Geology topics
Publications and source records attributed to Kathryn A. Converse.
This chapter contains section titled: Introduction Synonyms History Distribution Host Range Etiology Epizootiology Clinical Signs Pathogenesis Pathology Diagnosis Immunity Public Health Concerns Domestic Animal Health Concerns Wildlife Population Impacts Treatment and Control Management Implications Unpublished Data Literature Cited
No abstract available.
We analyzed data from pathologic investigations in the United States, collected by the USGS National Wildlife Health Center between 1971 and 2005, into aquatic bird mortality events. A total of 3619 mortality events was documented for aquatic birds, involving at least 633 708 dead birds from 158 species belonging to 23 families. Environmental causes accounted for the largest proportion of mortality events (1737 or 48%) and dead birds (437 258 or 69%); these numbers increased between 1971 and 2000, with biotoxin mortalities due to botulinum intoxication (Types C and E) being the leading cause of death. Infectious diseases were the second leading cause of mortality events (20%) and dead birds (20%), with both viral diseases, including duck plague ( Herpes virus ), paramyxovirus of cormorants ( Paramyxovirus PMV1) and West Nile virus ( Flavivirus ), and bacterial diseases, including avian cholera ( Pasteurella multocida ), chlamydiosis ( Chalmydia psittici ), and salmonellosis ( Salmonella sp.), contributing. Pelagic, coastal marine birds and species that use marine and freshwater habitats were impacted most frequently by environmental causes of death, with biotoxin exposure, primarily botulinum toxin, resulting in mortalities of both coastal and freshwater species. Pelagic birds were impacted most severely by emaciation and starvation, which may reflect increased anthropogenic pressure on the marine habitat from over-fishing, pollution, and other factors. Our study provides important information on broad trends in aquatic bird mortality and highlights how long-term wildlife disease studies can be used to identify anthropogenic threats to wildlife conservation and ecosystem health. In particular, mortality data for the past 30 yr suggest that biotoxins, viral, and bacterial diseases could have impacted >5 million aquatic birds.
In 1967, the first confirmed diagnosis of duck plague (DP) in the USA was made from pekin ducks ( Anas platyrhynchos domesticus ) on commercial duck farms on Long Island, New York. Within 10 mo, DP was confirmed as the cause of death in migratory waterfowl on a Long Island bay. This paper reviews 120 DP epizootics reported from 1967 to 1995 that involved waterfowl species native to North America or were reported in areas with free-flying waterfowl at risk. Duck plague epizootics occurred in 21 states with the greatest number reported in Maryland (29), New York (18), California (16), and Pennsylvania (13). The greatest frequency of epizootics (86%) was detected during the months of March to June. At least 40 waterfowl species were affected with the highest frequency of epizootics reported in captive or captive-reared ducks including muscovy ducks ( Cairina moschata ) (68%), mallard ducks ( A. platyrhynchos ) (18%) and black ducks ( A. rubripes ) (14%). The greatest number of waterfowl died in three epizootics that involved primarily migratory birds in 1967 and 1994 in New York (USA) and 1973 in South Dakota (USA). The greatest number of DP epizootics reported since 1967 appear to have involved flocks of non-migratory rather than migratory waterfowl; therefore, in our opinion it remains unknown if DP is enzootic in either non-migratory or migratory waterfowl.
A 1993 die-off of common loons ( Gavia immer ) in the coastal waters of North Carolina was investigated with emphasis on comparing mercury, selenium, arsenic, and lead between birds from the epizootic and reference specimens. Die-off specimens were emaciated but contained no ingested foreign bodies and no lesions suggestive of infectious disease. Results of bacteriology, virology, parasitology, and botulism testing were unremarkable. The geometric mean concentrations (wet weight) of liver mercury (10.9 ppm), and arsenic (0.96 ppm) did not differ between specimens from the die-off and reference loons from the same area that died of other causes. The geometric mean liver selenium concentration of die-off specimens (10.4 ppm) was significantly higher than that of reference loons. Liver lead concentrations were < 0.20 ppm in all but one sample (5.83 ppm). The geometric mean mercury concentration in the primary remiges of die-off specimens (5.44 ppm dry weight) was significantly lower than in reference birds. Liver mercury significantly correlated with liver selenium on a molar concentration basis. We interpret the range of liver mercury concentrations in birds from the epizootic, similar liver mercury concentrations in reference loons, and higher mercury concentrations in reference loon feathers as evidence that factors other than mercury were primarily responsible for the emaciation diagnosed as the cause of mortality.
A new mycoplasmal conjunctivitis was first reported in wild house finches ( Carpodacus mexicanus ) in early 1994. The causative agent was identified as Mycoplasma gallisepticum (MG), a nonzoonotic pathogen of poultry that had not been associated with disease in wild songbirds. Since the initial observations of affected house finches in the mid-Atlantic region, the disease has become widespread and has been reported throughout the eastern United States and Canada. By late 1995, mycoplasmal conjunctivitis had spread to an additional species, the American goldfinch ( Carduelis tristis ). This new disease exemplifies the rapid spread of a pathogen following introduction into a mobile wildlife population and provides lessons that may apply to emerging human diseases.
