Geology topics

B. Miller

Publications and source records attributed to B. Miller.

5 recordsLinked to original sources

USGS2011

Growth, morphology, and developmental instability of rainbow trout, Yellowstone cutthroat trout, and four hybrid generations

Hybridization of cutthroat trout Oncorhynchus clarkii with nonindigenous rainbow trout O. mykiss contributes to the decline of cutthroat trout subspecies throughout their native range. Introgression by rainbow trout can swamp the gene pools of cutthroat trout populations, especially if there is little selection against hybrids. We used rainbow trout, Yellowstone cutthroat trout O. clarkii bouvieri, and rainbow trout × Yellowstone cutthroat trout F1 hybrids as parents to construct seven different line crosses: F 1 hybrids (both reciprocal crosses), F 2 hybrids, first-generation backcrosses (both rainbow trout and Yellowstone cutthroat trout), and both parental taxa. We compared growth, morphology, and developmental instability among these seven crosses reared at two different temperatures. Growth was related to the proportion of rainbow trout genome present within the crosses. Meristic traits were influenced by maternal, additive, dominant, overdominant, and (probably) epistatic genetic effects. Developmental stability, however, was not disturbed in F 1 hybrids, F 2 hybrids, or backcrosses. Backcrosses were morphologically similar to their recurrent parent. The lack of developmental instability in hybrids suggests that there are few genetic incompatibilities preventing introgression. Our findings suggest that hybrids are not equal: that is, growth, development, character traits, and morphology differ depending on the genomic contribution from each parental species as well as the hybrid generation.

Transactions of the American Fisheries Society↗

USGS2002

Limitations of captive breeding in endangered species recovery

The use of captive breeding in species recovery has grown enormously in recent years, but without a concurrent growth in appreciation of its limitations. Problems with (1) establishing self-sufficient captive populations, (2) poor success in reintroductions, (3) high costs, (4) domestication, (5) preemption of other recovery techniques, (6) disease outbreaks, and (7) maintaining administrative continuity have all been significant. The technique has often been invoked prematurely and should not normally be employed before a careful field evaluation of costs and benefits of all conservation alternatives has been accomplished and a determination made that captive breeding is essential for species survival. Merely demonstrating that a species’ population is declining or has fallen below what may be a minimum viable size does not constitute enough analysis to justify captive breeding as a recovery measure. Captive breeding should be viewed as a last resort in species recovery and not a prophylactic or long-term solution because of the inexorable genetic and phenotypic changes that occur in captive environments. Captive breeding can play a crucial role in recovery of some species for which effective alternatives are unavailable in the short term. However, it should not displace habitat and ecosystem protection nor should it be invoked in the absence of comprehensive efforts to maintain or restore populations in wild habitats. Zoological institutions with captive breeding programs should operate under carefully defined conditions of disease prevention and genetic/behavioral management. More important, these institutions should help preserve biodiversity through their capacities for public education, professional training, research, and support of in situ conservation efforts.

Conservation Biology↗

USGS1999

Etologia aplicada al manejo de especies amenazadas: el caso del turon de patas negras (Mustela nigripes)

