Every hobby has slang and jargon that is often impenetrable to those who don’t share the hobby. Birding is no exception.
A nemesis bird is not the Hairy Woodpecker that pounds on your gutter early in the morning but rather an uncommon or secretive bird species that a birder can’t ever seem to find. When a birder says she dipped on the White-faced Ibis reported at Scarborough Marsh, she means she could not find it.
If you find a rare bird, you have found a Mega, or if it is really rare, a MEGA. There are other more colorful terms for such rare birds that can’t be printed in a family-friendly blog.
One of the most perplexing slang terms in the birding lexicon for the uninitiated is the Patagonia Picnic Table Effect. This phrase is applicable to Maine this winter. Before I explain, we need to review a little birding history.
Birders often keep lists of birds they have seen or heard. A life list contains all of the birds one has ever seen. There are many other variants: a year list, a Maine list, a North American list, a North American year list, a birds seen on Tuesdays list. You get the idea.
Any time people start compiling lists, a bit of competition may emerge. Some birders want to compile a longer list than their friends or other birders. Birders who avidly maintain their lists are called listers.
This competitive birding or sport birding took off in the late 1960’s. Jim Tucker, a lister from Texas, wanted to develop a way for other birders to compare their various list sizes. Thus was born the American Birding Association with its magazine, Birding. Birding had articles on sites where rare birds could be found, birding techniques and list totals to allow birders to see how they stacked up against other listers. Hard-core competitive birding was launched.
In the 1970’s, the holy grail for a North American lister was 700 life birds. Roughly 660 species of birds occur in North America every year. Some require trips to far-flung places like the Pribilof Islands for Red-legged Kittiwakes and Parakeet Auklets, Key West for Black Noddy and pelagic trips off both the Atlantic and Pacific coasts for various shearwaters and storm-petrels. But with effort, getting to 660 species can be achieved. Breaking the 700 barrier means finding 40 species (MEGAs if you will) that normally don’t occur in North America.
For the competitive North American lister, southeastern Arizona, the Rio Grande Valley of Texas and south Florida offer rich diversity as well as higher chances for rarities than other parts of the continent.
One must-visit area in southeast Arizona is the Patagonia Reserve, a property owned by The Nature Conservancy. It’s a delightful place that offers a great chance to see Gray Hawks and some uncommon hummingbirds.
In 1977, a few birders in the Patagonia area stopped at a roadside picnic table for a break. They were fortunate to discover a pair of Rose-throated Becards, a flycatcher relative not normally found in North America. MEGA sighting!
Other listers descended on this picnic table to add the becard to their life lists. Becards are secretive birds so it took some effort for birders to find them. In so doing, they saw other birds. Some of these were rarities: Black-capped Gnatcatcher, Thick-billed Kingbird, Five-striped Sparrow, and Yellow Grosbeak.
So, this snowballing phenomenon in which a rare bird attracts many birders, who find yet more unusual birds, drawing yet more birders who find even more rare birds was termed the Patagonia Picnic Table Effect. The effect is basically a positive feedback loop. A birder finds a rare bird, other birders come to see the rarity and find other rare birds, drawing yet more birders who find yet more rare birds.
Here in Maine, we recently had a possible example of the PPTE. On January 14, Frank Paul found a Black-headed Grosbeak at Capisic Pond in Portland. This species is closely related to our Rose-breasted Grosbeak. Black-headed Grosbeaks are normally found nesting broadly west of the Mississippi River and wintering in Central America. We have four accepted records for Maine and another dozen to be reviewed.
The Capisic Pond bird drew many birders. It turned out to be fairly reliable, so Capisic Pond was getting increased coverage by birders.
On January 29, Brendan McKay found a Redwing at Capisic Pond. Not to be confused with Red-winged Blackbirds, Redwings are members of the thrush family. In silhouette, a Redwing looks like a robin. Redwings are found widely throughout most of Europe and northern Asia. They colonized Greenland in 1990.
The species is a mega-rarity in North America. Vagrants are most likely to occur in Newfoundland. The Capisic Pond Redwing was only the second for Maine, the first having been seen earlier in February in Steuben on a single day.
January 29 was a Friday. Hordes of birders descended on Capisic Pond over the weekend to see the Redwing. It was a rather furtive bird but was fairly faithful to a large patch of roses. With patience, the bird could be seen. Sometimes, it rewarded birders with killer views.
The Portland Redwing stayed until at least February 22, drawing birders from far and wide. In early February, birders started to report a Dickcissel (perhaps the same one seen there in early January). Dickcissels are uncommon in the state but not in the same league as the grosbeak or the Redwing. They are a North American species with the populations closest to us being in extreme western Pennsylvania and Ohio.
Some birders in February were able to see the Black-headed Grosbeak, Redwing and Dickcissel on the same day in this jewel of an urban park. Is this an example of the PPTE?
Some recent research out of Oregon State University disputes the existence of the PPTE. The team, led by graduate student, Jesse Haney, used ten years of eBird data to ask if the discovery of a mega-rarity increases sightings of other rarities.
The team searched eBird for records of 81 species of mega-rarities. They determined the number of eBird records for the rarity and the range of days of observation. For instance, there were 419 eBird records for the Capisic Redwing over 25 days. The authors could then calculate the intensity of birding that a rarity engendered. One would expect higher birding intensity would lead to a higher discovery rate of more rarities.
The authors looked at 271 sightings of the mega-rarities from all around the country. One example was the Northern Lapwing that appeared in Poland, Maine from May 3-6 in 2013.
The authors found no support for the PPTE. Rarities that drew the most eager birders did not lead to a higher rate of discovery of additional rarities than rarities that were seen by few birders. So, the PPTE is a delightful myth with no scientific support.