Monday, April 9, 2012

Eastern Newt (Notophthalmus viridescens viridescens)

Also known as the Red-spotted Newt, and the terrestrial phase in the photos below is called a Red Eft – learn more about this amphibian's complex life cycle at Ontario Nature.

After four years of searching in vain and rolling over countless rocks and logs without finding so much as a single Red Eft, yesterday I found four of them hiding under the same decaying branch near a beaver pond east of Highway #37, about one kilometer south of Actinolite.

This one must be shy and doesn't want its picture taken.

A Red Eft in my hand to impart a sense of its size, they are quite small, no more than an inch and a quarter long at the most.

Don't eat me! I'm poison! The undersides of these tiny sub-adult newts are an even brighter shade of orange than their dorsal surfaces. Many amphibians bear toxins or distasteful chemicals on or underneath their skin as a defense against predators, and Red Efts do as well – tetrodotoxin, a very common toxin in nature, and the same poison found in pufferfish. While a few animals are immune, most hungry hunters have will pass a Red Eft by and look for a meal that's better for their health.

Accompanied by Elinor, Megan, and her husband Jason, I made a return trip to the beaver pond where the Red Efts were encountered. Dredging through the dead leaves in the bottom of the pond with a net, Jason managed to capture two adult Red-spotted Newts, and what was to all intents and purposes a Red Eft that had recently returned to the water to make the transformation to adulthood.

A lateral view of the adult Red-spotted Newt. This is a male newt, note the swollen cloaca at the base of the tail, the most reliable means to distinguish the sexes. This male is not in full breeding condition, in that case the tail fin would be much wider, and there would be black excrescences along the inner surfaces of the hind legs, as seen in these photos at CMNH Future Scientists.

A ventral view of the male newt.