ENVIRONMENTAL CONTAMINANTS & RAPTORS W.W. Bowerman (Oral)
Effects of Fish Removal on Bald Eagle Nesting Success The effects of prey availability on nesting success of raptors is well known. I studied the
effects of fisheries management practices which decreased fish populations taken by Bald Eagles (Haliaeetus leucocephalus) on the nesting success of eagles in the Upper Peninsula of Michigan, USA, for the period
1977-1987. Eagles nesting in breeding areas where fish were removed for sports fish management were significantly less successful (0.57 young per occupied nest) than those breeding areas where fish were not removed
(1.30). When fish were removed from within 1.0 km of a nest, productivity was significantly less successful (0.39) during treatment years than in non-treatment years (1.31). The species of fish removed comprise 87% of
all prey remains from this region. While environmental contaminants including DDE and PCBs were still causing impaired productivity for nest sites in this region located along the Great Lakes shorelines, none of these
breeding areas was located in areas of high contamination. Weather was also not found to be a factor related to this observed productivity. It is most likely that the effects of removal of fish species used as prey
during nesting by Bald Eagles was the cause of this impairment in reproduction. Department of Environmental Toxicology, Clemson University, P.O. Box 709, Pendleton, SC, 29670, USA, Tel: + (864) 646-2277 W.W. Bowerman and A.S. Roe (Oral) Can we pass Great Lakes Fish over Hydro-electric Dams? Analysis of nestling eagle
blood plasma The passage of Great Lakes fish over hydro-electric dams has been an issue since the late 1980s. Under the U.S. Federal Power Act,
the Federal Energy Regulatory Commission (FERC) is required to ensure that environmental studies of hydro-electric dams are conducted that study the effects on the environment, including fish and wildlife, prior to
re-licensing dams. A conflict between the benefits to spawning lake-run salmonids and the potential detriment to nesting Bald Eagles (Haliaeetus leucocephalus) due to the risk from environmental
contaminants within the flesh of these fish was studied in the early 1990s. FERC agreed with the U.S. Fish and Wildlife Service (USFWS) to reserve the right of the USFWS to withhold passage of these fish over the dams
until they no longer posed a risk to nesting Bald Eagles. Recent analyses of nestling Bald Eagle plasma yield a threshold concentration, related to effects on productivity, of 36 ug/kg PCBs and 11 ug/kg DDE wet weight.
We will examine the current concentrations of both PCBs and DDE in plasma from nestlings from nest sites along streams accessible to Great Lakes fishes in Michigan in relation to these threshold concentrations. These
concentrations will be related to expected risk to nesting success posed by these chemicals. Department of Environmental Toxicology, Clemson University, P.O. Box 709, Pendleton, SC, 29670, USA,
Tel: + (864) 646-2277 John Elliott1, P. Shaw2, S. Lee1, M.Wayland3, L Wilson1 (Oral)
and D. Muir4 An Assessment of Sources and Effects of Contaminants in Osprey (Pandion haliaetus) breeding in alpine areas of Western Canada We collected eggs and nestling plasma of Ospreys, and prey fish samples between 1999 and 2001 from water bodies situated at varying elevations and degrees of past chlorinated
hydrocarbon input throughout British Columbia. Osprey eggs were analyzed immediately after collection and elevated DDE concentrations targeted for satellite tagging of adults. Blood samples were taken from chicks. A
subset of study areas and nests were observed during the breeding season to identify Osprey prey species. Satellite tracking (N = 20) revealed wintering locations of Ospreys, where we attempted to make further diet
observations and collect fish samples. Highest concentrations of DDE (200 mg/kg wet wt.) in fish were found in samples of Rainbow Trout from a small lake at 1817m elevation in Revelstoke Park. With the exception of an
