In Fiji’s Pacific Harbor, tourists hold their noses as dive boats pour hundreds of pounds of discarded fish scraps into the ocean. This “chumming the water” as it’s called brings in sea life from miles around, including various kinds of sharks. And sharks are precisely what the tourists have paid to see. Yet biologists the world over state time and again that this constant activity will no doubt have an impact on normal shark behavior, and that the conditioning will lead the sharks and other wildlife into a downward spiral of abnormal activity. But one thing the tourists pay for is results, and unloading all that smelly refuse into the tank definitely brings in the sharks.
But was has this to do with birds? That answer rests in two activities: pishing and tape-luring. Together or apart, they represent the birding community’s equivalent of chumming the water.
According to Wikipedia, a pish is “an imitated bird call (usually a scold or alarm call) used by birders and ornithologists to attract birds (generally Passerines). The action of making the sound is known as pishing. This technique is used by scientists to increase the effectiveness of bird diversity surveys, and by birders to attract species that they might not otherwise see.”
Before I get to tape-luring, let’s stop here for a minute. Birders use pishing to attract species they might not otherwise see. In other words, birders use this method to interfere with a bird’s natural behavior simply because the birder wants to check off a name on a life list, not because they want to observe avifauna in its natural beauty and behavior. That’s important to note. And while I won’t delve into active and passive birding in this post, I will cover it later, and at that time I’ll remind you of pishing and tape-luring, and their arbitrary use by birders who have no sound scientific reason to employ the methods.
As for tape-luring, this method rests comfortably alongside pishing but relies on technology as opposed to pursed lips. Tape-luring is the use of prerecorded bird calls as means to bring birds out of hiding, such as a mating call, a threat call or a challenger call. By it’s very definition, it’s nothing more complicated than pishing with batteries.
I will admit the lack of centralized, coherent research on these practices leads many to believe that no word means a good word (i.e., if science hasn’t definitively blasted the practices, they must indeed be acceptable and even endorsed). Yet the issue is not a lack of research but instead a seemingly endless array of information tucked away in disparate places. Where ornithologists and biologists use these measures for scientific study, pishing and tape-luring are clearly spoken of as highly effective methods. Using the flawed logic of “if something is not expressly forbidden it is allowed,” the birding community has seized upon these acceptable scientific tools and made them an everyday part of their birding practice. And therein rests the problem.
In 2001 Professor Daniel J. Mennill from the Biology Department of Queen’s University in Kingston, Ontario, discussed a study involving black-capped chickadees which showed how tape playback impacted mating choices by females. In essence, his findings suggested “that female black-capped chickadees eavesdrop on male-male singing contests and that the information females gain through eavesdropping plays an important role in shaping female reproductive decisions.” Even more disturbing was that he found “that high-ranking males who lost song contests [against recorded songs] also lost paternity in their nests.” And since “females prefer males who have a high-ranking position in the previous winter’s flock,” use of these methods in nonbreeding seasons could still influence mating and paternity.
The question of recorded sounds to lure avifauna for birders became a point of discussion on NEOORN, the e-mail discussion group on Neotropical bird biology. When a question posted to the group asked for guidance on tape-luring and pishing in eco-tourism areas (the compiled discussion can be seen in this PDF), Dr. Jeffrey R. Lucas, a professor in the Department of Biological Sciences at Purdue University, said, “It is very common for us to instigate territory disputes in Carolina Chickadees (the birds that are the focus of almost all of our studies). This is because responses that we elicit from one neighbor are usually reacted to by other neighbors. So even if our playbacks, per se, are having no effect, the increased interaction between birds caused by frequent playbacks could potentially disrupt the social system. […] The point is that there are lots of ways to disrupt a social system through playbacks, and to do this in order to let some people see a rare bird seems a bit much.”
Dr. Bridget Stutchbury of York University, coauthor of Behavioral Ecology of Tropical Birds, offered this response: “I agree that playback should be discouraged, unless it is specifically for formal bird census and/or scientific research. Recreational playbacks for birding can be harmful if done repeatedly to the same pairs of birds; and it’s unnecessary … ‘real’ birders will use their instincts and patience to track down the bird the natural way.”
Dr. Philip Taylor of Acadia University and Associate Chair of the Atlantic Cooperative Wildlife Ecology Research Network added that, “compounded by tons of people, or focused on particular individuals or pairs repeatedly, I’m sure that [tape playbacks] are disruptive or even detrimental.”
But this all sounds like professional conjecture sprinkled with scientific fact, right? Besides Professor Mennill’s research, I mean. Though no one would question the credentials of these experts, and no one would doubt their knowledge in this area, they all appear to be offering opinion—and no matter how much learning and expertise stands behind that opinion, posts in various birding forums discussing these remarks clearly show that “the birding community” mostly enjoys or is agnostic about the use of these methods, and many frown upon “purists” who would deny them their use.
So let’s return to the research: The peer-reviewed and published results (PDF) from the work of Professor Mennill and his team state that “two short playback sessions were sufficient to alter high-ranking, but not low-ranking, females’ perceptions of their partners’ status.” Two short playback sessions. Think about that. The paper goes on to reveal that the impact of these encounters ripples through the community as a whole, a finding that supports “the idea that information may be transferred between individuals in a communication network rather than simply within a dyadic context [between two individuals] and provide a conceptual link between the attractive and repellent properties of male song where mate attraction and territory defense may be simultaneous functions of a common signal”—a finding that reinforces Dr. Lucas’s statement “that there are lots of ways to disrupt a social system through playbacks.”
Were we only discussing a single birder, perhaps the impact would be negligible. But we aren’t talking about a single birder, nor even a few dozen or a few hundred. In North America alone we are discussing many, many thousands of people. For example, there are more than 1,600 people subscribed to the TEXBIRDS mailing list, and that list focuses only on Texas; also, at any one time more than 100 people are visiting and viewing the Dallas Audubon discussion forums, and those focus on Dallas and surrounding areas. Accepting that not every birder is online and that not every birder knows of these resources, one need not be Stephen Hawking to extrapolate from those two examples precisely how large the birding community is on this continent, let alone around the world, and one need not be a mathematical genius to see how even a fraction of that number using these methods would equate to a very large group.
In closing, it is the last statement of the Mennill study with which I want to end this part of my discussion: “Finally, our results show that short playback sessions can have longlasting and far-reaching effects on individual fitness.” Wait a minute! How did we get from interfering with mating and social status to permanent impact on a bird’s health? The simple answer rests in a single word: physiology. Part 2 of “Pishing and Tape-Luring” will deal with research covering the health impacts on birds that stem directly from these two practices.
[cross-posted to The Clade]