Effects of methylmercury on reproduction in American kestrels

Albers, P.H.; Koterba, M.T.; Rossmann, R.; Link, W.A.; French, J.B.; Bennett, R.S.; Bauer, W. C.

Abstract:

Sixty breeding pairs of captive American kestrels (Falco sparverius) were exposed to a range of sublethal dietary concentrations of mercury (Hg), in the form of methylmercuric chloride, and their subsequent reproduction was measured. Egg production, incubation performance, and the number and percent of eggs hatched decreased markedly between 3.3 and 4.6 mg/kg dry weight of Hg (1.2 and 1.7 mg/kg wet wt), in the diet. The number of fledglings and the percent of nestlings fledged were reduced markedly at 0.7 mg/kg dry weight (0.3 mg/kg wet wt) and declined further between 2 and 3.3 mg/kg dry weight (0.7 and 1.2 mg/kg wet wt). Dietary concentrations of ?4.6 mg/kg dry weight (1.7 mg/kg wet wt) were associated with total fledging failure. The estimated decline in fledged young per pair (24%, Bayesian regression) for kestrels consuming 0.7 mg/kg dry weight (0.3 mg/ kg wet wt) raises concerns about population maintenance in areas subject to high inputs of anthropogenic Hg. Mercury concentrations in 20 second-laid eggs collected from all groups were related to dietary concentrations of Hg, and the Hg concentrations in 19 of these eggs were related to eggs laid and young fledged. Concentrations of Hg in eggs from the highest diet group (5.9 mg/kg dry wt; 2.2 mg/kg wet wt) were higher than egg concentrations reported for either wild birds or for captive birds (nonraptors) fed dry commercial food containing 5 mg/kg methylmercury. Accumulation ratios of Hg from diets to eggs were higher than those reported for feeding studies with other species.

Genre:

Article

ProdID:

5224822

Citation Author:

Albers, P.H.; Koterba, M.T.; Rossmann, R.; Link, W.A.; French, J.B.; Bennett, R.S.; Bauer, W. C.

Citation Contributing Office:

Patuxent Wildlife Research Center

Citation Datum:

Citation Day:

Citation Edition:

Citation Editor:

Citation End Page:

1866

Citation Issue:

Citation Keywords:

Citation Language:

English

Citation Larger Work Title:

Environmental Toxicology and Chemistry

Citation LatN:

Citation LatS:

Citation LonE:

Citation LonW:

Citation Month:

Citation No Pagination:

Citation Number Of Pages:

Citation Online Only Flag:

Citation Phsyical Description:

1856-1866

Citation Projection:

Citation Public Comments:

6826_Albers.pdf

Citation Publisher:

Citation Series:

Citation Series Code:

Citation Series Number:

Citation Search Results Text:

Effects of methylmercury on reproduction in American kestrels; 2007; Article; Journal; Environmental Toxicology and Chemistry; Albers, P.H.; Koterba, M.T.; Rossmann, R.; Link, W.A.; French, J.B.; Bennett, R.S.; Bauer, W. C.