is baffling to you. As you’re slowly freed from the clutches of the frogs, you realize the surface of the pond is almost a metre below you! And what’s this?
You catch a glimpse of your “saviour,” a bearded man in hip waders and a bicycle helmet. The bicycle helmet strikes you as a little odd, but biologists sometimes seem a little odd themselves. But it’s the camera that grabs your attention, as it immortalizes your ultimate shame. Oh no, I hope this doesn’t make it into the ACA newsletter!
On several occasions while conducting breeding surveys for wood frogs in Miquelon Lake Provincial Park, Nils Anderson has encountered groups of between 5 and 7 male wood frogs holding a tiger salamander in amplexus (the amphibian mating posture, where the male grasps the female from behind, using his enlarged thumbs to get a firm grip around her waist). Tiger salamanders have been known to feed on frog eggs, so these confused males may unwittingly be protecting their offspring, although this has not been tested.
Nils is currently working on his Master of Science degree in ecology at the University of Alberta, studying the effects of beavers on amphibian breeding, dispersal and abundance in the pothole wetlands of the Beaver Hills/Cooking Lake Moraine under the supervision of Drs. Cynthia Paszkowski and Glynnis Hood and supported by funding from an ACA Grant in Biodiversity.