Charles J. Henny

Nineteenth Century Mercury: Hazard to Wading Birds and Cormorants of the Carson River, Nevada

Contemporary mercury interest relates to atmospheric deposition, contaminated fish stocks and exposed fish-eating wildlife. The focus is on methylmercury (MeHg) even though most contamination is of inorganic (IoHg) origin. However, IoHg is readily methylated in aquatic systems to become more hazardous to vertebrates. In response to a classic episode of historical (1859–1890) IoHg contamination, we studied fish-eating birds nesting along the lower Carson River, Nevada. Adult double-crested cormorants (Phalacrocorax auritus), snowy egrets (Egretta thula) and black-crowned night-herons (Nycticorax nycticorax) contained very high concentrations of total mercury (THg) in their livers (geo. means 134.8μg/g wet weight (ww), 43.7 and 13.5, respectively) and kidneys (69.4, 11.1 and 6.1, respectively). Apparently tolerance of these concentrations was possible due to a threshold-dependent demethylation coupled with sequestration of resultant IoHg. Demethylation and sequestration processes also appeared to have reduced the amount of MeHg redistributed to eggs. However, the relatively short time spent by adults in the contaminated area before egg laying was also a factor in lower than expected concentrations of mercury in eggs. Most eggs (100% MeHg) had concentrations below 0.80μg/g ww, the putative threshold concentration where reproductive problems may be expected; there was no conclusive evidence of mercury-related depressed hatchability. After hatching, the young birds were fed diets by their parents averaging 0.36–1.18μgMeHg/g ww through fledging. During this four to six week period, accumulated mercury concentrations in the organs of the fledglings were much lower than found in adults, but evidence was detected of toxicity to their immune (spleen, thymus, bursa), detoxicating (liver, kidneys) and nervous systems. Several indications of oxidative stress were also noted in the fledglings and were most apparent in young cormorants containing highest concentrations of mercury. This stress was evidenced by increased thiobarbituric acid-reactive substances, low activities of enzymes related to glutathione metabolism and low levels of reduced thiols, plus an increase in the ratio of oxidized to reduced glutathione. At lower concentrations of mercury, as was found in young egrets, we observed elevated activities of protective hepatic enzymes, which could help reduce oxidative stress. Immune deficiencies and neurological impairment of fledglings may affect survivability when confronted with the stresses of learning to forage and the ability to complete their first migration.

Current impact of DDE on black-crowned night-herons in the intermountain west

Organochlorine contamination was studied in eight black-crowned night-heron (Nycticorax nycticorax) populations nesting in Washington, Oregon, and Nevada in 1978-80. DDE was detected in 220 eggs sampled; eggshell thickness was negatively correlated with residues of DDE and polychlorinated biphenyls (PCBs). Other contaminants were detected in 35% or fewer of the eggs. Except for the two Columbia River colonies in which local DDE contamination was a probable compounding factor, a strong north-south clinal pattern of DDE residues among colonies existed. Southern colonies were most contaminated, and observed productivity was below population maintenance in one colony (Ruby Lake). At DDE levels in eggs above 8 ppm, clutch size and productivity decreased, and the incidence of cracked eggs increased. No evidence of breeding-ground DDE-DDT contamination was found except along the Columbia River. J. WILDL. MANAGE. 48(1):1-13 DDT and its metabolites may have played a role in the decline of blackcrowned night-herons in the northeastern United States (Ohlendorf et al. 1978). For example, Anderson and Hickey (1972) reported 18% shell thinning by 1952 in New Jersey. The use of DDT in the United States was banned in 1972, and by the midto late 1970s, production rates at several locations in eastern North America (Wisconsin, Qu6bec, Rhode Island, and Massachusetts) appeared normal, eggshell thickness was normal or near-normal, and/ or residues of organochlorine pesticides were lower (Hoefler 1980, Tremblay and Ellison 1980, Custer et al. 1983), with the possible exception being Lake Ontario (Price 1977). Similar improvements have been reported for other species, including the osprey (Pandion haliaetus) (Henny 1977, Spitzer et al. 1978). An adult black-crowned night-heron died at Ruby Lake National Wildlife Refuge near Elko, Nev., in 1975-3 years after the DDT ban. Its brain contained 230 ppm DDE and 1.1 ppm DDT (wet weight) (Ohlendorf et al. 1979). Although DDE concentrations in eggs from the northeast were diminishing in the late 1970s, the mortality at Ruby Lake in 1975 led us to suspect that DDE was still a problem for bird populations in the Intermountain West. Most birds nesting in the region are migratory, and many winter in Latin America. We studied two colonies in 1978 and extended our efforts to eight colonies by 1980. This study was designated to (1) determine levels of DDE and other organochlorine residues in black-crowned nightheron eggs; (2) evaluate the most common contaminants in relation to shell thickness and egg breakage; (3) evaluate regional patterns and trends of DDE residues; (4) evaluate DDE in eggs in relation to productivity; (5) evaluate the source of the contaminants; and (6) evaluate residues in herons found dead to determine if pesticides were implicated. National Wildlife Refuge personnel who provided field assistance included S. H. Bouffard, J. E. Cornely, and S. P. ThompJ. Wildl. Manage. 48(1):1984 1 This content downloaded from 40.77.167.80 on Mon, 13 Jun 2016 06:09:49 UTC All use subject to http://about.jstor.org/terms 2 DDE IN BLACK-CROWNED NIGHT-HERONS * Henny et al.

