. The Canadian field-naturalist. 260 The Canadian Field-Naturalist Vol. 104 Table 3. Correlation coefficients (r values) between concentrations of different organochlorine compounds and eggshell thickness in Peregrine Falcon eggs from 36 different nesting attempts at Rankin Inlet. Heptachlor Eggshell DDE PCB Dieldrin Epoxide Thickness DDE PCB ** Dieldrin ** * Heptachlor Epoxide ** ** * Eggshell Thickness ** * ;^ ;^ ns = not significant; *P<; **P< Organochlorine Residues in Eggs A total of 52 per
. The Canadian field-naturalist. 260 The Canadian Field-Naturalist Vol. 104 Table 3. Correlation coefficients (r values) between concentrations of different organochlorine compounds and eggshell thickness in Peregrine Falcon eggs from 36 different nesting attempts at Rankin Inlet. Heptachlor Eggshell DDE PCB Dieldrin Epoxide Thickness DDE PCB ** Dieldrin ** * Heptachlor Epoxide ** ** * Eggshell Thickness ** * ;^ ;^ ns = not significant; *P<; **P< Organochlorine Residues in Eggs A total of 52 peregrine eggs, representing 36 clutches, was collected and analyzed for organoch- lorine residues. Two eggs were eliminated from data analyses because of excessive moisture loss, however, none of the remaining 50 eggs showed water content below 70%. Mean water content for all eggs was ± The mean lipid content was ± There was no significant difference in the water content of addled eggs collected at nests prior to 1986, and the "storm- killed" sample from 1986 ("pre-1986" n = 21 mean = +; 'storm-killed' n=14 mean = ± Student's t-test t33 = P=). Likewise, mean lipid content of eggs from the two groups did not differ significantly ('pre-1986' n = 21 mean = ± ; 'storm- killed' n = 14 mean = ± ) Student's t-test t33 = P=). Residues of the eight most commonly detected organochlorines in egg contents are summarized in Table 2. In most cases there was little variability in DDE residues in eggs from the same clutch; the difference between highest and lowest DDE levels in eggs of 12 clutches averaged ppm (arithmetic mean). Of the eggs sampled between 1982 and 1985, 12 were from pairs that successfully fledged young and 11 were from pairs that failed before eggs hatched; there was no significant difference in the mean DDE residues of eggs from the two groups (pairs succes
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