Swainson's Warbler, an uncommon and elusive species often subject to playback efforts by birders. Gouache painting copyright David Sibley.
With the recent surge in the availability of digital audio devices, the use of playback to attract birds into view has increased exponentially. This has fueled an ongoing debate among birders about the ethical issues surrounding the use of recorded bird songs in the field.
There is no debate that playback (playing a recording of a bird’s song) is one of the most useful tools in a birder’s struggle to see birds in the wild. Birds that might otherwise be too shy to come into the open can be lured into view by the sound of a potential rival. Whether this trickery has any significant impact on the birds is not so clear. Most of the debate has focused on the ethical question of whether or not playback should be used. In this post I assume that it
will be used, and instead focus on suggesting some best practices to allow birders to enjoy the birds while minimizing the impact of playback, on birds and on other birders.
Summary
First, it is important to point out that the use of playback is prohibited in many parks and refuges. It is also illegal to disturb any endangered or threatened species (and playback can be interpreted as disturbance). Any potential negative impacts of playback are more likely to occur in areas with a lot of birding pressure, so avoiding playback entirely in those places is a good idea. Where and how to use it in other situations is up the individual birder.
To be most effective and to minimize disturbance to the birds:
- have a plan (choose your spot and know your quarry, don’t just play sounds)
- play snippets of sound – no more than 30 seconds at a time, then a long pause before the next snippet (more silence than playback) and after five minutes or so give it a rest (but stay alert).
- be subtle – you are trying to tease the bird into the open, not stir up a fight
To minimize disturbance to other birders:
- No surprises – Announce your intention to play a recording, and hold the device above your shoulder while it plays (to avoid any confusion or false alarms)
- Keep the volume low, and use only occasional snippets of sound. Do not broadcast loud or continuous sound.
How does it work?
Playback works best on territorial species during their nesting season, when the real bird thinks the recording is a rival threatening to encroach on either its territory or its mate. The territorial male will then (ideally) come out to confront the intruder by patrolling the edge of its territory and singing, or it may stay silent and close to its mate to guard against an adulterer. For her part, sometimes the female will approach the recording to assess the “new guy” and may even solicit some attention. Playback will arouse the curiosity of any species at any time of year, but the response is most dramatic from a territorial bird in breeding season, and weakest from non-territorial birds such as migrants.
The debate
Arguments in favor of playback:
These are speculative and/or subjective, and assume that you accept the self-centered premise that as birdwatchers we need to see birds (that is a separate debate):
- Playback allows people to enjoy birds more fully (in this way it is analogous to bird feeding). It attracts birds into view that would otherwise be difficult to see well.
- Playback reduces the need to physically invade the bird’s habitat, and therefore (presumably) reduces damage to the habitat and disturbance to the birds. For example, playing a recording from a roadside so that twenty people can see a bird is likely to be better for the bird than having those twenty people walking through the habitat.
- Playback targets a single species, without disturbing other species, which is presumably better than physically walking through a bird’s territory, or using broad-spectrum attractants like pishing, which affect all species.
- It’s possible that in some circumstances playback may increase the social standing of a male bird among its peers (see Research below)
Arguments against playback
Most of these arguments are speculative, only the first one listed is documented by research on one species, and the last two are aesthetic impacts on other birders:
- Aggressive playback (with the real bird coming away as the “loser”) can cause a male bird to lose status with rivals and its mate, leading the female to seek extra-pair copulations (see Research below)
- Playback causes unnatural stress on the bird – the territorial male wastes energy chasing a phantom intruder
- Playback lures birds into the open, exposing them to predators
- Playback distracts birds from other more useful activities, such as foraging.
- Birders dislike hearing an electronic recording, as it detracts from the “natural” experience of birding
- Birders experience increased stress from confusion and false alarms when the song of a sought-after species turns out to be a recording.
Research
No research has demonstrated a negative impact of playback on birds. That doesn’t mean the practice is benign, it just means that no negative effects have ever been documented. Effects that have been documented include raised testosterone levels in males, and increased maternal behavior (nest-building, etc) in females exposed to playback.
One study found an impact on the status of males. When song is played in a bird’s territory, that bird’s response to the “intruder” is watched attentively by neighboring males and by females. In one study (Mennill et al 2002) high-ranking male Black-capped Chickadees exposed to aggressive playback lost status as their mates and neighbors apparently perceived them as losers, unable to drive away the phantom intruder. This led to a loss of fitness as their mate went to other males to seek extra-pair copulations. That study found no change in the status of low-ranking males, but presumably birds exposed to infrequent playback could potentially
gain status when they “win” the confrontation and drive away the intruder.
