Reproductive Abnormalities, Teratogenicity, and Developmental Problems in American Kestrels (Falco sparverius) Exposed to Polychlorinated Biphenyls

Abstract

This study found abnormalities in multiple reproductive stages in captive American kestrels (Falco sparverius) when exposed to polychlorinated biphenyls (PCBs) through dietary and in ovo exposure. American kestrels laid eggs with environmentally relevant total PCB levels (34.1 μg/g whole egg wet weight) when consuming PCB-spiked (Aroclor 1248:1254:1260) food (5–7 μg/g body weight per day) for 100 d only in 1998. In 1999, the same adults laid eggs with estimated total PCBs of 23 μg/g. Effects of maternal (only female exposed) and paternal (only male expose d) in ovo PCB exposure were investigated. Maternal F₁ eggs contained predicted total PCB concentrations of 0.34 μg/g. Specific abnormalities occurred more frequently during dietary F₀ exposure, particularly aggressive courtship interactions, clutch abandonment, occurrences of cracked eggs, and developmental effects. Multiple developmental effects were more pronounced during than after dietary PCB exposure of adults, and although these effects were limited, nevertheless they occurred in the F₁ maternal and F₁ paternal pairs. However, the incidence of multiple deformities throughout the breeding season increased dramatically from 1998 (13%) to 1999 (56%) in F₀ PCB-exposed pairs. Developmental abnormalities were unlikely to be attributed to the extrinsic factors of disease, genetics, or nutritional (vitamin D₃) deficiencies, but rather to adverse changes in parental behavior and intrinsic factors involving altered genetic material and PCB exposure. Readily cleared PCB congeners may induce specific types of behavioral and developmental abnormalities, but persistent congeners and metabolites are likely producing (1) odd laying patterns, (2) developmental effects including embryonic underdevelopment and edema, and (3) increased incidences of multiple deformities within a clutch.