Vaccination strategies for managing brucellosis in Yellowstone bison.

Concerns over migratory bison (Bison bison) at Yellowstone National Park transmitting brucellosis (Brucella abortus) to cattle herds on adjacent lands led to proposals for bison vaccination. We developed an individual-based model to evaluate how brucellosis infection might respond under alternate vaccination strategies, including: (1) vaccination of female calves and yearlings captured at the park boundary when bison move outside the primary conservation area; (2) combining boundary vaccination with the remote delivery of vaccine to female calves and yearlings distributed throughout the park; and (3) vaccinating all female bison (including adults) during boundary capture and throughout the park using remote delivery of vaccine. Simulations suggested Alternative 3 would be most effective, with brucellosis seroprevalence decreasing by 66% (from 0.47 to 0.16) over a 30-year period resulting from 29% of the population receiving protection through vaccination. Under this alternative, bison would receive multiple vaccinations that extend the duration of vaccine protection and defend against recurring infection in latently infected animals. The initial decrease in population seroprevalence will likely be slow due to high initial seroprevalence (40-60%), long-lived antibodies, and the culling of some vaccinated bison that were subsequently exposed to field strain Brucella and reacted positively on serologic tests. Vaccination is unlikely to eradicate B. abortus from Yellowstone bison, but could be an effective tool for reducing the level of infection. Our approach and findings have applicability world-wide for managers dealing with intractable wildlife diseases that cross wildlife-livestock and wildlife-human interfaces and affect public health or economic well-being.

Meningeal worm in a reintroduced elk population in Kentucky.

Meningeal worm (Parelaphostrongylus tenuis) has been implicated in the failure of several elk (Cervus elaphus) restoration attempts in the eastern United States. However, limited post-release monitoring and a paucity of published literature prevents a clear understanding of this parasite's role in past failures. During winters of 1997-2001, the Kentucky Department of Fish and Wildlife Resources translocated 1,044 elk from western states to eastern Kentucky (USA) in an effort to restore a free-ranging population. We monitored 521 radio-collared elk over 4 yr to determine the impact meningeal worm had on population establishment. Thirty (23%) of 129 non-capture related mortalities were attributed to meningeal worm. Twenty-two (73%) of these meningeal worm-caused mortalities were animals < 3 yr old. If younger elk born in Kentucky suffer higher mortality rates than older translocated elk, the population growth observed during the initial years of restoration may be temporary. Additional research is necessary to determine the influence meningeal worm will have on elk population growth in Kentucky.

Landscape Features and Panthers in Florida.

We used a geographic information system (GIS) to document spatial associations of Florida panthers, land cover, and other geographical features. Panther radio locations (n = 14,548) occurred in hardwood hammock, mixed hardwood swamp, and cypress swamp in greater proportion than in randomly positioned points (n = 8500). Panther radio locations occurred less frequently in agricultural, barren, and shrub and brush land cover. Panther home ranges consisted of a combination of preferred and avoided cover types, including freshwater marsh, cypress swamp, hardwood swamp, and agricultural land. These cover types accounted for 62% of the area in panther home ranges. We used correlation and discriminant function analyses to assess the potential importance of 20 landscape features. These panther locations were effectively distinguished from random points using four landscape variables: (1) the size of a contiguous patch of preferred land cover; (2) the proximity to preferred land cover; (3) the diversity of three preferred cover types within a window 120 × 120 m, and (4) the matrix within which preferred cover types occurred. Eighty-three percent of the panther locations and 81.9% of the random points were correctly classified based on a linear model constructed using these four variables. Large, contiguous areas of preferred land-cover types were especially important because 96% of all panther locations occurred within 90 m of preferred land cover. The average preferred forest patch size that was used by these panthers was 20,816 ha, and a regression equation suggests that patches larger than 500 ha are important. Maps of panther habitat suitability were developed using coefficients derived from discriminant analysis. Large areas of suitable land cover that are heavily used by panthers occur on private ranches covering 3606 km2 . Conservation of preferred habitat on these private lands is essential to maintaining a free-ranging population of panthers in southwest Florida. Características del paisaje y las panteras en Florida.

Resumen: Utilizamos un Sistema de Información Geográfico (SIG) para documentar las asociaciones espaciales de las panteras de Florida, cobertura de la tierra y otras características geográficas. La localización de las panteras (n = 14,548) se dió en mayor proporción en colinas de bosques de madera dura, humedales mixtos de madera dura y humedales de ciprés, que en puntos situados al azar (n = 8500). La localización de las panteras ocurrió con menor frecuencia en tierras yermas, y áreas con cobertura agrcola, arbustiva y de matorrales. Las áreas de distribución nativas a la pantera consistieron en una combinación de los tipos de cobertura preferidos y eludidos incluyendo pantanos de agua dulce, humedales de ciprés, humedales con árboles de madera dura y tierras agrícolas. Estos tipos de cobertura abarcaron el 62% del área de distribucion nativa de la pantera. Utilizamos correlación y análisis de funciones discriminantes para determinar la importancia potencial de 20 características del paisaje. Estos sitios caracteristicos para la pantera fueron diferenciados eficientemente de puntos al azar, utilizando cuatro variables del paisaje: (1) el tamaño de un parche continguo de la cobertura preferida; (2) la proximidad a una cobertura preferida; (3) la diversidad de tres tipos de cobertura preferida dentro de una ventana de 120 × 120 m y (4) la matriz dentro de la cual se dan los tipos preferidos de cobertura. Un 83% de los sitios de la pantera y un 81.9% de los puntos al azar fueron correctamecnte clasificados en base a un modelo lineal construído utilizando estas cuatro variables. Resultaron especialmente importantes áreas extensas y contínuas de los tipos de cobertura preferidos, ya que el 96% de todos los sitios con panteras se encontraron dentro de los 90 m de la cobertura preferida. El tamaño promedio de los parches del bosque preferido que fue utilizado por estas panteras fue de 20,816 ha y una ecuaciónde regresión sugiere que los parches de más de 500 ha son importantes. Los mapas de aptitud del hábitat para la pantera fueron desarrollados utilizando coeficientes derivados del análisis de funciones discriminantes. Extensas áreas con cobertura propicia, que son intensamente utilizadas por las panteras, se encuentran en ranchos privados cubriendo 3,60 km2 . La conservación de los hábitas preferidos en estas tierras privadas resulta escencial para mantener una población de panteras libres en el sudoeste de Florida.