Avian Thyroid: Effect of p , p ′-DDT on Size and Activity

Abstract
Feeding sublethal amounts of p,p'-DDT to pigeons caused an increase in thyroid weight and a reduction in colloid content of the follicles. This may reflect a hyper- or hypo-functioning gland and may be cotnnected with recent reductions in egg shell weights in wild birds. The effect was accompanied by increased liver weight.