title: The effect of heavy metal exposure on egg size, eggshell thickness and the number of spermatozoa in blue tit Parus caeruleus eggs.
abstract: In this study we compared the egg size, the eggshell thickness and the number of spermatozoa trapped on the perivitelline layer of the eggs in three blue tit (Parus caeruleus) populations across a heavy metal pollution gradient. No significant differences were observed in egg characteristics among study sites. Eggs from the two most polluted sites however, had significantly less spermatozoa on the perivitelline layer than eggs from the least polluted site. Our results suggest a significant effect of pollution on blue tit sperm concentrations in the infundibulum. Determining the number of spermatozoa on the egg membranes is relatively cheap and straightforward, which renders this technique a new and useful tool in biomonitoring.
authors.affiliation: Department of Biology, University of Antwerp, Universiteitsplein 1, B-2610 Wilrijk, Belgium. tom.dauwe@uz.ac.be
authors.forename: T
authors.initials: T
authors.lastname: Dauwe
authors.forename: E
authors.initials: E
authors.lastname: Janssens
authors.forename: B
authors.initials: B
authors.lastname: Kempenaers
authors.forename: M
authors.initials: M
authors.lastname: Eens
mesh_terms: D000818:Animals; D004531:Eggs; D004781:Environmental Exposure / Q000009:adverse effects*; D004784:Environmental Monitoring / Q000379:methods; D004785:Environmental Pollutants / Q000633:toxicity*; D008297:Male; D008566:Membranes / Q000502:physiology; D019216:Metals, Heavy / Q000633:toxicity*; D020308:Songbirds / Q000502:physiology*; D013076:Sperm Count / Q000379:methods
chemical_list: D004785:Environmental Pollutants; D019216:Metals, Heavy