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.

 

Vernal Pools: Getting My Feet Wet

“Getting my feet wet,” as an idiom, means just starting something new or gaining initial experience. This is a good expression to describe me this year as I am beginning to learn about life in vernal pools in Eliza Howell Park.

In this case, “getting my feet wet” can also be taken literally – or could be if it were not for rubber boots.

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Vernal (spring) pools are shallow temporary pools that typically fill with water in early spring and dry up by summer or fall. Several species of animals rely upon vernal pools for survival, such as wood frogs, spotted salamanders, and fairy shrimp. Because vernal pools dry up, fish do not survive there and frog and salamander eggs will not be eaten by fish.

There are 3 or 4 different spring watery spots in EHP that might be considered vernal pools. For my beginning study, I am focusing my attention on one. This is the largest one, in the heart of the wooded area.

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The approximate location of the pool, with no claim to be accurate in size, is marked in red on the map here.

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The pool in late March is some 80-90 yards long and averages about 20-25 yards wide, with water several inches to a foot deep in most of it. It is deep enough to attract Wood Ducks and Mallards at this time of the year. This particular pool, if I recall correctly from other years, does not usually dry up until at least the end of August.

Here is another view, taken while standing in the pool.

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Vernal pools are important habitats for amphibians and for invertebrates and I am hoping to learn something of the life in this pool in EHP. Fortunately, I know where to look for expert tutoring and advice. Yu Man Lee is Wildlife Ecologist and Herpetologist for Michigan Natural Features Inventory (a program of MSU Extension). She, accompanied by her husband Jon, came to Eliza Howell Park earlier in March to check out the vernal pools here.

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My new venture will involve a lot of looking down in the water, looking for/at “critters” and eggs and plants. The bottom of the pool is now covered with last year’s fallen leaves, deposited after the water died up in 2017.

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It is possible that I may want to post an update on what I am finding in this vernal pool in 2018. On the other hand, since I am just getting my feet wet, I may very well have too little to report.

 

Grassland Spring Pond: The Annual Cycle Begins

The recent late February thaw and rains re-filled the shallow pond that I have come to know as “The American Toad Breeding Pond.” This temporary pond exists each year from late Winter or early Spring until the summer. It is a pond for only about 4 – 5 months, but a lot happens in the months that are beginning now.

The pond is found in the grassy area within the road loop and borders (sometimes overflows) the walking path. This picture is from this week.

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When pond appears each year about this time, I modify my wanderings to make sure that I take a careful look at it each time I am in the park. I don’t want to miss the life it attracts.

For most of the year, adult American Toads are solitary, mostly nocturnal, and rarely seen. When they are found, they are typically on land, not in water.

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Sometime in April, the exact time probably determined by temperature and rain, breeding adults head to the pond. Then, throughout the day, the males sound forth with their loud trilling mating calls, announcing themselves to the females.

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Dozens, perhaps hundreds, of males and females converge on the pond and engage in what appears to me to be a mating frenzy. The phenomenon is short-lived; in a couple of days, the adults depart and the pond is quiet again. A few days later the eggs begin to hatch and the tadpoles quietly develop over the next several weeks.

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Killdeer and a few other “shorebirds,” like Solitary Sandpiper, can occasionally be found at the edges of the pond and dabbling ducks, especially Mallards, frequently forage in the water.

A couple years ago this pond was, over a period of days, the hangout of an odd couple – a male Wood Duck and a female Mallard. They were constantly together and may very well have produced hybrid ducklings after they moved on.

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These are some of my memories when the pond fills again. And I look forward to what I might witness at the grassland pond in 2018.