Give a bird a seed, you feed it for a day. Give a bird a bird feeder, and you start driving its evolution. Who knew?
Scientists didn’t, at least not until they started studying the migratory patterns of Central European blackcaps in southern Germany and Austria. The small gray birds that summer there traditionally winter on the Iberian Peninsula, fleeing the nutritionally sparse region for the lush olives and fruits of sunny Spain every year. But in the 1950s, a small part of the population began overwintering on the British isles instead of Spain. It seemed like a case of different strokes for different songbirds, until German scientists discovered in 1992 that a genetic basis for the behavior had developed. The light cues that send the birds back to Germany each year come earlier in the more northerly United Kingdom than in Spain. The British birds, then, arrive 10 days earlier every year and were therefore more likely to pair up with mates that shared their migratory habits. Over time (even a period as short as 30 years, it seems), genetic differences between the two groups built. The scientists discovered that, indeed, the offspring of captive blackcaps that wintered in Britain followed the same route as their parents.
New research presented in this month’s issue of Current Biology suggests that bird feeders may be behind these sudden first steps in possible speciation between the British and Spanish blackcaps. To be sure, the genetic differences between the two are growing, even as they continue cohabitating in summer. The British birds have rounder wings, a trait associated with shorter migratory flight. Their feathers are browner than their gray counterparts. And, perhaps most telling, their beaks are longer and narrower: A diet of Spanish fruits and olives requires a broad bill, the researches suggest, while the British birds’ beaks reflect what the researchers describe as the “more generalistic feeding behavior” of birds at birdfeeders. In other words, it takes a bigger mouth to eat olives than it does to peck at seeds innocently put out by Brits who just like watching birds outside their living room windows. (They never thought they were playing God!)
The media loved this discovery, giving it significant word counts and air time. This makes sense, as far as science journalism goes: The work was easy to understand by a popular audience, and featured a favorite subject of science journalism — ourselves. But the story also contained the kind of discordance that gave it a quirky edge. Here you have something as simple and small as the bird feeder shaping something as complex and dynamic and all-encompassing as the evolution of life itself. LIFE!
But the thing is, bird feeding isn’t so small and simple. And if you think it is, then you must still be covering pine cones in peanut butter and rolling them in seeds. Bird feeders are big business. The U.S. Fish in Wildlife Service estimates that 53.4 million people feed wild birds. An exhaustive 2001 survey — “Birding in the United States: A Demographic and Economic Analysis,” the most recent to offer such specific data — found that Americans spent more than $2.2 billion on bird food that year, and $628 million on bird houses, feeders, baths, and nesting boxes.
And have you tried to buy a feeder? Search for a bird house and you end up with plenty of straightforward, folksy choices, birds seemingly sharing tastes with the people who describe their personal aesthetic as “country.” The search for a bird feeder, however, is a much more technical process, one that requires you to first think long and hard about what exactly you hope to accomplish. If you want to attract small birds, like finches or chickadees, you’d probably like a tube feeder — those tall, skinny feeders with holes for eating and perches for perching around the bottom or all along the feeder’s length. If you’re hoping to attract larger birds — your orioles and your woodpeckers — you’d be better off with a platform feeder, which is basically a tray, sometimes covered by a small roof. Seed choice is important, too. Want Painted Buntings? Buy sunflower seeds. Jays? Corn.
And that’s the easy part. The variety of actual birdfeeders is stunning. There are feeders with trays that keep seed from falling on the ground. Feeders that display a variety of seeds in a decorative spiral. Feeders that look like barns, angels, Conestoga wagons, and lighthouses. Feeders with adjustable perches. Should you hope to extend to birds both the pleasure of staying dry while eating in the rain and, more important, a choice of food, you might consider the Arundale Mandarin Bird Feeder with Divider. And if you’re hesitant to spend $59.99 on a bird feeder, you can rest assured that this connection to nature is “engineered to last a lifetime.”
Of course barns and wagons and lighthouses and the suppression of the idea that these are in fact engineered isn’t for everyone. Have an eye instead for restrained, modern design? You could choose a glass-topped sphere from Eva Solo. The Museum of Modern Art offers a collapsible feeder made of white-painted steel. Design Within Reach sells a pastel orb with what’s perhaps the most discrete display of bird food — a single line of peanuts barely peek out of the bottom. Like bold colors? Try one of J Schatz’s shiny, egg-shaped feeders for $135, or pony up $395 for the ceramic mobile feeder, hoping it does anything but blend in with the landscape. Drawing an unsubtle line in the feeder sand, Blomus makes a stainless steel house silhouette and roof that it claims brings “a note of urban sophistication to the garden” — the implication being that gardens were bastions of poor taste before Blomus came along.
