Spadefoot Toad Conservation Project Logs Second Year of Success
Last year at this time, the Long Pasture spadefoot toad team was celebrating a break-through. After ten years of translocating thousands of Eastern Spadefoot Toads from a healthy population at Barnstable’s Sandy Neck to a new habitat created at the Ashumet Holly Wildlife Sanctuary in East Falmouth, the team documented its first evidence of breeding toads at the new site.
But despite that long-awaited success, the team immediately faced its next challenge: would the toads’ reproductive success be repeated the following year? Or was the burst of spadefoot breeding in 2021 just a lucky break?
Unlike other toads and frogs, Eastern Spadefoot Toads, a threatened species in Massachusetts, don’t necessarily breed every year. They are opportunists that hold off for a confluence of environmental conditions, such as adequate rainfall and groundwater levels. If conditions are too dry, they’ll delay or even forego breeding.
Making the Most of the Rain
With a drier than usual spring, the 2022 field season wasn’t very promising. But two days of rain from June 9-10 provided enough water to activate spadefoots at Ashumet. Long Pasture’s Ian Ives says it was the only spadefoot breeding activity recorded in New England this year, and he thinks the sanctuary’s artificial wetlands were one reason.
The wetlands use buried fish-safe liners which collect rain like a bucket.” Ian explains. “Water in natural wetlands holds for a shorter period because of infiltration into the soil or from absorption through transpiration.”
Like last year, the spadefoot project team noted calling and amplexing (mating) toads, egg masses and hatched tadpoles at the Ashumet wetlands. Unfortunately, none of last year’s tadpoles survived to metamorphosis. But this year it appears the tadpoles metamorphosed into toadlets (small toads)! This milestone represents the first successful reproduction in the project’s 11-year history, and only the second confirmed successful reproduction of a translocated population of eastern spadefoots anywhere (the first being a population managed by Mass Fish and Wildlife in Southwick, Massachusetts).
“Spadefoots are specially adapted to respond to rapidly drying wetlands, “ Ian explains. “ They can develop from egg to toadlet in as little as 14 days, if necessary. And it was exactly 14 days after the eggs were laid that all the tadpoles apparently metamorphosed and headed for cover in the uplands.” While predation is a possibility, Ian says it’s very unlikely every tadpole or toadlet would have been eaten.
The team will continue searching to document tiny spadefoots, but Ian says he’s pleased with the project’s success over the last two years. “To have two back-to-back breeding events with an introduced population of this size is pretty remarkable and a good indication this population is not just breeding occasionally but sustainable, the goal of this project.”
Experience a summer night at the Ashumet Holly spadefoot breeding pools with our spadefoot team and WCAI Radio.