American Toad Breeding Pond: The 2018 Story

It was on February 28, I think, that I posted comments on the “Grassland Spring Pond,” where American Toads breed in Eliza Howell Park, and about my looking forward to what I might observe this year. The 2018 story is not what I had hoped for, but it is a story to be told.

Toads come to the breeding pond to mate and lay eggs for only about three days each April. I usually expect them slightly later than the middle of the month, but the timing is dependent upon the weather. April was colder than normal this spring, but in order to make sure I did not miss anything, I started checking the pond on April 12.

It wasn’t until late in the month that the weather conditions were right for the males to head to the pond. I first heard their loud trilling mating calls on April 25, loud enough to be heard by the females.

The field was starting to turn green by then.

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During these mating days, male toads call both during the day and at night, but toads travel to and from the pond only nocturnally. My frog-and-toad-survey colleagues and I visited the pond after dark on April 26 and listened to their very loud chorus for several minutes.

In the beam of the flashlight, I saw this toad, probably a female just arriving.

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April 27 was the last date we heard toads in the pond. American Toads, when they are ready to breed, normally return to the same pond where they were tadpoles. While I don’t know how the numbers compared with previous years, it was great to see – and hear – them in the same location again this year.

How quickly toad eggs hatch is also temperature dependent. The weather remained cool and it was a longer time than usual before the tadpoles emerged. It was not till May 21 that I found them in good numbers, three and a half weeks after the adults left the pond. (By comparison, I first saw many tadpoles on May 6 in 2017.)

This picture was taken on May 24.

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Following the long cool spring, the weather became quite warm. Actually, it was hot. The high was in the 80s the whole last week of May, reaching 90 degrees on May 28.

The pond plants grew rapidly and on May 29, the pond looked like this.

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The weather was all wrong for American toad breeding in the pond this year. The cold spring delayed mating; further cold weather delayed hatching; hot weather dried up the pond before the tadpoles could develop.

On May 29, the water was gone and I saw dozens of dead tadpoles in the mud. They were still weeks away, it appeared, from metamorphosis, weeks away from being able to leave the water as toadlets.

The Eliza Howell toad population will be smaller for at least a year.

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The 2018 toad pond story leaves me with a question about the future of the pond. While I think one can rightfully point to the long cool spring followed by a very hot late May this year as the basic reason for breeding failure, I also wonder whether the pond is becoming more shallow over the years, whether it will be able in other years to maintain sufficient water into June to serve as a viable toad breeding pond.

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While the grassland pond has been an American Toad breeding hotspot, it is not the only location in or near the park where they breed. Recently, I saw clear evidence of this, two small toads, not much more than an inch in length, in the bottomland by the river. This is one.

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Somehow, seeing these new toads made me finally ready to tell the story of the grassland pond 2018 breeding failure.

It will be interesting to see what happens next year.

 

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