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About the frog Rana viridiana: "Rana viridiana. Order: Anura. Family: Ranidae. Commonly known as the red-belly frog. Grows from one to over four inches long. Diurnal -- that means it's active during the day. Green to reddish brown in color, with a dark mask bordered by a light stripe on the jaw. The underside is yellow with a wash of red -- that's why it's called ëred-belly.' Feeds primarily on crawling insects. Habitat: found near ponds or other permanent water with extensive vegetation. Its egg masses look like grape clusters and are laid in permanent bodies of water. Eggs hatch in one to two weeks into tadpoles; tadpoles change into juvenile frogs in two to three months; juveniles mature into adults in one to two months." TOP |
About recent weather in the city: "Let's see. Pretty normal temperatures and rainfall over the past two-and-a-half months, except for that very heavy rain we had four weeks ago. Caused a bit of flooding in places." TOP |
About Slow Water Park: "The park was established about seventy years ago to preserve a beautiful natural spot: the Slow Water Springs and the forest, meadows, streams and ponds that are fed by them. The park managers have struggled throughout the years to keep most of the park and especially the stream banks in a natural condition, and generally they've succeeded." TOP |
Where the water in Slow Water Park comes from: "I looked through the hydrology maps. The springs of Slow Water Park are fed from a deep aquifer, so the water is of unusually high quality. I also saw a drainage map, which shows that the city has installed a system of storm drains, so that excess water generally goes into the sewer system, not into the park." TOP |
Where the water in Slow Water Park goes to: "Below the park is Lake Amberjean, a small reservoir which supplies the drinking water to the central part of the city." TOP |
About environmental studies of the Way Out There factory: "There were three studies, each of which caused a major change to the original factory design. The first was a visual study which eliminated clutter in the building design. The second was a traffic study which changed the layout of the factory access roads and parking lot. The third was a wildlife study which prevented the factory from building a fence. No problems were detected in the planned factory wastewater system, so it was built as originally proposed." TOP |
About declining amphibian populations: "It's well documented that amphibian populations the world over have been declining for 25 years now or more, but it's still unclear as to why. The worry is that some sort of global problem -- a diminished ozone layer, for example, or a chemical pollutant -- is causing the decline. Recent discoveries show that actually a naturally occurring fungus may be a prime contributor to the decline. But reality is complex, and resists simple, only-one-cause solutions." TOP |
About frogs and water pollution: "Like most frogs, Rana viridiana possesses a very permeable skin. Plus it lays its eggs in water, in grape-like clumps, which hatch into tadpoles that swim in the water. Thus it is very sensitive to pollutants in the water, which can destroy the eggs, poison the tadpoles or frogs, or cause deformities." TOP |
About frogs and habitat destruction: "Rana viridiana is a classic sort of frog, living both on the land and in the water. Frogs like these are very sensitive to habitat destruction." TOP |
About frogs and invasive species: "Lots of stuff about invasive species. Zebra mussels in the Great Lakes and kudzu in the American South and stuff like that. But I only found one reference to frogs dying out because of an invasion by an exotic species. That was when they brought cane toads to Australia in the 1930s. The cane toads displaced a lot of native frogs -- sometimes they ate up their food, and sometimes they ate up the frogs." TOP |
About frogs and predators: "Around the world, lots and lots of other animals eat frogs -- including toads and bats, if they're big enough. In this area, only foxes, coyotes, and herons eat adult frogs, plus catfish and bass eat young frogs. But mainly I learned that it's rare for natural predators to cause a steep decline. In a balanced ecosystem, natural predators at worst cause a gradual decline, and usually don't threaten to wipe out their prey." TOP |
About recent events in the city: "I looked through the news archive. I only found one thing that seems suspicious. Turns out the city installed a bat house in Amberjean Park last year, big enough to hold up to two thousand bats. Amberjean Park is about a mile from Slow Water Park. The article said that the bats would migrate north to the bat house in the spring. That means the bats probably began to occupy that bat house about three months ago." TOP |
About the Mexican free-tailed bat: "Scientific name is Tadarida brasiliensis. A medium-sized bat, with a body about nine centimeters in length, and weighing about fifteen grams. Its fur color varies from dark brown to gray; ears are wide and set far apart on the head to help with echolocation. "Mexican free-tailed bats live in colonies, usually within caves, and emerge at night to feed on flying insects such as mosquitoes. The largest colony, at Bracken Cave in Texas, numbers nearly 20 million adult bats, which can eat up to 250 tons of insects per night! This species is very important for the natural control of insects, but its populations have fallen because of the use of pesticides and the destruction of roosting caves." TOP |
About the cane toad: "The cane toad is actually Bufo marinus, also called the giant toad. Giant indeed -- it can measure from 6 to 9 inches and (in captivity) weigh four pounds! The toad is squat and plump with rough warty skin; protruding eyes with thick warty eyelids; prominent poison glands on its shoulders. Native to tropical America. "Nocturnal. A voracious eater, it eats anything it can fit into its mouth – usually crawling insects, but also small birds, mammals, and other amphibians, including smaller cane toads. Breeds year round and in large numbers. Eggs are usually laid in strings in standing water; they hatch into tiny black tadpoles which metamorphose 12 weeks later. "Thanks to people, Bufo marinus is the world's most widespread amphibian. Back in the 1920s and 1930s, sugarcane farmers in countries all over the world imported the toad in attempts to control pest beetles. The toad is now permanently established in Australia, Hawaii, New Guinea and the Caribbean, where it wreaks havoc on native wildlife." TOP |
Distinguishing frogs from toads: "Generally, frogs are sleeker, have smooth skin, and jump better. They depend much more on water. Toads are squat, have warty skin, and hop; they are less dependent on water. But this is just a language thing. Scientifically speaking, they are the same - all members of the order Anura." TOP |
About the rainbow trout: "It's not native to Slow Water Park. But the rainbow trout has been introduced into many streams and lakes because it is a favorite with fishermen. Invasive trout can destroy frog populations over time, primarily because young trout eat the frog eggs." TOP |
About amphibians: "When they hear 'amphibian,' most people think of frogs and maybe toads, but the class Amphibia also includes salamanders and newts, plus caecilians, which are limbless, burrowing creatures. Amphibians are in the news a lot recently, because people who study them have noticed a worldwide decline of formerly vigorous populations. People are wondering if this decline signals some sort of significant decline in the quality of our global environment." TOP |
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