Biology Commons^™

Distribution And Current Status Of The Threatened Dismal Swamp Southeastern Shrew, Sorex Longirostris Fisheri, Robert K. Rose, Roger K. Everton, Thomas M. Padgett

Biological Sciences Faculty Publications

The Dismal Swamp southeastern shrew, Sorex longirostris fisheri, was given "Threatened" status by the U.S. Fish and Wildlife Service in 1986 because of its limited distribution and the potential threat of interbreeding with the nearby upland subspecies, Sorex l. longirostris. Known from about 20 specimens collected before 1980 and a few dozen taken since then, "fisheri" seems to have morphologically diverged from the smaller upland "longirostris" in association with the development of the Dismal Swamp. The detection of southeastern shrews that are intermediate in size between the two subspecies, coupled with the location of these collection sites on …

The Identification Of The Threatened Southeastern Shrew Using Multivariate Statistical Techniques, Thomas M. Padgett, Roger K. Everton, Robert K. Rose

Biological Sciences Faculty Publications

The threatened subspecies of the southeastern shrew, Sorex longirostris fisheri, is endemic to the Great Dismal Swamp of southeastern Virginia. Previous studies based on discriminant analysis of external measurements determined that intergrades with the upland form, Sorex l. longirostris, exist along the periphery of the Swamp. To better discriminate among these populations, a study of cranial morphology was initiated. Fifteen cranial measurements were taken, using 59 specimens of Sorex collected previously form southeastern Virginia, including the Dismal Swamp. Both Principal Component and Cluster Analyses revealed no significant cranial variation or morphometric patterns within the specimens examined, but a …

Reproductive Strategies Of Meadow Voles, Hispid Cotton Rats, And Eastern Harvest Mice In Virginia, Robert K. Rose

Biological Sciences Faculty Publications

Patterns of reproduction in small mammals in Virginia were examined by autopsying samples of meadow voles (Microtus pennsylvanicus) collected for 23 months near Charlottesville, of hispid cotton rats (Sigmodon hispidus) collected for 14 months in Portsmouth, and by evaluating live-caught eastern harvest mice (Reithrodontomys humulis) trapped for 15 months in Suffolk and for 12 months in Chesapeake. The meadow vole, a microtine rodent with a north temperate and sub-arctic distribution throughout North America, suspended breeding during the winter of peak density but not of declining density. High metabolic rates and other adaptations for winter …

Gametogenesis En Chthonerpeton Indistinctum (Gymnophiona: Typhlonectidae), Rafael O. De Sá, Nibia Berois

Biology Faculty Publications

RESUMEN:

Histológicamente, las gónadas de Chthonerpeton indistinctum son similares a las ya descritas para otras especies del orden Gymnophiona. Los lóbulos testiculares se hallan compartimentados en unidades estructurales denominadas lóculos. La espermatogénesis ocurre en cistos sincrónicos de células germinales. Durante la espermiogénesis se identifican cuatro estados consecutivos de desarrollo: 1) cistos de espermátidas redondeadas; 2) cistos de espermátidas arrifionadas; 3) cistos de espermátidas bastoniformes y 4) espermátidas en ramillete.

El análisis histológico de los ovarios mostró la presencia de tres estados en la maduración de los folículos ováricos. Estas etapas pueden ser identificadas de acuerdo a: 1) ubicación del folículo …

Community Ecology, Robert K. Rose, Elmer C. Birney

Biological Sciences Faculty Publications

COMMUNITIES with Microtus tend to be structurally simple, usually grasslands or tundra, and to have no more than two species of Microtus and rarely more than six species of small mammals. Microtus often dominates both numerically and in total small mammal biomass, especially at higher latitudes. The small mammal community is most influenced by Microtus through its fluctuations in density, and thus also in biomass, by its relatively high level of diurnal activity, and by its year-round activity. Other species of small mammals may be adversely affected because Microtus usually is larger and behaviorally dominant and also because the mere …

Comparative Study Of Lactate Dehydrogenase Activity In Diving And Nondiving Reptiles, Dennis A. Baeyens, Deborah Bursey, Robert Rountree

Journal of the Arkansas Academy of Science

The properties of lactate dehydrogenase (LDH) were examined in two snake species and one turtle species. The snakes used in the study were the semi-aquatic Nerodia rhombifera and the terrestrial Elaphe obsoleta, while Pseudemys scripta represented the turtle species. Our purpose was to compare the LDH activity of nondiving reptiles (Nerodia and Elaphe) with that of the well established diver Pseudemys. The kinetic properties of LDH and its susceptibility to inhibition by elevated pyruvate concentrations were investigated in the brain and heart of the three species. Brain and heart were chosen because they are highly aerobic tissues and therefore should …

Morfología Y Funciones Del Conducto De Müller De Chthonerpeton Indistinctum (Reinhardt Y Lutken, 1862) (Amphibia: Gymnophiona) En Relación Con Los Mecanismos Reproductivos De La Especie, Nibia Berois, Rafael O. De Sá

Biology Faculty Publications

El orden Gymnophiona comprende anfibios ápodos, ciegos, de hábitos cavícolas y acuáticos. Como consecuencia de estos hábitos resulta muy difícil su colecta, lo cual redunda en un escaso conocimiento de la biología del orden y sobre las relaciones filogenéticas del mismo.