Fall Migration Routes, Timing, and Wintering Sites of North American Ospreys as Determined by Satellite Telemetry

Abstract Satellite telemetry was used to determine fall migratory movements of Ospreys (Pandion haliaetus) breeding in the United States. Study areas were established along the lower Columbia River between Oregon and Washington; in north-central Minnesota; on Shelter Island, New York; and in southern New Jersey. Seventy-four adults (25 males, 49 females) were tracked from 1995 through 1999. Migration routes differed among populations but not by sex. Western Ospreys migrated through California and to a lesser degree other western states and wintered in Mexico (88%), El Salvador (6%), and Honduras (6%) (25.9°N to 13.0°N and 108.3°W to 87.3°W). Minnesota Ospreys migrated along three routes: (1) through the Central U.S. and then along the east coast of Mexico, (2) along the Mississippi River Valley, then across the Gulf of Mexico, or (3) through the southeastern U.S., then across the Caribbean. East Coast birds migrated along the eastern seaboard of the U.S., through Florida, and across the Caribbean. Midwestern birds wintered from Mexico south to Bolivia (22.35°N to 13.64°S, and 91.75°W to 61.76°W), while East Coast birds wintered from Florida to as far south as Brazil (27.48°N to 18.5°S and 80.4°W to 57.29°W). Dates of departure from breeding areas differed significantly between sexes and geographic regions, with females leaving earlier than males. Western birds traveled a shorter distance than either midwestern or eastern Ospreys. Females traveled farther than males from the same population, which resulted in females typically wintering south of males. Rutas de Migración Otoñales, Coordinación y Sitios de Invernada de Pandion haliaetus Determinados por Telemetría Satelital Resumen. Se utilizó telemetría satelital para determinar los movimientos de migración de otoño de individuos de Pandion haliaetus que nidifican en los Estados Unidos. Las áreas de estudio se establecieron a lo largo del Río Columbia entre Oregon y Washington; en el centro-norte de Minnesota; en la Isla Shelter, Nueva York; y en el sur de Nueva Jersey. Setenta y cuatro adultos (25 machos, 49 hembras) fueron seguidos mediante telemetría desde 1995 hasta 1999. Las rutas de migración se diferenciaron entre poblaciones pero no entre sexos. Los individuos de P. haliaetus del oeste, migraron a través de California y en menor grado a través de otros estados del oeste e invernaron en México (88%), El Salvador (6%) y Honduras (6%) (25.9°N a 13.0°N y 108.3°O a 87.3°O). Las aves de Minnesota migraron a lo largo de tres rutas: (1) a través del los E.E.U.U. centrales y luego a lo largo de la costa este de México, (2) a lo largo del valle del Río Mississippi y luego a través del Golfo de México, o (3) a través del sur de los E.E.U.U. y luego a través del Caribe. Las aves de la costa este, migraron a lo largo de la costa este de los E.E.U.U., por Florida y a través del Caribe. Las aves del medio-oeste, invernaron desde México hacia el sur hasta Bolivia (22.35°N a 13.64°S, y 91.75°O a 61.76°O), mientras que las aves de la costa este invernaron desde Florida hasta tan al sur como Brasil (27.48°N a 18.5°S y 80.4°O a 57.29°O). Las fechas de partida desde las áreas de nidificación difirieron significativamente entre sexos y regiones geográficas, partiendo las hembras antes que los machos. Las aves del oeste viajaron distancias más cortas que las aves del medio-oeste y del este. Considerando una misma población, las hembras viajaron más lejos que los machos, lo que resultó en que las hembras invernaron típicamente más al sur que los machos.

