
Peter Kaestner has been birding since toddlerhood, when his older brother introduced him to the hobby. He started a life list by age 7 and took his first international birding trip at age 10. At age 14, he flew to the Bahamas without adult supervision. The Maryland native, now 65, no longer remembers how he paid for anything or got around, yet he vividly recalls the birds he saw, such as Thick-billed Vireo and Bahama Woodstar.
Sign up for our newsletter, full of birding tips, news, and more!
After college, Kaestner joined the U.S. Foreign Service, in large part because it enabled him to travel the globe looking for birds. In 1986, he became the first person to spot at least one species in every bird family, and in 1989, he discovered a new species of antpitta in the Colombian Andes. (Its scientific name is Grallaria kaestneri in his honor.) He has been birding in about 150 countries and supposes he’ll still be birding on his deathbed. “I love watching birds, I love twitching birds, I love studying about birds, and I love studying about their biology,” Kaestner says. “I get enjoyment from so many different dimensions of birds that it’s absolutely inevitable that birds would be a very important part of my life.”
It’s the counting of birds, however, that truly drives him. As of December 2018, Kaestner’s life list stood at 9,193 species, including one bird that’s now extinct (Atitlán Grebe) and two that are extinct in the wild (Guam Kingfisher and Guam Rail). Though no other American has seen more, he remains determined to add to that figure. “I am consumed by numbers,” he says. “I want to get to 10,000 before I die, no question about it.”
Not long ago, the idea of one person seeing 10,000 bird species, about 95 percent of the world’s total, would have been unimaginable. In the last few years, however, the top Big Listers, as birders with the largest life lists are known, have begun closing in. The birding website Surfbirds, which maintains the most comprehensive ranking of Big Listers, reports that 10 birders — four Brits, two Swedes, a Belgian, a German, a South African, and Kaestner — have topped 9,000 species and more than 30 others have reached 8,000.

The world’s top lister, Jon Hornbuckle, died at age 74 in February 2018, months after being injured in a car crash in the south of France. A retired British metallurgist, Hornbuckle is still atop the list with 9,600 species after a 2017 trip to Jamaica netted him his final six ticks. Claes-Göran Cederlund (9,548 species), Philip Rostron (9,499 species), and Hugh Buck (9,449 species) are in a close race for second.
As in professional boxing, there are no universally accepted rankings in competitive birding. The American Birding Association, eBird, and iGoTerra, among others, maintain their own rankings, which, like the Surfbirds list, rely on self-reporting and the honor system. Theoretically, some Big Listers may not publicly list anywhere at all.
Competitive birding also lacks universally accepted methodologies. Some Big Listers count only birds they’ve seen, whereas others include birds they’ve heard. Some employ playback tapes, and others would never do so. Meanwhile, North Americans tend to use the eBird/Clements Checklist of Birds of the World, which recognizes about 300 fewer species than the European-preferred IOC World Bird List and partially explains why Europeans dominate the Big Lister rankings. “I look forward to the day when we can all agree on a world bird list, but it’s not happening yet,” says Noah Strycker, who in 2015 smashed a world record by seeing 6,042 bird species in a single year. (His record has since been broken.)
Originally Published