DDE and reproductive success in some Alberta common terns

• Published in: Canadian Journal of Zoology
• Main Authors: Switzer, Bruce, Lewin, Victor, Wolfe, Fred H.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Canadian Science Publishing 1973
• Subjects: Sterna hirundo
• Online Access: http://dx.doi.org/10.1139/z73-157; http://www.nrcresearchpress.com/doi/pdf/10.1139/z73-157

A study of the relationship of DDE to reproductive success of an inland breeding population of common terns. Sterna hirundo, had been carried out in 1969 and 1970 at Chip Lake, Alberta. Although a continuing decrease of DDE residues in eggs bad occurred, eggshell thickness remained unchanged. In addition, reproductive success markedly increased in 1970; however, the percentage of eggs suffering breakage did not change between years. Low correlations between DDE and eggshell thickness or weight in both years suggest that DDE is unrelated to these eggshell parameters, which in turn are not related to reproductive success in this population.