Christine Custer

The population estimate for greater (Aythya marila) and lesser (Aythya affinis) scaup (combined) has declined dramatically since the early 1980s to record lows in 1998. The 1998 estimate of 3.47 million scaup is far below the goal of 6.3 million set in the North American Waterfowl Management Plan (NAWMP), causing concern among biologists and hunters. We summarize issues of concern...

In 1994 and 1995, nesting success of double-crested cormorants (Phalacrocorax auritus) was measured at Cat Island, in southern Green Bay, Lake Michigan, Wisconsin, USA. Sample eggs at pipping and unhatched eggs were collected and analyzed for organochlorines (including total polychlorinated biphenyls [PCBs] and DDE), hepatic microsomal ethoxyresorufin-O-dealkylase (EROD) activity in...

In 1994 and 1995, Double-crested Cormorants Phalacrocorax auritus were monitored from egg-laying through 12 days of age at Cat Island, Green Bay, Wisconsin, USA. Sample eggs at hatching were analysed for organochlorines (including total PCBs, PCB congeners, and DDE), hepatic microsomal ethoxyresorufin-O-dealkylase (EROD) activity in livers of embryos, and eggshell thickness. The number...

Green Bay, Wisconsin is contaminated with polychlorinated biphenyls (PCBs) however, whether these contaminants affect reproduction in insectivorous birds is unknown. Tree Swallows, Tachycineta bicolor, are secondary cavity nesters that will nest in boxes and tolerate handling. Because Tree Swallows are aquatic insectivores, residues in their tissues are primarily indicative of...

In 1994 and 1995, Double-crested Cormorants Phalacrocorax auritus were monitored from egg-laying through 12 days of age at Cat Island, Green Bay, Wisconsin, USA. Sample eggs at hatching were analysed for organochlorines (including total PCBs, PCB congeners, and DDE), hepatic microsomal ethoxyresorufin-O-dealkylase (EROD) activity in livers of embryos, and eggshell thickness. The number...

No abstract available.

No abstract available.

Abstract not submitted to date

Green Bay, Wisconsin is contaminated with polychlorinated biphenyls (PCBs) however, whether these contaminants affect reproduction in insectivorous birds is unknown. Tree Swallows, Tachycineta bicolor, are secondary cavity nesters that will nest in boxes and tolerate handling. Because Tree Swallows are aquatic insectivores, residues in their tissues are primarily indicative of...

Concentration, accumulation, and effects of polychlorinated biphenyls (PCBs) o nreproduction in tree swallows (Tachycineta bicolor) were studied at four sites in the Fox River drainage and in Green Bay, Lake Michigan, Wisconsin, USA, in 1994 and 1995. Total PCBs in eggs and newly hatched young (mean = 3.01 μg/g wet weight, years and sites combined) and 12-d-old nestlings (mean = 2.34 μg...

We measured biomass, percent coverage, and length-frequency of zebra mussels in near-shore areas of western Lake Erie between 16 September and 10 November 1993 as part of a larger study on the ecological relationship between diving ducks and zebra mussels. Wet weight biomass of zebra mussels, determined by SCUBA diving, ranged from 0 to 3,611 g/m2 and averaged ( ± 1 SE) 1,270 ± 380 g/m2...

Double-crested cormorant (Phalacrocorax auritus) fresh eggs and sibling embryos at pipping were collected from a polychlorinated biphenyl (PCB)-contaminated colony in Green Bay, Wisconsin, USA. Egg contents were analyzed for organochlorine (OC) contaminants, including 15 arylhydrocarbon-active PCB congeners. In order to determine the significance of tissue removal on the subsequent...