Identification and Reproduction
- American bullfrog has a large robust body that can reach 20 centimeters in length.
- They are green or brown in colour and have yellow or pale cream to white throats.
- The baritone call of the bullfrog is so deep and resonant, it resembles the mooing of a cow.
- Only males emit this trademark "jug-o-rum" bellow, and their choruses can be heard during the day or night during mating season.
- Look for: the circular “ear drums” on the side of the head behind their eyes.
- This species breeds from the late spring to early fall.
- Males are territorial. Mating success is influenced by the quality of the territory.
- Females lay one or two clutches per season with average clutch size is 12,000 eggs.
- Clutches are laid in a film on the water surface with eggs hatch in approximately 5 days.
- Tadpoles can be very large, 125-150 mm.
- Metamorphosis usually takes 1 year, larvae will overwinter in ponds and larval survivorship is about 18%.
- This species typically reaches sexual maturity one year after metamorphosis .
Habitat & Ecology
- They are among the most wide-ranging of all North American amphibians, found in freshwater ponds, lakes, and marshes.
- Average lifespan in the wild is 7 to 9 years
- Can grow up to 1.5 lb and 20 cm long.
- American bullfrogs displace native frogs in habitats they invade by outcompeting and depleting the food sources of native frogs.
- Causing decline in the native red-legged frog and pacific chorus frog populations.
- Do not move any tadpoles (regardless of species), and do not move frogs from one waterbody to another - this helps them spread.