Photo credit: D. J. Powell/CLO

Female Wood Duck at a nest box. Nesting records of the Wood Duck, one of TBN's Most Wanted, are rare but increasing in TBN's database.

Since 1997, participants of The Birdhouse Network (TBN) have contributed more than 36,000 records of nesting attempts by cavity-nesting birds. These records have provided scientists with a plethora of information about the birds' breeding success and biology—especially for Eastern Bluebirds, Tree Swallows, and House Wrens. These species account for more than 70 percent of all nesting attempts in our database. TBN is seeking more data on these birds, as well as on 37 other cavity-nesting species.

In 2001, as the number of TBN nesting records for many of the common cavity nesters was steadily increasing, records for lesser-known cavity nesters were holding steady or becoming more rare. According to Breeding Bird Survey data, more than half of these species were declining across North America. This prompted the creation of TBN's Most Wanted, a list of cavity-nesting birds about which we had little information in our database or that were declining survey-wide. TBN's Most Wanted encourages participants to take a proactive approach to conservation by erecting nest boxes in suitable habitat to attract these birds. Biological information and tips on how to attract each species are featured in Birdscope and on The Birdhouse Network's web site www.birds.cornell.edu/birdhouse.

Since the debut of the Most Wanted list, nesting records for 14 of the 16 species have increased in our database—some, such as the Brown-headed Nuthatch, by 2,300 percent (see Table 1). Even though the average number of records per year for this species increased from 1 to 24, the total is still a tiny fraction of what is needed to monitor its breeding success using baseline data. Other species, however, have begun to show analytical promise in our database: American Kestrels, Bewick's Wrens, Prothonotary Warblers, Purple Martins, and Wood Ducks all number more than 100 nesting records.

As participants learn more about the Most Wanted, attracting these cavity-nesters becomes a thrill. Ginny Walker of Columbia, Maryland, writes, “After receiving Birdscope with the article on TBN's Most Wanted, we followed the instructions and mounted a screech-owl nest box in our backyard. We were wonderfully surprised to see a gray-morph owl and a red-morph owl soon thereafter. In late June, I heard evidence of nestlings based on some small squeaky noises as I stood under the box.”

Lisa Meacham of Austin, Texas, writes, “I just saw that the Bewick's Wren is on your Most Wanted list. I have a pair nesting in my backyard; six eggs were laid, and when I checked the box yesterday, three had hatched. Can I help you obtain data on Bewick's Wrens with my nest?”

We encourage anyone who provides a nest box to contribute data to TBN. Although monitoring nest boxes is important, and, to many, the most exciting part of attracting cavity-nesting birds to yards and neighborhoods, it is equally important to submit these nestbox observations to the Lab so scientists can study breeding bird data on broad geographic scales. For less common birds, such as our Most Wanted species, submitting data is even more critical. Only if citizen scientists tell us what's happening inside their nest boxes will we be able to study rarer species such as the Bewick's Wren and Prothonotary Warbler.

TBN would like to thank the dedicated nest-box monitors who have begun attracting our Most Wanted birds—keep up the good work! If inviting cavity nesting birds into your yard sounds appealing, we encourage you to join The Birdhouse Network and send us your valuable observations. For more about TBN, check out the TBN web site at www.birds.cornell.edu/birdhouse.

Return