The adrenocortical response of greater sage grouse (Centrocercus urophasianus) to capture, ACTH injection, and confinement, as measured in fecal samples.

Investigators of wildlife populations often utilize demographic indicators to understand the relationship between habitat characteristics and population viability. Assessments of corticosterone may enable earlier detection of populations at risk of decline because physiological adjustments to habitat disturbance occur before reproductive diminutions. Noninvasive methods to accomplish these assessments are important in species of concern, such as the greater sage grouse (GRSG). Therefore, we validated a radioimmunoassay that measures immunoreactive corticosterone metabolites (ICM) in fecal samples and used it to characterize the adrenocortical response of 15 GRSG exposed to capture, intravenous injection of 50 IU/kg adrenocorticotrophic hormone (ACTH) or saline, and 22 h of confinement. Those animals injected with ACTH exhibited a more sustained (P = 0.0139) and less variable (P = 0.0012) response than those injected with saline, indicating different levels of adrenocortical activity. We also found that potential field-collection protocols of fecal samples did not alter ICM concentrations: samples held at 4 degrees C for up to 16 h contained similar levels of ICM as those frozen (-20 degrees C) immediately. This study demonstrates a multiphasic adrenocortical response that varied with the level of stimulation and indicates that the assay used to measure this phenomenon is applicable for studies of wild GRSG.

Avian mortality events in the United States caused by anticholinesterase pesticides: a retrospective summary of National Wildlife Health Center records from 1980 to 2000.

We reviewed the U.S. Geological Survey National Wildlife Health Center (NWHC) mortality database from 1980 to 2000 to identify cases of poisoning caused by organophosphorus and carbamate pesticides. From the 35,022 cases from which one or more avian carcasses were submitted to the NWHC for necropsy, we identified 335 mortality events attributed to anticholinesterase poisoning, 119 of which have been included in earlier reports. Poisoning events were classified as confirmed (n = 205) when supported by findings of > or =50% inhibition of cholinesterase (ChE) activity in brain tissue and the detection of a specific pesticide in the gastrointestinal contents of one or more carcasses. Suspected poisonings (n = 130) were defined as cases where brain ChE activity was > or =50% inhibited or a specific pesticide was identified in gastrointestinal contents. The 335 avian mortality events occurred in 42 states. Washington, Virginia, and Ohio had the highest frequency of events, with 24 (7.2%), 21 (6.3%), and 20 (6.0%) events, respectively. A total of 8877 carcasses of 103 avian species in 12 orders was recovered. Because carcass counts underestimate total mortality, this represents the minimum actual mortality. Of 24 different pesticides identified, the most frequent were famphur (n = 59: 18%), carbofuran (n = 52; 15%), diazinon (n = 40; 12%), and fenthion (n = 17; 5.1%). Falconiformes were reported killed most frequently (49% of all die-offs) but Anseriformes were found dead in the greatest numbers (64% of 8877 found dead). The majority of birds reported killed by famphur were Passeriformes and Falconiformes, with the latter found dead in 90% of famphur-related poisoning events. Carbofuran and famphur were involved in mortality of the greatest variety of species (45 and 33, respectively). Most of the mortality events caused by diazinon involved waterfowl.

Contaminants in molting long-tailed ducks and nesting common eiders in the Beaufort Sea.

