The Red-Eyed Treefrog

 Amphibians, Central America, Tropical Forests  Comments Off on The Red-Eyed Treefrog
Jan 112010
photo provided courtesy of flickrfavorites on Flickr Creative CommonsHomeCentral America
Habitat Tropical Forest
Nicheamphibious insectivore
Favorite Foodinsects
Lengthup to about 3 inches
StatusLocally Common
Threatshabitat loss, pollution, climate change

The red-eyed treefrog inhabits tropical forests of Central America, using its squishy toe pads to gain footing on wet branches in its search for insects. Because of the constant humidity in its habitat, adult red-eyed treefrogs and other treefrogs are able to live a mostly terrestrial life and only need standing water during the mating season. It is one of the most colorful frogs in the world, with striking red eyes, orange feet, and blue decals along the sides its green body.

Mating is an interesting affair for red-eyed treefrogs. Although they don’t need to mate in standing water like many other frogs, they still need to gather an amount of freshwater to allow the movement of sperm and eggs. This task falls on the female, and she carts the male on her back down to a pool of water to gather enough to lay 50 or so eggs on a chosen leaf. Ever the hard-worker, the female will continue this process a few times until she has finished laying eggs. The loafer on her back will then leave, having fulfilled his purpose of providing sperm. The eggs only take about 5 days to hatch and the newborn tadpoles will drop off of the egg-laden leaves into water. Like all amphibians, quantity of eggs laid is important. Since the eggs are so attractive to predators, only batches of hundreds will produce enough offspring with a chance to reach adulthood.

Red-eyed treefrogs are still locally common in the remaining stretches of tropical forest across Central America. As deforestation continues to reduce tree cover to make way for farmland, treefrog numbers will continue to decrease. However, loss of trees is not the only threat facing red-eyed treefrogs and others of their kind. Amphibians are notoriously vulnerable to even small changes in temperature, and the quality of water and air. Industrial pollution, even in minute amounts, has triggered massive die-offs of frogs, toads, and salamanders in all regions of the world.

The Marine Toad

 Amphibians, Australia, Invasive Species, South America  Comments Off on The Marine Toad
Jan 012010
photo by Sam Fraser-Smith on Flickr Creative CommonsHomeCentral and South America, and introduced worldwide
Habitatnearly every temperate habitat, from rainforest to savannah, farmland to suburbia
Nichelarge opportunistic predator
Favorite Foodinsects
Lengthup to 9 inches
Invasive Species

The marine toad is the largest toad on Earth by far, growing as big as 9 inches in length. They are insatiable hunters, prowling their territories by night and gobbling up anything that can fit in their mouths. In addition to their staple diet of insects, they will scarf down unlucky salamanders and even small frogs. As if their massive size wasn’t enough to deter predators, marine toads also sport a deadly defense mechanism. If an animal picks up the toad in its jaws, special glands in the amphibian’s skin will ooze a highly toxic venom. The hapless predator scarcely has time to wish it never chose the toad as its last meal, as most are killed within 15 minutes of ingesting the poison.

In many regions of the world, especially Australia, the marine toad is an invasive species, competing with native frogs and toads for food and water. In certain cases, the introduction of marine toads was deliberate, particularly in countries that grow sugar cane. Since these toads are so voracious and are useful in pest control, they were thought to be effective watchdogs of sugar cane crops and earned the name cane toad. Although some farmers may have benefited from the introduction of cane toads, local ecosystems have been devastated. Marine toads are tough amphibians that can thrive in just about any environment on earth. Unlike frogs, they have thick, warty skin that allows them freedom from standing water except for mating. They are also tolerant to salt water, which amphibians usually shun, and can go without water entirely for long stretches of time. They are the ultimate survivors of the amphibian family, for better or for worse.

Because of their wide distribution, high tolerance, and high reproductive rate (over 20,000 eggs are laid in a clutch), marine toads are common and unlikely to be impacted by many of the same forces jeopardizing the survival of their frog and toad cousins. The marine toad is an example of how a hardy survivor can carve out its own niches in new areas, to the detriment of other species.