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Bullfrog Tadpoles

Interesting Information About Bullfrog Tadpoles

You can spot bullfrog tadpoles just about as easily as you can their parents since they can be up to an amazing 15 centimeters long.  It is not uncommon for them to spend one to two years in this stage of their life which is quite long compared to most frog species that remain tadpoles for only a couple of months.

Tadpoles may appear to be black in color but they are usually just a very dark shade of green.  Their body is shaped like an arrowhead and they have a dorsal fin beginning behind the main portion of their body and extending outward.  Although newly metamorphosed bullfrogs are much smaller than the adults, they are still easily distinguished by their large tympanum, which is an external hearing organ right behind their eyes.

See Related: Toad Tadpoles


Adults of the species gather in the early summer at large breeding ponds which is quite late in the year compared to other frogs.  The males will stake out suitable sites to lay eggs at and then they will defend their territory.  They will loudly call to attract females which also chases other males away.  After mating, the female will lay as many as 20,000 eggs in the water’s surface in a protective film.  Depending on the temperature of the air and the water, they will usually hatch between four to six days later.

Bullfrog tadpoles hatch in July and stay in their pond for the rest of summer all the way through the following winter and then they complete their metamorphosing in late summer or early fall of their second year.  Adults can live to be 10 years old in the wild but the mortality rate for bullfrog tadpoles is very high.


Bullfrog tadpoles are typically categorized as herbivores, grazing on detritus and algae.  However, they have also been observed eating both eggs and other newly hatched tadpoles.  It is believed though that this may be simply due to browsing habits and having to compete for food with other native frogs and their tadpoles.

When tadpoles turn into adults, they will eat pretty much anything that they can fit into their extra-large mouths.  They are extremely predatory so in addition to the typical diet of insects that other types of frogs enjoy, their diet is quite expanded.  Adult bullfrogs will eat birds, snakes, small mammals and even other bullfrogs that are smaller than them.  They have been observed devouring ducks and quite large snakes on occasion so basically, the bigger the bullfrog, the larger the prey that they will choose to eat.


While bullfrogs do spend the winter hibernating under water, it is a misconception that they bury themselves in mud the way that turtles do at the bottom of the pond.  In fact, they would actually suffocate if they remained submerged completely in mud for extended periods of time.  Hibernating aquatic frogs of any species need oxygen-rich water and usually they just lay on the surface of the mud and they may even swim around a bit from time to time.

Wildlife Act

Bullfrog tadpoles, as well as the adults are protected under the Wildlife Act which means that it is illegal to capture, keep, transport or sell them.  Therefore, if you want these musical creatures in your pond, you have to create an attractive environment for them.  This means eliminating chemicals and providing shelter, water and insects for food.  Never move bullfrogs or other frog spawn because you can easily kill the eggs and spread disease.  It is important to note that these are territorial creatures that you may not want in your backyard pond if you enjoy the other frogs, turtles or aquatic life that is currently residing there.

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