In 2000, we collected blood from long-tailed ducks (Clangula hyemalis) and blood and eggs from common eiders (Somateria mollissima) at near-shore islands in the vicinity of Prudhoe Bay, Alaska, and at a reference area east of Prudhoe Bay. Blood was analyzed for trace elements and egg contents were analyzed for trace elements, organochlorine pesticides, polychlorinated biphenyls, and polycyclic aromatic hydrocarbons. Except for Se (mean=36.1 microg/g dry weight (dw) in common eiders and 48.8 microg/g dw in long-tailed ducks), concentrations of trace elements in blood were low and, although several trace elements differed between areas, they were not consistently higher at one location. In long-tailed ducks, Se in blood was positively correlated with activities of two serum enzymes, suggestive of an adverse effect of increasing Se levels on the liver. Although common eiders had high Se concentrations in their blood, Se residues in eggs were low (mean=2.28 microg/g dw). Strontium and Ni were higher in eggs near Prudhoe Bay than at the reference area, but none of the other trace elements or organic contaminants in eggs differed between locations. Concentrations of Ca, Sr, Mg, and Ni differed among eggs having no visible development, early-stage embryos, or late-stage embryos. Residues of 4,4'-DDE, cis-nonachlor, dieldrin, hexachlorobenzene, oxychlordane, and trans-nonachlor were found in 100% of the common eider eggs, but at low concentrations (means of 2.35-7.45 microg/kg wet weight (ww)). The mean total PCB concentration in eggs was 15.12 microg/kg ww. Of PAHs tested for, residues of 1- and 2-methylnaphthalene and naphthalene were found in 100% of the eggs, at mean concentrations of 0.36-0.89 microg/kg ww.

Lead poisoning of waterfowl by contaminated sediment in the Coeur d'Alene River.

The Coeur d'Alene River basin in Idaho has been contaminated by mine tailings that have impaired the health of wildlife since the early 1900s. In other parts of the world, virtually all lead poisoning of waterfowl is caused by the ingestion of manmade lead artifacts, primarily spent lead shotshell pellets or, occasionally, fishing sinkers. However, in the Coeur d'Alene River basin in Idaho, nonartifactual lead poisoning was the ultimate cause of death of most of 219 (77%) of 285 waterfowl carcasses that had been found sick or dead from 1992 through 1997. The majority of these 219 waterfowl (172 tundra swans [Cygnus columbianus], 33 Canada geese [Branta canadensis], and 14 other species) were poisoned by ingesting river sediment that was contaminated with lead. The next most common cause of death (20 instances, 7%) was lead poisoning accompanied by ingested shotshell pellets. The remaining 46 waterfowl succumbed to trauma, infectious diseases (aspergillosis, avian cholera, tuberculosis), or miscellaneous problems, or the cause of death was not determined.

Perfluorooctane sulfonate in fish-eating water birds including bald eagles and albatrosses.

Perfluorooctane sulfonate (PFOS) was measured in 161 samples of liver, kidney, blood, or egg yolk from 21 species of fish-eating water birds collected in the United States including albatrosses from Sand Island, Midway Atoll, in the central North Pacific Ocean. Concentrations of PFOS in the blood plasma of bald eagles collected fromthe midwestern United States ranged from 13 to 2,220 ng/mL (mean: 330 ng/mL), except one sample that did not contain quantifiable concentrations of PFOS. Concentrations of PFOS were greater in blood plasma than in whole blood. Among 82 livers from various species of birds from inland or coastal U.S. locations, Brandt's cormorant from San Diego, CA, contained the greatest concentration of PFOS (1,780 ng/g, wet wt). PFOS was also found in the sera of albatrosses from the central North Pacific Ocean at concentrations ranging from 3 to 34 ng/mL. Occurrence of PFOS in birds from remote marine locations suggests widespread distribution of PFOS and related fluorochemicals in the environment.

Use of serum biochemistry to evaluate nutritional status and health of incubating common eiders (Somateria mollissima) in Finland.

During 1997-1999, we collected serum samples from 156 common eider (Somateria mollissima) females incubating eggs in the Finnish archipelago of the Baltic Sea. We used serum chemistry profiles to evaluate metabolic changes in eiders during incubation and to compare the health and nutritional status of birds nesting at a breeding area where the eider population has declined by over 50% during the past decade, with birds nesting at two areas with stable populations. Several changes in serum chemistries were observed during incubation, including (1) decreases in serum glucose, total protein, albumin, beta-globulin, and gamma-globulin concentrations and (2) increases in serum uric acid, creatine kinase, and beta-hydroxybutyrate concentrations. However, these changes were not consistent throughout the 3-yr period, suggesting differences among years in the rate of carbohydrate, lipid, and protein utilization during incubation. The mean serum concentrations of free fatty acids, glycerol, and albumin were lowest and the serum alpha- and gamma-globulin levels were highest in the area where the eider population has declined, suggesting a role for nutrition and diseases in the population dynamics of Baltic eiders.

