Colorado’s brown booby has flown for the last time
Excitement in the Boulder County birding community over the June sighting of a female brown booby, the first ever spotted in Colorado, has been supplanted by disappointment over that bird’s demise.
Its frozen carcass is now stored at the Denver Museum of Nature & Science, awaiting its being processed for scientific sampling, which it is hoped might reveal more about its life and death — and perhaps the path that it traveled, far from its normal habitat.
The brown booby’s status as representing the 500th bird species to be recorded in Colorado appears secure, for now.
“That’s accurate, but, you know, actually, the poor thing is a lost bird. It’s a vagrant,” said Jeff Stephenson, collections manager for zoology at the Denver Museum of Nature & Science.
There is no reason at this point, he said, to presume that the brown booby will become a common occurrence far from its typical nesting spots on islands in the tropical Pacific, Atlantic and Indian oceans.
The bird was first spotted by Louisville’s Peter Bandurian while cycling up Lefthand Canyon on June 22.
It reached its for-now-final resting place after the U.S. Fish & Wildlife Service contacted Stephenson to say it had died in the middle of August after an unsuccessful rehabilitation at the Birds of Prey Foundation in Broomfield, and that the museum would be an appropriate next destination.
“One of their volunteers found the bird trying to cross a street,” Stephenson said, describing its condition upon arrival in Broomfield as emaciated and dehydrated. “We know it was in the vicinity of the Ward-Nederland area, or the Lefthand Canyon area. The people at the Birds of Prey Foundation are trying to
get that location for me now.”
The Birds of Prey Foundation did not respond to a reporter’s inquiries. Stephenson said he took custody of the bird’s remains at the Denver museum on Sept. 8.
“Being the 500th species in Colorado, there was a lot of value in saving that specimen and learning what we could from it,” said Scott Somershoe, land bird coordinator with the U.S. Fish and Wildlife Service in Lakewood. “I figured they’d want the bird and I didn’t want to it to get discarded. It would be really nice to preserve the history.”
Although he referred to the brown booby as the 500th bird species identified in Colorado, Somershoe actually added a bit of an asterisk to that distinction.
“That’s pending approval by the Colorado Bird Records Committee,” Stephenson said. “There’s a group that will decide whether it was somehow escaped from captivity, or some other unusual circumstance … I don’t know why they would not accept it, honestly.”
Bill Kaempfer, of Boulder, past president of the Colorado Field Ornithologists, concurred.
“The brown booby is most certainly still in the loop as an official record,” he wrote in an email. “In fact, since what is referred to as a ‘specimen’ of the bird was collected, the record can be processed even more quickly.”
The process of determining more about the circumstances of the brown booby’s arrival in Colorado will take place under Stephenson’s direction.
“We’ll be creating a scientific specimen from this,” he said. “Typically, we try to make as many parts available for future scientific reference as possible. In the case of a bird, what we call a salvage specimen, we will try to make a study skin, and then also preserve its skeleton.
“We also preserve any parasites that we find either on the outsides, ectoparasites, or inside, endoparasites, as well as tissue samples from various organs, for future genetic and other molecular work.”
A necropsy typically would have already been performed at the Birds of Prey Foundation, and Stephenson said he has a preliminary report from that facility. He said the foundation’s post-mortem work on the bird, followed by his own, overlap to a degree.
Any speculation as to how the bird arrived in Boulder County, whether it migrated up the Missouri and Platte rivers from the Gulf of Mexico, or followed some other route, is at this point just that, Stephenson said.
“We won’t know that until the genetic work is done,” he said.
Because no brown booby was spotted in Colorado before June of this year doesn’t mean it’s the only one that has ever visited the state, or that there’s not another one currently ensconced here. And they have become more common of late in several landlocked states.
In fact, in the 50th anniversary issue of Colorado Birds, the journal of the Colorado Field Ornithologists, one ornithologist had even predicted that a brown booby would be the bird to earn the honor of Colorado’s 500th winged species.
“They’re coming from the Gulf of Mexico,” Somershoe said. “Iowa had one last year, Nebraska has had one, inland Texas, it’s almost a regular pattern now. I’m not surprised. And they disperse, or show up unassociated with tropical systems.
“They have shown up in Arkansas two or three years in a row now, and no tropical systems have blown them in. They’re just flying in for some reason. I’m not sure anyone has any idea what’s going on there.”