Species of the Month, April 2021: Yellow-Spotted Salamanders
by Mary Gartshore
Salamanders dance but don’t sing.
Four species of large mole salamanders occur in the Carolinian Zone of Ontario. These are Small-mouthed Salamander on Pelee Island and Blue-spotted, Jefferson and Yellow-spotted Salamanders on the mainland including Norfolk County. Cross-breeding and some pretty complicated genetics have happened with Blue-spotted, Jefferson and Small-mouthed Salamanders that have produced large numbers of all-female animals with three sets of chromosomes. Yellow-spotted have played no part in this genetic turmoil as far as we know.
Yellow-spotted Salamander is common in upland forests and spends most of its time underground as a predator of invertebrates. They may use tunnels of Star-nosed and Hairy-tailed Moles. Sometime between mid-March and the first week of April during intense spring rains, these salamanders emerge en mass at night and walk to their pond to breed. They favour ponds that are fishless, isolated and are over half a meter deep.
Males arrive first and gather in dancing groups to deposit sperm packets on leaves on the bottom of the pond. Some females may arrive and are courted by males. However, intense competition amongst males have them pretending to be females so they can deposit their own sperm packet on top of their rival’s sperm. Later the same night or the following night females may arrive to collect sperm deposited by several males to fertilize their eggs and begin egg-laying.
Once egg-laying is completed, they leave the pond to spend the summer and fall in the forest. The egg mass is a firm gelatinous mass the size of a tennis ball containing about 200 eggs. The tadpoles are elongated with four legs and feathery external gills. They leave the pond as juveniles around mid-July before the water dries out. Adult Yellow-spotted Salamanders may live as long as 30 years.