Retrospective study of the diagnostic criteria in a lead-poisoning survey of waterfowl.

Between 1983 and 1986 the National Wildlife Health Center (NWHC) conducted a nationwide study of lead poisoning of waterfowl from federal and state refuges. This survey was done to assist in identifying zones with lead-poisoning problems. One thousand forty one moribund or dead waterfowl were collected and examined. The presence or absence of 13 gross lesions selected as indicators of lead poisoning and three lesions indicating body condition was recorded. Lead-poisoning diagnoses were based on the finding of at least 6-8 ppm (wet weight) lead in the liver and either lead shot in the gizzard content or at least one convincing gross lesion indicative of lead poisoning. Four hundred twenty-one of these waterfowl were diagnosed as lead poisoned. The NWHC survey provided a comprehensive basis for estimating the sensitivities, specificities, and likelihood ratios of the gross lesions of lead poisoning and the associated hepatic lead concentrations for several species of waterfowl. Some of the 13 defined gross lesions were more common than others; frequencies ranged from 3% to 80% in the 421 lead-poisoned waterfowl. The most reliable indicators of lead poisoning were impactions of the upper alimentary tract, submandibular edema, myocardial necrosis, and biliary discoloration of the liver. Each of the 13 lesions occurred more frequently in the lead-poisoned birds, but each of the lesions also occurred in waterfowl that died of other causes. The number of lead shot present in a bird's gizzard was only weakly correlated with its hepatic lead concentration; however, this weak correlation may have been adequate to account for differences in hepatic lead concentrations among species, once the weights of the species were taken into account. Although lead-poisoned ducks tended to have higher hepatic mean lead concentrations than did lead-poisoned geese or swans, the differences were probably a result of a greater dose of shot per body weight than to kinetic differences between species. Hepatic lead concentrations were independent of age and sex. Ninety-five percent of waterfowl diagnosed as lead poisoned had hepatic lead concentrations of at least 38 ppm dry weight (10 ppm wet weight). Fewer than 1% of the waterfowl that died of other causes had a concentration that high. This fifth percentile, of 38 ppm dry weight (10 ppm wet weight), is a defensible criterion for identifying lead-poisoned waterfowl when interpreting hepatic lead concentrations in the absence of pathological observations.

Winter mortality of common loons in Florida coastal waters.

Diagnostic findings are presented for 434 common loons (Gavia immer) found sick or dead on Florida beaches from 1970 through 1994, primarily during the months of December to April. The most commonly recognized problem was an emaciation syndrome (66%), followed by oiling (18%), aspergillosis (7%), trauma (5%) and miscellaneous disease entities (1%). The cause-of-death for 3% of the birds was not determined. Many of the carcasses examined (n = 173) were obtained during an epizootic which occurred from January to March of 1983 in which more than 13,000 loons were estimated to have died. An emaciation syndrome, characterized by severe atrophy of pectoral muscles, loss of body fat and hemorrhagic enteritis, was the primary finding in this epizootic. It was postulated to have a complex etiologic basis involving synergistic effects and energy costs of migration, molting and replacement of flight feathers, food resource changes, salt-loading, intestinal parasitism, environmental contaminants, and inclement weather.

Diagnostic findings in the 1992 epornitic of neurotropic velogenic Newcastle disease in double-crested cormorants from the upper midwestern United States.

