Category Archives: Vocalizations

Visualize Bird Song

Screenshot from Bird Song Hero tutorial (Cornell Lab of Ornithology)

Now that the birds are singing again and more singers will arrive on migration, it’s time to practice identifying songs by ear. Yes, it’s hard to do but it’s easier if you can visualize the song.

Just like a sheet of music, a spectrogram of bird song shows how the frequency (pitch) goes up and down. The black dashes graph the frequency and length of the notes. The brown wave graphs loudness in decibels.

Song sparrow spectrogram for Xeno Canto audio XC374118 (audio by Ted Floyd)

Play the matching audio to hear the graph: a song sparrow recorded by Ted Floyd, Xeno Canto XC374118.

This is just one example but you can learn to do it yourself and practice with two quizzes at Cornell Lab’s All About Birds.

  1. Learn how to read the spectrograms that visualize bird song in this video: Bird Song Hero Tutorial.
  2. Two quizzes follow the video or you can try them independently at the Bird Song Hero Challenge. TIP: Watch the sonogram as it plays! Some of them are tricky.

p.s. Did you know that birds sing harmonies we can’t hear? On the song sparrow spectrogram, above, there are tall vertical dashes during the fast part of the song. The bird is harmonizing with himself in the 12,000 HZ frequency. If you’re older than 30-something, you probably can’t hear it.

(screenshot from Bird Song Hero tutorial (Cornell Lab of Ornithology, sonogram and audio from Xeno Canto XC374118 by Ted Floyd)

p.p.s Xeno Canto calls the graphs “sonograms.” It’s an older word for spectrogram. Here’s the difference between “spectrogram” and “sonogram.”

I Can See, But Not Hear Them Singing

Can you hear the golden-crowned kinglets in this video? They are very loud but I can’t hear them at all, though I can see their beaks moving. Their voices are at a high frequency I no longer hear.

All About Birds explains:

Golden-crowned kinglet (photo by Steve Gosser)

Golden-crowned kinglets sing an ascending, accelerating series of up to 14 very high-pitched tsee notes lasting up to 3 seconds and sometimes ending in a musical warble that drops an octave or more in pitch. This is one of the first bird songs that people stop being able to hear as they age. 

All About Birds, Golden-crowned kinglet sounds

If you can’t hear the kinglets you are probably over age 65, perhaps younger, and probably have age-related hearing loss. Presbycusis affects 1 out of 3 of people by age 65 and half of us by age 75. The CDC explains that “the most important sounds we hear every day are in the 250 to 6,000 Hz range.” Kinglets vocalize around 8,000 HZ.

What are HZ? Sounds cause vibrations and are measured in vibrations per second: 1 Hertz (HZ) is 1 vibration/second. High-pitched sounds vibrate faster than low pitched sounds so “high pitch” is also “high frequency.”

At birth humans can hear sounds from about 20 to 20,000 HZ but we start losing our upper range of hearing at age 18! Most of us don’t miss sounds above 17,000HZ but some teenagers in the UK will. They capitalized on the age-related hearing difference by creating a “mosquito whine” ringtone that teachers cannot hear. See and hear it on NPR.

The kinglets in the video are vocalizing at 7700 to 8400 HZ as shown in this graph from the Spectroid app on my mobile phone. The pink scale at the bottom shows the kinglets singing in the 8000 HZ area (at right) and my voice below 5000 HZ (long pink lines on the left). (Top graph shows loudness in decibels.)

So now I have two ways to see golden-crowned kinglets singing. I can watch their beaks or I can watch the Spectroid graph on my mobile phone.

Perhaps if I point my cellphone in the woods I’d see if any golden-crowned kinglets are out there.

p.s. Click here for a video that explains age-related hearing loss & helps you answer the question “How Old Are Your Ears?

(photo of golden-crowned kinglet by Steve Gosser, Spectroid graph recorded by Kate St. John; video by The Wood Thrush Shop on YouTube)

Identifying Bird Song: You Know More Than You Think

Eastern phoebe, Schenley Park, 27 May 2018 (photo by Peter Bell)
Eastern phoebe, Schenley Park, 27 May 2018 (photo by Peter Bell)

After months of silence, spring is coming and the birds are singing again. It’s the best time of year to practice identifying birds by song.

No matter your skill level there’s always more to learn. If you’re an expert, it’s time to practice songs heard only once a year during spring migration. (Cape May warbler!)

If you’re new to bird song you probably think, “It’s so hard to learn bird song. I don’t know anything!”

Here are two hot tips to help birders at any level.

