Website to check out

I strongly encourage you to check out the Cape May Bird Observatory's View from the Field.  The site is mostly daily data and counts from the various research projects run by CMBO (morning flight, hawk watch, seawatch, and Monarch migration project).  Lately, the morning flight reports have been interesting!  All of the birds recorded by morning flight are identified as they fly past.  This year's counter, Tom Johnson, does a great job of identifying birds as well as photographing them.

Semipalmated and Baird's Sandpipers flying past the Morning Flight count.  Photo: Tom Johnson.

 Northern Waterthrush as it flies past the dike at Higbee's Beach, the site of the Morning Flight count.  Photo: Tom Johnson.

Warbler Identification

This warbler clearly shows a bright yellow face and strong wingbars.  Upon closer inspection, this bird appears to have a dark throat.  These characteristics fit a Black-throated Green Warbler.

This birds appears to be black with and orange belly, however, the photo was taken just at sunrise.  When the sun is low, be careful that the colors are not being altered before making a positive identification.  Although the underside may appear orange, it is actually white.  The pattern on black on the face and the band down the side are characteristics of a male Black-throated Blue Warbler.

At first, this warbler had me stumped.  I knew it was a warbler based on flight, tail pattern, and flight call (which I was unfamiliar with), but I could get it down to species.  After studying the photo and consulting a few friends, I have come to the conclusion that this is a Cape May Warbler based on the streaking on the underside.

Note the face pattern and the streaking on the side of this Cape May Warbler.

This male Hooded Warbler is unmistakable in flight.  The yellow body and face and the black chin really stand out.  This guy was uttering its flight call, which is a distinct buzz, similar to the flight call of a Common Yellowthroat.

This warbler shows a yellow underside and an all-dark tail.  These characteristics, combined with other observations in the field, help identify this Tennessee Warbler.

Many field marks are visible on this Northern Parula, including the bluish head, strong white wingbars, and yellow throat.

Check the radar!

A look at the radar indicates that there are birds flying!  I will be up early tomorrow listening for migrants, but unfortunately I cannot do any birding after sunrise.  Get out and listen!

Flycatcher Identification

Eastern Kingbirds are one of the most abundant flycatchers during migration.  The neat thing about kingbirds is that they can be aged and, if an adult, sexed. The way to tell is by primaries 9 and 10.  In young birds, these feathers are blunt. In adult females, these feathers have a slight notch at the tip. In adult males, like the one above, the tips of these feathers are deeply notched.

Eastern Phoebes can be identified by their lack of wingbars and eyering.  They are smaller than an Olive-sided Flycatcher which might seem similar in appearance.

This flycatcher shows broad white wing bars and no distinct eye-ring.  Those characteristics along with the fact that it sang its "whisper song" while flying, make this an Eastern Wood-Pewee.  The Empidonax flycatchers are similar in flight.

During migration, there is always the possibility of finding an unusual bird.  This Olive-sided Flycatcher was identified by the dark "vest" and by its lack of strong wingbars and eyering.  This bird eventually perched and called confirming the identification.

Listening for Flight Calls

During migration season, I often wake up early in the morning to listen for flight calls.  Flight calls are short vocalizations given by birds as they fly over duting their nocturnal migration.  These calls are often unique to each species (although some are very similar), so identification is often possible.

Flight calls are an under-appreciated part of birding.  First of all, few people are willing to spend several hours outside in the pitch dark hoping to hear a peep that only lasts 50 milliseconds.  Also, many flight calls can be difficult to learn.  Warblers in particular are known for their difficult flight calls; the calls are short, high-pitched, and are often very similar to other species.  However, the flight calls of thrushes, cuckoos, and other similar species are fairly easy to learn.  The calls of these larger birds are often longer, lower-pitched, and more distinctive.  Although it may turn many away, the challenge of flight calls is what lures birders who are dedicated and curious.  Here are some common questions I have been asked regarding flight calls:



What is a nocturnal flight call?

Basically, a nocturnal flight call is a short (often between 50-200 milliseconds) vocalization given by nocturnally migrating birds.  It is believed that these calls are used as contact calls to keep a flock of birds together.


When is the best time during the night to listen for nocturnal flight calls?

Migrating birds will call throughout the night, but the highest frequency of calling occurs in the hour before sunrise.  This may be because the birds are changing altitude and are making sure they stay together, or it may be that when the birds are higher up it is more difficult for humans to hear the calls.


What time of year is best for listening?

Since birds make these calls as they are migrating, the best time to listen is during the migration seasons.  For songbirds, the best times are April-May and late August-mid October.  Other birds, such as ducks and geese often make flight calls as well.  For these species March and November have been the most productive for me.


Are some days better than others?

Yes.  Bird migration is very dependent on weather patterns.  The best nights for listening to migrants is the night after a cold front has passed.  Sometimes huge numbers of birds migrate on nights like this, making listening very worthwhile.  Before heading out to listen, I often check the NEXRAD radar.  Migrating birds are visible on this weather radar, so I can determine whether there is a good flight or not.  A good site for checking this radar is the NCAR radar site.  For more information on using radar to view bird migration check out woodcreeper.com.  Finally, windy nights are not the best for listening.

