Friday, September 19, 2008

Wren Duets – For Togetherness or War?


For years, it has been known that wrens sing duets with their mates. Recently, the availability of new technology has allowed researchers to figure out the purposes behind the songs.

Studies were conducted using a series of microphones which were used to listen to the songs and calculate the birds’ positions. This technology eliminates the need to capture and tag birds, or even be able to see them in the dense forests that they inhabit.

As it turns out, the birds use duets like children play “Marco Polo”. One bird will begin to sing and then, upon hearing its partner’s half of the song, it can figure out its mate's location and move toward it.

The duets also have another purpose. As found by this study, when one pair of wrens hears the duet of a rival pair in their territory, the songs are now used as battle cries. At the arrival of the new pair, the frequency of the duets increases dramatically. If the songs fail to ward off the intruders, physical violence can incur.

This research has proven the value of the new multi-microphone technology. Because of this, scientists hope to use this technology to uncover behaviors of others species that also sing duets.

The full article can be found here.

Listen to the duets.

Posted by Allison Cornell (1).


Updated 9/23/08:

To answer some of your questions, I searched for another article. (The website I found also has more samples of the wrens’ songs.) I discovered that males and females each have a set of songs they sing, specific to their gender. The set of songs among different females are similar in pattern and song structure, but vary slightly between different birds. The same holds true for males. As for the gender roles in these duets, both the males and the females initiate them. Therefore, it is not always the same one calling first every time.


Post Update by Allison Cornell (1).


13 Comments:

At 7:23 PM, Anonymous Anonymous said...

I cannot say that I am surprised at this kind of technology that is used to study duets in birds. We have made such incredible advances in that field! What I am surprised at, though, is that the songs used by the birds to locate their mate was also used as a "battle cry". Are there any variations at all between locating a mate and warding off others? Maybe the tune or notes are sharper as well as louder. If you do any follow up to find out if other birds do this as well, post it please because I am definitely interested in knowing!

Sarah Moltzen

 
At 12:43 PM, Anonymous Anonymous said...

I find the Marco Polo analogy interesting. Does this mean that the birds will call back and forth taking turns moving towards each other, or is a single bird doing the calling and the other doing the movement? If only one is doing the calling is it gender based? I have the same curiosity about the "battle cry". Are they both making that call and if so is it gender based?

Posted by Alex Jackson

 
At 4:28 PM, Anonymous Anonymous said...

I found it interesting that the wrens have dual uses for one song. I would assume that it saves them time from learning another song. Do they know any other songs? Are there any slight variations between this one song?

Duy Nguyen

 
At 1:31 AM, Blogger Dan said...

It's nice to see that technology is helping to better understand the behavior of some animals. I'm curious though, does the rival bird have to sing the exact song as the current owner of the territory for their battle cry?

-Dan Hong

 
At 9:30 AM, Blogger PWH said...

This comment has been removed by the author.

 
At 9:33 AM, Blogger PWH said...

Interesting article. What I find really great about this article is that it is an example of a technology that successfully limits a wild animal’s contact with humans. The stress incurred by an animal that is trapped then tagged can have a very negative effect on the well being of the individual. By limiting the contact with the birds it makes so that the researchers can collect their data with the birds acting in as natural a way as possible with a limited amount of changes in the behaviors. This way of recording results in a more accurate data set and happier wildlife.

While in Australia this summer I experienced this type of bird calling first hand with the eastern whip bird. The male will call first and the female reciprocates to finish the song (which coincidentally sounds in a whip like fashion). The two calls are so synced that it's hard to differentiate that they are actually two calls put together and not one.

Lindsay Goodyear

 
At 1:56 PM, Anonymous Anonymous said...

I am not surprised at all that the song has a dual purpose. If you think about the fact that one of the main reasons for battle between animals revolves around the ability to mate and reproduce it makes perfect sense. A male tries to locate a female and get her to mate with him, if he encounters "resistance" to his cause he "goes to battle" with the other male that is in his way. the battle cry, in this case could serve two purposes simultaneously: the first would be to attempt to discourage the competition prior to a physical engagement and the second is to let "his" female know that he is able to protect himself and his interests and would therefore be successful at producing a next generation.
With that in mind- is it still surprising that the songs have a dual purpose?

Noam Pelleg (21997016)

 
At 8:25 PM, Blogger PWH said...

This is an interesting article. Have they found out how many different songs duets normally sing? Since the birds use the song to find each other does that mean that they are monogamous throughout the season? If so, would the female be more inclined to mate with a male the following year if it had the same or a similar song as her mate of the prior year?


Rob Lubenow

 
At 8:35 PM, Anonymous Anonymous said...

The fact that the birds play Marco-Polo action was really interesting because it shows how the children play and the importance of games. The hide and seek game, that seems childish to us, is teaching
them the essential tools for communication later in their lives. It seems to me
that their ability to sing determines their fitness in such a crucial way.

The progress of science is also heartening to see, maybe one day in the future
we'll be able to observe animals without any disturbance, allowing for greater
detail.

David Byun

 
At 10:02 PM, Anonymous Anonymous said...

I think it is really interesting that the article says many duet singing birds are very secretive, I wonder why? I am impressed by how highly synchronized the two birds can sing. This type of technology will be very useful in determining what all bird songs mean and I would be interested to read more about this since these songs and calls are something we hear all the time and usually just ignore. I always wonder what the birds are trying to say.

posted by Julie Riley

 
At 11:10 PM, Blogger PWH said...

I thought this article was interesting and though it did not entirely surprise me, it sparked a few questions. I was wondering if there is a lot of variation between one pair's duette and another, and if the tone or pitch of the battle cry differs between males based on their size or rank.


-Jen Kodela

 
At 11:17 PM, Anonymous Anonymous said...

I love how new technology can completely change how we can study in the field. it is very fascinating how it can totally flip what we think we can see. much like UV spots on similar birds.

Matthew Sousa

 
At 11:27 PM, Blogger PWH said...

I think this was an interesting topic. It left me thinking about the duets themselves. Can one take this a step further and assume that the duets are used for mating purposes and that the frequencies of the calls vary with more or less testosterone (or with the beginning of mating season and the end of another)??



Ahmed Sandakli

 

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