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News From the Prairie
PWLC Monitor 17 Bluebird Boxes at the PWLC
By Molly Stoddard
Volunteers Greg and Sandy Slotto of Pelican Rapids, MN donated more than 55 hours monitoring 17 bluebird boxes at the Prairie Wetlands Learning Center in Fergus Falls, MN this past nesting season. Their data, the most reliable and complete set compiled since the boxes were installed more than five years ago, has recently been processed by staff and reported to Cornell Lab of Ornithology's NestWatch web site, a continent-wide citizen science program (http://watch.birds.cornell.edu/nest/home/index).
The PWLC has 17 boxes and all were monitored with 10-18 visits per box by Greg and Sandy. Three species used our boxes: bluebirds in one box, house sparrows in one box, and tree swallows in 15 boxes. The first egg laid date ranged from 4/20 to 7/11, depending upon the box, with by far the most first egg dates in May, particularly 5/16-5/23. The birds laid 120 eggs total, an average of seven eggs per box. Thirteen eggs did not hatch (.75/box avg.). They counted 97 young or nestlings (5.7/box avg.), and only 3 dead young. Ninety-two young are estimated to have fledged (5.4/box avg.).
Nest records submitted to NestWatch's online database are compiled with those of other participants in a continent-wide effort to better understand and manage the impacts of environmental change on bird populations. For example, scientists have discovered that the best direction for the nest hole to face is east or northeast. They theorize that these directions allow early morning light to warm the box more effectively at a time when air temperatures are at their lowest.
Once fully populated, the database will house nearly 400,000 stored nest records spanning more than 40 years and 500 species. NestWatch data are publicly available online for anyone to view, download, and explore. The NestWatch database makes it easy for participants to manage and organize their bird nesting records and to see their data alongside everyone else’s.
Bluebird populations declined greatly in the 20th century. The causes were:
- habitat loss,
- introduction and competition of aggressive and non-native house sparrows and starlings that evict or kill birds using cavities,
- allowing cats to roam,
- increased use of harmful pesticides,
- replacement of wooden fence posts with metal posts, and
- clearing of field borders and fence rows to increase cropland acreage
It became much more difficult for these native birds to survive and breed.
The Bluebird Recovery Program of the Audubon Society of Minneapolis partnered with the MN Department of Natural Resources Non-game Wildlife Program to sponsor workshops, publish education materials and promote the placement of bluebird houses to bring back this wonderful songbird. Minnesota now has one of the most successful bluebird recovery projects in the nation, and the future of the eastern bluebird is now secure thanks to active wildlife management.
Bluebirds today heavily on nest boxes provided by humans. Monitoring nesting boxes is important because it increases the likelihood that boxes are used by native birds and have more young survive to fledge.
Greg and Sandy followed protocol for monitoring provided by NestWatch. With their insightful observations, PWLC staff are poised to move on recommendations from them to re-locate some boxes and increase the likelihood of bluebirds nesting in the boxes next spring. In the meantime, the PWLC is interested in finding volunteers who would like to monitor purple martin gourds near the barn. For more information, please call Molly Stoddard at 218-998-4489.
Information from www.sialis.org, NestWatch, and Minnesota DNR web sites was used to compile this article.