Tip #1: You’ll learn the song better if you see the bird singing. We humans are visual learners. Look for the unknown singer and watch him sing.

The eastern phoebe pictured above looks plain but he’s easy to identify by song because he says his name: FEE bee! FEE bee! The author of the video below went looking for the bird to watch him sing. It’s a bit seasick-making 😉

Tip #2: Keep at it! You already know some bird songs. Just build from there, one bird at a time.

Here are three birds most people can identify. I bet you can, too.

Bird #1 (Xeno Canto 454252, recorded in Norfolk County, MA by Will Sweet)

Bird #2 (Xeno Canto 421264, recorded in Tompkins County, NY by Gabriel Leite)

Bird #3 (Xeno Canto 399153, recorded in Harrison Hills Park, Allegheny County, PA by Aidan Place) This recording is faint so you may have to turn up the sound … and hear it raining.

You already know more than you think.

(photo of eastern phoebe by Peter Bell. Xeno Canto recordings identified and linked in the captions above)

Tell Me Who’s Singing

Ovenbird singing (photo by budgora on Flickr, Creative Commons license)

Have you ever wished for a tool that could accurately identify a single bird’s voice among dozens of singers? You aren’t alone. Ornithologists are eager for a way to census birds using field recordings, but the sheer volume of data and complexity of bird song makes this a daunting task. A free tool that can identify huge volumes of song data doesn’t exist yet, but the Kitzes Lab at the University of Pittsburgh is creating one.

In December 2018 Assistant Professor Justin Kitzes of the Department of Biological Sciences won an AI for Earth Innovation Grant, awarded by Microsoft and National Geographic, to develop the first free open source model for identifying bird songs in acoustic field recordings. Its name is OpenSoundscape.

OpenSoundscape uses machine learning, a subset of artificial intelligence (AI), to scan recorded birdsong and algorithmic hunches to arrive at a song’s identity. To do this the Kitzes Lab starts with real life recordings.

The team places small AudioMoth recorders in an array in the forest, much the same way human observers do point counts except that the Audio Moths are all recording at the same time.

Audio Moth in the field(photo courtesy Kitzes Lab)

The team brings the recorders back to the lab and downloads the sound files to the database. (Some day the software will be able to triangulate GPS from several Audio Moths and determine a single songbird’s location!)

AudioMoth recorder used by field study at Kitzes Lab (photo by Kate St. John)

Here’s one recording of at least six individual birds. OpenSoundscape is learning how to identify them.

An Audio Moth recording from the field (courtesy Kitzes Lab)

It makes a spectrogram of the sound file (below), then picks out each pattern and uses algorithms and the classifier library to identify the individual songs.

The more songs it successfully identifies, the better its algorithms become.

By the end of 2019 the OpenSoundscape models, software, and classifier library of birdsong will be ready for researchers on a laptop, cloud service or supercomputer. Ornithologists will be able to gather tons of data in the field and find out who was singing.

p.s. WESA featured this project in their Tech Report on 26 Feb 2019. Click here to listen.

(credits: photo of ovenbird by budgora on Flickr, Creative Commons license. Photo of Audio Moth on a desk by Kate St. John. All other photos and sound file, courtesy the Kitzes Lab)

A Sound That Reminds Me of Home

Last March while birding along Panama’s Pipeline Road we heard a sound that reminded me of home. 

The bird was loud and its sound was tropical — not a Pennsylvania bird — but something about it seemed familiar.

Here’s what we heard:

Rufous piha (audio from Xeno Canto XC107022)

Our guide identified it as the rufous piha (Lipaugus unirufus) a member of the Cotinga family.

So why was his song familiar?  

I used to hear a similar sound in the Wetlands Room at the National Aviary. The sound is gone now — the bird passed away — but for many years his voice defined that room.

Screaming piha (audio from Xeno Canto, XC444908)

The screaming piha (Lipaugus vociferans) is a member of the Cotinga family native to the Amazon. The bird looks boring but his voice is not.

Screaming piha (photo by Dick Daniels via Wikimedia Commons)

It’s too bad he’s no longer with us at the National Aviary.  His voice from the Amazon reminds me of Pittsburgh.

(photo of rufous piha by Amy E. McAndrews on Flickr, Creative Commons license; photo of screaming piha from Wikimedia Commons; audio from Xeno Canto. Click on the captions to see the originals.)

Raven Gets Creative

Crows are common in the city but ravens are rare so I was surprised to hear a raven this week in Schenley Park.  It called and circled overhead waiting for its companion to arrive. “Brrrock! Brrrock!”  When the second raven caught up they flew away together.