Una de las características más particulares del grupo se refiere a la modalidad reproductora, ya que aproximadamente el 50% de las especies presentan viviparidad y la totalidad de ellas tienen fecundación interna. Es por esta razón que el estudio del aparato reproductor ha sido encarado por diversos autores, en especial por Wake (1968, J. Morphol. 126: 291) con una …

Corticocortical Projections Of A Visually Responsive Area In The Cat Brain, Joseph Mcgrath

Journal of the Arkansas Academy of Science

The Clare-Bishop (CB) area bears the name of the investigators who first (1954) demonstrated a cortical area in the cat brain located along the lateral aspect of the middle suprasylvian gyrus which responded electrophysiologically to both optic nerve and striate cortex (area 17) stimulation. More recent studies of CB or the lateral suprasylvian (LS) area have supported its role in visual and/or oculomotor functions. Silver degeneration methods were undertaken to clarify some of the corticocortical connections of this cortical region. The data accumulated provides a morphological basis in support of the CB area's role in visual and/or oculomotor activities

Estructura Del Ovario De Chthonerpeton Indistinctum (Reinhardt Y Lutken, 1862) (Amphibia: Gymnophiona) Durante La Gestación, Rafael O. De Sá, Nibia Berois

Biology Faculty Publications

La morfología e histología del ovario para varias especies del orden Gymnophiona ha sido reportada por Wake (1968, J. Morphol. 126, 291) y para C. indistinctum por los autores (1984, XXIV Reunión de Comunicaciones, Soc. Zool. Uruguay).

Continuando con los estudios sobre el aparato genital de esta especie vivípara, se presenta ahora la estructura del ovario durante la gestación.

Se procesaron con fines histológicos, ovarios de dos hembras grávidas colectadas en las costas de los Dep. Montevideo y San José en abril, 1983. El número de ejemplares trabajados es muy reducido dado lo difícil que resulta su colecta …

Leptodactylus Podicipinus (Cope, 1862) Y Leptodactylus Chaquensis Cei, 1959 (Anura, Leptodactylidae), En El Uruguay, Raúl Vaz-Ferreira, Rafael O. De Sá, Federico Achaval, Annelise Gebrau

Biology Faculty Publications

En base al estudio de las colecciones obtenidas principalmente en excursiones a la zona NO de Uruguay con motivo del relevamiento faunístico del área de Salto Grande, se avanzó considerablemente en el conocimiento de la distribución de Leptodactylus podicipinus (Cope, 1862) y Leptodactylus chaquensis (Cei, 1950), en nuestro país.

Se cita el material estudiado y las observaciones de campo realizadas; se dan los caracteres generales de ambas especies, se describen los hábitats, y se tratan las características de las vocalizaciones.

An Evaluation Of Small Rodents In Four Dismal Swamp Plant Communities, F. Elizabeth Breidling, Frank P. Day Jr., Robert K. Rose

Biological Sciences Faculty Publications

Diversity and density of small rodents in the Dismal Swamp are believed to be low. Reasons for this may be excessive predation, heavy interspecific pressure from large rodents, lack of suitable habitat, low food availability or flooding.

Rodent populations were evaluated using live-traps and pitfall traps in four different Dismal Swamp plant communities. Habitat was compared on the basis of phytomass studies previously reported. Flood levels were recorded during live-trapping sessions. Mast from trees was collected in modified mast collectors, and fed to Peromyscus leucopus in the laboratory.

Only two small rodent species were captured: Ochrotomys nuttalli and Peromyscus leucopus …

Observaciones Sobre La Biología De Phyllomedusa Iheringi Boulenger, 1885, (Anura, Hylidae), Rafael O. De Sá, Annelise Gerhau

Biology Faculty Publications

RESUMEN:

Se presentan las características que permiten diferenciar las larvas de Phyllomedusa iheringi de las de otros anuros que habitan en nuestro territorio, junto con algunas observaciones sobre la biología de esta especie poco conocida en el Uruguay.

SUMMARY:

The characteristics that differentiate the larvae of Phyllomedusa iheringi from other anurans that live in Uruguay are presented here. Some observations on the biology of this species are also recorded.

