Exposure to dietary methyl-mercury solely during embryonic and juvenile development halves subsequent reproductive success in adult zebra finches

Long-term exposure to methyl-mercury has deleterious effects on avian reproduction. However, little is known about whether exposure to mercury solely during embryonic and juvenile development can have long-lasting effects on subsequent reproductive performance as adults. Birds that hatch on contaminated sites but disperse elsewhere will be exposed only during development. Hence, it is important to understand the reproductive consequences of avian exposure to methyl-mercury during early life. Accordingly, in this experiment, domesticated zebra finches (Taeniopygia guttata) were exposed to dietary methyl-mercury (1.20 μg/g wet weight) from conception through independence (50 days post-hatching). Following maturity, developmentally exposed and control finches were paired within treatment groups and allowed to breed repeatedly for 8 months. Developmentally exposed pairs hatched 32% fewer eggs and produced 50% fewer independent juveniles despite transferring only traces of mercury into their offspring. This is...