Nocturnal Flight Calls

Nocturnal Flight Calls

The night before birding on a given morning during migration is spent excitedly talking about the predicted migration with my friends. Messages are exchanged on anything from wind patterns to Cornell’s BirdCast and predicting which species we think will finally make it to our area for the first time this season. Then we all head to bed, excited for the migrants that await us in the morning.

Some of these nights, there is enough activity overhead that I try to listen to what birds are flying over. When it’s quiet, you can hear faint chips overhead as birds pass by. With a microphone, you’re able to hear them much clearer and even identify them to species! These “nocturnal flight calls” provide a whole new insight and level of excitement to birding in migration!

I clearly remember sitting in the audience at one of the Ohio Young Birders Club conferences. The keynote speaker was telling us how he was able to listen to the birds migrating overhead each night and identify them to species by call or spectrogram. I was no older than middle school at the time, but it stuck with me. I knew someday I wanted to be able to do that myself, and see what birds migrated over my house on a given night.

This spring, I decided it was finally time to make the dream come true. I’d seen a lot of eBird lists coming in with recordings marked “NFC”. These “NFC’s,” or Nocturnal Flight Calls, are a series of typically short notes given by birds during migration. Many are high-pitched and similar enough that they can’t be identified to species. However, some, such as Yellow-billed Cuckoo, give calls similar to those you would hear on a typical summer morning. Thankfully, I had a few friends who had experience with these identifications, and others who were also trying to learn. This allowed us to work through IDs and technical difficulties together.

A very busy road runs behind my house here in Clermont County, making hearing overhead birds difficult at times. Once it was late enough at night, usually around midnight, I would go set out my microphone. In my case, this was a sensitive directional microphone in a 5-gallon bucket, allowing sound to be funneled into the mic. The cable was usually run 30 feet or so over to my computer, where I had headphones plugged in and Cornell’s Raven Lite software open. Some people run their NFC mics all night and go through recordings the next morning to see what calls they detect. Since I am just getting started with this, I chose to run the mic only as long as I could be awake, and listen to the calls in real time. This allowed me to learn more in the moment. As I watched the spectrogram of the live recording coming in, I would save just short segments as I heard them.

The area my house is in is relatively urban, just adding significance to the variety and numbers of species passing overhead. There is little habitat anywhere in the county for some of the species I observed to even stop, making it even more exciting to hear them!

Within my first hour of running the microphone, I was already amazed at the diversity overhead. April 23rd was still early enough in the season to detect earlier migrants, such as sparrows. My NFCs were mostly Savannah, Chipping, and White-throated Sparrows. Some of the exciting surprises were difficult birds for Clermont County, such as Grasshopper Sparrow, Pine Warbler, and Great Egret! I was very excited after this night and couldn’t wait to see what came later in the season.

The call of a Chipping Sparrow is a “U” shape, often with a second line in the middle (as shown in the second call) or sometimes a single “U” as shown in the first.

A few days later on April 28th, my sister, Cassidy, and I decided to try the microphone again. Due to less road noise in the middle of the week, we were able to start as early as 10:45pm. As I went outside to set up the microphone, I heard a Spotted Sandpiper calling overhead and knew that this was going to be a fun night to listen. A few unidentified warblers called too distantly to confidently ID, but still had me excited to see the species change in such a short time. Sparrow numbers were significantly lower, and thrushes had begun to pick up. Hermit and Veery both were recorded. The most exciting finds of the night were the Least Sandpiper (a very fun yard bird) as well as THREE Virginia Rails, one of my most wanted birds for Clermont County in general.

Four faint “Kek” calls of a Virginia Rail. They have one of the lower calls I heard over my house. They were easier to hear than the computer picked up.

The third (and unfortunately final) time I ran the microphone this season just happened to be the craziest night yet! May 18th was just after the main peak in migration for the Cincinnati area, and I had no idea what to expect. I only had an hour to run the microphone before bed, because I wanted to get early for one of the last big pushes of birds in the area. I went outside to set up the mic, and within the first 30 seconds I heard 8 Swainson’s Thrushes overhead. Once recording started, Swainson’s Thrushes were calling once every 15 seconds, resulting in a call rate of nearly 250 birds per hour! A number of Veery and Gray-cheeked Thrushes called as well. Other surprises included 45 Indigo Buntings, Blue Grosbeak, Grasshopper Sparrow, Green Heron, and two Yellow-billed Cuckoos!

One of the almost 250 Swainson’s Thrushes that passed over my house in the hour I ran the microphone! The thrushes all have pretty distinct calls while migrating.

Learning to identify these calls wasn’t easy. I spent a lot of time on both oldbird.org and eBird’s Macaulay Library, as well as texting friends for help. It took time to familiarize myself with the most common calls and learn to help classify them into families. There are certain common patterns to recognize, you must note the time and frequency of every call, and have patience while browsing other samples. These were the most beneficial ways for me to learn. It may be a bit of a learning curve, but was a very fun new way to experience migration. When birds are migrating overhead, you never know what could fly over your yard!