Los turones de patas negras (Mustela nigripes) son considerados como uno de los mamíferos más amenazados del mundo. La última población silvestre fue descubierta en 1981 en Meeteetse, Wyoming, y en 1985 se extinguió debido a una epidemia de moquillo canino en combinacion con una epidemia de peste bubónica. Antes de su extinción total en la naturaleza, se lograron capturar 18 individuos para comenzar un programa de cría. La cría en cautividad se ha llevado a cabo con éxito y, durante los últimos 11 años han nacido más de 2600 turones en centros de propagación. Desde 1991, aproximadamente 870 turones han sido reintroducidos en 5 áreas de distribución histórica original repartidas entre los estados de Wyoming, Montana, Dakota del Sur, y Arizona. La investigación científica ha sido, y continúa siendo, una herramienta crítica para dirigir el Programa de Recuperación. Los estudios etológicos llevados a cabo tanto con turones cautivos como con turones reintroducidos han demostrado que un entorno cautivo naturalístico, especialmente durante las etapas iniciales del desarrollo de estos carnívoros, ayuda a desarrollar conductas necesarias para la supervivencia en la naturaleza. Dicho entorno ayuda a los turones a refinar sus técnicas de caza, a reconocer las madrigueras de los perritos de la pradera como un refugio donde establecerse y como una vía de escape frente al acoso de depredadores, y a mejorar su forma física. A raíz de estos estudios, se han readaptado las técnicas de manejo de turones cautivos para ayudar a llevar a cabo la recuperación de esta especie de un modo más eficaz y rentable. Black-footed ferrets are considered one of the world's most endangered mammals. The last wild population was discovered in 1981 in Meteetsee, Wyoming, and, in 1985 it collapsed due to an epizootic of canine distemper in combination with sylvatic plague. Prior to the extinction of the last remnant population, 18 wild black-footed ferrets were captured to initiate captive propagation efforts. Captive breeding has been successful and, during the last 11 years, more than 2600 black-footed ferrets have been born in captive breeding centers. Since 1991, approximately 870 ferrets have been reintroduced in 5 areas located within the ferret's original geographic distribution, including sites in Wyoming, Montana, South Dakota, and Arizona. Scientific research has been, and continues to be, a critical tool to direct recovery efforts. Studies in applied ethology conducted on captive and reintroduced ferret populations have demonstrated that a naturalistic captive environment, particularly during early developmental periods, enhances the expression of behaviors necessary for survival in nature. Ferrets raised in a naturalistic environment develop better predatory skills, are able to recognize prairie dog burrows as a home and shelter from predators, and are more physically fit. Results from these studies have been adapted into management strategies to help implement a more cost-effective road to black-footed ferret recovery.

Etologia↗

USGS1994

Reintroduction of the black-footed ferret ( Mustela nigripes )

The black-footed ferret ( Mustela nigripes ) (Figure 27.1) is a small, secretive, nocturnal member of the family Mustelidae (Hall, 1981; Honacki, Kurman and Koeppl, 1982). Ferrets have an obligate dependence on the prairie dog ( Cynomys spp.) community, utilizing the prairie dog for food and its burrows for shelter (Campbell et al., 1987).

Book chapter↗

USGS1994

Charadrius montanus : Montane, grassland, or bare-ground plover?

The Mountain Plover ( Charadrius montanus ) is an aridland member of the Charadriidae. This plover is generally considered an associate of the North American shortgrass prairie, which is dominated by blue grama ( Bouteloua gracilis ) and buffalo grass ( Buchloe dactyloides ; Graul 1975). The species breeds at many locations across the western Great Plains plus at isolated locales in western Colorado, Wyoming and New Mexico (Leachman and Osmundson 1990) and recently in eastern Utah (K.S. Day pers.comm.). Continental populations of the Mountain Plover declined 63% from 1966 to 1991 (Knopf 1994), with the historic and current breeding stronghold being the Pawnee National Grassland in Weld County, Colorado (Graul and Webster 1976). Currently, a second major breeding population of Mountain Plovers is on the Charles M. Russell National Wildlife Refuge, Phillips County, Montana. Unlike when found on the grassland landscape of Weld County, Mountain Plovers in Phillips County selectively nest in prairie dog ( Cynomys spp.) towns (Knowles et al., 1982, Olson and Edge 1985) in vegetative settings that include prickly pear ( Opunitia polyacantha ), fringed sagewort ( Arteminisia frigida ), big sagebrush ( A. tridentata ), western wheatgrass ( Agropyron smithii ), and blue grama, Collectively, Weld and Phillips counties provide nesting habitat for approximately one-half of the continental population of Mountain Plovers,

The Auk↗