This weekend, Birdgirl and I made a trip back to the old homestead in the Toronto area. Friday night was mild, and Birdgirl set up her mothing sheets. While out checking the sheets, it was apparent that the warm weather was prompting the toads in the area to move to breeding ponds. On Saturday, it was warm and sunny and the trills of male toads calling from the vernal pool announced that the breeding season for the Eastern American Toad (Bufo americanus americanus) was moving into high gear. Birdgirl and I waded through the mud to check out the pond and were able to see numerous toads intent on attracting a mate. Males generally arrive at the breeding site before females, and we only saw one female. She was the object of a lot of male attention! The photo above shows the competition amongst her suitors. The males are noticeably smaller than the female. The tan-coloured male held on tenaciously and eventually came away the winner.
Toads prefer to breed in shallow, temporary pools. During amplexus the male grasps the female’s body from above and can fertilize the female’s eggs externally as they are laid. Toad eggs are laid in two gelatinous strings and a female may lay from 2000 to over 20,000 eggs. The small blackish tadpoles hatch in 2 to 14 days, depending on water temperature. They will eat algae and planktonic organisms and soft vegetation as they grow. Tadpoles transform into tiny toadlets in 6 to 10 weeks. Only a few will survive the two to three years it takes to reach sexual maturity.
The male toad’s song is easy to recognize, a high-pitched extended trill that may last over 30 seconds. Pictured below is a trilling male. You can listen to the call at the Adopt-A-Pond site. Next weekend, May 2nd and 3rd, is the 10th Annual Spring Toad Festival at the Toronto Zoo in the America’s Wetlands. Also, April 28th, 2009 is the 1st Annual ‘Save The Frogs Day‘