Organophosphate insecticide (famphur) topically applied to cattle kills magpies and hawks

A systematic field study of a black-billed magpie (Pica pica) population revealed that magpies and red-tailed hawks (Buteo jamaicensis) were killed by famphur (=famophos, Warbex?) used as a pouron to control cattle warbles (Hypoderma sp.). Magpie mortality began on treatment day and continued for more than 3 months (38 found dead); mortality peaked between Day 5 and Day 13. Estimates of magpie density (based on transects) decreased in both the control and treatment areas, but the decrease was greater in the treatment area. A red-tailed hawk found dead on Day 10 had eaten a famphur-contaminated magpie. Another red-tailed hawk was found alive but immobilized, and a third died outside the study area. Brain cholinesterase (ChE) activity was 70-92% depressed in all dead birds examined; famphur residues were detected in all 17 magpies and the 2 hawks analyzed. The amount of famphur obtained by the dead magpies was estimated at 5.2-6.1 mg/kg (based on residue concentrations in the gizzard), which was above the acute oral LD, for several bird species. The cow hair portion (12%) of the pooled gizzard contents from 13 other dead magpies produced extremely high famphur residues (4,600 ppm). The residues persisted on cattle hair for more than 90 days post-treatment. Magpie populations in the far western states declined between 1968 and 1979, which corresponds with widespread use of famphur, although other factors may be involved. J. WILDL. MANAGE. 49(3):648-658 Organophosphate (OP) insecticides are now used extensively in agriculture. The topical use of famphur (O,O-dimethyl O-[p-(dimethylsulfamoyl)phenyl] phosphorothioate) in the autumn as a systemic insecticide for control of warbles in cattle was recommended in 1970 (Every et al. 1970). Famphur can be administered to livestock dermally as a pour-on (the only method we observed), orally (mixed with feed), or by intramuscular injection (Ivey et al. 1976). The larvae are killed within the animal during the autumn before they develop into grubs the following year. Grubs emerging on the backs of untreated cattle during the spring may be eaten by magpies (Bishopp et al. 1926), but this is not an adequate control. Observations of magpies dying after famphur use on cattle were reported by ranchers as early as 1973 (unpubl. data, Oreg. Dep. Fish and Wildl., La Grande). Magpies and other species of birds were found dead after cattle were treated with famphur in the United Kingdom (Felton et al. 1981). Magpie brain ChE activity was severely depressed and famphur was identified in the gizzard contents. Another organophosphate (fenthion), also used as a pouron to control Hypoderma larvae in cattle, was implicated in magpie mortality in Canada (Hanson and Howell 1981). Despite relatively rapid degradation in the environment and tissues of homeotherms, some OP insecticides are highly toxic to wildlife for varying periods of time after application (Zinkl et al. 1978, White et al. 1979). The degree of exposure of nontarget wildlife species to OP insecticides can be assessed by measuring ChE activity in tissues and blood (Bunyan et al. 1968, Ludke et al. 1975, Hill and Fleming 1982). The depression of brain ChE activity by 20% or a decrease of 2 SD in wild birds (relative to species baseline data or concurrent controls) has been used as a co servative criterion to indicate absorption of OP chemicals. Depression of brain ChE activity by >50% and confirmation of suspected OP residues in tissues or ingesta are criteria for cause-effect diagnosis of death in birds exposed to anti-ChE chemicals. We studied a magpie population that lived on or near seven ranches where 535 cattle were treated with Warbex? (13.2% famphur). Warbex? was poured along the back line of the cattle at the recommended rate of 0.326 ml/kg body weight, not to exceed 118 ml/animal. The field study was prompted by: (1) reported magpie mortality in Oregon and the United Kingdom; (2) a magpie population decline in the far

Osprey: Worldwide Sentinel Species for Assessing and Monitoring Environmental Contamination in Rivers, Lakes, Reservoirs, and Estuaries

