| ecosystem-based management of predator-prey relationships: piscivorous birds and salmonids. | predator-prey relationships are often altered as a result of human activities. where prey are legally protected, conservation action may include lethal predator control. in the columbia river basin (pacific northwest, usa and canada), piscivorous predators have been implicated in contributing to a lack of recovery of several endangered anadromous salmonids (oncorhynchus spp.), and lethal and nonlethal control programs have been instituted against both piscine and avian species. to determine the ... | 2008 | 18488627 |
| concentrations and time trends of polybrominated diphenyl ethers (pbdes) and polychlorinated biphenyls (pcbs) in aquatic bird eggs from san francisco bay, ca 2000-2003. | concentrations of polybrominated diphenyl ethers (pbdes) and polychlorinated biphenyls (pcbs) were measured in 169 avian eggs. we analyzed randomly collected eggs of two species of piscivorous birds: caspian tern (sterna caspia) (n=78) and forster's tern (sterna forsteri) (n=76). we also analyzed fail-to-hatch eggs from two species protected under the federal endangered species act of 1973, that breed in the san francisco bay region: the piscivorous california least tern (sterna antillarum brown ... | 2008 | 18466953 |
| mercury bioaccumulation and risk to three waterbird foraging guilds is influenced by foraging ecology and breeding stage. | we evaluated mercury (hg) in five waterbird species representing three foraging guilds in san francisco bay, ca. fish-eating birds (forster's and caspian terns) had the highest hg concentrations in their tissues, but concentrations in an invertebrate-foraging shorebird (black-necked stilt) were also elevated. foraging habitat was important for hg exposure as illustrated by within-guild differences, where species more associated with marshes and salt ponds had higher concentrations than those mor ... | 2009 | 19398255 |
| selenium bioaccumulation and body condition in shorebirds and terns breeding in san francisco bay, california, usa. | the present study evaluated se bioaccumulation in four waterbird species (n=206 birds) that breed within san francisco bay, california, u.s.a.: american avocets (recurvirostra americana), black-necked stilts (himantopus mexicanus), forster's terns (sterna forsteri), and caspian terns (hydroprogne caspia). selenium concentrations were variable and influenced by several factors, including species, region, reproductive stage, age, and sex. adult se concentrations (microg/g dry wt) in livers ranged ... | 2009 | 19459720 |
| mercury correlations among six tissues for four waterbird species breeding in san francisco bay, california, usa. | despite a large body of research concerning mercury (hg) in birds, no single tissue has been used consistently to assess hg exposure, and this has hampered comparisons across studies. we evaluated the relationships of hg concentrations among tissues in four species of waterbirds (american avocets [recurvirostra americana], black-necked stilts [himantopus mexicanus], caspian terns [hydroprogne caspia; formerly sterna caspia], and forster's terns [sterna forsteri]) and across three life stages (pr ... | 2008 | 18444697 |