I was able to record a Least Sandpiper during the April 29, 2020 session below.

eBird Checklist - April 23, 2020

This checklist features 16 species, 15 with audio recordings. Click Here

eBird Checklist - April 29, 2020

This checklist features 10 species, 8 with audio recordings. Click Here

eBird Checklist - May 18, 2020

This checklist features 14 species, 13 with audio recordings. Click Here

An Important Message from the OOS

An Important Message from the OOS

Your opinion matters!

It is time to take a walk in an Ohio forest.  Whether it is a local birding hot-spot or a pine forest planted by the Civilian Conservation Corps (CCC) in the 1940s, the Ohio Division of Forestry (ODF) has been tasked with providing a Forestry Action Plan for ALL of Ohio’s forest resources — public and private, local, state, federal.

The Division of Forestry wants your opinion.  If you are convinced already, simply go to, and fill out, a brief forestry survey found here. before the end of February. 

If not, read on!

Birders are great observers.  We routinely go to field or woods to look for birds.  Wintering birds, migratory birds, nesting birds, common birds, rare birds — it doesn’t matter.  We want to see them all.  We even keep track of them by making lists and taking pictures.  

We conduct official counts.  How many bird observers were out scouring Ohio in December?  How many birders also noted habitat destruction in their annual Christmas Bird Count area?  Whether it was wholesale bulldozing and burning for suburban sprawl or a timber harvest affecting a beloved patch of woods, you felt the sting.

The National Audubon Society tells us birds are in decline.  Many countries throughout the world are directly addressing climate change by planting trees.  But, according to Ohio’s 2019 State and Private Forest Fact Sheet (stamped with the ODF and U.S. Forest Service logos), there were no dollars spent on “Landscape Scale Restoration” in 2018.

Birders throughout Ohio can bear witness to timbering, which has created forest fragmentation as well as the bisecting of State Forests for more ATV trails.  Only 12% of Ohio’s forests are publicly owned, including local, state, and federal holdings.  While we support science-based cutting performed for the benefit of plant and animal species that need succession and second growth to thrive, we believe that more effort should be made to keep forests intact.  

Birders love to share their opinion.  And here is your chance – no, DUTY — to express yours in order to influence the future of Ohio’s forests.  ALL of Ohio Forests, both public and private.  Do you want to see more reforestation?  Are you concerned about the decline of birds and wildlife which require large scale, unfragmented habitats only found in state forests?  Do you value bird habitat and water quality?

Here are several key areas that OOS believes provide the greatest opportunity for impact:

– maintaining large tracts of unfragmented forest (reducing non-science based cutting)

– performing reforestation by planting trees in tracts not cut for wildlife benefit

– making decisions based on improving water quality

– increasing forest health education for Ohioans

– continuing emphasis on work to address invasive pest and disease (including education programs)

– supporting state leaders and representatives committed to adequately funding our state forests

The Ohio Division of Forestry has a huge task before it but has limited resources to fund their priorities.  It has a worthy goal to improve the educational outreach to private landowners.  You can help them understand your priorities by going to the link and filling out the survey; response time is limited to February!

Make your opinion known now.  You can bet that those with financial interests in the forests have already logged in.

Tim Colborn
Ohio Ornithological Society, President

To learn more, visit the Ohio Department of Natural Resources Forestry page.

2018 Annual Membership Drive Raffle Winners

2018 Annual Membership Drive Raffle Winners

Alvin Miller, a local Amish young man, was the recipient of first prize from our annual membership drive, Zeiss Conquest HD 8×42 binoculars. Since I was the closest board member to Arvin, I was tasked with delivery of the bins.

Friend Su and I were out birding, were close to Millersburg, so decided to make delivery.

When we arrived at the address, we realized that we had chased a Harris’s Sparrow at this Amish farm many years ago. After checking old records we found that the bird showed up on 1/27/2007 and stayed until 5/3/2008. It had been a very cold and snowy winter so far. Only 3 of us showed up for our annual Castalia trip so we decided to stay local and chase this rarity. Over 400 birders came to see this bird!

The amazing thing about this story is that the young boy who found this rarity, among a flock of White-crowned Sparrows, was ALVIN MILLER. He is now a hard-working young man. When we showed up he had just returned from work and was totally surprised. He knew nothing about the drawing since he did not see any ads for the membership drive or has internet access. He was just renewing his membership to continue with OOS. (Out of respect for the Amish, we did not request a photo.) After reminiscing with him about the Harris’s Sparrow, seeing his smile, we said our goodbyes and went on our way.

Then, on February 18, OOS Treasurer Bruce Miller was honored to present Joy Alcalde with the 2nd Place prize from our annual membership drive!

Joy won a new pair of Vortex Optics Diamondback 8×42 binoculars. She was ecstatic to have won! She said the time could not have been any better as she will be leaving for a trip to Key West and is going to Dry Tortugas National Park! She is hoping these new binoculars will help her spot a Sooty Tern!

Congratulations, Joy! We hope these binoculars reward you with some great views of the birds for many years to come!

Third and fourth prizes were sent to Don Hollenbaugh and Ronald Baker via U S Mail.

CONGRATS TO OUR WINNERS!!

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