Small Mammals In Openings In Virginia's Dismal Swamp, Robert K. Rose

Biological Sciences Faculty Publications

In a study of small mammals of openings in the Dismal Swamp of Virginia, seven species were obtained using pitfall traps. Samples included several species rarely caught in the Swamp - seven specimens of the Dismal Swamp subspecies of the southern bog lemming, Synaptomys cooperi helaletes, the first collected in this century; two least shrews, Cryptotis parva; and 15 southeastern shrews, Sorex longirostris fisheri . Results are compared to previous studies, conducted primarily in forested habitats, in which the white-footed mouse, Peromyscus leucopus, and the golden mouse, Ochrotomys nuttalli, were numerically dominant.

Remembrance Of Places Lasts: Proactive Inhibition And Patterns Of Choice In Rat Spatial Memory, William A. Roberts, Robert H.I. Dale

Scholarship and Professional Work - LAS

A series of experiments was carried out to evaluate the notion that rats given a sequence of massed daily trials on the radial maze reset working memory at the end of each trial by deleting its contents. Although curves presented by D. S. Olton [Scientific American, 1977, 236, 82-98: In S. H. Hulse, H. Fowler, & W. K. Honig (Eds.), Cognitive processes in animal behavior, 1978, Hillsdale, N.J.: Erlbaum] show that rats return to errorless performance at the beginning of each trial after the first, the fact that accuracy falls less rapidly over choices on Trial 1 …

Attributes Of Dispersing Meadow Voles In Open-Grid Populations, Raymond D. Dueser, Marcia L. Wilson, Robert K. Rose

Biological Sciences Faculty Publications

Dispersal was investigated in two open-grid populations of meadow voles, Microtus pennsylvanicus (Ord, 1815) an central Virginia (U.S.A.) from November 1974 to April 1978. "Dispersal" was defined as immigration onto open, occupied population grids. Dispersers were distinguished from residents by weight at first capture. Individuals first captured at weights <30 g were classified as residents; those first captured at >30 g were classified as dispersers. Three independent lines of evidence support the validity of the 30-g criterion for recognizing dispersers in these vole populations. With frequent trapping and high trappability, particularly of young animals, this open-grid method of study offers two advantages in the study of dispersal. First, dispersers identified …

Front Matter, Elephant Editors

Elephant

Table of Contents and Cover credits

Observations In Tsavo National Park, Kenya, Evans E. Mgaah

Elephant

Personal observations from four years as a game ranger in Tsavo National Park, Kenya.

Captive Elephant Population Of North America: 1979 Update, Elephant Editors

Elephant

Survey of elephants in captivity, 1979.

Observations Of Elephants In East And Southern Africa, Jeheskel Shoshani

Elephant

Selected short observations on African elephants (Loxodonta africana) made during 1978 in East and Southern Africa.

Iucn/Wwf Help Wanted, Elephant Editors

Elephant

A published plea from the IUCN/World Wildlife Fund Conservation Programme in Indonesia asking for information regarding endangered elephants in Sumatra.

Elephant Symposium And Related Activities, Elephant Editors

Elephant

Agenda for the upcoming Elephant Symposium at the American Society of Mammalogists 59th Annual Meeting, June 20th, 1979.

Information From The Elephant Interest Group Questionnaire, Elephant Editors

Elephant

Elephant-related activities of answering respondents to the newsletter's questionnaire.

Report On The Elephants Of Tongaland, Clive Walker

Elephant

Report from a preliminary survey of elephants in Southern Africa by the Endangered Wildlife Trust Elephant Group.

Financial Report And Acknowledgments, Elephant Editors

Elephant

Accounting of the Elephant Interest Group for production of the journal.

Bibliography, Elephant Editors

Elephant

Updates to the selected bibliography covering references from 1970 - mid-1979.

Isolation Of Mycoplasma From The Genital Tracts Of Elephants, Harold W. Clark, Daniel C. Laughlin, Jack S. Bailey, Thomas Mcp Brown

Elephant

The authors report finding arthritogenic agents, mycoplasmas, for the first time in a large group of captive elephants that are frequently crippled with rheumatism.

Iucn Elephant Survey And Conservation Programme: Summary Of Interim Report On Elephants In Kenya, Alison K. K. Hillman

Elephant

Preliminary summary of evidence on the status and population trends of elephants in Kenya, condensed from the original.

Klaserie Elephant Project: Progress Report, Clive Walker

Elephant

Report from an aerial survey of elephant population in the Klaserie Private Nature Reserve in South Africa.

The Elephants Of Interview Island, Romulus Whitaker

Elephant

Report from survey work on elephants living on the Andaman Islands in the Bay of Bengal, June, 1977.

Known Elephant Distribution In Africa: An Updated Map, Iain Douglas-Hamilton, Alison K.K. Hillman

Elephant

Map depicting the elephant distribution in Africa as of Spring 1979.