1.   But in heavily forested study areas, cowbird parasitism was too low to be a significant cause of reproductive failure.

2.   DDT was blamed for weakening shells of eagle eggs, causing widespread reproductive failures.

3.   Early on, the researchers had ruled out reproductive failure.

4.   Nor does reproductive failure appear to be a factor in the decline because the otter birth rate remains unchanged, Estes said.

5.   Some scientists believe that the immune systems of women suffering from recurrent reproductive failure may lack this protective response.

6.   The theory holds that this fragmentation of the breeding grounds of neotropical migrant songbirds is leading to widespread reproductive failure.

7.   They include DDT, dioxin and PCBs, which have been linked with cancer, reproductive failure and birth defects.

8.   Chronic exposure of animals to PCBs can lead to disrupted hormone balances, reproductive failures as well as carcinomas.