A rare bird find does not lead to another
One of the most widely held and colorfully named beliefs in bird watching, the Patagonia Picnic Table Effect, is more of a funny myth than a true phenomenon, according to research by Oregon State University.
Owing to its nickname at a rest stop in Arizona, the Patagonia Picnic Table Effect, often shortened to PPTE, has been described by participants in the multi-billion dollar recreational bird watching business for decades as the main driver of behavior and success in finding rare species – an industry that did so during a pandemic that has stopped many other activities, has become even stronger.
However, a study done by an OSU College of Science PhD student shows that the PPTE – which says that after a rare bird is spotted somewhere, bird watchers flock to the area and then find more rare species more quickly – of the PPTE does not confirm data.
“Bird watching is one of the fastest growing recreational activities in the world,” said the OSU Integrative Biology Ph.D. Student Jesse Laney. “The lure of finding very rare birds adds extra excitement that draws bird watchers from faraway places.”
Thick-billed Kingbird, Copyright Brandon Holden, from the Surfbirds Galleries
The peculiarities of the history of the creation of the Patagonia Picnic Table Effect have become a bit cloudy over time, but its basic idea is rooted in the tradition of bird watchers.
Patagonia is a tiny town near the Arizona-Mexico border, and a picnic table that is part of the name grew out of a nearby rest stop. Sometime in the 1960s or 1970s, bird watchers spotted a rare black-capped mosquito catcher or possibly a nesting pair of rose-throated becards at the rest area.
Whatever it was, or if it was something else entirely, the news spread and bird watchers descended on Patagonia, leading to other interesting sightings including the thick-billed kingbird, the five-striped sparrow, and the yellow grosbeak. The rest area remains a place of pilgrimage for bird watchers.
“It’s anecdotal that when rare species are reported, increased activity by bird watchers trying to add rarities to their personal lists leads to the discovery of more rare birds,” Laney said. “The US bird watching community has been a huge subscriber to the Patagonia Picnic Table Effect – they really believe it.”
Laney and coworkers at OSU College of Agricultural Sciences and Cornell University investigated the veracity of the PPTE by analyzing a decade of information in eBird, Cornell’s public public birding database.
“We wanted to know how often a discovery of a rare bird draws so many bird watchers to one place that even more rarities are discovered?” Laney said. “We found that bird watchers in locations where a rare species was spotted had no better chance of finding additional rarities than looking for rare species elsewhere. In short, we’ve found little support for the Patagonia Picnic Table Effect, so we have to consider it a myth – while also acknowledging that it’s a really fun myth. “
Laney and coworkers Tyler Hallman and W. Douglas Robinson of the College of Agricultural Sciences and the alumna Jenna Curtis of the OSU, now a coworker at Cornell, focused on sightings of North American “mega-rarities”, 81 of the hardest to spot bird species on the continent – all rated 4 or 5 on the American Birding Association’s five-point rarity scale.
Scientists examined 273 mega-rarity discoveries involving these 81 birds over a 10-year period from 2008, and the resulting draw and decay bird watchers who descend to an area after a sighting and then the decrease in bird watching activity after the pulling tips. Mega-rarity events included a northern Maine lapwing in 2013, a Eurasian hobby on the Washington Olympic Peninsula in 2014, and a stripe oriole in Carlsbad Caverns National Park in 2015.
“For these 273 mega-rarities, eBird data shows that bird watcher effort has increased above baseline levels prior to the event,” Laney said. “The ability of rare species to attract bird watchers’ attention has been influenced by location factors such as latitude and proximity to an airport and the year in which events took place.”
The rate at which bird watchers lost interest in finding each rarity – the rate of decay – was influenced by how long these rare birds were still being discovered, he added.
“Still, the rate of decay among these events was fairly variable,” Laney said. “We found no evidence that the draw was influenced by species identity or rarity. For us, this means that mega-rarities have a profound impact on bird watchers’ behavior simply because they are very rare. “