Bullfrogs have a much higher critical thermal maximum than most other frogs, meaning that they are able to thrive in higher water temperatures. Bullfrogs have a longer breeding season and a higher rate of premetamorphic survivorship, which also allows them to be more successful than other frogs. Colorado, among many other places, is experiencing problems due to the introduced bullfrog population. Bullfrogs may have been introduced accidentally to trout streams and lakes during the Colorado Divisions of Wildlife fish stocking operations. Bullfrogs occasionally invade fish hatchery ponds and their larvae are caught along with the fishes routinely stocked in ponds and reservoirs.
Most fish are adverse to eating bullfrog tadpoles due to their undesirable taste.
Positive The bullfrog helps to control insect pests. Also, bullfrogs are important for medical research because their skeletal, muscle, digestive, and nervous systems are similar to those of higher animals. In many areas, such as California, bullfrogs are driving other frog populations to extinction. An interesting reason to explain why bullfrogs in California might have an advantage over other species native to that state is that bullfrogs evolved with a diverse predatory fish fauna in eastern North America. For many years in California people have been introducing new fish species that are predators of frogs.