egg from a mid-elevation lake in Alberta, with 12 mg/kg DDE, all Osprey eggs had <5 mg/kg DDE. Plasma sampling of chicks did not indicate any exceptional uptake of DDE in alpine drainages; chicks from the south
Okanagan valley, an area of known DDE contamination, exhibited breeding ground uptake of DDE. Sampling of prey fish from both breeding and wintering grounds were consistent with the generally low levels of chlorinated
hydrocarbons in Osprey samples. 1. Canadian Wildlife Service, 5421 Robertson Rd., Delta, BC, V4K 3N2
Tel: Private: 604 514 9900 Office: 604 940 4680 Telefax: 604 946 7022 Email: john.elliott@ec.gc.ca2. Environment Canada, Vancouver, BC 3. Canadian Wildlife Service, Saskatoon, SK 4. National Water Research Institute, Burlington, ON Keisuke Saito1, Nobumichi Kurosawa2 and David K. Garcelon3 (Oral)
Lead Poisoning of Steller's (Haliaeetus pelagicus) and White-tailed (H. albicilla) Sea Eagles in Japan The Steller's Sea Eagle is
one of the largest birds of prey in the world, and breeds exclusively in the coastal regions of eastern Russia. The population size is estimated to be 4000 to 5000 individuals. Steller's Sea Eagles, along with
White-tailed Sea Eagles, winter in large numbers in northern Japan on the island of Hokkaido. Between 1994 and 2002 a total of 78 Steller's and 26 White-tailed Sea Eagles have died and been diagnosed with lead
poisoning. Necropsies and radiographs indicate both large and small fragments of lead that are consistent with remains from rifle bullets. Because of the extreme topography and harsh climate, the actual number of eagles
dying and going undiscovered is likely much higher. While northern pollack, the principal prey of these eagles, has been reduced, hunting of Sika Deer (Cervus nippon) has increased significantly around the
island. Their carcasses have become a major food item for these wintering eagle populations and are the source of lead consumed by the eagles. Recent legislation in Japan against the use of lead rifle bullets and lead
shotgun pellets holds promise to greatly reduce the exposure of these eagles to this toxin.
1. Wildlife Preservation Bureau of Hokkaido, 2-2101 Hokuto, Kushiro, Hokkaido, Japan 084-0922 Tel & Fax: + 81-154-56-2051 Email: k_saito@marimo.or.jp
2. Agricultural Mutual Aid Association of Kushiro, Teshikage, Hokkaido, Japan 3. Institute for Wildlife Studies, P.O. Box 1104, Arcata, California 95518, USA,
Tel: + 1 707 822 4258 Fax: + 1 707 822 6300 Email: garcelon@iws.org David K. Garcelon1 and Peter B. Sharpe2 (Oral)
Severe DDE Contamination in a Population of Bald Eagles (Haliaeetus leucocephalus) off the coast of Southern California, USA Bald Eagles
were once a common resident of the California Channel Islands, but were extirpated by 1960. In 1980 a project was initiated to reestablish eagles on the Channel Islands via hacking. Between 1980 and 1986, 33 individuals
were released onto the islands. The first eagle eggs were produced in 1987, and in both 1987 and 1988 eggs were found broken in the nests. Subsequent contaminant analyses of the eggs revealed high concentrations of DDE.
Starting in 1989, eggs were removed from the nest, replaced by dummy eggs, and then artificially incubated. Most (80%) of the eggs did not hatch and contaminant analysis indicated a geometric mean DDE concentration of
23.3 ppm (fresh weight; range 5.9 - 60.5 ppm). DDE concentration in the serum of adult birds was similarly high, with a range of 0.9 - 4.7 ppm (n = 6). Most of the DDE contamination appears to have originated in the
marine mammal and marine bird components of the eagles' diet. The population has been maintained by annual manipulation of nests through the introduction of foster chicks and through continued hacking efforts.
1. Institute for Wildlife Studies, P.O. Box 1104, Arcata, California 95518, USA,
Tel: +1 707 822 4258 Fax: +1 707 822 6300 Email: garcelon@iws.org2. Institute for Wildlife Studies, P.O. Box 2500, Avalon, California 90704, USA.
