Professor Robert Benson, retired but most recently a teacher at Texas A&M University-Corpus Christi, sounded out some pretty strange sounds to explain how birds have calls and songs. The audience of about 30 people was enthralled.
Benson, who has a graduate degree from Texas A&M University-College Station in physics, said he became interested in wildlife, particularly birds, in his retirement. Now, he is considered an expert in bio-acoustics.
Benson gave an overview of about 20 birds, most of them common to South Texas.
“When you are going out in nature and loving it for the views, you can hear it, too,” Benson said.
“Efficiency of identifying birds, will be rewarding,” he said, adding that it takes some training, but it can be done.
His presentation, “Birding by Ear,” began with a definition of “oscine,” a suborder of birds considered songbirds.
He said there are about 800 species of birds in North America, half of which are songbirds.
Species tend to evolve into more species. For example, the Northern Cardinal in Austin compared to the Northern Cardinal in Bayside have different dialects.
Benson said it would be like asking if a Texas girl would be attracted to a Brooklyn accent – maybe, but most likely not.
He said song sparrows have 900 different songs as opposed to field sparrows having only one song.
He said a long-billed thrasher in one incident had 464 different song types for 113 minutes.
Another example is the red-eyed vireo, or preacher bird, who was recorded to have 22,197 songs during the course of a day.
“Bird songs must be important to birds or they wouldn’t spend so much time singing,” Benson said.
For example, he said the field sparrow spends nine hours singing, nine hours sleeping and six hours eating.
He said a bird song is a series of notes, often times variations of those notes, and they are likely sung for making a territory, mating or making friends.
“The songs substitute for physical fights. The bird does it by singing better, more aggressively and stronger,” Benson said.
And frequency is another term used for pitch, he said. Birds have a wide spectrum of pitches – some that carry far, penetrate barriers, are effective in the dark and some that vanish as quickly as they are uttered – all using a modest expenditure of energy.
Songs also are identified in different ways: by descriptive words, comparative idea, biogrammatic systems (notation on a bar) and phonetically.
For example, descriptive words might be “The bird sounds like a flute,” or a canyon wren’s song has descending notes.
The use of “it sounds like” is a comparative identification. For example, “It sounds like a squeaky wheel.”
Also phonetically, some birds say their names, such as Bob Whites and Kill Deer. And some birds seem to be saying something as in a phrase.
For example, the Inca dove seems to be saying “No hope ... no hope ... no hope” in a sad high pitch. Inca doves, white-winged doves and mourning doves among others all have their distinctive songs.
Benson played several audios of birds in the area and South Texas. They included the Inca dove, mourning dove, white-winged dove, barred owl, golden fronted woodpecker, ladder-backed woodpecker, white-eyed vireo, Bell’s vireo, red-eyed vireo, Caroline chickadee, tufted titmouse, black crested titmouse, Carolina wren, Bewick’s wren, northern mockingbird, yellow breasted chat, olive sparrow, northern cardinal, long-billed thrasher and red-winged blackbird.
Without a doubt, each bird has its specific individuality expressed through song.
Benson said when one starts to pay attention to all the bird songs, an entire new appreciation and discovery of birds (many not easily seen) is had.