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Reproductive Success Of The White-Faced Ibis: The Effects Of Pesticides And Colony Characteristics, Benjamin B. Steele
Reproductive Success Of The White-Faced Ibis: The Effects Of Pesticides And Colony Characteristics, Benjamin B. Steele
All Graduate Theses and Dissertations, Spring 1920 to Summer 2023
Reproductive success of white-faced ibis (Plegadis chihi) was measured in nine colonies on marshes in northern Utah during 1979. The effects of pesticides and characteristics of colonies and sub-colonies on reproductive success were examined.
DDE was present in all 80 eggs sampled and had a geometric mean concentration of 1.25 ppm. Shell thickness of 176 eggs was 4.3 percent below pre-1945 thickness. Shell thickness was weakly correlated with residues of DDT, DDE, Dieldrin, and heptachlor epoxide. Residues of these four pesticides were all correlated with each other. However, because of the stronger correlations between shell thickness and two …