Here is an example of a good migration night.  From rap.ucar.edu/weather/radar

This is what the radar might look like on a night with few birds in migration. From rap.ucar.edu/weather/radar

Where should I go to listen for flight calls?

Since nothing stops birds from spreading out once in the sky, so in theory, flight calls could be heard from anywhere on land.  However, certain factors make some locations better than others.  Human-created distractions are often the biggest problem.  Busy roads can be a pain while listening.  Cars passing by will limit the number of birds you hear.  It is best to pick a spot set back or away from any roads that have a lot of early morning or late night traffic.  It is also good to be set back from any buildings.  Walls can create annoying echos which can be confusing.

It is also good to stay away from forests.  As well as muffling the calls, trees can bring unwanted annoyances (tree crickets, tree frogs, katydids) which can make listening close to impossible at times.  A large field or other open area is great as it eliminates many of this unwanted noises.  Finally, positioning yourself on the top of a hill, ridge, or mountain can be very helpful.  The higher up you are, the closer you are to the calling birds.  Also, these high areas are often the first places birds land when coming down from the sky.  Once the sun comes up, ridgetops are sometimes hopping with migrants!

Here is my Big Sit spot.  The Big Sit is a birding competition where birders stay at one spot for a day and find as many birds as they can.  Nocturnal flight calls are an important part of the Big Sit.  As you can see, my spot is in an open field away from any roads and trees.  Although not visible from this photo, my spot was at the top of a ridge.  There is a larger mountain in the distance, but since there are no good clearings there, I decided to pick the next best ridge.  Photo ©David Husic

Ok, so I know where to go and when.  What do I do once I get to my listening spot?

Listen and enjoy.


I have no clue what I am hearing and I want to identify the calls.  What should I do?

The easiest way to help identify the calls is by recording them.  I record calls using a Zoom H4 recorder.  While out listening I record the calls in case I hear something unfamiliar.  I also record the calls for part of the Lehigh Gap Nature Center's Sound Field Guide.  Once the calls are recorded, I download them to my computer.  Using the program Audacity, I cut out calls and amplify them so that they are easier to hear.  Then I use Raven Lite to create and adjust the spectrogram of the call.  Both Audacity and Raven Lite are free software.  Then, to identify the calls, I use a CD from Oldbird.org.  This valuable resource has recordings and spectrograms of almost every bird in eastern north america that makes a nocturnal flight call.  It is available from the Oldbird website.

 Here is an example of a sonogram opened in Raven Lite.  The program allows you to adjust the image so that it is easier to see the call .  There are several calls in this image.

I would love to record flight calls, but do not want to get up every morning at 4:30am.  What should I do?

The best way to get around this problem is by installing the microphone unit as designed by the Oldbird team.  Detailed instructions on how to make a relatively inexpensive microphone can be found on the Oldbird website.


If you have any other questions, feel free to leave a comment.

Veery Flight Call

Here is a spectrogram of two Veery flight calls.

Savannah Sparrow Flight Call

I mentioned in the introductory post about flight calls.  Here is an example of a spectrogram of a Savannah Sparrow's flight call that I recorded yesterday morning from my yard.

Swallows

This time of year, swallows often group up before migrating south. On sunny August days with a N or NW wind, these groups often take to the sky. I was able to pick out four swallow species in the flock over my house.

In this area, Tree Swallows become very numerous in late August into September and
often dominate swallow flocks. Tree Swallows seem to have fairly broad
wings and a completely white underside.



Barn Swallows are also quite common this time of year. Compared to Tree Swallows,
Barn Swallows have skinny, pointed wings. Also, Barn Swallows have a buffy-yellow
underside, a red throat, and a distinctive forked tail.



Bank Swallows are an exciting species to find. During the breeding season, this species
is difficult to find away from sandy areas near water courses. Even during migration,
they often stay close to or over water, so this was a treat to see. Bank Swallows
have wings more like a Tree Swallow than a Barn. The underside is mostly
white expect for a broad brown band across the chest.



The most exciting swallow I found was this Cliff Swallow. These guys are neat birds and
are less common than the three other swallows mentioned. To identify these guys, look
for a swallow with a white belly, but a red throat patch. Above, this species has a large,
buff-colored patch on the rump, which is distinctive and easy to see, even from a distance.

Birds In Flight Project

For as long as I can remember, I have been fascinated by birds.  Since a young age, I have pursued an interest in these creatures learning as much as I can about them.  Along the way, I have met many people who share my interest and fascination.  Many are birders, people extremely interested in birds.  These people can often identify all of the birds in the region by sight and sound.  Although they are enthusiastic and knowledgeable about birds, there is one aspect of advanced birding that they often choose to ignore or set aside because they believe it is too difficult--identification of birds in flight.  Although many of these birders are fascinated by flight, they often overlook or ignore a small songbird flying above them.  

I understand their feeling, identifying a warbler zipping overhead can be difficult, but it is not always impossible.  I hope that through this blog, more people will become educated about identification birds in flight.

I would also like to mention that this blog will not only include information about seeing birds in flight, but also hearing them.  Many birds migrate at night when we cannot see them, therefore, we must use their flight calls.  These unique set of vocalizations will open any birder into a new realm of bird identification.

As a final note, I would like to say that I am still learning about this topic and that I am not an expert in fight identification.  So bear with me, and I hope that we can learn more about this intriguing topic together.