New Study Shows Blue Jays Roost Upside-Down

Erie, PA—A recent discovery has shown that Blue Jays (Cyanocitta cristata), common backyard birds in the eastern United States, spend their nights hanging upside-down from perches, similar to bats. This ground-breaking finding was made recently by the three young women who run the Audubon banding station in Presque Isle State Park, located in Erie, Pennsylvania.

It was Assistant Bird Bander Amy Gondran who first realized something was unusual. “We’ve banded a lot of Blue Jays, but this one was weird. I put the band on, and took all the required measurements: measuring the wing, taking a weight, determining amount of fat deposits, aging and sexing the individual, looking for ticks. Then, when I was done, it just hung by its feet from my finger, dangling head-first.”

Assistant Bird Bander Amy Gondran with the Blue Jay hanging from her finger

Head Bander Mattie VandenBoom was mystified by the odd behavior. “It [the Blue Jay] hung there for quite a few mintues, in a trance. I took a picture with my phone so we would have proof that it actually happened,” she says. “In all my 10 years of banding experience, I’ve never seen behaviors like this in a wild bird.” 

Adds Lauren Smith, Associate Bander of Birds, “It hung there by its feet for like two minutes, and it closed its eyes at one point, so we figured it was sleeping.”

“We believe it was probably slightly stressed from being caught in our mist net and then having been handled during the banding process, which made it tired,” says Gondran. 

After the birds are removed from the mist nets, they are placed in cloth bags and transported to the banding area, where they are processed. “Our hypothesis is that the dark bag calmed the Blue Jay down, which caused it to fall asleep once the banding process was complete,” says Gondran.

During the spring migration earlier this year the women banded approximately 60 Blue Jays, but had not noticed any unique behaviors. “We have had other Blue Jays rest on our hands for a few moments before flying away [after the banding process], but this was definitely a unique behavior,” says VandenBoom.  

This discovery seriously alters the way scientists think about Blue Jays, says Smith. “Before, we just assumed that they all huddled on a branch at night. This completely changes everything we know about their social structure and basic behavioral ecology.”

 

Other birds do hang upside down, including black-capped chickadees, which can be quite acrobatic in their foraging [see http://www.youtube.com/watch?v=P87zzgHhKBE and http://www.youtube.com/watch?v=1l05MU2tQO4&feature=watch_response], and male oropendolas, tropical birds which will fall forward head-first off a branch, wings open, in order to attract a mate [see http://www.youtube.com/watch?v=-HjNZ1a0PTY&NR=1 ]. However, no bird species have ever been observed roosting in this hanging position.  

The discovery is currently under review for publication in the scientific journal Nature.  “Our sample size is one, but we have photographic evidence, so I don’t see how anyone could doubt our findings,” says Gondran.

Further studies are already underway, and the banders are working on a book about their discovery, tentatively titled “The Bird Who Hung by His Feet.” Film rights have already been purchased by 20^th Century Fox, with Kristen Stewart, Anne Hathaway, and Drew Barrymore reportedly signed as the leads. 

On a related note, the banding team may or may not have also discovered the only remaining population of Ivory-billed Woodpeckers in the world. “It was crazy, the Ivory-bill was flying around in this mixed-species flock, with a Bachman’s Warbler, a couple Passenger Pigeons, and a Carolina Parakeet,” says Smith. “Amy left her camera at home that day, but we’re confident that we’ll soon have photographic evidence to confirm our newest discovery for the ornithological community.”

“Apparently all the species have modified their behaviors in order to survive the rigors of the modern world together,” says VandenBoom.  Research is in progress to support this claim, but the results “look positive” for these species.

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