title: Mercury contamination and effects on survival of American avocet and black-necked stilt chicks in San Francisco Bay.
abstract: We evaluated whether mercury influenced survival of free-ranging American avocet (Recurvirostra americana) and black-necked stilt (Himantopus mexicanus) chicks in San Francisco Bay, California. Using radio telemetry, we radio-marked 158 avocet and 79 stilt chicks at hatching and tracked them daily until their fate was determined. We did not find strong support for an influence of in ovo mercury exposure on chick survival, despite observing a wide range of mercury concentrations in chick down feathers at hatching (0.40-44.31 microg g(-1) fw). We estimated that chick survival rates were reduced by < or =3% over the range of observed mercury concentrations during the 28-day period from hatching to fledging. We also salvaged newly-hatched chicks that were found dead during routine nest monitoring. In contrast to the telemetry results, we found that mercury concentrations in down feathers of dead chicks were higher than those in randomly-sampled live chicks of similar age. However, capture site was the most important variable influencing mercury concentrations, followed by year, species, and hatching date. Although laboratory studies have demonstrated negative effects of environmentally relevant mercury concentrations on chick survival, our results concur with the small number of previous field studies that have not been able to detect reduced survival in the wild.
authors: U. S. Geological Survey, Western Ecological Research Center, Davis Field Station, University of California, One Shields Avenue, Davis, CA 95616, USA. jackerman@usgs.gov
authors: Joshua T
authors: JT
authors: Ackerman
authors: John Y
authors: JY
authors: Takekawa
authors: Collin A
authors: CA
authors: Eagles-Smith
authors: Samuel A
authors: SA
authors: Iverson
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D046091:Charadriiformes / Q000254:growth & development*; D005241:Feathers / Q000378:metabolism; D005260:Female; D005618:Fresh Water; D008297:Male; D008628:Mercury / Q000378:metabolism / Q000633:toxicity*; D008954:Models, Biological; D011156:Population Density; D012495:San Francisco; D013686:Telemetry; D013997:Time Factors; D014874:Water Pollutants, Chemical / Q000378:metabolism / Q000633:toxicity*
chemical_list: D014874:Water Pollutants, Chemical; D008628:Mercury
references: Environ Pollut. 1987;46(4):263-95
references: 15092724
references: Arch Environ Contam Toxicol. 1994 Aug;27(2):162-7
references: 8060159
references: Bull Environ Contam Toxicol. 1974 Apr;11(4):386-92
references: 4433825
references: Sci Total Environ. 2007 Oct 1;384(1-3):452-66
references: 17590414
references: Ecotoxicology. 1993 Mar;2(1):33-40
references: 24203117
references: Bull Environ Contam Toxicol. 1975 May;13(5):554-64
references: 1148410
references: Ecotoxicology. 2005 Mar;14(1-2):223-40
references: 15931968
references: J Wildl Dis. 2000 Jul;36(3):411-22
references: 10941725
references: Comp Biochem Physiol A Mol Integr Physiol. 2002 Nov;133(3):703-14
references: 12443928
references: Arch Environ Contam Toxicol. 1999 Oct;37(3):369-76
references: 10473794
references: Environ Toxicol Chem. 2005 Dec;24(12):3078-84
references: 16445088
references: Ecotoxicology. 2003 Feb-Aug;12(1-4):171-82
references: 12739866
references: Teratology. 1979 Dec;20(3):453-61
references: 542897
references: Ecotoxicology. 2005 Mar;14(1-2):193-221
references: 15931967
references: J Wildl Dis. 2000 Jul;36(3):423-35
references: 10941726
references: Arch Environ Contam Toxicol. 2006 Feb;50(2):264-79
references: 16307214
references: Environ Toxicol Chem. 2001 Aug;20(8):1816-23
references: 11491567