Several consecutive warm and sunny days, aided by the leafless shrubs and trees, really heated up the ground, shallow bays and ponds last week. By Sunday afternoon, one vernal pond had soaked up so much solar heat that it was warmer than the air temperature, registering 66 degrees!The ability of our dark-bottomed, shallow, woodland vernal ponds to absorb lots of solar energy at this time of year benefits many of our amphibian species that congregate in the ephemeral freshwater pools during late winter and early spring to mate, lay eggs, and pass through an aquatic larval stage before transforming into four-legged terrestrial creatures.
For many, the period of time spent in egg and larval phases is related to water temps; the warmer the water, the shorter the incubation time, and the quicker the larvae grow and metamorphose into adults. And the quicker they can get out of the vernal ponds, the less likely they will become tadpole and larval carcasses as the pond dries up.
The important vernal breeding ponds for our mole salamander species (tiger, spotted, marbled and blue-spotted), arboreal frogs (spring peepers, gray treefrogs), and terrestrial frogs and toads (wood frog, Fowlers toad and Eastern spadefoot toad) are temporary ponds that occasionally dry up completely in midsummer, thereby eliminating one big problem for the eggs and larva: fish predation.
Mating and egg laying for tiger, blue-spotted, and spotted salamanders, as well as for wood frogs, have already peaked. Wood frog egg masses can be distinguished from others by the lack of an overall gelatinous mass that covers and protects all the individual eggs, as is found in the salamander egg masses. Instead, the individual spherical eggs adhere to one another, making the egg mass more fragile than that of the salamanders.
Peepers have been calling for about two weeks now, but I have not found any eggs. They do not lay their eggs in conspicuous clusters, as the wood frog and mole salamanders do, so they are more difficult to find. The tiny eggs are laid individually on the pond bottom under vegetation and debris and are hard to detect. This is our smallest frog (less than 1 inch in length), yet a female will lay as many as 900 eggs!
A freshly killed osprey was reported last week on the roadside near Burnett Creek in Water Mill. “Freshly killed,” as in the fish it had caught was still alive. Based on the description of the bird and its location, near the base of a utility pole, we guessed that it had landed atop the pole to dine and was electrocuted.
Unfortunately, the carcass was not recovered. Being a top-of-the-food-chain species, the State Department of Environmental Conservation’s Wildlife Pathology Department is interested in examining recently deceased osprey. If you happen on an unfortunate event such as this, move the bird off the road, note its exact location, and report it to the DEC at (631) 444-0308.
While participating in the East Hampton Town Spring Sweep beach cleanup organized by Dell Cullum, those of us working under the Montauk ocean bluffs were treated to small clusters of brilliant yellow flowers growing on the precarious bluff slopes. This was coltsfoot (Tussilago farfara), a non-native plant but a nice sign of spring nonetheless.
Coltsfoot has been used in herbal medicine, but its leaves, which are not visible when in bloom, contain an alkaloid that can cause severe liver problems. A variety has been developed in Europe for herbal use that is free of the toxic alkaloid.
For more signs of spring, consider joining me on Saturday at Big Fresh Pond in North Sea for the first nature paddle of 2015, sponsored by the South Fork Natural History Society. Call (631) 537-9735 to register.