Tel: +1 310 510 0978 Fax: +1 310 510 0982 Email: sharpe@iws.org Charles J. Henny, Robert A. Grove, James L. Kaiser and (Oral) V. Raymond Bentley An Evaluation of Columbia River Ospreys for Long-term Contaminant Monitoring in Large Rivers An Osprey (Pandion haliaetus)
population nesting along the lower 405 km of the Columbia River was studied to test the species' usefulness for a long-term monitoring programme of large rivers for selected contaminants that biomagnify in food chains.
We collected 29 Osprey eggs (1 per nest) from four different reaches of the Columbia River and evaluated organochlorine pesticides, polychlorinated biphenyls (PCBs), polychlorinated dibenzo-p-dioxins, polychlorinated
dibenzofurans, and mercury. Contaminants from several species of fish captured near the nest sites were integrated and biomagnified in Osprey eggs. PCB105 was significantly higher in eggs from River Reach II (below
Bonneville Dam) than those collected in Reach I (upstream) or Reach III (downstream). Also, nearly all other PCB congeners were higher in eggs from River Reach II. A recently reported dump site at Bonneville Dam
contained PCBs. High egg concentrations of other contaminants were associated with known point sources. Other investigators monitored contaminants using semi-permeable membrane devices and whole fish; comparisons among
approaches are made. With most Osprey populations now recovered, and nests distributed at regular intervals (instead of clumped in colonies) along large rivers and estuaries, and with several other important life
history traits, the Osprey can play a strategic monitoring role. USGS-Forest & Rangeland Ecosystem Science Center, 3200 SW Jefferson Way,
Corvallis, OR 97331, USA. Tel: + 1 541 757-4840 Fax: + 1 541 757-4845.Email: charles_j_henny@usgs.gov Igal Horowutz1, Michel Bellaiche2 and Alan Shlosberg2
(Oral) Safety of Atropine and 2-PAM in Birds Organophosphorus and carbamate insecticides are commonly used in
Israel and over much of the world. Raptors at the top of the food chain are especially susceptible. In birds, these life-threatening anticholinesterase toxicants present clinical signs that can resemble other bird
diseases, in contrast to mammals where the symptoms are clear and often diagnostic. Precise and rapid diagnosis and the correct antidote can save the intoxicated bird. However when wild birds are found with a suspicion
of intoxication, there is often a prolonged timelag until they can be brought to a hospital or rehabilitation center for laboratory tests and treatment. When potentially fatal intoxication is suspected in the field, it
would be useful to have immediate first aid treatment with a safe antidote.This study investigates the safety of very high dosages (compared to mammals) of the antidotes atropine and 2-PAM. Non-poisoned
raptors, which were designated for euthanasia for various health reasons, were injected with high levels of the antidotes with no clinical signs manifested. The significance of this for first aid treatment in the field
is paramount. It means that when a suspected intoxicated bird is found, the antidotes can be administered safely with no additional harm to the bird, even before receiving the toxicology diagnosis. Verification of the
impact of atropine and 2-PAM on various organs of the bird, was examined in three domestic bird species. The analysis consisted of measuring blood enzyme changes after the treatment. There were no significant changes
that could show organs' damage. 1. Zoological Center Tel Aviv-Ramat Gan (Safari), Israel.
