Northern Prairie Wildlife Research Center
John T. Lokemoen and Rolf R. Koford1
Northern Prairie Science Center
National Biological Service
8711 37th Street SE
Jamestown, North Dakota 58401 USA
Determining the incubation stage of bird eggs can provide important information to investigators conducting nesting studies. We describe the use of candlers in the field to determine the incubation stage in eggs of Lark Buntings (Calamospiza melanocorys) and other small birds with an incubation period of 11 - 13 d. Candling was accomplished easily using simple tools and did not involve the destruction of eggs or lengthy disturbance of nests. Candling is often preferable to other methods that rely on egg mass, mass-growth curves, or immersion of eggs in water.
Lokemoen, John T. and Rolf R. Koford. 1996. Using candlers to determine the incubation stage of passerine eggs. Journal of Field Ornithology 67(4):660-668.This resource should be cited as:
Lokemoen, John T. and Rolf R. Koford. 1996. Using candlers to determine the incubation stage of passerine eggs. Journal of Field Ornithology 67(4):660-668. Jamestown, ND: Northern Prairie Wildlife Research Center Online. http://www.npwrc.usgs.gov/resource/birds/candegg/index.htm (Version 16JUL97).