PORTER — A telltale sign of spring is bird song at daybreak.
Nearly 50 people gathered Saturday afternoon at the Nature Center at the Indiana Dunes State Park to learn how to identify the birds who make those songs at the park’s first Bird Sounds Workshop.
Led by park naturalist Brad Bumgardner, the group learned why birds sing, how they sing and what types of songs they sing, and then they went for a walk in the woods to test their newfound knowledge.
Bumgardner said the park decided to offer the workshop because “people kept asking for it.”
He said learning to identify birds without learning the different bird sounds is like “watching TV with the sound off.”
“You’re missing most of the story,” Bumgardner said. “So much of bird watching is identifying their sounds.”
Bumgardner said birds make sounds for a number of reasons, including locating mates and family members, to warn other birds of nearby predators, to establish territories, to distract predators from their young, and to beg for food.
The bird’s vocal organ, called the syrinx, produces the sounds, which are created by the contraction of muscles which force air from air sacs. Birds can produce two different notes at the same time, and most birds can produce three to four different songs depending on the situation.
Bumgardner said bird sounds can be grouped into six sound categories, which include warbles, trills, buzzes, simple songs, sing songs, and frenetic songs. Each type of bird produces a song that falls into one of these categories. For example, orioles, robins, and cardinals produce sing songs. An amateur birder can categorize a “mystery song” he or she hears into one of these groups and thereby narrow the identification down to a bird that creates that type of sound.
Some birds are born knowing their songs, but others have to learn how to sing “properly,” Bumgardner said. Some species have thousands of songs — the red-eyed vireo, which will arrive in the dunes in a few weeks, has 24,000 songs.
Birds can also be named by other sounds they make. For example, woodpeckers can be identified by the speed and frequency of the “drums” they make on trees. A downy woodpecker, for example, drums 16 times per second, while a hairy woodpecker is faster at 25 drums per second.
Bumgardner said 371 bird species are found in the Indiana dunes, which means birders have the potential to identify up to 1,000 different songs, which makes learning both an opportunity and a challenge.
“It’s a pretty good place and a pretty horrible place to learn bird sounds,” Bumgardner said.
Kim Gawron, of Portage, used the workshop as an opportunity to…