The white-throated sparrow delivers songs typically described using the mnemonic “Old-Sam-Peabody-Peabody-Peabody.” Juveniles learning to sing in the fall deliver a version that becomes jumbled and tends to trail off. Pam Wells/Maine Audubon

The woods are very quiet right now. The nesting season for our local birds has wrapped up and there is no need for birds to be singing. Singing is only done to attract a mate or defend a territory, so being too noisy in the fall would probably only attract predators. On a recent bird walk (join Maine Audubon every Thursday at 7 a.m. for a free bird walk at Gilsland Farm in Falmouth) we heard some birds singing, but to be honest, they were horrible at it. That leads us to a commonly asked question this week: “What’s the deal with these untalented singing birds in the fall?”

To start, let’s make a distinction between birds that learn their songs and those that know it from birth. The latter group, known as innate learners, include birds like flycatchers that often have very basic songs and sound identical across the species (in other words, there is very little variation between individuals). Our other group, those that have learned their song through experience, are the ones we’re interested in just now. Within these, most juveniles (born this summer) have just finished a “sensory learning” period where they are listening to birds around them, most likely their fathers, and learning the songs they are hearing. They do this by creating a template in their minds that they’ll use as a reference for the rest of their lives.

This leads us to the odd songs we are hearing right now. As we head into the fall, these juvenile birds are switching into their “sensorimotor learning” period; now they are singing, trying out their voices and attempting to match the templates that they’ve memorized. Much in the same way that infants have to learn certain noises (“goo-goo gaa-gaa”) before they can assemble full words (“Let’s go birding, Uncle Doug”), young birds go through a similar process and sing what are called “sub-songs.”

By practicing these sub-songs, juvenile birds will eventually learn how to sound like an adult. A great species to listen for right now – the one we heard on our bird walk — is a white-throated sparrow. Their songs are typically described using the mnemonic “Old-Sam-Peabody-Peabody-Peabody,” given in a series of clear whistles that drops in pitch between each of the first three phrases. The song that you hear juveniles practicing right now will often just sound like “Old-Sam . . . ” with maybe a few jumbled notes as it trails off. Though the forests are getting progressively quieter as even insects stop singing, it is fun to keep an ear open for the training juvenile birds out there!

AN AUTUMNAL ‘BIG NIGHT’ FOR FROGS?

There is a well-known “Big Night” each spring when, on the first warm rain of the year, there is a mass movement of amphibians (frogs and salamanders) as they migrate to vernal pools to mate and lay eggs. On these nights, it is common to encounter hundreds, if not thousands, of these fresh-from-hibernation creatures as they swarm across roads to find mates. I was a bit stumped by a handful of folks from around the state reporting observations of mass movements of frogs a few weeks ago (in early September), which led to some fun topics I wanted to share here.

While the highly synchronized spring movements of many amphibians are well-known and easy to observe, the fall movements, which are just as far and involving more individuals (assuming reproductive success in the preceding summer), are less known and certainly less conspicuous. We know a lot more about the movements of birds and other migratory animals, and while there is more research to be done, there are some obvious similarities. Like birds, our frogs go through a period before migrating when they are attempting to eat a lot, packing on as much fat, or “fuel,” as possible. Some of these reserves will be burned up during migration, but are also necessary for frogs to have throughout the winter when they are hibernating.

Studies have shown that species like leopard and green frogs, as well as American toads, have periods of “hyperactivity” on rainy nights ahead of their autumn migrations. They are traveling over short distances (shorter than a typical migration), and not toward bodies of water where they would over winter. These behaviors all point toward foraging. So the mass movements that folks were reporting seem to match these hyperactivity periods of frogs bulking up for winter.

As we progress through the fall, there are a few helpful things that you can do to assist frogs as they settle down for the winter. Most importantly, leave the leaves! Having leaf cover on the ground is very important for a wide variety of wildlife. Some use it for protection all winter, like caterpillars, butterflies and bees, and some species use the cover in transit, like our frogs.

Do you have a nature question for Doug? Email questions to ask@maineaudubon.org and visit maineaudubon.org to learn more about backyard birding, native plants, and programs and events focusing on Maine wildlife and habitat. Doug leads free bird walks on Thursday mornings, 7 to 9 a.m., at the Gilsland Farm Audubon Sanctuary in Falmouth.