A Beer Drinking Bird?

a photo of an olive-side flycatcher
The olive-sided flycatcher is sometimes described as wearing an unbuttoned vest.

Copyright photo courtesy of
Mike Danzenbaker.

The olive-sided flycatcher, a nesting species in Rocky Mountain National Park, is on a national “bird watch” list. This species has undergone significant range changes during the 20th century, including extirpation (local extinction) in some states. Evidence in the western U.S. links the olive-sided flycatcher with clear cuts and burns suggesting that the birds use mosaic habitats. Thus, in some cases, the disappearance of the flycatchers may reflect natural processes of forest recovery.

a photo of ponderosa and aspen woodlands
In the park, the olive-sided flycatcher is most often spotted in ponderosa and aspen woodlands, often on a high dead tree limb.

Photo courtesy Rocky Mountain National Park.

Monitoring populations of highly mobile bird species is challenging. Cornell Ornithological Laboratory has developed a simple field process (called a protocol) that allows “citizen scientists” to use taped bird songs and calls to assess presence and observe nesting behaviors for several forest species of concern, including the olive-sided flycatcher. What makes the Cornell Birds in Forested Landscapes Project powerful is that data is collected by teams, throughout the range of the bird, using the same techniques.
a photo of volunteers listening for olive-sided flycatchers
Eagle Rock School students and a park volunteer look and listen for the olive-sided flycatcher.

Photo courtesy of Eagle Rock School

At the park, Eagle Rock School students from Estes Park under the leadership of science instructor Janet Johnson are using the Cornell protocol to check for the nesting presence of the flycatcher at four locations. Flycatchers are notoriously difficult to identify, but students study pictures and listen to taped birds calls until they can confidently know “their bird.” It helps that the mnemonic for the olive-sided flycatcher song is “quick THREE BEERS.”

Last updated: March 31, 2012

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1000 US Hwy 36
Estes Park, CO 80517


(970) 586-1206
Through winter, the Information Office is open 8:00 am–4:30 pm Mon–Fri. Recorded Trail Ridge Road status: (970) 586-1222.

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