It is important to stress that this is a single study, of a single species, and the results (if typical) may not be applicable to other species. Researchers generally agree that the effects of playback are poorly-known, but are probably (paradoxically) both far-reaching and small.
There is
evidence that birds quickly become habituated to recordings, responding less strongly over time, and eventually ignoring the recordings entirely. Think of the loud distress calls sometimes played to keep birds like gulls or starlings from roosting on buildings. Additionally, playback has been used very effectively to
attract birds to suitable nesting habitat (for example, puffins and terns in Maine, Black-capped Vireos in Oklahoma). In those cases, at least, playback does not drive birds out of their territories, and instead signals a suitable breeding site.
What Not to do
Under no circumstances should you play a recording continuously or at very high volume. The epitome of bad playback etiquette is the birder who walks around with a device continuously and loudly broadcasting sound. This is ineffective, unnecessary, and is the kind of playback most likely to be harmful to birds and disturbing to other birders.
A note on volume: I have found that the built-in speaker on the iPhone 3G is adequate for every playback situation I have tried, even though it is not as loud as an actual bird. If you are using a device with a built-in speaker, there is probably no need for an added, powered speaker. Whatever device you are using, your starting volume should be lower than the sound you imagine the bird would produce.
Respect for the birds
Plan carefully and understand your quarry so that you can guess where the bird is, or where it is likely to be. If you have already heard it or seen it, consider those locations when deciding where to play audio. You must be in (or very near) the bird’s territory to get a useful response.
Choose your spot and set the stage – Visualize the scenario of the bird coming into view. How will it approach the recording, and where will it sit so that you can see it? You should play the recording from a location that offers the bird a comfortable approach through its preferred habitat, and also has openings, edges, and/or prominent perches where it will come into view. Many playback efforts are unsuccessful either because the bird will not cross unsuitable habitat, or because dense vegetation allows it to approach closely while remaining hidden.
Begin by playing the recording quietly for just a few seconds – for example just two or three songs, then stop, watch, and listen.
Use short snippets – If there is any response, try very short snippets of song after that, even stopping the recording after half of a normal song, to try to tease the bird into the open without posing a serious challenge to its self-esteem.
Watch for a response – If there is no obvious response after 30-60 seconds, play another 15-30 seconds of sound. Remember that the bird may respond by approaching silently, or by guarding its mate, so a lack of song is not necessarily a lack of response, and you can assume that you are being watched. Watch the vegetation carefully on all sides for an approach, and also watch and listen for a response from neighboring males.
Remain calm – If you still don’t detect any response, play the recording again, watch and wait, and repeat. But don’t keep this up longer than about five minutes, and resist the urge to finish with a prolonged, loud barrage of song.
Check back later – Many birds will remain silent in the immediate aftermath of the playback, and then begin singing vigorously minutes later. Males in other territories might monitor the playback, and the challenge to their neighbor, and also be stimulated to sing minutes later. If you can wait around, or circle back to check on the area after 10 to 30 minutes, you may find that the desired response to playback is occurring then.
Respect for fellow birders
Be courteous – Before starting, ask your fellow birders if anyone objects to using playback.
Don’t surprise people – Before each burst of playback, announce to the group that you are about to start playback (just quietly saying “playback” will do), and hold the device up above your head during playback so other birders can see at a glance the source of the sound.
Be unobtrusive – Keep the volume low and play only short clips of sound – 30 seconds or less – then pause to watch and listen for a response.
In conclusion
With playback, you are effectively teasing a bird into the open, just like trying to get a fish to bite a lure. If a fish makes a pass at your lure on one cast, you wouldn’t switch to a bigger, more colorful lure and throw it right on top of the fish. No… you would use the same lure, cast it carefully and gently beyond the fish, and retrieve it with as much finesse as you can muster. In the same way, if you are trying to attract a bird into the open and it shows some interest in what you are doing, your next move should be the same thing again but lighter, with more finesse, trying to pique the bird’s curiosity.
As in all things related to birds, there is a lot that is unknown about their response to playback. More research on the effects of playback, including varied species with different social systems, would be very helpful. In the meantime, being courteous and respectful to the birds and to fellow birders should avoid most of the potential conflicts and allow us to continue to enjoy birding with minimal impact on the birds.