I see ravens in town about twice a year but I only hear them make the Brrrock call.  If I lived where common ravens (Corvus corax) are common, I’d hear their wide variety of sounds.

This video from Anchorage, Alaska gives you an idea of the ravens’ vocal range.  He starts with Brrrock.   Then he gets creative.

(video by dougbrown47 on YouTube)

The Lookout Bird

Dusky-throated antshrike at banding station (photo courtesy of Cameron Rutt)

When you’re vulnerable to predators it pays to stick together and have a good lookout to warn you of danger.

The dusky-throated antshrike (Thamnomanes ardesiacus) doesn’t look important but he’s quick to notice the presence of hawks and falcons and has a distinctive alarm call that wakes up the forest to impending danger.  It turns out that he’s key to the foraging location and cohesion of his mixed species flocks in the Amazon.

Early this year, a study by San Francisco State University temporarily removed dusky-throated antshrikes from their mixed species flocks in Peru. They discovered that within hours the flocks left their semi-open mid-story locations for denser parts of the forest.  Often the flocks without an antshrike completely dissolved.

What does the alarm call sound like?  Is it loud? Does it grab your attention? You bet!  Here’s the sound of a worried dusky-throated antshrike:

His role in the flock works so well that the same mix of species sticks together for generations. As San Francisco State Professor Vance Vredenburg remarked, “You come back to the same habitat after 20 years, and the same flocks are using the same areas of the forest.”

Read more about the study here in Science Daily.

p.s. When the antshrike is not afraid he sings this buzzy, rising song. (audio by Peter Boesman at Xeno Canto #271766)

Dusky-throated antshrike song (Xeno Canto 271766)

(media credits: photo of dusky-throated antshrike by Cameron Rutt, audio alarm call from Macaulay Library, audio song from Xeno Canto; click on the captions to see the originals)

What Is This Chicken Saying?

If we want to understand what birds are saying the easiest way to learn is from the birds that live with us.

Sue Cross at The Holistic Hen observes her free range chickens closely to find out what they’re saying.  Sometimes a message isn’t clear at first.  

This hen flew up to touch the door repeatedly.  Watch the video to find out why.

Read more about chicken behavior and organic forest farming at The Holistic Hen.

(video from The Holistic Hen on YouTube)

Purple Martins Sing

Purple martin male, singing near his nest, Chicago (photo from Wikimedia Commons)
Purple martin male, singing near his nest, Chicago (photo from Wikimedia Commons)

We don’t think of swallows as songbirds but indeed they do sing.  Our largest swallow, the purple martin (Progne subis), has a unique sound that carries far.  With practice, you can recognize their voices even when you can’t see them.

Purple martins nest communally so the best place to learn their song is near a purple martin colony.

As you approach you’ll hear them singing as they fly, a liquid gurgling warble with throaty chirps.  (This in-flight recording, Xeno Canto XC13689 by Chris Parrish, includes other bird songs in the background.)

 

In early summer near their nests, you’ll hear songs, creaky rattles and the sound of begging juveniles. (Purple martins vocalizing near their nest, including begging calls of young, from Xeno Canto XC139568 by Russ Wigh)

 

The throaty, gurgling chirps are unique to purple martins.  When you hear it overhead, look for a nearby colony and go see the swallows sing.

For more sound samples visit the purple martin sound page at All About Birds.

 

(photo from Wikimedia Commons; click on the image to see the original.  Audio from Xeno Canto; click the links for the original recording pages)

The Sound of a Water Drop

water drop (photo from Wikimedia Commons)
A water drop (photo from Wikimedia Commons)

A water drop sounds like this  …

… but that noise was made by a bird. (named at the end of the recording: XC148304 by Gary Stiles.)

It’s my favorite bird sound from Panama, made by a black-bellied wren (Pheugopedius fasciatoventris).

In his preferred habitat the wren is hard to see.  Mostly black and brown, his white throat looks like a splash of sunlight from below.

Black-bellied wren, Panama (photo by Fransceso Veronesi from Wikimedia Commons)
Black-bellied wren, Panama (photo by Fransceso Veronesi from Wikimedia Commons)

But he’s easy to hear. When he really gets going he doesn’t sound like a water drop at all.  This long melodious song (xeno-canto XC15653) was recorded by Don Jones on Semaphore Hill Road, the road to Canopy Tower.

 

The “water drop” is just a tiny snatch of song.

 

(photos from Wikimedia Commons; click on the images to see the originals. recordings downloaded from Xeno Canto; links provided to the originals)