Summer is in full swing and animals of every kind are in full reproductive capacity. The there is limited time to produce the next generation in our short northern summers. Frogs are no exception to this rule. There was still ice on my pond when I heard my first Western Chorus Frog (Pseudacris triseriata) calling this spring. (See my previous post Frog Sex Party) The chorus frogs have been finished with their breeding frenzy for about a month now. As the summer progresses different species begin and end their specific breeding seasons. It all starts with the Chorus and Wood Frogs (Rana sylvatica) start calling the moment there is open water. Soon after Northern Leopard Frogs (Rana pipiens) add their soft snore to the chorus. Then the American Toad’s (Bufo americanus) high pitch trill dominates the pond. By the time the toads start calling the Leopard and Wood frogs are finishing their season. The last to call in my pond are the Eastern Gray Tree Frogs (Hyla versicolor). The tree frogs are the last species finish their breeding season here in early July. In a couple of weeks my pond will fall silent until next spring.
All these amphibians call from my pond for one purpose, reproduction. Now is the time of year when the fruits of their labor begin to emerge. Mowing my lawn is a absolute chore. I raise the blade of my mower to the highest setting and have to stop several dozen times to guide tiny frogs and toads away from the spinning blade of death!
Frogs go through Complete Metamorphosis, or the juveniles (tadpoles) look nothing like the adults. Butterflies, beetles, and many other insects also go through complete metamorphosis. (Caterpillars look nothing like butterflies!) As tadpoles frog and toads are vegetarian, eating algae and other aquatic plants. When they emerge from the pond as froglets they become carnivores for the rest of their lives.
Western Chorus Frog (Pseudacris triseriata)
Note the vestigial remnants of the tail on this tiny frog. Froglets emerge from the water less than half the size of their adult counterparts. Western Chorus Frogs are only about an inch and a half long as adults so the froglets are smaller than most insects!
American Toad (Bufo americanus)
When the toads emerge from the pond it is not in a small numbers but a flood. Thousands and thousands of the tiny toads emerge at the same time. Through and evolutionary lens this make sense. Large numbers will overwhelm predators surrounding the pond and ensure that at least some of the offspring survive to reproduce. Those thousands of toads that emerge from the pond already represent the minority of all the eggs laid. They are the individuals who have evaded all danger lurking in the pond. Of those that emerged only an extremely small percentage, maybe a couple percent, will return to the pond to produce the next generation.
Look at the scale of the objects around this toad. I take a lot of pictures of insects but this toad is smaller than most of the insects!!
Wood Frog (Rana sylvatica)
I found this wood frog in my backyard. This was a pleasant surprise for me. I only heard two male wood frogs calling all spring. This is an extremely small group to sustain a viable population. In all reality I know it is a fragment of a population that was here before my housing development paved over the habitat. The population I hear today is destine for extinction.
Note the vestigial tail.
Amphibians around the world are dying. Many of them as a direct result of human activity. This is not a natural extinction, this is a direct result of the lives we choose to live. Denial or dismissal of this fact only reveals the veil of ignorance that we choose to live in. You, and I, are a part of the natural world no matter how hard we attempt to distance ourselves from it. The choices we make, the way we live, the actions we take do make a difference, positive or negative.
Up Next: Mish Mash