Small pond above a larger:
Permanent rather than vernal, but amphibians don’t know that. –Nor that, as a human artifact with no direct connection to any natural pool or stream, it is free of egg-devouring fish. (Tadpoles, snakes, salamanders, dragonfly nymphs and other predators… Well, it’s tough world, even submerged.)
Through the winter, melted and refrozen repeatedly, most years with the roof open often and long enough to sustain respiration by torpid residents, especially with a leaf net to reduce biological oxygen demand.
Frogs here typically migrate up from Farrar Pond on the first late-winter or early-spring night that meets three conditions: open water at the edges of source and destination, damp ground and a largely snow-free path between, and air temperature above about 40ºF. (Bright moon and rain are apparently helpful but not necessary.)
This was an exceptionally warm late winter and early spring—enough so to trick many trees and shrubs into early flowering, leading to destructions of a year’s bloom and seed when late frosts snickered at hopeful gardeners. This spring, there was also a shortage of rain at the appropriate time. So even with water and ground clear, travel was apparently too parching for skin-breathers until a week or so later than normal. By March 17th, however, wood frogs were noisily engaged and married, then in the still consummation of amplexus both afloat as usual
and (less commonly) ashore nearby:
Both techniques proved productive, quickly delivering a considerable number of embryonic offspring:
Afternoon of the 18th brought a gloomy front,
and then sharp cold. By the morning of the 20th, the top inch or so of each high-laid egg mass was frozen solid
while parents rested safely beneath the blurry crust:
The next day it warmed and snowed—insult to injury, where earlier snow or heavy rain might have left the precious deposits safely insulated.
The mushy thawed eggs provided welcome early food for a hundred or so over-wintering bullfrog tadpoles, and probably other creatures as well. But half a myriad is still thousands, and when warmth returned, hatching seemed to occur all the more quickly, carrying forward the next cycle of life:
