Sunday, March 20, 2022

Last night's amphibian run

 

A Green Frog (Lithobates clamitans) stares inscrutably at the cameraman. It was one of a number that I saw last evening.

Last night's conditions were very good for a vernal amphibian migration. The temperatures stayed in the mid-50's F, and late afternoon showers persisted into the early evening. The ground was wet, the air was warm, and the amphibians were hopping and crawling overland to breeding pools.

Rather than go to some wooded vernal pool sites where I knew there would be scads of species such as Spotted Salamanders (Ambystoma maculatum) and other subjects, I opted for the open country of the hinterlands of Champaign and Logan counties in west-central Ohio. The primary reason: our largest mole salamander, which I will share shortly.

Spring Peepers (Pseudacris crucifer) filled the nighttime air with their loud peeps. Shallow wetlands harbored many of the tine blowhards, and their collective song was audible for long distances. Joining them were numerous Western Chorus Frogs (Pseudacris triseriata). The latter's song is a raspy grate, often likened to running a finger down the teeth of a comb. But amplified through a Marshall stack.

The Northern Leopard Frog (Lithobates pipiens) was the most common frog on the move. This handsome amphibian thrives in open country and marshes. Joining them were many American Toads (Anaxyrus americanus).

At one spot, where a country lane bisects a small woodlot, a Unisexual Salamander (Ambystoma hybrid) was crossing the road. This locale has many of these strange hybrids, but by this time late in the evening the rain had ceased, conditions were drying, and amphibian movement had slowed.

The "Unis" are a strange and imperfectly understood group of mole salamanders. They include the DNA of several species, potentially, including Blue-spotted, Eastern Tiger, Jefferson, and Smallmouth salamanders. All of them, or nearly so, are females. To delve into deeper detail about the Unisexual Salamanders, go RIGHT HERE.

And the star of the show! An Eastern Tiger Salamander (Ambystoma tigrinum) pushes its way through grasses as it marches to - or perhaps from - a breeding pool. This is our largest mole salamander, and exceptional individuals can be nine inches or so in length.

A tiger crosses a road. As always, after taking photos it was moved off the road (on the side that it was headed for). We saw five of them in total, and four were in a breeding pool. We thoroughly checked that pool first thing after nightfall and could not locate any. Several hours later, we easily and quickly found the four, suggesting that they were just entering the pool. No egg masses or spermatophores (male sperm packets) could be seen, further suggesting that the big mole salamanders were just arriving at their breeding pools.

All in all, a wonderful night of communing with the amphibians.

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