Neurotropic velogenic Newcastle disease (NVND) occurred in juvenile double-crested cormorants, Phalacrocorax auritus, simultaneously in nesting colonies in Minnesota, North Dakota, South Dakota, and Nebraska and in Lakes Michigan, Superior, Huron, and Ontario during the summer of 1992. Mortality as high as 80%-90% was estimated in some of the nesting colonies. Clinical signs observed in 4- to 6-wk-old cormorants included torticollis, tremors, ataxia, curled toes, and paresis or weakness of legs, wings or both, which was sometimes unilateral. No significant mortality or unusual clinical signs were seen in adult cormorants. Necropsy of 88 cormorants yielded no consistent gross observations. Microscopic lesions in the brain and spinal cord were consistently present in all cormorants from which Newcastle disease virus (NDV) was isolated. Characteristic brain lesions provided rapid identification of new suspect sites of NVND. Lesions were also present in the heart, kidney, proventriculus, spleen, and pancreas but were less consistent or nonspecific. NDV was isolated at the National Wildlife Health Center from 27 of 93 cormorants tested. Virus was most frequently isolated from intestine or brain tissue of cormorants submitted within the first 4 wk of the epornitic. Sera collected from cormorants with neurologic signs were consistently positive for NDV antibody. The NDV isolate from cormorants was characterized as NVND virus at the National Veterinary Services Laboratories, Ames, Iowa. The NVND virus was also identified as the cause of neurologic disease in a North Dakota turkey flock during the summer of 1992. Although no virus was isolated from cormorants tested after the first month of submission, brain and spinal cord lesions characteristic of NVND were observed in cormorants from affected sites for 2 mo, at which time nesting colonies dispersed and no more submissions were received. Risk to susceptible populations of both wild avian species and domestic poultry makes early recognition and confirmation of NVND in wild birds a priority.

Probable epizootic chlamydiosis in wild California (Larus californicus) and ring-billed (Larus delawarensis) gulls in North Dakota.

During the summer of 1986, more than 400 California gulls (Larus californicus) and ring-billed gulls (Larvus delawarensis), primarily fledglings, died on an island in Lake Sakakawea near New Town, North Dakota (USA). Mortality was attributed largely to chlamydiosis. Necropsy findings in nine carcasses included splenomegaly (n = 9), hepatomegaly (n = 4), and pericarditis (n = 1). Livers from three California gulls and two ring-billed gulls, and spleens from the same five birds plus a third ring-billed gull were positive for Chlamydia psittaci by the direct immunofluorescence test. Chlamydia psittaci was isolated from separate pools of liver and spleen from one California gull and one ring-billed gull. This is believed to be the first record of epizootic chlamydiosis in gulls and the second report of epizootic chlamydial mortality in wild birds in North America.

Lead poisoning of spectacled eiders (Somateria fischeri) and of a common eider (Somateria mollissima) in Alaska.

Lead poisoning was diagnosed in four spectacled eiders (Somateria fischeri) and one common eider (Somateria mollissima) found dead or moribund at the Yukon Delta National Wildlife Refuge, Alaska (USA) in 1992, 1993, and 1994. Ingested lead shot was found in the lower esophagus of one spectacled eider and in the gizzard of the common eider. Lead concentrations in the livers of the spectacled eiders were 26 to 38 ppm wet weight, and 52 ppm wet weight in the liver of the common eider. A blood sample collected from one of the spectacled eiders before it was euthanized had a lead concentration of 8.5 ppm wet weight. This is the first known report of lead poisoning in the spectacled eider, recently listed as a threatened species by the U.S. Fish and Wildlife Service.

Heavy metals in seaducks and mussels from misty fjords national monument in Southeast Alaska.

Quartz Hill, in Misty Fjords National Monument near Ketchikan, Alaska, is the site of a proposed molybdenum-producing mine. To provide baseline data for use in post-development comparisons, we analyzed tissues of Barrow's goldeneyes (Bucephala islandica), common mergansers (Mergus merganser), and blue mussels (Mytilus edulis) for seven heavy metals that could potentially be released into the environment as a result of mining operations. Specimens were collected in 1980, 1981, and 1982 from two fjords likely to be used for discharge of tailings from the proposed mine and from two control fjords. Concentrations of arsenic, cadmium, copper, chromium, molybdenum, lead, and zinc were measured in soft tissues of mussels and in kidney, liver, and muscle of birds. The highest mean concentrations of metals found in bird tissues were 55.7 ppm dry weight cadmium in kidneys and 154 ppm dry weight zinc in livers of Barrow's goldeneyes. Concentrations of several metals in blue mussels differed among seasons and locations, but the most significant finding in mussels was a maximum mean cadmium concentration of 9.6 ppm dry weight, a level higher than normally found in undisturbed areas. With the exception of 104 ppm dry weight cadmium in the kidney of one common merganser and 12.7 ppm dry weight lead in the kidney of another, concentrations of other metals in seaduck and mussel tissues were low, consistent with what would be expected for a pre-development environment. Molybdenum was found in low concentrations (<10 ppm dry weight) in all avian kidney samples and most liver samples, but was not detected in blue mussels.

