A Powerful Tool For
Attracting Purple Martins

How to Broadcast Dawnsong Effectively

Ken Kostka
Purple Martin Preservation Alliance
Pittsburgh PA

        Prior to using the dawnsong, I witnessed a grand total of two Purple Martins investigate the housing in my parent's backyard over a ten year period. After I began broadcasting the dawnsong over an outdoor loudspeaker, I saw, on average, one martin a day visit the site! If you are serious about attracting martins, you should get serious about dawnsong, especially if you live in an area where martins are scarce.

Dawnsong is the unique set of vocalizations that adult male martins emit during the predawn hours of spring while flying high above their breeding sites. It is a loud, continuous series of chirps that attracts other martins to the colony site, a musical beacon of sorts, which advertises the location of the colony to younger martins that are looking for a place to nest. Dawnsinging is the older martins' way of saying "Here's a good place to breed; check it out!" These vocalizations are a very strong signal to other martins. Any martins that hear the dawnsong will be stimulated to investigate.

This article contains instructions on how best to broadcast these vocalizations with audio equipment that you probably already own, like boomboxes and home stereo systems. Several features and simple modifications are necessary to play the dawnsong effectively.

The Importance of a timer: Genuine dawnsong is performed by adult male martins between 4:00-6:00 a.m., in the darkness preceding dawn. Why? Because early morning acoustics allow the vocalizations to travel farthest; other birds are not yet singing, and there is very little background noise. Therefore, the dawnsong tape works best when played during these same early morning hours. However, even the most enthusiastic landlord-hopeful will find it difficult to wake up every morning at 4:00 a.m. for 4-6 weeks to turn on a tape or CD player. Your best chance of attracting martins occurs when the dawnsong tape is played consistently every morning, not just those mornings you can muster the enthusiasm to drag yourself out of bed and turn it on. In order to avoid interrupting your sleep every morning, use a tape or CD player that is capable of starting the dawnsong automatically. In order for your tape or CD player to start playing the dawnsong automatically, it must have either a built-in timer feature, or be compatible with a programmable lamp/appliance timer. A built-in timer feature allows the player to begin playing the tape or CD automatically at a preset, preprogrammed time. The owner's manual of your tape or CD player will indicate if this feature is included.

A programmable appliance timer is a small, inexpensive device commonly sold at department and home supply stores like WalMart or Home Depot for about $10.00 (see photo). The tape or CD player's power cord plugs into the timer, which itself plugs into a standard electrical power outlet. The timer then activates your tape or CD player by turning the power on automatically. The most common use of timers is for lamps which people set to go on and off while they're away on vacation in order to make their house look occupied.

At left, a timer to start the dawnsong automatically. At center, an outdoor speaker capable of fitting inside a 6" x 6" x 6" compartment. At right, an endless-loop tape for use in tape players lacking an auto-reverse/ continuous playback feature. Choose a CD Player that has a "timer feature," meaning that the unit will start playing the CD automatically when powered up using an appliance timer. Many Kenwood 5 CD changers have this feature.


To determine if your player will work properly with a programmable lamp/appliance timer, it is first necessary to determine whether the player has "manual" or "touch" controls. Manual controls are the type which require a control button such as "PLAY" to be pressed into a different physical position to activate the "PLAY" function. The control button stays in that depressed position until "STOP" is pressed, at which point the button clicks/snaps back into its original off position. Players that have manual controls are compatible with appliance timers; simply leave the "PLAY" button in the depressed position so that when the timer turns on the power, the player automatically starts playing the tape. Touch controls are the type that are activated by just a light touch of the fingertip. Tape players with touch controls cannot be used with an appliance timer unless they are equipped with a built-in "timer switch" that makes the player start the tape as soon as power is turned on through the timer. Your player's instruction manual will indicate if this feature is included.

If you purchase a boombox, tape deck, or CD player specifically for playing the dawnsong, make sure it either has a built-in timer feature or can be started with a programmable lamp/appliance timer. If you already own a tape or CD player, but don't think your equipment has these features, carefully check the instruction manual - you might be surprised to find it does! Many Kenwood CD 5 CD players have this feature and can be purchased at a steep discount on Ebay. The Kenwood 5 CD Changers that have this timer feature include the CD-103, CD-104, CD-203, CD-204, CD-206, DPF-R6010, DP-R5070, DPF-R4010, DPF-R3010, and a bunch of others.  If in doubt, check Kenwood's operation manuals at http://www.kenwoodusa.com

Auto-reverse, continuous playback, or endless loop tape: In addition to having your tape or CD player start playing the dawnsong automatically, you will want to be sure it can play it continuously so that you don't need to keep pressing "PLAY" when the tape or CD ends. There are two ways to achieve this. The first is to use the tape in a player which has an "auto-reverse/continuous playback" feature. This feature allows the tape to be played continuously without anyone having to press rewind or play. In the case of a CD player, it should have a "continuous-play/repeat" feature. The other option is to use what is known as a three minute "endless loop tape," which can be purchased at Radio Shack (see photo on page 10). This tape will repeat automatically every three minutes. It is sold for use in answering machines, and will work in some (not all) tape players. The dawnsong tape is not sold in the endless loop format, so if you need to use one, you must get someone to copy the standard dawnsong tape onto a loop tape. Again, if you purchase audio equipment to broadcast the dawnsong, make sure it either has an "auto-reverse" or "continuous-play" feature, or will play an "endless loop tape."