In the United States, many fish and wildlife species have been used nationwide to monitor environmental contaminant exposure and effects, including carcasses of the bald eagle (Haliaeetus leucocephalus), the only top avian predator regularly used in the past. Unfortunately, bald eagles are sensitive to investigator intrusion at the nest. Thus, the osprey (Pandion haliaetus) is evaluated as a potential sentinel species for aquatic ecosystems. Several characteristics support the choice of the osprey as a sentinel species, including: (1) fish-eating diet atop the aquatic food web, (2) long-lived with strong nest fidelity, (3) adapts to human landscapes (potentially the most contaminated), (4) tolerates short-term nest disturbance, (5) nests spatially distributed at regular intervals, (6) highly visible nests easily located for study, (7) ability to accumulate most, if not all, lipophilic contaminants, (8) known sensitivity to many contaminants, and (9) nearly a worldwide distribution. These osprey traits have been instrumental in successfully using the species to understand population distribution, abundance, and changes over time; the effects of various contaminants on reproductive success; how contaminants in prey (fish on biomass basis) contribute to egg concentrations (i.e., biomagnification factors); and spatial residue patterns. Data summarized include nesting population surveys, detailed nesting studies, and chemical analyses of osprey egg, organ, blood, and feather samples for contaminants that bioaccumulate and/or biomagnify in aquatic food webs; and biochemical evaluations of blood and various organs. Studies in the United States, Canada, Mexico, Europe, and elsewhere have shown the osprey to be a useful sentinel species for monitoring selected environmental contaminants, including some emerging contaminants in lakes, reservoirs, rivers, and estuaries.

Case histories of bald eagles and other raptors killed by organophosphorus insecticides topically applied to livestock

Since 1982 when secondary poisoning of a red-tailed hawk (Buteo jamaicensis) was documented following the recommended use of famphur applied topically to cattle, the Patuxent Wildlife Research Center has tested dead birds of prey for poisoning by famphur and other pouron organophosphorus (OP) insecticides. Brain cholinesterase (ChE) activity was first determined, then if ChE was depressed ≥50%, stomach and/or crop contents were evaluated for anti-ChE compounds. This report presents the circumstances surrounding the OP-caused deaths of eight bald eagles (Haliaeetus leucocephalus), two red-tailed hawks, and one great horned owl (Bubo virginianus) between March 1984 and March 1985. OP poisoning of raptors by pour-on insecticides in the United States is widespread, but its magnitude is unknown.

Biomagnification factors (fish to Osprey eggs from Willamette River, Oregon, U.S.A.) for PCDDs, PCDFs, PCBs and OC pesticides.

A migratory population of 78 pairs of Osprey (Pandion haliaetus) nesting along the Willamette River in westernOregon was studied in 1993. The study was designed to determinecontaminant concentrations in eggs, contaminant concentrationsin fish species predominant in the Ospreys diet, andBiomagnification Factors (BMFs) of contaminants from fish specieseaten to Osprey eggs. Ten Osprey eggs and 25 composite samplesof fish (3 species) were used to evaluate organochlorine (OC)pesticides, polychlorinated biphenyls (PCBs), polychlorinateddibenzo-p-dioxins (PCDDs), and polychlorinated dibenzofurans(PCDFs). Mercury was also analyzed in fish. Geometric meanresidues in Osprey eggs were judged low, e.g., DDE 2.3 μg g-1 wet weight (ww), Σ PCBs 0.69 μg g-1, 2,3,7,8-TCDD 2.3 ng kg-1, and generally well below known threshold values for adverse effects on productivity, and the population was increasing. Osprey egg residue data presentedby River Mile (RM) are discussed, e.g., higher PCDDs were generally found immediately downstream of paper mills and eggsfrom the Willamette River had significantly elevated PCBs and PCDDs compared to reference eggs collected nearby in the CascadeMountains. Prey remains at nest sites indicated that the Largescale Sucker (Catostomus macrocheilus) and NorthernPikeminnow (Ptychocheilus oregonensis) accounted for an estimated 90.1% of the biomass in the Osprey diet, and composite samples of these two species were collected from different sampling sites throughout the study area for contaminant analyses. With the large percentage of the fishbiomass in the Osprey diet sampled for contaminants (and fisheaten by Ospreys similar in size to those chemically analyzed),and fish contaminant concentrations weighted by biomass intake, a mean BMF was estimated from fish to Osprey eggs for the largeseries of contaminants. BMFs ranged from no biomagnification(0.42) for 2,3,7,8-TCDF to 174 for OCDD. Our findings for themigratory Osprey were compared to BMFs for the resident HerringGull (Larus argentatus), and differences are discussed. Webelieve a BMF approach provides some basic understanding ofrelationships between contaminant burdens in prey species offish-eating birds and contaminants incorporated into their eggs,and may prove useful in understanding sources of contaminants inmigratory species although additional studies are needed.

