Have you noticed any new sounds emanating from the woods as the ground thaws and temps rise? It could be the mating calls of wood frogs, one of the first amphibians to wake up to spring. Some say they sound like clucking chickens. You decide!
Or it could be spring peepers, the tiny but loudly vocal frogs that dominate our sound landscape in spring. Only three-quarters of an inch long, they have a distinctive “X” on their backs and small discs on the ends of their toes that enable them to cling to vertical surfaces.
All the action is happening in vernal pools right now! Vernal pools are depressions in the forest that fill with melting snow and spring rainfall, but dry up by the end of summer. Vernal pools are critical breeding grounds for amphibians. Because they are ephemeral (temporary), they contain no fish that would dine on the frog and salamander eggs that develop in them.
It’s a great time to go into the woods in search of vernal pools at this time of year. You can see wood frogs, spring peepers, spotted salamanders, and if you’re lucky, fairy shrimp. And, you should see LOTS of frog and salamander eggs.
Wet spring nights bring out amphibians, but under cover of darkness. Herpetologists (folks who study reptiles) have dubbed as ‘Big Night,’ the first night many amphibians move from their usual habitat in or under the forest floor to the nearest vernal pool. You can tell whether this annual migration has begun by a) whether frogs are calling, and b) whether egg masses are visible in a vernal pool.
There are many resources for learning about vernal pools. For the youngest, check out this great field guide and coloring book for vernal pools. Adults and older children can learn about the ecology of vernal pools from this presentation. You can also learn the basics of the creatures that inhabit vernal pools from this short video.
If you visit a pool, this short video will help you learn how to identify egg masses of different species. If you do visit, don’t wade into the pool, as you’ll disturb and potentially damage the developing egg masses.
Observe from the edge, but look for fairy shrimp – the tiny crustaceans that live their short lives in vernal pools. They grow to one inch max. They live in the pools, the females lay eggs/cysts which tolerate heat, cold, and drought, and the eggs hatch when the pool fills up again.
You can see the cycle of life on display in vernal pools and it’s happening now in the woods around us!