Robert E Anthony

We used data from Northern Spotted Owl (Strix occidentalis caurina) territories to model the effects of habitat (particularly intermediate-aged forest stand types), climate, and nonhabitat covariates (i.e., age, sex) on owl reproductive rate and apparent survival in southwestern Oregon. Our best model for reproductive rate included an interaction between a cyclic, annual time trend and...

Northern spotted owls (Strix occidentalis caurina) have been studied intensively since their listing as a threatened species by the U.S. Fish and Wildlife Service in 1990. Studies of spotted owl site occupancy have used various binary response measures, but most of these studies have made the assumption that detectability is perfect, or at least high and not variable. Further, previous...

Emperor Geese (Chen canagica) are a species of concern because their population has declined rapidly since the mid-1960s and continues to remain below management objectives (Petersen et al. 1994). Emperor Geese are restricted primarily to Alaska and exhibit an east-west migration pattern, whereby most birds begin breeding on the Yukon-Kuskokwim Delta by mid-May, stage on the Alaska...

Northern spotted owls (Strix occidentalis caurina) are known to be associated with late-successional forests in the Pacific Northwest of the United States, but the effects of habitat on their demographic performance are relatively unknown. We developed statistical models relating owl survival and productivity to forest cover types within the Roseburg Study Area in the Oregon Coast Range...

Columbian white-tailed deer (Odocoileus virginianus leucurus; CWTD) are an endangered subspecies on which little demographic information exists. We determined survival rates and causes of mortality for 64 radiocol- lared adults from 1996 to 1998, and for 63 radiocollared neonatal fawns during the summer and fall months of 1996-2001 in Douglas County, Oregon, USA. Annual adult survival...

We assessed DNA repair and resistance to solar radiation in eggs of members of the western spotted frog complex (Rana pretiosa and R. luteiventris), species whose populations are suffering severe range reductions and declines. Specifically, we measured the activity of photoreactivating enzyme (photolyase) in oocytes of spotted frogs. In some species, photoreactivation is the most...

Road closures frequently are used to manage for Rocky Mountain elk (Cervus elaphus nelsoni), but no studies have evaluated the effects of limited vehicle access on movements and survival of Roosevelt elk (C. elaphus roosevelti). We studied movements and survival of female Roosevelt elk before Road Management Areas (RMA) were designated, and during limited vehicular access from 1991 to...

During the last 4 decades, numerous studies on a variety of raptor species have described breeding success and productivity, but few studies have reported the causes of nesting failures. Newton (1979:358) described causes of nesting failures for 6 species of raptors, but only 2 of these species (bald eagle [Haliaeetus leucocephalus], prairie falcon [Falco mexicanus]) inhabit North...

Eggs, blood, and carcasses of bald eagles (Haliaeetus leucocephalus) and fish were collected and breeding success of eagles was monitored in the Columbia River estuary, 1980-87, to determine if contaminants were having an effect on productivity. High levels of dichloro diphenyl dichloroethylene (DDE), polychlorinated biphenyls (PCB's), and 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) were...

Kesterson Reservoir (Kesterson) received subsurface agricultural drainwater containing high levels of salts and selenium from farmland in the San Joaquin Valley of California. The accumulation of selenium in wetlands and waterfowl foods at Kesterson was investigated during May, August, and December of 1984. High concentrations of selenium were found in water, sediments, terrestrial and...

No abstract available.