Critical Stages in Avian Development: Estrogen Hazards to Altricial and Precocial BirdsEPA Grant Number: R825294
Title: Critical Stages in Avian Development: Estrogen Hazards to Altricial and Precocial Birds
Investigators: Fry, D. Michael , Millam, James R.
Institution: University of California - Davis
EPA Project Officer: Reese, David H.
Project Period: November 1, 1996 through October 31, 2000
Project Amount: $521,971
RFA: Endocrine Disruptors (1996) RFA Text | Recipients Lists
Research Category: Endocrine Disruptors , Economics and Decision Sciences , Health , Safer Chemicals
This project will determine the critical developmental stages of avian embryos and neonatal chicks which are at risk from exposure to endocrine disrupting pesticides and pollutants. Many species of birds are altricial, whose chicks are hatched helpless, naked, and blind, and are incompletely developed compared to precocial chick species which are hatched covered in down and able to leave the nest and self-feed the day they are hatched. We hypothesize that the critical stages at risk from exposure to estrogenic chemicals are extended to the neonatal period for altricial bird species, and that exposure to estrogenic chemicals during the early chick period may permanently impair the development and subsequent functioning of the brain and reproductive systems of exposed birds. Japanese Quail (Coturnix coturnix japonica) and Zebra Finch (Taeniopygia guttata) eggs and newly hatched chicks will be exposed to estrogens and potentially estrogenic chemicals, and the reproductive tracts and brain will be examined for evidence of alterations in sex-specific developmental patterns. The potency of estrogenic xenobiotic chemicals will be compared with estradiol, and the doses required to cause impaired development will be compared with exposure risks for wild birds, especially in agricultural areas. A second part of this project will evaluate metabolism of xenobiotic compounds in liver tissue culture, with the aim of identifying the active metabolites responsible for estrogenic effects. Results from this project are expected to provide techniques for evaluating chemicals with endocrine disrupting activity and determine whether songbird species are at risk from exposure to environmental chemicals.