Can we call it love song?

The early risers among us may have noticed that songbirds are singing again. For Northern Cardinals and Carolina Wrens in our gardens spring has started with the change in day length on December 21. One can really notice now that the mornings get light earlier with every day and the males of our local songbird species are getting ready for the next breeding season. They set up territory and woo females. But more about our local birds on Friday, let’s travel to the tropics!

In the tropics, birds barely take a break from singing. If conditions allow it, they will breed year-round and thus most of them keep their territory and mate. Such long-term relations call for special communications: males and females of many neo-tropical wrens sing very precisely coordinated duets. For the untrained listener it may sound like one song, that’s how closely the phrases are linked. Researchers, however, have shown that both male and female contribute to this continuous song, thus performing a duet.

Can you hear whether these are two birds singing or one?

Sandy Gaunt, curator emerita from the Borror lab and longtime volunteer, recorded these Stripe-breasted Wrens Cantorchilus thoracicus in the dense undergrowth of the tropical lowland wet forest in Costa Rica on no other day than February 14 in 1992. Sandy found these birds near the Hitoy Cerere Biological Reserve, southwest of Puerto Limon in Costa Rica, a rugged and undeveloped park with abundant wildlife.

The song of a close relative to the Stripe-breasted Wren, the Plain Wren Cantorchilus modestus zeledoni, has been studied in some detail by Karla Rivera-Cáceres from the University of Miami, Florida. These wrens perform precisely coordinated duets as you can see for yourself in the spectrogram below – a visual representation of sound with frequency or perceived pitch over time. Both males and females adjust their song and pauses between songs to coordinate with their partner. Red bars indicate the female’s contribution, bluish bars the male’s.

Spectrogram of highly coordinated Plain Wren duet

Highly coordinated duet of male and female Plain Wrens (Fig.1 in Rivera-Caceres et al 2016)

Listen to these male and female Plain Wrens duetting as recorded by Jacob R. Saucier. The recording is archived with Xeno-canto, an online collection of bird songs from around the world (XC319021).

spectrogram of Plain Wren duet (XC319021)

Duet of male and female Plain Wren as recorded by Jacob R. Saucier (XC319021).

So, shall we call this a love song? There are many hypotheses for why birds duet, one suggests that the level of coordination may signal pair bond strength, the level of commitment a mated male and female have of cooperating with one another. Other hypotheses suggest that duetting may help mates to stay in contact in dense habitat, or two singing birds may be more intimidating and thus more effective when defending a territory. Future research will show which of these hypothesis is most likely for the Stripe-breasted Wren.



Rivera-Cáceres, K. D., Quirós-Guerrero, E., Araya-Salas, M., & Searcy, W. A. (2016, November). Neotropical wrens learn new duet rules as adults. In Proc. R. Soc. B (Vol. 283, No. 1843). The Royal Society.


About the Author: Angelika Nelson is the curator of the Borror Laboratory of Bioacoustics and instructor for the OSU Ohio Birds class each spring.


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Interview with long-time volunteer in the Borror lab

Sandy Gaunt was the curator of the Borror Laboratory of Bioacoustics until 2002 when she retired and decided to start volunteering in the lab.

Sandy Gaunt digitizing in the Borror lab

Sandy Gaunt digitizing in the Borror lab (photo A Nelson)

As an adjunct Assistant Professor of our department, Sandy did research on the syringeal structure in various bird species and has published her findings in numerous scientific journals.

In her role as a volunteer digitizer in the lab, Sandy has digitized many recordings. She was pivotal in the NSF-funded digitization project of Don Borror’s over 14,000! recordings. Lately she has digitized recordings by Arthur Borror, Don’s son. Of this collection, Sandy has to date digitized 173 cuts of 113 bird species in three different countries, Belize, Canada and USA from Arthur Borror’s collection.

Listen for yourself as Sandy tells about her favorite bird species, some bizarre recordings, some challenges and what she enjoys about working in the Borror lab:


Here are some photos and sounds of the species that Sandy mentions:

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Sandy does not only donate her time to our lab, she also makes a monetary donation each year to support student workers in the lab. We are extremely grateful for having Sandy in these capacities.


Interview by Angelika Nelson, curator of the Borror Laboratory of Bioacoustics with Sandy Gaunt, long-time volunteer in the lab.

Happy Turkey Holiday!

