Saturday, October 10, 2015

Ritter Springs Hike


Several Master Naturalist volunteers* led a Discover Nature Schools field trip for Watkins 4th graders at Ritter Springs Friday.  Actually we spent more time following as they scoured the paths for all living creatures and a few dead ones.  The stars of the show were these cricket frogs.

These are Northern Cricket Frogs, Acris crepitans.  They were born and raised in the pond but now were hopping around a hundred yards away, undoubtedly searching for food in the rain-dampened grass.  I would have had trouble catching them with their erratic hops in the duff but surrounded by students built closer to the ground we collected several to study. 

 Cricket frog at water's edge - MDC Discover Nature Field Guide
Barely larger than my thumbnail, they resemble toads with warty bumps on their back and thighs.  Their brown color with moss green down their backs is perfect camouflage in the fall leaf litter.  Their coloration may be variable but the  distinctive backward-pointing triangle between their eyes separates them from other members of the tree frog family.
Northern Cricket Frog tadpole - USGS

They breed from spring through fall, attracting mates with this clicking call.  Females lay around 400 eggs in the submerged vegetation.  Large numbers of eggs are important as they are at the bottom of the pond food chain, eaten by aquatic insects, leaches, crayfish and fish.  The tadpoles that emerge will feed on algae and bacteria.

Only a few will reach adulthood when they will consume small insects such as mosquitoes.  Some of them in turn will be eaten by larger frogs, snakes and other predators.  They will crawl into damp underground spaces to avoid freezing during the winter, crawling out in spring to start the cycle again.

* Coordinated by Shae Johnson with Lorie Breidenstein and Holly Welch
Special thanks for ID and details from Brian Edmond.
Detailed information is at Amphibiaweb.org.

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