Screamers: Vocalizations

Summary: Do Screamers actually scream? Find out in this episode of Ten Things I Like About Screamers.

 

For my hearing impaired followers, a complete transcript of this podcast follows the show notes on Podbean

 

Show Notes: 

“Observations on the Horned Screamer,” by Frank B. Gill, F.J. Stokes, and C.C. Stokes. Wilson Bulletin, Vol. 86 (1974), Iss. 1, Art. 6. https://digitalcommons.usf.edu/wilson_bulletin/vol86/iss1/6

Screamer Vocalizations: https://birdsoftheworld.org/bow/species/horscr1/cur/sounds

Music written and performed by Katherine Camp

 

Transcript

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Kiersten - This is Ten Things I Like About…a ten minute, ten episode podcast about unknown or misunderstood wildlife.

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Welcome to Ten Things I Like About… I’m Kiersten, your host, and this is a podcast about misunderstood or unknown creatures in nature. Some we’ll find right out side our doors and some are continents away but all are fascinating. 

This podcast will focus ten, ten minute episodes on different animals and their amazing characteristics. Please join me on this extraordinary journey, you won’t regret it.

  Listeners, let me first apologize for missing a week in the middle of Screamers. Spring has started off extremely busy for me and time got away from me.

Let’s jump back in with episode eight of Screamers. The eighth thing I like about Screamers is their vocalizations. Yes, that’s right we are finally going to talk about the attribute that gives these birds their common name, Screamers.

Most of the research I found on the vocalizations of Screamers focused on the Horned Screamer, Anhima cornuta, so what we talk about today pertains to this species. All species of Screamers make similar calls and vocalizations that’s where the name come from, but the specific details in this episode are about the Horned Screamer.  

Most of what we know about Horned Screamer vocalization and related behaviors come from the research of Frank B. Gill. Three vocalizations have been observed and described from observations of wild Horned Screamers.  I promise you that none of them are a melodious song that you associate with songbirds. Their calls are definitely more like their close relatives swans, ducks, and geese. I cannot play any of these calls for you in this episode due to copyright agreements, but I will post links in the show notes that you can follow to listen to these calls.

The first call that we’ll talk about what is titled the Moo Co call. M-O-O C-O is the spelling. This call is bisyllabic meaning it has two notes. The second note has a distinctly lower frequency than the first note. The intensity of this call varies from a melodious call to a harsh bark to a coughing note. The volume of this call can vary from soft and only heard when close to the bird or very loud and can be heard from over a mile away. That’s quite a call!

The Moo Co calls are often given by couples in a duetting sequence. When this happens the birds combine their calls by overlapping the second note of the first individual with the first syllable of the second individual. This can result in a trisyllabic call Ha Moo Co or Ha Moo-o Co. This call is where the local name for Horned Screamers, jamuco, comes from. This triple call is only performed by couples, most likely mated pairs, as it was never heard from a single, lonely individual. The triple Moo Co call is the call that mated pairs use to reinforce their bond through the year and at the beginning of each breeding season.

It is believed that males produce a louder and deeper pitched Moo Co call than females which makes the duetting a bit more musical. It can also aide in identifying sexes through vocalizations. Moo Co calls are used for alarm calls, distance calls, and greetings.

The second call is called honking as it closely resembles the honking calls of a goose. This call consists of two distinct patterns given in various combinations. One of the patterns has seven to eight strongly developed harmonics. This sequence typical lasts about 30 seconds and is often accompanied by head and neck bobbing, especially when multiple screamers are together. Honking is typically used for distance calling and greetings.

The third call is a loud bugle-like call titled the Trumpet call. This call consists of two syllables with a low introductory note and a second inflected note. This one is meant for long distance communication as is it the loudest of all three vocalizations.

With these three call descriptions, we can clearly see why these birds are called Screamers, when you listen to these calls it will reinforce this name. These birds do a lot of screaming! I do have to admit that the duetting between two Screamers is quite hypnotic and has a lovely sound. I can see why they reestablish their bonds and their territories using this call.

In the wild, screamers typically do most of their vocalizing in the early morning, but will call sporadically throughout the day. Morning brings Moo-Co calls to greet the morning and talk to the neighbors. Remember this species of screamer lives in small groups of 5 to 10 with everyone helping define a territory, so knowing that everyone made it through the night and where they are is important.

If nothing really happens during the day, the screamers are quiet but, if they decide to move locations or other screamers encroach on their territory, things can get loud.

Moo Co calls are made when groups decide to move locations and can be heard during take-off when individuals are close together. If an individual within an established group changes location they are quiet upon take-off but are greeted loudly with honking upon landing.  Honking between isolated groups, up to a mile apart, happens a lot. One group will begin honking with occasional trumpet calls and then nearby groups will respond. This kind of check-in can last about 20 minutes and involve up to seven different groups. We are not entirely sure why they do this, but it is certainly a great way to get information about your surrounding environment. 

Honking and trumpeting erupt when other groups of screamers land near territory boundaries or cross over into an established territory. 

There is one last call we need to discuss. Screamers also produce a nonvocal sound using the unusual subcutaneous air sacs we discussed on the last episode. This call is a low-intensity sound created during pair bonding activity and family greetings. It is produced with the body in a horizontal position, with the tail slightly lowered. Feathers in the middle of the neck region are repeatedly raised and flattened in concert with this “ugh” sound. We are not exactly sure how Screamers produce this sound, but it is hypothesized that it is created by forcing air through the subcutaneous air sacs in the neck. Well, Screamers just get more and more interesting with each episode.

I hope you enjoyed this look at Screamer vocalizations because it is my eighth favorite thing about this amazing bird.

If you're enjoying this podcast please recommend me to friends and family and take a moment to give me a rating on whatever platform your listening. It will help me reach more listeners and give the animals I talk about an even better chance at change. 

Join me next we for another exciting episode about screamers.  

    

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This has been an episode of Ten Things I like About with Kiersten and Company. Original music written and performed by Katherine Camp, piano extraordinaire.