Tel: 972-54-650000 Fax: 972-3-6314774 Email: igal@safari.co.il2. Kimron Veterinary Institute, P.O.Box 12, Bet Dagan 50250 Israel
Tel: 972-52-315161 Fax: 972-3-9681730 Email: michelb@moag.gov.il P. Mineau1, P.A. Martin2&3, L.K. Wilson4, J. Duffe2, J.R Stedelin
5 (Oral) and B. Puschner6 Second Generation Anticoagulant Residues in Birds of Prey - Modern-day Organochlorines? Single feed second-generation anticoagulant rodenticides such as brodifacoum, bromadiolone and difethialone are registered in Canada only for mouse and rat control in and
around buildings or by special permit for rat eradication on seabird colonies. We sampled Great Horned Owls and Red-tailed Hawks in Ontario and Barn Owls in British Columbia. None of the birds had been formally
diagnosed as rodenticide-poisoned nor were any diagnosed with excessive bleeding. Nevertheless, 51% of Great Horned Owls (N=35) and 37% of Red-tailed Hawks (N=38) from Ontario had measurable residues of brodifacoum in
liver ranging from 0.005 to 0.25 ppm. A similar proportion of Barn Owls in British Columbia (37.5%; N=32) was also positive for brodifacoum at levels ranging from 0.01 ppm to 0.5 ppm. Bromadiolone residues were also
detected in all three species although the frequency of detection varied with two different analytical methods. The high level of exposure despite stringent labelling requirements raises serious questions about possible
effects and correlates of this contamination.
1. Pierre Mineau: Tel: 819 998 0518 Fax: 998-0458 Email: pierre.mineau@ec.gc.ca
2. Canadian Wildlife Service, National Wildlife Research Centre, Carleton University Campus, Ottawa, ON K1A 0H3 Canada (PM, JD)
3. Canadian Wildlife Service, 867 Lakeshore Road, Box 5050, Burlington, ON L7R 4A6 Canada (PAM) 4. Canadian Wildlife Service, Pacific Wildlife Research Centre, 5421 Robertson Road, RR#1 Delta, BC V4K 3N2, Canada (LKW)
5. Animal Disease Laboratory, Illinois Dept. Agriculture, 9732 Shattuc Road, Centralia IL 62801-5858, USA (JRS)
6. California Animal Health and Food Safety Laboratory, W. Health Sciences Drive, University of California, Davis CA 95616, USA (BP) Ngaio L. Richards1, Pierre Mineau2
and David M. Bird3 (Oral) Exposure of Eastern Screech-Owls (Otus asio) to Cholinesterase-inhibiting Insecticides, Anticoagulant Rodenticides and Organochlorines applied in
Orchards of Southern Québec, Canada Every year, organophosphate insecticides and anticoagulant rodenticides are applied in Quebec apple orchards.
Historically, DDT applications were also intensive. Debilitation, mortality and population decline have been documented in wildlife exposed to these compounds. The sedentary and non-migratory Eastern Screech-Owl resides
near and hunts in orchards and is present during the entire pesticide application period. Our objectives were to assess exposure to the three classes of pesticides and evaluate the species' suitability as a monitor of
exposure and as a natural pest control agent. Individuals and pairs were located in the winter of 2000-2001, then monitored the following winters. Nest boxes (95) were installed at sites where owls were observed and
were inspected for pellets and prey remains on a quarterly basis. Pellets were dissected for a prey inventory. Several small mammal species were captured in orchards for prey residue analysis. Results were incorporated
into a risk assessment addressing exposure risk, given prey residue and preponderance in Screech- Owl diet. Finally, case files (950) were obtained from several rehabilitation facilities (1998-2001). Tissues of
Screech-Owls admitted to one of these were analyzed for evidence of insecticide and rodenticide exposure. Case files and tissues were examined to evaluate pesticide exposure as an underlying or contributing cause of
admission for rehabilitation. 1. Ngaio Richards, 165 Ch. de la Diligence, South Stukely, Quebec, J0E 2J0 Canada.
Tel: + 1-450-539-1309 Fax: + 1-450-539-2051 Email: ngaio_richards@hotmail.com
2. Pierre Mineau, Canadian Wildlife Service/National Wildlife Research Centre, Carleton University Campus, Raven Road, Ottawa, K1A 0H3 Canada. 3. David M. Bird, Dept. of Natural Resource Sciences, Avian Sciience and
Conservation Centre, McGill University, Macdonald Campus, 21, 111 Lakeshore Road, Ste-Anne de Bellevue, Quebec, H9X 3V9 Canada. |
