Population ecology of the invasive American Bullfrog (Rana catesbeiana) in Southeastern Arizona

Native to eastern North America, the American bullfrog (Rana catesbeiana) was introduced to Arizona for sport hunting in the early 1900s and has since come to dominate many aquatic systems and threaten native amphibians through four primary mechanisms. First, American bullfrogs (hereafter bullfrogs) are carriers of pathogens (e.g., ranavirus, chytrid fungus) and can spread these pathogens to native amphibians that are more susceptible to infection. Second, bullfrogs are voracious predators and are known to prey upon and outcompete many native amphibians. Invasive bullfrogs are also known to prey upon other native wildlife including snakes, turtles, birds, small mammals, and fish. Third, bullfrog eggs and larvae are unpalatable to many native fish in their invasive range allowing bullfrog larvae to persist in large numbers. Finally, bullfrogs have high reproductive and dispersal potential allowing them to readily invade previously unoccupied habitats. In this report, we present the current results of our project studying the dispersal and reproductive ecology of bullfrogs in southeastern Arizona. The results discussed in this report are from data collected from 14 March 2024 through 15 September 2024. We plan to continue collecting data to address our project objectives during the summer and fall of 2025.

DOI: https://doi.org/10.3996/css36183173