It’s the time of year when ONE BIRD receives all the attention, at least here in the USA: the turkey. Turkeys have been part of the human food chain for a long time, Native Americans hunted them for food and so did the first settlers. Due to unregulated hunting turkeys declined dramatically with the increasing human population. By 1904 turkeys had all but disappeared from Ohio. Today the Wild Turkey Meleagris gallopavo is again a common sight in many metro parks in Ohio. Blendon Woods, for example, has a good population that can be observed easily, often even at the feeders at the nature center.

Note the bristly “beard” extending off the chest of male turkeys and the spurs on their legs as seen in the photos above. The two males on the right are displaying and probably make some “gobbling” sounds.

As a bioacoustician I am of course most interested in the sounds these birds make. You are probably familiar with the famous “gobble” call males make in spring to attract a mate but also in response to other males calling. Here is a recording from our archive (BLB21391):

The gobble is a loud, rapid gurgling sound, it’s the turkey’s version of a rooster’s crow.

Females make quite different calls (BLB12583):

Here is an example of calls given by a juvenile female (BLB13261):

I hope this made you appreciate the diversity of turkey calls and you will listen for their calls next time you visit one of the metro parks.

All recordings are of captive birds at the Ohio Agricultural Research and Development Center, Wooster, Ohio in 1974. You can listen to the full recordings by clicking on the cut numbers above.


angelika_nelson_birdingAbout the Author: Angelika Nelson is curator of the Borror Laboratory of Bioacoustics.


Impacts of Rain Gardens on Urban Bird Diversity

Rain gardens have proven to be a useful tool to mitigate stormwater run-off in cities. They are depressions on the side of the road or sidewalk with plants that absorb rainfall and prevent water from picking up pollutants and carrying them to the nearest stream. The plants and soil also filter the water. But this is not the only service rain gardens provide, the diversity of plants used in them increases habitat for many animals. Many insects and spiders are drawn to the local plants and they in return attract birds and small mammals. Rain gardens can provide nice shelter for these animals too.

As part of project “BluePrint” the City of Columbus plans to install some 500 rain gardens in the Clintonville area to manage stormwater runoff. Dr. Jay Martin, Professor of Ecological Engineering at OSU joined the project to holistically quantify the impacts of stormwater green infrastructure on societal services such as stormwater management, public health, community behavior, economics, and wildlife habitat. Dr. Martin’s PhD student David Wituszynski focuses on the animal aspect and recently contacted the Borror lab to discuss his research idea. David wants to test the hypothesis that implementation of such a large network of rain gardens will increase the diversity of urban bird species.

SongMeter mounted (

SongMeter mounted (

Specifically, he wants to develop automated acoustic methods to track urban bird populations. He will deploy SongMeters, automated recordings units, and program them to record surrounding sounds at certain times of the day. It is easy to record thousands of hours of bird and insect sound, but one needs to analyze them afterwards and identify vocalizing species.

This takes us back to the problem of automated sound recognition raised in Monday’s post. Dr. Martin and David are collaborating with Don Hayford from Columbus Innovation Group who will develop techniques to filter out background noise (such as human voices, machinery, cars, barking dogs – all familiar sounds to our neighborhoods) and produce files of target sounds that can then be analyzed with existing software.

My role will be to provide reference sounds for the software as we need to train the software to recognize known vocalizations of local bird species. This is not an easy task because some bird species have quite varied vocalizations. Our large and diverse archive of sound recordings will come in handy, we have many recordings of local Ohio species. These should cover most of their diverse vocalizations. Our goal is to build classifiers that automatically recognize and label species in the recordings.

map of Clintonville area with proposed rain gardens (project BluePrint, Columbus OH)

Will you get a rain garden on your street? check this map

We have just submitted a grant application to help us fund some of this research. The first SongMeters will be deployed this fall and we will start monitoring the areas to get a baseline level of bird activity. Come spring the city will install rain gardens in the neighborhood and we can compare our recordings before and after the installation. This certainly is a multi-year project. We will keep you updated.

Should you see a rain garden in your neighborhood, take a picture and share it on social media #BLB #raingarden #songmeter!


Further resources:

The project BluePrint was featured in the Columbus Dispatch last January!

Learn more about rain gardens in Central Ohio!


About the Author: Angelika Nelson is the curator of the Borror Laboratory of Bioacoustics at OSU and Co-PI on the project “Determining Impacts of Rain Gardens on Urban Bird Diversity” with Dr. Jay Martin, David Wituszynski and collaborator Don Hayford.