Wood Frogs in the Pond
Phenology – “a branch of science concerned with the relationship between climate and periodic biological phenomena (as the migration of birds or the flowering and fruiting of plants).
Snow lingers in the woods, though a few bare spots have emerged under the firs, where the snow never amounted to much. The ice is mostly gone from the pond, and now, in mid-April, we listen carefully for the wood frogs - lovely tan creatures with black masks who find the merest signs of spring reason enough to wake up and go for a swim. One day you might hear a couple of frogs, and then a day or two later you will hear hundreds of them, their low-key quacking easily mistaken for ducks.
April 19, 2019. 70 degrees, mostly cloudy. The Pond is only 10% ice free, but 80% of the ice is rotting and grey. I heard a dozen or so wood frogs making sporadic calls, but they hopped into the pond as I approached. The first one I saw was floating by on a tiny iceberg only 1.5 inches across.
[1] Photos and text by Carl D. Martland, founding member of ACT, long-time resident of Sugar Hill, and author of “Sugar Hill Days: What’s Happening in the Fields, Wetlands, and Forests of a Small New Hampshire Town on the Western Edge of the White Mountain”. Quotations from his book and his journals indicate the dates of and the situations depicted in the photos.
The males are the first to reach the pond. Some command a foot or so of shoreline, hoping a female will hop down the hillside; others spread out across one of the coves, spacing themselves about a yard apart, hoping to intercept the females who must swim across from the opposite shore.
April 30, 2015: dozens of wood frogs in the reeds and along the southeast bay about 10am. At 5pm, all was quiet, and there were several dozen clumps of eggs.
When a female arrives, males will try to climb on her back and then grasp her very tightly around her neck, gaining a position that will allow them to fertilize the eggs when they are eventually deposited, a process known as “amplexus”. Since two or more males will, if they can, glom onto a single female, it is essential that the females be much larger than the males so that they can pop up for a breath of air whenever they want to.
April 14, 2020. Two males fight for position on a female wood frog.
One Sunday in mid-April, I found a spot near the shore where I could see five dozen males without even moving my head. While sitting there, I would hear rustling behind me and then watch crazed males take wild leaps into the pond. One was so anxious that he landed on his back, rolled over and only then hit the water. While any quick movement would cause all the males to submerge, an extremely loud sneeze had no effect!
Finally, a female appeared. Redder and larger than the males, she swam up under some grass clippings and stuck her nose up, the grass hanging over her forehead making her seem like a teenager who’d died her hair to upset her parents. She sat there for a while with her belly bulging as she added a croak or two to the general chorus. Eventually, she set out for the nearest male, who was just hanging in the water four feet away. But she quickly veered off and swam within a couple of inches of the next male, then sped past. This guy quickly caught up, jumped on, and grabbed her around the neck. They swam off about seven yards to the right and I lost sight of them.
Another female made passes at three males. Each time she approached and stopped, allowing the male to swim by for her inspection. The first two times, she apparently didn’t like what she saw and swam away. The third time, she swam past the male, paused, and allowed the male to mount. A would-be suitor contested the pairing, but the first male held on tightly enough and the pair swam off.
The wood frogs continued most of that Sunday, taking a break for a couple of hours during the middle of the afternoon, then continuing until at least 9pm. On Monday morning, there were only a few dozen frogs left in the pond, but there were more than 325 clumps of eggs in the reeds, each with two hundred or so eggs. In all, there were well over 50 thousand eggs!
A female wood frog will lay a hundred or more eggs in a single, rounded mass. Over just two or three days, hundreds of females will deposit their eggs all jumbled together in the same small opening in the reeds. [Photo: April 25, 2019]
It was the first real day of spring when I next went out to check on the wood frog eggs. Numerous migrating birds had arrived overnight, including a small flock of evening grosbeaks, a phoebe, a flicker, a pair of wood ducks and three mergansers. Two ruby-crowned kinglets, faster even than warblers, flitted about in the willows and the brush, while a song sparrow serenaded a pair of tree swallows that were checking out a bird house by the pond. A lovely 65-degree day.
The wood frogs were gone, but their egg masses attracted a lot of notice. Nine newts squirmed in, around and through the jumble of egg clumps, sometimes twisting around each other and at other times plunging solo through the gooey masses. Several huge leeches attached to the clumps of eggs, and a painted turtle swam by, checking out the whole operation.
April 23, 2017. A day or two after the eggs were deposited, the tadpoles appeared to be tiny balls. A caddis fly larva has dropped by to see what’s going on.
May 4, 2017: yesterday, most tadpoles were still encased in their eggs. Today, they nearly all have emerged, but they haven’t traveled more than a foot or two, and they seem unaware of the large bull frog tadpole that is messing around in the decaying egg masses.
Within five or six days, about half of the tadpoles were out or active within their sacs; within a week, all had emerged; within another day or two, the egg cases themselves were mostly gone. I couldn’t tell who was eating these cases – it could have been ducks, newts, other frogs, the muskrat I noted hiding in the reeds, or perhaps they just dissolve.
May 13, 2015. On the 11th, the tadpoles started to emerge from the egg masses, but they stayed right nearby. A day later, the 12th, the tadpoles were all out, still staying close to the egg masses, and the egg masses were collapsing. Today, on the 13th, six days after I first saw the ball begin to unfurl and two weeks after the first eggs were laid, the tadpoles had all swum away and the egg masses had disappeared.
It may or may not be coincidence that ducks and a magnificent pair of great blue heron began to visit our little pond just after the wood frogs arrived. They were certainly enjoying their feeding, though I never could see what they were capturing. Over the next several weeks, I would from time to time see a vast swarm of tadpoles a yard wide, a foot deep, and more than 50 feet long, moving slowly along the edge of the pond, feeding on minute bits of vegetation and detritus and generally cleaning up the grasses and sedges at the edge of the pond. What a marvelous example of the incredible explosion of life in the pond!
June 3, 2015, 1230pm, 65 degrees. A dense stream of tadpoles moved slowly along the reeds toward our end of the pond. The stream was more than twenty feet long, two feet wide and a foot deep, and it was moving at a rate of about five feet per minute. By 6pm, the swarm had stretched out along the dam, and it was now a hundred feet long and three to four feet wide.
By late June or early July, the tadpoles lose their tails, and the multitude of inch-long frogs begins to leave the pond. For a couple of days, hundreds may be seen jumbled all together along the edge of the pond, some still in the water while others have made it a foot or so inland. Within a couple of days, they are nearly all gone, although you may see a tiny straggler or two climbing through the grass, wondering where everybody went.
July 5, 2006. A few wood frogs were still struggling to get through the grassy areas near the pond.
Few wood frogs will stay anywhere near the pond, and fewer still will ever be seen, for their colors provide perfect camouflage. Once in a while, I have seen one out in the woods, but I suspect many have escaped my notice simply by sitting still, like the one in the final photo.
August 25, 2017, 65 degrees, mostly cloudy, seems like early autumn. After venturing a ways into Foss Woods, I took a picture of a small wood frog that was nearly invisible in the duff by the trail.