Spend some time in the hobby and you may begin to crave things you never knew you needed when you started feeding birds. Maybe you’re disappointed with the quality or quantity of birds you attract. You could buy the Songbird Magnet — a device that attracts birds to feeders by playing their calls. If you travel often, you may need the $199 BirdCam 2.0 to capture missed birds. And if you like feeding animals, but not ALL animals, you could try the Squirrel Buster PLUS — “proven technology” that utilizes polycarbonate resins and power-coated aluminum components to resist squirrels’ tendency to smell food and want to eat it.
Of course any industry with sales in the area of $3 billion is going to attract attention, and it may not be positive. For the people of bird feeding, that came in 2001 — the last time bird feeders made major news. That year, The Wall Street Journal ran a front-page article critical of the hobby (“Crying Fowl: Feeding Wild Birds May Harm Them and Environment,” written by James P. Sterba). Among the charges: Bird feeders favor birds that eat at them or on the ground below, skewing their populations relative to the birds that can’t or don’t feed from feeders. People should clean their feeders with bleach every two weeks, but few do, and diseases spread quickly. People should drape their windows or cover them with decals, but few do, and anywhere from 98 million to a billion birds die each year flying into glass. And then there’s the niger seed of Burma, a popular bird seed that human-rights groups have asked birders to boycott in protest of that country’s military junta. Few have, the owner of a New York gardening center told the reporter.
The article riled feeder fans and their defenders. Among them was the Cornell Lab of Ornithology, which issued a statement that ran in its own Birdnotes and was excerpted in the Journal. The famed academic center for all things avian had a lot of problems with what it described as the Journal’s “meandering” article, but was most outspoken about the data used to argue that feeders spread disease. Sterba had reported that the House Finch population in the Eastern U.S. had declined 60 percent over the previous decade due to the spread of House Finch conjunctivities, a disease with the deadly effect of swelling shut a bird’s eyes and putting it at risk for starvation or predation. Cornell refuted the connection, arguing that the disease is most prevalent in summer and fall, when finches minimally use feeders, and lowest in midwinter, when finches go crazy for feeders. And besides: House Finches aren’t even native to the Eastern U.S. Their populations exploded dramatically after being introduced to the area only several decades earlier and they lacked the disease resistance native finches had developed — a double whammy that made them particularly susceptible to an outbreak. “All animal populations are controlled to some extent by disease,” the Lab wrote, “and it was only a matter of time before the eastern House Finches encountered this one.”
But even back before we knew of their role in shaping species, feeders were doing more than feeding. Every winter since 1987, the Cornell Lab has used a national network of feeder owners to track the number and distribution of birds. Project FeederWatch, as it’s known, is underway now and runs through April. Interested in joining the 15,000 feeder watchers who currently track? Send $15 to Cornell (amateur bird monitoring systems don’t grow on trees!) and in return you’ll receive a tally sheet, bird identification guide, and poster of common feeder birds. Set up any number of feeders in your yard and then choose two consecutive days to count the species and numbers that visit your feeders. These can change week to week, but don’t cheat. “It’s best to schedule counts in advance and not start a count just because there are great birds in the yard that day,” the narrator of an instructional video warns, knowing how tempting it would be to start counting when there’s something to count.
This is important because “0 birds” is still data. Valuable data at that, and not so unexciting, if you think about it. “There’s really no such thing as a boring count,” a FeederWatch represenative reminds us. “If people only reported the great sightings that they had, we’d have a very biased view of how bird populations are actually doing.” According to the Project, for example, data indicating a decline in Florida’s Painted Buntings in winter led that state’s Game and Freshwater Fish Commission to begin its own, more exhaustive study of the species population.
Of course, even as Project FeederWatch hits its annual stride, bird feeders have already begun to fade from the public consciousness, just as they did back in 2001. The culprit this time was probably the octopus that uses coconut shells as a mobile defense system. Who’s going to keep thinking about bird feeders and their connection to design and commerce and human rights and the environment and what may be the last gasp of the amateur scientist when you have what might be the first known case of an invertebrate using tools? Plus the story came with video, and Current Biology can’t compete with that, as far as popular audiences go. • 30 December 2009