Bird Banding at the Allegra Collister Nature Preserve

Important Note about the Allegra Collister Nature Preserve:
It is clear that the Allegra Collister Nature Preserve holds an attraction for many birds, and other creatures too. Because of its value as a study site for a variety of disciplines, the BCNA has negotiated for, and administers, a conservation easement for this critical habitat. It is private property.  It is important that the landowner's wishes be respected, and the intent of the agreement honored.  Unless accompanied by an authorized BCNA site custodian, written permission must be obtained prior to entering the property.  Requests for access must be submitted, in writing, to the president of the BCNA, or to a designated authorizer / site custodian. Trespassers will be prosecuted. The complete access protocol is available upon request.

Bird Banding at Allegra Collister Nature Preserve - Spring 2001
Spring 2001 bird banding was, in a word, exceptional.  Only fifteen mornings were worked; that's fewer than usual.  Only 71 hours were spent attending the nets; that's also fewer than usual.  However, more birds were captured and banded than in any previous spring season.  Five hundred thirty five of fifty two different species.

Our weather was somewhat cooler than expected.  On May 20th, it snowed!  On the 21st we captured 53 birds.  Then, on the 22nd, 110 birds were captured.  Could have kept the nets open and probably caught many more.  But, banding from dawn until noon, or later, makes for a long and tiring morning.

The moisture and early season coolness contributed to a spectacular display of blossoms and foliages.  Plum, currant, choke cherry,  grape, hawthorne and many wild flowers created a profusion of colors and fragrances.  The wealth of pollen and nectar attracted swarms of butterflies, moths and other flying insects.

And, the birds seemed to enjoy this time of plenty:

• More Western Tanagers (78) than in all prior seasons combined.

• More Bullock's Orioles (39) than in any previous spring season.

• A record number (82) of Yellow-rumped Warblers  ----  Audubon's, Myrtle and possible hybrids.

• One of the highest counts of Western Wood Peewee (16).

•  Twenty-four empids is unusually high.

• Two Northern Parulas were fun catches.

• A first time at the gulch Blue-winged Warbler  ----  a handsome male.

• A busy Lazuli Bunting count (51).

• Also, new on the species "sight list", a flock of 20 plus White-throated Swifts performed overhead.

• The second busiest spring for Yellow Warblers (54).

• A strong presence of Chipping Sparrows (20).

Noticeably absent from the gulch was the Northern Waterthrush  ----  didn't see or hear a single one.  Finally caught a Blue Grosbeak on the last day of banding; otherwise, it too would have been an absentee.

Not many raptors were noticed overhead.  Nor any prairie dogs across the road.  Fewer coyotes too.  Wapiti and White-tailed Deer were seen.  Did see evidence of raccoon and skunk continuing to prowl the watercourse.  No voles or mice darted across the trails ahead of us.  Two bull snakes copulating near the "office".  Had a fleeting glimpse of some kind of rat near the eastern most net ---- maybe a wood rat.

Last day of banding was June 2nd.  Previously banded resident birds were being recaptured.  Some were showing signs of nesting.  Its time to let them get on with the process of reproducing.  We'll have a chance to see and band their offspring in the fall.

Of all the birds banded at ACNP, since 1991, only two reported encounters have occurred.  An American Robin recovered at Avon, CO; and, a Gray Catbird recovered near Burns, WY.  Its seems like a disappointing result.  For the sake of keeping things in perspective; we selected, at random, 5 species for a comparison.  Consider the following examples of national statistics as reported (1914 through 2000) by the Bird Banding Laboratory:
 

Notice, also, the interesting longevity records revealed by these recoveries.  Encounter data is only a small fraction of the information learned from banding.  To find out more, go to http://www.pwrc.usgs.gov/.
 
The vegetation study is still in progress.  Again, a special thanks to the City of Boulder Open Space Herbarium Volunteers.  We look forward to incorporating their data with what has already been learned from the birds.

Because of time constraints, the insect study has been put on hold.

The bird banders:

Virginia Dionigi
Tony Esposito
Joe Harrison
Maggie Boswell
Tom Delaney

If you would like additional information, or have unanswered questions, don't hesitate to ask. For more information contact Joe Harrison.

The data below is presented in a spreadsheet format.  There are no summaries at this time, because it is an on-going project.  A summary will be presented after 10 years of data are accumulated (2001).

Download the bird banding data in PDF format, 274 Kbytes

B.C.N.A.
P.O. Box 493
Boulder, CO 80306