Effects of heptachlor on American kestrels in the Columbia Basin, Oregon

Wheat seeds treated with heptachlor to control wireworms (Ctenicara pruinina) resulted in American kestrels (Falco sparverius) in the Columbia Basin accumulating residues of heptachlor epoxide (HE) that reduced productivity and caused some adult mortality. The kestrel is more sensitive to HE residues in eggs than the Canada goose (Branta canadensis moffitti), i.e., reduced productivity occurs at >1.5 ppm in kestrel eggs vs. > 10 ppm in Canada goose eggs. Neither kestrel eggshells nor Canada goose eggshells were thinned by HE. The reduced use of heptachlor in 1979, because of a partial ban, resulted in an immediate lowering of HE concentrations in kestrel eggs the following year. J. WILDL. MANAGE. 47(4):1080-1087 The history of heptachlor as a wheat seed treatment to control wireworms in Umatilla and Morrow counties, Oregon, is poorly understood. Through 1970, it was listed in the Pacific Northwest Insect Control Handbook (Anon., various dates) after aldrin and dieldrin with an application rate on seed of 1 oz/bushel. It was not listed in 1971, 1972, and 1973. Then from 1974 to date, heptachlor was listed at 2 oz/bushel (=2,000 ppm). In 1976 and 1977, die-offs of several species of birds occurred in Umatilla and Morrow counties, Oregon. Residues of heptachlor epoxide (HE) that are considered lethal (Stickel et al. 1979) were found in brains of ring-necked pheasants (Phasianus colchicus), black-billed magpies (Pica pica), California quail (Callipepla californica), Canada geese, and a golden eagle (Aquila chrysaetos) (Blus et al. 1979). This history of wildlife mortality associated with heptachlor prompted a detailed study of the Canada goose population nesting on the Umatilla National Wildlife Refuge (NWR) (Blus et al. 1979). HE in eggs was correlated with hatching success; 95% of the nests in which sample eggs contained ?:1 ppm HE were successful compared with only 20% of those with eggs that contained >10 ppm. The source of HE in geese appeared to be ingestion of seeds treated with heptachlor for wireworm control. The present study involving the American kestrel was designed to complement the Canada goose investigation. We reasoned that Canada geese were obtaining heptachlor directly from the ingestion of treated seeds; however, if American kestrels obtained heptachlor, it would indicate that residues moved through food chains. American kestrels eat mostly insects, especially grasshoppers, but also mice, small birds, and some lizards and amphibians (Brown and Amadon 1968). Biological technicians collecting field data for this study included B. E. Foreman, G. A. Green, R. A. Grove, K. D. Hansen, E. G. Huff, and R. R. Sheehy. C. M. Bunck provided statistical assistance. J. E. Kurtz and G. M. Constantino, refuge managers at Umatilla NWR, kindly allowed use of the refuge facilities.

FIELD STUDIES ON PESTICIDES AND BIRDS: UNEXPECTED AND UNIQUE RELATIONS

We review the advantages and disadvantages of experimental and field stud- ies for determining effects of pesticides on birds. Important problems or principles initially discovered in the field include effects of DDT (through its metabolite DDE) on eggshell thickness, reproductive success, and population stability; trophic-level bioaccumulation of the lipid-soluble organochlorine pesticides; indirect effects on productivity and survival through reductions in the food supply and cover by herbicides and insecticides; unexpected toxic effects and routes of exposure of organophosphorus compounds such as famphur and dimethoate; effects related to simultaneous application at full strength of several pesticides of different classes; and others. Also, potentially serious bird problems with dicofol, based on laboratory studies, later proved negligible in the field. In refining field tests of pesticides, the selection of a species or group of species to study is important, because exposure routes may vary greatly, and 10-fold interspecific differences in sensitivity to pesticides are rel- atively common. Although there are limitations with field investigations, particularly un- controllable variables that must be addressed, the value of a well-designed field study far outweighs its shortcomings.

Butyltin Compounds in River Otters (Lutra canadensis) from the Northwestern United States

Abstract. Butyltin compounds, including mono-, di-, and tributyltin (MBT, DBT, and TBT) were measured in livers of 40 adult river otters (Lutra canadensis) collected from rivers and coastal bays in Washington and Oregon, USA. Butyltins were found in all the river otters, at a concentration range of 8.5–2,610 ng/g, WW. The greatest concentration of total butyltins of 2,610 ng/g, WW, was found in a river otter collected in Puget Sound from Fort Ward, Washington. River otters collected near areas with major shipping activities, such as the Puget Sound, contained significantly greater concentrations (geometric mean: 367 ng/g, WW) of butyltins than those from rivers. Among butyltin compounds, MBT and DBT predominated in livers. The concentrations of butyltins in river otters ranged from comparable (Puget Sound) to less (rivers) than what was found in coastal cetaceans.