Thermal Characteristics of Painted and Unpainted Eastern Bluebird (Sialia Sialis) Nest Boxes

1. Thermal Characteristics of Painted and Unpainted Eastern Bluebird (Sialia Sialis) Nest Boxes Rebecca A. Beale Funded by the National Science Foundation Committee Members: Dr. Charles Blem (Dept. of Biology, VCU) Dr. Randy Bell (Curry School of Education, UVa.) Dr. Stephen Thornton (Dept. of Physics, UVa.)

2. Eastern Bluebird (Sialia sialis) • Family: Thrush (Turdidae) • Length: approximately 7 inches (or 18 cm) • Description: Males Bright blue heads, tails, backs, and wings; chestnut red sides, flanks, and throat; underparts chestnut red from chin to belly; white belly Females Generally less colorful than males; light gray-blue heads, dull brown backs, blue tails and wings; slight white ring around eye • Diet: Summer Predominantly insects, spiders, and caterpillars Winter Fruits, berries, and seeds http://www.fifthdaycreations.com/articles/bluebird.asp

3. Bluebird Decline House Sparrow (Old World Weaver Finch) • Both species introduced from Europe • House Sparrow-1850 • European Starling-1890 • Both birds compete successfully with • native species for nesting cavities. • Believed to have led to a dramatic • decrease in bluebird population from • about 1940 until the late 1970’s • Not protected by federal law (nests can be • removed from nest boxes) http://www.kwic.com/~pagodavista/schoolhouse/species/birds/hsparow.htm European Starling Photo by Patricia Michaels http://greennature.com/article2323.html

4. Nest Construction • Secondary cavity nesters, meaning that they cannot excavate their own cavity in trees • Rely on humans or other birds (such as woodpeckers) for places to build nests • Readily adapt to man-made cavities in the form of nesting boxes • Nests constructed by the female • Nest building takes 1-6 days • Cup-shaped nest composed mostly of dry grasses and pine needles www.junglewalk.com

5. Eastern Bluebird Nesting Season • Eggs laid in late March or early April (usually 1 egg laid each day until clutch is completed) • 3 to 6 (usually 4 or 5) eggs per clutch • Eggs rich sky blue, but may be light blue or white; about 21 x 16 mm in size • Incubation by female approximately 13-15 days • About 15 to 20 days old at fledging • Can have up to 3 broods per season Photo by Elizabeth Nevin http://birds.cornell.edu/birdhouse/news/your_photos_bluebirds.html

6. Temperature Parameters • Eggs must be warmed to at least 95° F to develop properly. • Female’s body at about 106° F • Bluebird eggs and nestlings cannot survive temperatures exceeding 107° F. Photos by R. Luther http://birds.cornell.edu/birdhouse/news/your_photos_bluebirds.html

7. 3 Factors in Construction that Affect Internal Temperature of Nest Box • Materials • Color • Ventilation

8. What is the effect of color on internal temperature of the nest box?

9. Painting the Nest Boxes • Exterior Latex Paint will be used. • Color possibilities (white, light tan, gray, dark brown, black) • Some boxes to be left unpainted

10. Data Collection • CBLs, temperature probes, and graphing calculators will be used to monitor surrounding air temperature and interior temperature of nest boxes during 24-hour intervals. • Cloud cover will be described as sunny, partly cloudy, or overcast. • Wind conditions will be described as calm, breezy, or windy.

11. VBS Weekly Nest Box Monitor Form

12. Rappahannock River Valley National Wildlife Refuge, Tayloe Unit • Approximately 1,111 acres • Founded in 1996 largely to protect critical habitat for bald eagles • Large concentrations of bald eagles found on the river year-round • Dirt road runs through hardwood swamp and onto open fields • Agricultural land being restored to manage native grasslands for ground-nesting birds

13. TAYLOE TRACT IN RICHMOND COUNTY, VIRGINIA http://monarch.tamu.edu/~maps2/newmaps.va.htm

14. See #19 for Tayloe Tract location Map: http://www.dgif.state.va.us/wildlife/vbwt/site.asp?site=CNN19&loop=CNN

15. Bluebird Nest Boxes at the Tayloe Tract • Approximately 50 top-opening standard boxes mounted on wooden posts • Located 4-6 feet above ground • 1 ½ inch entrance hole diameter • Stovepipe pole guards to deter raccoons and other climbing predators • Wooden nest hole extensions to prevent animals (such as squirrels) from making entrance holes bigger; helps prevent predators from reaching into nest http://www.birdsforever.com/bluepdts.html

16. Nest Box Layout at the Tayloe Tract Courtesy of U.S. Fish and Wildlife Service

17. Fall 2003 • Repair damaged nest boxes. • Make sure all boxes to be used have hole extensions and stovepipe pole guards. • Mow grassy areas located near nest boxes. • Clean out old nesting material. • Paint nest boxes. • Begin collecting data on temperature of painted and unpainted boxes. http://www.puffin.net/wildlife/bird/land/blu_e_1.htm

18. Spring 2004 • Begin monitoring nest boxes and continue collecting data on temperature. www.junglewalk.com

19. Resources • Bluebird Book: The Complete Guide to Attracting Bluebirds, by Donald and Lillian Stokes • Bluebirds and Their Survival, by Davis and Roca • Eastern Bluebird, by Gary Ritchison • http://monarch.tamu.edu/~maps2/newmaps/va.htm (creating the map of Richmond County) • http://www.dgif.state.va.us/wildlife/vbwt/site.asp?site=CNN19&loop=CNN (Northern Neck Loop map) • The Bird Box, Publication of the Virginia Bluebird Society, July 2003 • The Bluebird Monitor’s Guide to Bluebirds and Other Small Cavity-Nesters, by Berger, Kridler, and Griggs http://washingtondcmetroweb.com/bluebird.htm