Lead exposure and recovery rates of black ducks banded in Tennessee.

American black ducks (Anas rubripes) wintering in Tennessee during 1986 to 1988 were tested for exposure to lead. Twelve percent of the birds had blood lead concentrations exceeding 0.2 ppm. Significant differences in the prevalence of lead exposure were found for adults (14.4%) and juveniles (8.2%). Exposed birds had higher blood lead concentrations at one study site, corresponding with a lower survival index.

Septicemic pasteurellosis in elk (Cervus elaphus) on the United States National Elk Refuge, Wyoming.

Septicemic pasteurellosis caused by Pasteurella multocida is believed responsible for the deaths of 48 elk (Cervus elaphus) on the National Elk Refuge near Jackson, Wyoming (USA) during 1986 and 1987. Clinical signs included depression and salivation; necropsy findings included congestion and petechial and ecchymotic hemorrhages in lymph nodes, diaphragm, lungs and endocardium. Pasteurella multocida was isolated from femur marrow of eight carcasses and a variety of tissues from eight others.

Biochemical and hematological effects of lead ingestion in nestling American kestrels (Falco sparverius).

One-day old American kestrel (Falco sparverius) nestlings were orally dosed daily with 5 microliters/g of corn oil (controls), 25, 125 or 625 mg/kg of metallic lead in corn oil for 10 days. Forty per cent of the nestlings receiving 625 mg/kg of lead died after 6 days and growth rates were significantly depressed in the two highest lead dosed groups. At 10 days hematocrit values were significantly lower in the two highest lead treated groups, and hemoglobin content and red blood cell delta-aminolevulinic acid dehydratase (ALAD) activity was depressed in all lead treated groups. Plasma creatine phosphokinase decreased in the two highest treatment groups. Brain, liver and kidney ALAD activities, brain RNA to protein ratio and liver protein concentration decreased after lead exposure whereas liver DNA, DNA to RNA ratio and DNA to protein ratio increased. Brain monoamine oxidase and ATPase were not significantly altered. Measurements of the ontogeny of hematological variants and enzymes in normal development, using additional untreated nestlings, revealed decreases in red blood cell ALAD, plasma aspartate amino transferase, lactate dehydrogenase, brain DNA and RNA and liver DNA, whereas hematocrit, hemoglobin, plasma alkaline phosphatase, brain monoamine oxidase, brain ALAD and liver ALAD increased during the first 10 days of posthatching development. Biochemical and hematological alterations were more severe than those reported in adult kestrels or precocial young birds exposed to lead. Alterations may be due in part to delayed development.

Enzyme activities in plasma, kidney, liver, and muscle of five avian species.

Activities of alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), creatine phosphokinase (CPK), and lactate dehydrogenase (LDH) were determined in plasma, kidney, liver, and muscle from five species of captive birds. Few differences occurred in plasma activities between sexes but considerable differences occurred between species. All five enzymes were detected in each of the tissues sampled. Relative enzyme activities in liver, kidney, and muscle were similar for each species. CPK activity was much higher in muscle than in liver or kidney and, of the five enzymes studied, may be the best indicator of muscle damage. Most of the other enzymes were more evenly distributed among the three tissues, and no organ-specific enzyme could be identified for liver or kidney. Because of interspecific variations in plasma enzyme activities, it is important to establish baseline values for each species to ensure accurate interpretation of results.