Red-winged blackbirds ( Agelaius phoeniceus ) were collected during an epizootic in southeastern North Carolina (USA). Activity of brain cholinesterase (ChE) was inhibited by 14 to 48% in three of five specimens, and returned to normal levels after incubation. Gastrointestinal tracts were analyzed for 30 anti-ChE agents. Carbofuran, the only compound detected, was present in all specimens at levels from 5.44 to 72.7 μg/g wet weight. Application of granular carbofuran in an adjacent corn field, results of necropsy examinations, and chemical analyses are consistent with a diagnosis of carbofuran poisoning in these specimens.
Wetlands accumulate pollutants from adjacent areas through intentional discharge of sewage or industrial wastes, runoff of agricultural fertilizers and pesticides, and discharge from municipal storm drains. Coastal wetlands receive more pollutants indirectly as the endpoint for upland drainage systems and directly through petroleum spills and insect abatement. Wetlands that serve as evaporation basins during seasonally high water, especially in more arid climates, concentrate natural compounds and as well as pollutants. The ability of wetlands to be effective filtration systems for wastewater nutrients through microbial transformations, uptake by plants, and deposition of particulate matter, and the shortage of water in arid climates has resulted in revision of wetland regulations. Wetlands can now be developed for wastewater treatment and natural wetlands can be restored or converted to wastewater treatment systems. The effect of these accumulation pollutants on wetland ecology and wildlife health needs to be recognized.
Captive propagation, introduction, and translocation (relocation) programs for many animals have been undertaken by federal, state, and private agencies for more than 20 years. These programs help aid the recovery of endangered and threatened species, reestablish lost species, augment declining populations, increase recreational opportunities, reduce nuisance species, and introduce non-native species. Davidson and Nettles (1992) discuss translocation as a component of successful early restorations of game species including wild turkey ( Meleagris gallopavo ) and white-tailed deer ( Odocoileus virginianus ), and recovery of endangered species such as the peregrine falcon (Falco peregrinus). Despite some successes, the total number of translocations that occur yearly is unknown, as is the success and effects of these programs, because there is rarely appreciable monitoring after release (Griffith et al. 1989; Gogan 1990). This report focuses on trends in the use of translocation programs and disease transmission following translocation of wildlife vertebrates other than fish. In the absence of a national data base on wildlife translocations, a search for publications with information on translocations was performed by using Wildlife Review and the U.S. Fish and Wildlife Reference Service CD-ROM data bases for the 20-year period, 1971-91. In addition, personnel from multiple federal, state, and private agencies that conduct propagation and translocation programs were contacted for supplemental information and literature. Increasing numbers of books (Neilsen and Brown 1988), journals (Ullrey 1993), and meetings (Junge 1992; Wolff and Seal 1992) discuss wildlife translocations and many contain information on the effects of translocations on animals and their environment.
We evaluated the vasectomy of 72 male Canada geese as a method to control growing populations of nuisance geese in Westchester County, New York. Thirty-three of the vasectomized males paired with a female and were located during ≥1 breeding seasons; 7 treated males were not seen following surgery. The remaining 32 males were never observed paired with a female during the breeding season. Of 56 nesting attempts by the 33 pairs in ≥1 breeding seasons, 84% of the nests were unsuccessful. Fidelity to nest sites during the second and third breeding seasons occurred for 17 of the 18 vasectomized males and their females that were observed for ≥2 seasons. The results suggest that male sterilization may reduce productivity of nuisance Canada geese providing one carefully selects areas and flocks suitable for this type of control.
Despite more than 4 decades of effort, development of effective wildlife damage control programs based on sterilization of target species has met with limited success. This is partly due to the fact that investigators have assumed, rather than empirically tested, whether the reproductive strategies of the target populations were vulnerable to the planned treatment. Equally important, methods selected to include sterility usually involve a chemical agent that can affect sociosexual behaviors of the nuisance population. In this report, we illustrate how surgically induced sterility circumvents both problems--how the concept without the potentially confounding secondary effects of a chemical. We assessed the merits of initiating research to develop a male chemosterilant for Norway rats, red-winged blackbirds, beaver, and Canada geese by inducing sterility surgically. The infidelity of many red-winged females to their polygynous territorial male was surprising and argued against searching for a male sterilant. On the other hand, beaver and Canada goose studies confirmed previous reports that both form par-bonds and are monogamous. Both should be vulnerable to a male chemosterilant approach, and research toward this goal is justified.
It wasn't so long ago that the wild cries of Canada geese overhead were enough to draw most people out of their homes to look skyward. It was a rare sound heard only in the spring and fall when migrating flocks of these magnificent birds marked the change of the seasons. But today the sound is less delightful to growing numbers of people as goose populations have become permanent residents of the Northeast and caused numerous problems. Non-migratory flocks of Canada geese are now present from Cape Cod to Virginia. According to the Atlantic Flyway Council, these geese have provoked nuisance complaints from local communities in every one of the states involved, except Delaware. Delaware has had problems in the past but they are presently under control. These resident populations cause numerous sanitation problems in local communities. Examples are accumulations of feathers and droppings, odor, noise, landscape and crop destruction, the decoying-in of additional geese, and overfertilization of ponds, thus causing algal growth and concerns about health problems, especially in swimming and other recreational areas.