Abstract
Eggshell weight and thickness indices of Richardson’s Merlin (
Falco columbarius richardsonii) eggs collected in southeastern Montana were significantly (p < 0.01) lower than pre-1946 samples. Montana eggshells showed reductions of 13% in shell weight and 20% in shell thickness indices when compared to eggshells collected before 1946. The decreased eggshell weights and thickness indices and the occurrence of 7 organochlorine compounds in Merlin eggs recently collected in southeastern Montana indicates that this raptor population merits periodic monitoring.
Keywords
0rganochlorines,
Merlin,
Falco columbarius,
pesticides,
Montana
Citation
Becker, Dale M.; Sieg, Carolyn Hull. 1987. Eggshell quality and organochlorine residues in eggs of merlins, Falco columbarius, in southeastern Montana. Canadian Field-Naturalist. 101(3): 369-372.