Where in the world are bullfrogs located?

Question

where in the globe, ....

Answer 1

Identification: Bullfrogs are very large, aquatic creatures typically measuring 3.5 to 8 inches in length, making them the largest frog in North America. They have an olive-brownish color (which can frange from green to yellow) with brown spots scattered over the body and webbed feet. They have large external eardrums and lack ridges on the back. Male bullfrogs have a yellow throat, whereas the female throat is white. Bullfrog tadpoles are olive-green, long tadpoles with dots on the head, body and tail. Their voice is a deep-pitched, bassy "jug-o'-rum" which can be heard over distances of a quarter mile in the forest.



Location: Bullfrogs are widely spread out over the eastern and central US, and although their limit is generally the Nebraska/Texas area, populations have been found in Colorado and New Mexico. They are abundant throughout New England.



Habitat: Bullfrogs are aquatic and can be found in almost any permanent water body, such as lakes, ponds, rivers, marshes, swamps, etc. Bullfrogs can usually be found on the bank or along the water's edge. These areas are usually well vegetated , and when the frog is startled it is just as likely to hide in vegetation as the water.



Reproduction: Bullfrogs will begin their mating call starting in late April. Eggs are laid in large numbers in "mats" that float on the water surface. Tadpoles, like the ones shown in this picture, will begin to metamorphosis in mid-June, and could take up to three years to mature.



Food: Bullfrogs will eat almost any moving prey that they can catch, and have been observed cannibalizing other newly metamorphosized bullfrogs. They are heavily preyed upon by many vertebrates, including humans (Bullfrogs are the main source of frog legs in the US). Their usual diet consists of insects, crayfish, minnows, and large frogs have even been known to catch and eat small birds and young snakes!

Answer 2

Bullfrogs

The bullfrog (Rana catesbeiana) has successfully spread throughout the low elevations of Washington. Large populations of this species are believed to have contributed both directly and indirectly to the drastic decline of native amphibians and reptiles.

The bullfrog is the largest true frog in North America. It can measure 8 inches in length, leap up to 3 feet, and live nearly ten years. Bullfrogs are occasionally seen crossing roads, even during periods of dry weather, and may travel overland up to a mile. This movement allows them to expand their range from the source where they were introduced. The large number of eggs in each egg mass laid by the females allows bullfrogs to quickly establish themselves within a new territory.

Bullfrogs get their name from the bar-room mating call made by the males. Juveniles and adults of both sexes emit a squeak just prior to jumping into water when avoiding an intruder.

The original native range of bullfrogs was the eastern United States, but they have been introduced to most of western North America, from southern British Columbia to Baja California. Bullfrogs were first introduced into Washington during the Great Depression (early 1930s) to provide opportunities for frog hunting, food (i.e., frog legs), and stock for frog farms, enterprises that rarely succeeded.

Bullfrogs thrive in the warm waters of natural and man-made ponds, marshes, sloughs, reservoirs, and sluggish irrigation ditches and streams. Bullfrogs tolerate polluted and muddy waters better than do most native frogs, and may be found within cities in wetlands, reservoirs, and stormwater ponds.


Figure 8. Bullfrogs are expanding their range as individuals colonize suitable habitats—often using constructed stormwater ponds as stepping-stones between natural wetlands. Bullfrogs also spread to new habitats when released as unwanted pets and after people share frog eggs with their neighbors, not knowing the damage they can do. (Photo by Jim Pruske.)
In their northern range and in cooler climates, bullfrogs persist only in year-round bodies of water because they require two years to develop from eggs into adult frogs. In their southern range and in warmer areas, they have been known to fully metamorphose in one year and colonize semi-permanent and seasonal ponds. (Such cases have been documented by biologists in Oregon.)

Bullfrogs breed only after the nights warm up and reach the high 60s and 70s (Fahrenheit), generally June and July here in Washington.

Adult bullfrogs and tadpoles overwinter in mud on the bottom of ponds and other bodies of water. They hibernate by burying themselves in surface mud or by digging cave like holes underwater. Adults also hibernate on land near ponds where they bury themselves within the soil. Their body temperature may drop virtually to the freezing point, and their hearts slow so drastically they seem to atop altogether. But they continue to absorb oxygen through their moist skin, and when their surroundings thaw, they emerge into the spring sunshine to resume their business of catching insects and other prey.

Adult bullfrogs usually are "sit and wait" predators that readily attack almost any live animal smaller than themselves—insects, frogs, tadpoles, fish, small snakes, turtle hatchlings, newts, salamanders, bats, hummingbirds, and ducklings. Bullfrogs use their sticky tongues to subdue prey, but that's not their only method of securing food. Large frogs are more likely to lunge at their targets. Once they get a grip with their wide, sturdy jaws, they use their front feet to shove the items down their gullets.

Garter snakes regularly catch and eat bullfrog tadpoles and adults. Painted turtles also eat some in late summer, when adult and developing bullfrogs become sluggish for some unknown reason. Large bullfrogs also capture smaller ones and eat them.

The relatively unpalatable nature of bullfrog tadpoles may give them the ability to coexist with many otherwise potential fish predators. Bullfrog eggs can be eaten by many predators (leeches, salamanders, fish) with no obvious detrimental effects to the predator.

Under no circumstances should you take or purchase bullfrog tadpoles for your home pond, transfer wild-caught bullfrogs, or in any way encourage them to expand their range. If you are adding plants or water to a small pond, make sure you are not also adding bullfrog eggs or tadpoles.

Each female bullfrog creates one thin-jelly egg mass that may contain 6,000 to 20,000 very small eggs, which are black on top and white underneath. Egg masses are generally found in water that is less than 2 feet deep in mid to late summer. The eggs start out as a round, basketball-size mass (below or near the surface) that then rises, flattens out, and forms a 2- to 4-inch gelatinous mass 2 feet in diameter. The egg mass floats on the surface of the water or rests on the bottom within sparse vegetation. The mass remains attached to deep vegetation in some places and is often covered in algae.

The tadpoles are dark green with black dots, orange or bronze eyes, and opaque yellow underbellies (Fig. 9). A two-year-old tadpole may be 4 to 6 inches long.

The juveniles are green to brown with a peppering of tiny black spots, and have orange or bronze eyes. A fold of skin extends from the eye around the eardrum.

Adult bullfrogs have thickset bodies, large, exposed eardrums, and are green, tan, or dark brown above (with dark spots). Male bullfrogs have a yellow throat. The eardrums on males are larger than the eyes, while the female's eardrums are the same size as the eyes. The eyes of both sexes are gold.
Bullfrog tadpoles are dark green with black dots, orange or bronze eyes, and opaque yellow underbellies