Recent reports revealed by government scientists stated that, the incursion of American bullfrogs (which will eat anything including each other) is spreading all around the Yellowstone River in the northwestern state of Montana. It seems to be a major threat to native frogs, researchers said.
Adam Sepulveda, USGS (U.S. Geological Survey) biologist said Thursday, “According to the recent surveys conducted, bullfrogs are found along a 100km widen river from the Laurel area downstream to Custer.”
He further told that, “These bullfrogs can eat anything which could fit their mouth easily. It really does not matter either it’s would be the similar frog, a bird, or a mosquito.” This study is published in the Aquatic Invasions journal.
When bullfrogs have been stretched out as long as 30 cm it’s usually found. One of them was caught and open last year near the Audubon Conservation Center in Billings and it was seen that its stomach consist of oriole. At first the state and federal agencies tried to kill them off to stop the attackers in their track, but afterwards they gave up after the number of bullfrogs inundated the effort. And now they are trying to at least hold their spread and making plans for this. Bullfrogs are inhabitant of the eastern U.S., but are known to have been spread by humans to every state except North Dakota.
Sepulveda says that, by attacking on the native frogs, these bullfrogs have caused a problem, opposing other animals as their food, and are spreading a fungus which could cause a widespread decline in amphibians.
Certainly, these bullfrogs were documented for the first time in Eastern Montana, way back in 1999. The researchers think that they fall down from released pet frogs or bullfrog tadpoles used as bait by fishers.
Moreover, another documentary has been made on another population of bullfrogs in Eastern Montana, researchers told.
Since 1920s, these bullfrogs were populated in the regions of Western Montana, probably from a farming operation that sold their legs to be eaten, Sepulveda told.