Outdoor Speaker(s): A basic sound system consists of three components: a tape or CD player that reads the tape or CD, an amplifier which amplifies the signal, and a speaker (or speakers) that deliver the sound. A boombox combines all three components into one unit, whereas in a home stereo system, these components are separate. A boombox placed under the martin housing may seem like an easy way to broadcast the dawnsong, but there is a major drawback: your boombox could be ruined by the hot sun or a rainstorm; it is too vulnerable to the elements. Indoor home stereo speakers are similarly unsuitable. What is needed is an outdoor, weatherproof speaker. (If using a boombox without external speaker jacks, it must have detachable/unpluggable speakers in order for you to substitute an outdoor speaker.) Only the outdoor speaker is placed outside, and speaker wire or lamp cord is used to connect it to your amplifier or boombox, which is left safely inside your home.

A subadult male Purple Martin sitting on a speaker broadcasting dawnsong at the uncolonized site of Gerald Presley in Sarver, PA. This male is one of several martins that came to the site in response to the dawnsong.


Several reasonably-priced outdoor speakers can be purchased at Radio Shack. They range in price and size from about $15.00 for a small 5-watt speaker (catalog # 40-1227A) to $50.00 for the much more powerful 40-watt "Super Powerhorn" (catalog # 40-1307). The 5-watt speaker will fit inside a 6" x 6" x 6" compartment of a martin house (see photo on page 10). Of course, the more powerful horn speakers will be louder and broadcast the dawnsong farther. In any case, check the power rating on the boombox or amplifier you'll be using. This rating is usually listed in the "Technical Specifications" section at the back of the instruction manual, if not printed on the unit itself. The power rating (measured in wattage) for the speaker should not be significantly higher than the power rating of the boombox or amplifier it is connected to. For example, in order to fully utilize the Super Powerhorn mentioned above, your boombox or amplifier must be rated for at least 40 watts (per speaker). Also, most amplifiers are designed to drive two speakers, and with larger, more sophisticated units, connecting only one could damage the amplifier circuitry or cause the unit to overheat. If you plan to connect just one outdoor speaker, leave an indoor speaker connected to the other speaker jack, and position the balance control knob (a dial that allows you to control how much volume you want to flow through each speaker) so that the volume is only directed through the outdoor speaker. You might consider connecting two outdoor speakers - a powerful one (like the Super Powerhorn) for long-range broadcasting of the dawnsong, and a smaller one which will fit inside a martin house compartment (see photo below). You can then use the balance control knob to switch from the larger speaker to the smaller one. When martins appear at your site to investigate, use the balance control to direct the dawnsong through the smaller speaker positioned inside the martin house. This will create the illusion that martins are calling from inside the martin house, and the arriving martins will enter or look into the rooms as they investigate.

Speaker wire; connecting the outdoor speaker: You will need to purchase as much speaker wire or lamp cord as is needed to go from the boombox or amplifier setting inside your house to the outdoor speaker(s) positioned on, in, or near your martin housing. If you are using a Powerhorn and running it more than 50 feet from your house, you should use at least 16-gauge wire. The thinner 18-gauge wire can be used for low power speakers run at a short distance. Lamp cord is less expensive than speaker wire and works just as well. It can be purchased for about 16 cents a foot at almost any electronics, lighting, or home supply store like Lowes or Builder's Square.

Speaker placement and volume: When deciding where to position your outdoor "dawnsong speaker," remember that you want it to act as a sound beacon. It should be out in the open where the sound won't be blocked by obstructions like buildings or trees. Since you also want the investigating martins to associate the dawnsong with the martin housing, the two should be very close together. In fact, one option is to place the speaker right on the roof or pole of the martin house. Martins are high flying birds, so you should point the speaker skyward at about a 45 degree angle rather than parallel to the ground. Since outdoor horn speakers that are pointed skyward can fill up with rainwater that will distort the sound, drill several small (1/8") holes near the bottom of the horn to let water drain. It is best to point the speaker in a direction away from human houses, just in case someone in the sound path is a very light sleeper or sleeps with the windows open. You don't want an angry neighbor pounding on your door at 4:00 a.m. complaining about that infernal racket your "birds" are making. That is unlikely to happen, however, because the dawnsong is a natural sound which most people won't even know is being artificially generated. If possible, point the speaker in the direction of any areas you suspect martins might roost or feed, like a large body of water or swampy area. If there is an active colony nearby, point the speaker in that direction. In general, the louder you can play the dawnsong without distorting it or annoying anybody, the more martins you will get to investigate. However, if you play the dawnsong loudly during the day, lower the volume when the martins arrive to investigate the site.

When to play the dawnsong: Dawnsong functions best in the predawn darkness, but martins will also respond to it during the daytime hours, so playing it during the day as well will increase the number of martins you get to investigate your site. You can play it constantly, or intermittently until dark. However, once the martins you have attracted become established at your site (this usually takes several weeks), stop playing the dawnsong altogether. Real Purple Martins do a much better job of advertising your site to other martins than the dawnsong tape.

Also consider playing the dawnsong at the end of the season when the fledglings and adults are roaming over vast areas prior to flocking for migration.

Dawnsong works! If you live in an area where martins are scarce and have tried unsuccessfully for years to attract them, you should definitely give these dawnsong broadcasting methods a try. Seeing a Purple Martin land on martin housing that has gone unoccupied for years is something just short of a religious experience. Do not underestimate the power of the dawnsong tape; if you play it, they will come to investigate. There is no guarantee that they will stay to nest, but even seeing them visit your site is a thrill. So next spring, don't just sit back and passively hope for martins to discover your housing by chance. Advertise! Recruit Purple Martins to your site by broadcasting the dawnsong!


Ken Kostka is on staff at the Purple Martin Preservation Alliance in southwestern Pennsylvania, where he is working hard to help martins make a comeback.