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Audio Quiz!

Put your ID skills to the test with this brief bird sound quiz! (Don’t worry, it’s not a songbird flight call.)

CLICK THIS LINK to hear the sound (20 seconds, 1 MB).

And here’s the spectrogram (an excerpt), just because I think it’s a really cool one:

This was recorded pre-dawn on 10/31/10 in Rye, NY. There is only one species in the recording. Feel free to answer in the comments!

(Oh, and if you are one of the couple of people to whom I’ve shown this recording, don’t answer please :).)

Good luck!


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Cape May Warbler flight call from Rye, NY on 9/10/10.

Flight calls. Exceedingly short, often similar-sounding, most easily heard in the wee hours of the night–and present in substantial numbers during only a handful of nights per year. Sure, the idea is interesting: the ability to “tune in” to birds migrating overhead at night by listening to the calls they utter. But there is a notoriously steep learning curve for anyone who dares to delve further. No wonder many birders shy away from these vexing vocalizations that last–at most–two-tenths of a second.

So why bother? There are more reasons than one might think. Often we settle for the results–the aftermath–of a good migration night. Perhaps our local birding spot has some new arrivals, or a rarity is reported nearby. But rarely do we have the opportunity to experience thousands of birds pouring overhead, many of which may end up hundreds of miles away by daybreak. Sometimes, well-placed floodlights on skyscrapers can help. But in most other cases, flight calls can provide this window onto migration–both recreationally, and as a powerful tool to learn more about the species that do call.

One of my favorite aspects of listening to flight calls is the ability to hear species that are normally cryptic or hard to find. Catharus thrushes are great examples of this; whereas a lucky observer at a migration hotspot might find only a handful of thrushes during a good morning, call counts in the hundreds during good migration nights are not uncommon. It’s conceivable (though unlikely) that six North American thrush species could all be heard along the Atlantic coast on the right night in mid-September!

Swainson's Thrush flight call from Katonah, NY on 9/11/10.

Audio: Swainson’s Thrush flight call from Katonah, NY.

Veery flight call. Rye, NY on 9/10/10.

Audio: Veery flight call from Rye, NY on 9/10/10.

Routinely recording flight calls, in addition to allowing one to hear calling events at a convenient time, can provide important data about migrants that do call–from the migration timing of certain species to changes in relative abundance over many years. Acoustic monitoring can also shed light on which species use different areas for migratory stopovers during the day.

Three "whip-poor-will" calls. 8/26/10 in Rye, NY. This bird was not flying over the microphone, but if we had not been recording, we would not have known it had chosen Rye as a place to stay--this was recorded before 6 AM!

Audio: Whip-poor-will in Rye, NY.

Dickcissel flight call from October '10 in Rye, NY. Recorded flying over the microphone in the early morning hours (in daylight).

Audio: Dickcissel flight call (calls 3 times in recording).

Plus, there’s always the chance that interesting flight calls might be detected. Le Conte’s Sparrow is an interesting species–as a grassland bird, it tends to hide in inaccessible areas. Through January 2011, only twelve records of this species in New York State had been accepted. But it has a fairly distinctive flight call: long, high-pitched and descending. And interestingly, in the very limited time I’ve been looking through recorded flight calls, I’ve stumbled upon two presumed Le Conte’s Sparrow calls–one from Danby, NY in October 2009, and one from Rye, NY in October 2010. Is this just coincidence, or is Le Conte’s Sparrow a more common migrant through New York than previously thought? Only time–and more acoustic monitoring–will tell!

Presumed Le Conte's Sparrow flight call. 10/17/09 in Danby, NY.

Audio: Le Conte’s Sparrow flight call in Danby, NY

Probable Le Conte's Sparrow flight call. 10/25/10 in Rye, NY.

Audio: Le Conte’s Sparrow flight call from Rye, NY.

So when is the best time to hear flight calls? Peak migration is usually the best–in the northeast, that’s September in the fall and May in the spring. Of course, birds need to be migrating (northerly winds in the fall, southerly in the spring). And interestingly, although we know from Doppler radar studies that the amount of migrating birds in the atmosphere peaks 2-3 hours after sunset, flight calls peak much later in the night, in the hours before dawn. Why this is–birds forming flocks in anticipation of the day, perhaps–has yet to be determined. But it does mean that you might be better off getting up early, rather than going to bed late, to listen.

The vast majority of flight calls recorded in Rye, NY this past fall occurred in the later hours of the night.

If this has piqued your interest, I encourage you to try listening for flight calls this spring. Purchasing Bill Evans and Michael O’Brien’s flight call guide CD is also a good idea. But it’s really not that hard–don’t feel you have to identify anything–just pick a quiet spot with lots of sky (hills appear better than valleys, and coast better than inland), and listen!

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After much thought, I decided to purchase the $30 Sibley eGuide to the Birds of North America, a new iPhone app just released about two weeks ago. It is a digital version of David Sibley’s immensely popular North American bird field guides.

UPDATE (6/4/10): A new version of the app has been released that fixes some of the small grievances I mention here. This makes it, in my opinion, the #1 birding app on the app store. Click here to see what was changed.


The app includes almost all of the text, maps and illustrations in the book version of The Sibley Guide, as well as a diverse collection of high-quality recordings covering about 95% of the species present. However, while the app has some good features, it is not perfect by any means, and the aesthetics and design are arguably sub-par.

The main screen when the app is opened.

When the app is opened, the user is presented with the option to view birds taxonomically (by family), alphabetically, or to use the smart search function to narrow down birds by visual attributes (color, size, certain field marks, abundance). The “My Location” option lets a certain state or province be selected, and the list of possible birds is narrowed down to those expected in that area (including ones that are rare but regular). Finally, “My List” provides the functionality to record your sightings, though in my opinion this feature falls short of actual usefulness.

Species Indices

Tapping “Taxonomic Index” or “Alphabetical Index” opens the list of species, shown here.

The beginning of the species list.

Notice that in the above picture, it says “Main Menu (NY)” in the upper left, since I had set my location to New York. Because of that, certain species that aren’t expected to occur in New York, such as Arctic Loon, don’t appear. If you tap “Quick Search” at the top, you can search for a specific species, starting at any word in the common name (i.e. searching “Cerulean” or “Warbler” will return a list with Cerulean Warbler included, but searching “rbler” won’t get you anything).

Species Pages

The page for Cerulean Warbler.

The species page includes all the textual and range information about the bird that you would find in the East/West versions of the Sibley Guide, as well as all the illustrations that are found in the “Big Sibley,” which covers all of North America and includes more plumages than the regional ones. These are accessed by dragging your finger down on the image. One minor annoyance is that, when subspecies are displayed (such as the Western subspecies of Red-tailed Hawk), you have to scroll all the way through to get to the one you’re looking for. If a location isn’t set, you can’t blame the developer, but it would be smart if the application looked at the state you have selected and display the most relevant illustrations.

Another thing I would personally like to see is information on similar species, both visually and acoustically. Though not included in the book, this would be a wonderful addition. There is a great compare species function (more on that later), but if you don’t know which species might be similar, you won’t know which birds to compare!


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