Wednesday, May 24, 2017

Toad Pool Success - Part 2

Blue Jay Barrens is experiencing an influx of thousands of young Eastern American Toads emerging from the still under construction Toad Pool 2. This little guy has fully absorbed his tail and, looking every bit like the adult version of his species, is moving away from the pool towards the open fields.

The pool experienced no shortage of water this spring. Frequent rains provided above average rainfall totals causing the water to regularly be at a level higher than intended.

Toad eggs appeared in the pond on March 29 and began hatching on April 2. By April 5 the eggs had completed hatching, but the tadpoles were not yet mobile and their pattern on the bottom of the pool continued to match the strings of eggs that had been laid out a week before.

After exiting the egg membrane, the tadpoles remain stationary for several days as they absorb their yolk sacs and mature into a more traditional tadpole form. Their first food will be the algae seen growing on the empty jelly strings and pool bottom.

Once they become mobile, with tadpoles migrate upslope to shallower water where the generally warmer temperatures will aid in their growth and development. Their initial efforts cause them to congregate atop the slightly higher mounds on the pool bottom.

A few days later their improved swimming ability allows them to reach the shallow water at the edge of the pool.

The unfinished condition of the toad pool caused an unintended broad expanse of shallow water to become available to the tadpoles.

The shallow area, which had been left smooth when construction was halted last fall, had become pocked with depressions caused by deer visiting the pool.

As water levels receded during uncharacteristic hot periods between rainfalls, the depressions became isolated pockets that rapidly dried after their connection to the main body of water was severed. Tadpoles caught in these depressions quickly perished.

Fortunately, I still retained the mud puddle engineering skills that I had honed as a child and was able to make periodic adjustments in the way of dams and channels to ameliorate the desiccation threat to the tadpoles. If weather conditions allow me to complete my construction activities is fall, the hazard should not exist next year.

Transformation from tadpole to terrestrial toad form began a week ago and is now proceeding at a rapid pace.

Once all four legs appear, the tail quickly shrinks and the young toad pushes himself free of the water.

It spends a day or two near the water’s edge before heading off to begin a terrestrial lifestyle.

The little toads are so numerous in the vicinity of the pool but I can’t walk in that area without stepping on a few, so I’m waiting until they’ve had a chance to disperse before checking the pool again. I’m looking forward to encountering these little guys through the summer. It will be two or three years before this year’s hatch is mature enough to return here to breed. By that time Toad Pool 2 will be completed and, with any luck, there should also be a Toad Pool 3.

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