Spotted salamander congress
We were so lucky we got to see hundreds of swirling, thrashing, and breeding Spotted salamanders tonight. What a treat. Everyone was so happy and amazed. One of the ten year olds said it was the best night of her life. One of the twenty year olds said she wanted to stay all night.
During the March to April breeding season, the males come out of hibernation ahead of the females by a day or two and arrive at the vernal pools first. There they form large clusters of writhing males called congresses. As females arrive, individual males will separate from the congress and perform a courtship dance with a female. They will circle and put their heads under one another's tails. The male may climb on the female's back and rub her with his chin. The male will then swim away wiggling his tail and the female may decide to follow. He leads her to spermatophores he deposited earlier on submerged leaves on the pool's bottom. The female squats over the spermatophores and picks them up through her cloaca, the opening amphibians use for breeding and laying eggs. The female may pick up spermatophores from more than one male. Fertilization of her eggs takes place internally. Then she lays her egg clusters on leaf litter or vegetation at the bottom of the pool.
The following photographs aren't very clear since they're through the water at the bottom of the pool and there is so much frenzied movement. But you can see there are a lot of them in a small space. The bottom photo shows one of the males coming up for air. There were so many of them and they sure didn't come up very often so they don't have to breathe frequently.