Boom Year for Wood Frogs (Rana sylvatica)

Observation by Brandie Radigan:

We usually hear them begin their calls in late May but this year there seem to be hundreds rather than just a couple dozen and starting earlier than usual.

Joshua Ream, member of the Alaska Herpetological Society, writes:

This is really great to see an observation submitted on Wood Frogs from the Copper River area. Wood Frog populations like many amphibians fluctuate greatly from year to year, usually based on the previous summer's productivity AND the winter's severity. More snow often results in greater winter survival since this insulates the frogs from the ambient temperature extremes in the interior. Early emergence is likely due to earlier ice melt in the area; the species has done so well across North America, including in arctic regions, because of their ability to emerge, breed, and develop to the metamorph stage during a very short ice-free season. I don't think this sighting is unusual but always good to know that boom years are continuing to occur.

Comments from LEO Editors:

Rick Thoman, climate scientist at the Alaska Center for Climate Assessment and Policy (ACCAP), presented an Alaska Winter 2019-2020 Climate Review and Spring 2020 Outlook on April 21st, 2020. In his review, he describes unusually warm winter temperatures from October to December, which turned colder than normal over mainland Alaska from mid-December to March. However, precipitation levels were higher than normal for most of the state. The snow depth chart for Glenallen, shown below, shows higher than average snow depth in early 2020. Warm spring temperatures have caused rapid snowmelt beginning in late April and continuing in to May. Erica Lujan