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Article
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The Amphibians at the Fluvarium
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(This article was first published in Spring 2002, once in the "In Pippy Park" newsletter, and also in 50+ Seniors magazine)
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By Llewellyn Thomas
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Frogs and toads are not native to Newfoundland. The first frogs arrived on
the island in the 1860's, having been brought here by settlers and visitors who
wanted something familiar in this strange new land. Toads arrived much later,
around 1960, as an apparent (albeit not technically legal) experiment to see how
they would do in Newfoundland's climate. Neither species was capable of crossing
the salt water surrounding the island, and thus were never able to migrate here
on their own. Besides the American toad, three other species of frog were introduced
at the same time: the Wood frog, the Chorus Frog, and the Northern Leopard frog.
Green frogs (Rana clamitans) have successfully settled just about everywhere on the
island. They provide, among other things, food for local wildlife, an effective
biological predator of insects (said mosquitoes and black flies), and of course,
endless hours of joy and wonderment to those of us who just enjoy watching frogs
in their natural environment.
American Toads (Bufo americanus) are located in several areas of the island, mainly
near the Corner Brook area, and north into the Gros Morne National Park area. There
are several small populations near St. John's. They too consume huge amounts of
insects, slugs, spiders and other crawly things. Great for all the gardeners who
dread the onslaught of slugs and other garden pests after the spring planting.
Both frogs and toads are amphibians, which, in ancient Greek, means "two lives".
One in the water, as a tadpole, and the other on land, as an adult. The whole
transformation period is truly one of natures wonders, as the young tadpole grows
legs and loses it's tail, to become a frog or toad. Salamanders also belong to
Amphibians; however, there are none on the island, but they are found in Labrador.
Frogs are usually green, brown, or a combination of both, with a smooth, shiny moist
skin, and long legs for jumping and escaping danger. They use their mouth to actually
catch the prey, and not always their tongue, as we are taught in school and on TV.
Toads are generally more stout and stocky than frogs, even though they have the same
basic body shape. Their legs are a little shorter, so that they actually hop instead
of jumping. Toads skin is rough, covered in little bumps. As a result they are much
easier to hold on to. And no, one does not get warts from handling frogs or toads.
Frogs tend to stay put during the day, waiting patiently for food to walk or slither
by. Toads, on the other hand, are very active hunters, who patrol their territory in
search of food, hiding under rocks or logs when there is danger around.
While frogs use their color and leg/swimming power to evade predators, toads have
something different. Toads have poison sacs behind their eyes, and should a predator
grab the toad, the toad will emit the poison into the animal's mouth. The taste from
the poison is so bad tasting that 99% of animals will drop the toad when poisoned.
The toad can then hop away to safety.
Here at the Fluvarium, we have recently upgraded the Amphibian exhibit, so that
it now has recessed aquariums, lights and better signage. The adult frogs have
their own enclosure; the young frog shares a tank with more tadpoles. The adult
toads have a very large aquarium just for them, allowing them much needed space
and territory. There is also a tank for the young toad (approx. age 11 months).
This toad is so small it would fit on a child's pinky fingernail. As we feed it,
it should get bigger and eventually move into the large tank with the adults.
We also have, as part of the Pond Display, an aquarium with some 30 green frog
tadpoles, donated to us by Charlie Horwood from the Provincial Department of
Works, Services and Transportation. These are well on their way to developing
into 30 little green froglets.
Interest in amphibians is always growing, especially in light of the fact that
populations all over the world are declining. Perhaps it is due to pollution,
habitat loss, or even ozone depletion and increased UV light levels. No one
really knows, not even the scientists. It is always a relief to see one or two
frogs or toads in the wild, or at least hear their mating calls in the spring.
Many older Newfoundlanders mention to us (Fluvarium Education staff) that when
they were young, there used to be many frogs, but now there are none. Or we get
the common "There were none around when I was young, but now they seem to be
everywhere". Either way, it is refreshing and encouraging that so many people
are interested in these wonderful, ancient creatures that light up our world
with their timeless energy, not to mention the fact that they eat many of our
most despised of pests, those mosquitoes and black flies.
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