Mercury exposure and altered parental nesting behavior in a wild songbird

Environmental Science & Technology
By: , and 



Methylmercury is a neurotoxin and endocrine disruptor and may impair avian reproduction directly through embryotoxicity or by altering parental care behaviors. We studied mercury exposure and incubation behavior of free-living tree swallows (Tachycineta bicolor) nesting in artificial nest boxes. Using small temperature dataloggers, we measured incubation constancy (the proportion of each day the female spent incubating eggs), the number of incubation recesses taken per day, and the duration of incubation recesses. We also assessed maternal mercury exposure by measuring mercury concentrations in both blood and eggs. Females with higher mercury concentrations exhibited lower incubation constancy, took more frequent and shorter incubation recesses, and were more likely to take incubation recesses that caused nest temperature decreases that were likely to slow embryonic development. Overall, females that laid eggs with the highest observed mercury concentration (0.53 μg/g fww) spent an average of 12% less time incubating their eggs over the 14-day incubation period than females that laid eggs with the lowest mercury concentration (0.07 μg/g fww). Because less time spent incubating can lower egg temperatures, slow embryonic development, and potentially lengthen the incubation period, these results suggest that environmentally relevant mercury concentrations may negatively influence reproduction by altering parental nesting behaviors of wild songbirds
Publication type Article
Publication Subtype Journal Article
Title Mercury exposure and altered parental nesting behavior in a wild songbird
Series title Environmental Science & Technology
DOI 10.1021/acs.est.8b07227
Volume 53
Issue 9
Year Published 2019
Language English
Publisher American Chemical Society
Contributing office(s) Western Ecological Research Center
Description 10 p.
First page 5396
Last page 5405
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