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Articles 2011 - 2040 of 2200

Full-Text Articles in Zoology

Thermoregulation In Swimming Mallard Ducklings (Anas Platyrhynchos), Aaron James Lynott May 2003

Thermoregulation In Swimming Mallard Ducklings (Anas Platyrhynchos), Aaron James Lynott

All-Inclusive List of Electronic Theses and Dissertations

Temperature regulation in birds has been studied for several decades. However, most studies have been limited to the thermal effects of air. This is surprising considering the abundance of waterfowl and the significant amount of time that many birds spend immersed in water. While we do know that water has a thermal conductivity that is 23 times that of air, the effect of water temperature on temperature regulation remains unknown. Though the thermal effect of water seemingly has a strong influence on the thermoregulation of birds, neonatal aquatic birds seem particularly susceptible. Many aquatic neonates, such as mallard ducklings, enter …


An Unusually Colored Red-Backed Salamander (Plethodon Cinerus) From Northern Virginia, Joseph C. Mitchell, Thomas K. Pauley, C. Todd Georgel Apr 2003

An Unusually Colored Red-Backed Salamander (Plethodon Cinerus) From Northern Virginia, Joseph C. Mitchell, Thomas K. Pauley, C. Todd Georgel

Virginia Journal of Science

We describe an orange-pink, patternless, translucent morph of the Red-backed Salamander (Plethodon cinereus) found in northern Virginia on 27 September 2001. This is the first description of this unusual phenotype in this terrestrial salamander.


Keys To The Mammals And Mammal Skulls Of The Northern Coastal Plain Of Virginia, John F. Pagels, A. Scott Bellows, Joseph C. Mitchell Apr 2003

Keys To The Mammals And Mammal Skulls Of The Northern Coastal Plain Of Virginia, John F. Pagels, A. Scott Bellows, Joseph C. Mitchell

Virginia Journal of Science

This publication is designed to function as a tool for the identification of mammal species that occur on the Coastal Plain of northern Virginia. We provide whole-body and skull keys to the 40 species that occur in this region. Baseline data for this work were collected during several studies conducted on Fort A.P. Hill, Caroline County. The intended audience includes interested naturalists, teachers, students, field biologists, and natural resource managers.


Growth And The Expression Of Alternative Life Cycles In The Salamander Ambystoma Talpoideum (Caudata: Ambystomatidae), Travis J. Ryan, Raymond D. Semlitsch Jan 2003

Growth And The Expression Of Alternative Life Cycles In The Salamander Ambystoma Talpoideum (Caudata: Ambystomatidae), Travis J. Ryan, Raymond D. Semlitsch

Scholarship and Professional Work - LAS

Complex life cycles (CLCs) contain larval and adult phases that are morphologically and ecologically distinct. Simple life cycles (SLCs) have evolved from CLCs repeatedly in a wide variety of lineages but the processes that may underlie the transition have rarely been identified or investigated experimentally. We examined the influence of larval growth rate on the facultative expression of alternative life cycles (metamorphosis or maturation as gill-bearing adults [= paedomorphosis]) in the salamander Ambystoma talpoideum. We manipulated growth rates by altering the amount of food individuals received throughout larval development. The expression of alternative life cycles in A. talpoideum is influenced …


The Tadpole Of Phrynobatrachus Mababiensis Fitzsimons, 1932 (Anura, Ranidae, Petropedetinae), Rafael O. De Sá, Alan Channing Jan 2003

The Tadpole Of Phrynobatrachus Mababiensis Fitzsimons, 1932 (Anura, Ranidae, Petropedetinae), Rafael O. De Sá, Alan Channing

Biology Faculty Publications

The puddle frog genus Phrynobatrachus Günther, 1862 comprises about 64 currently recognized species (Frost, 1985). Of these, only the tadpoles of P. natalensis (Smith, 1849) (Power, 1927; Channing, 2001), P. guineensis Guibé & Lamotte, 1961(Rödel,1998) and P. alticola Guibé & Lamotte, 1961 (Rödel & Ernst, 2002) have been described. Phrynobatrachus mababiensis FitzSimons, 1932 (Dwarf Puddle frog, Wager, 1986; Mababe River frog, Frank & Ramus, 1996) is a small frog that usually calls from low in thick vegetation on flooded terrains close to the water. Very little has been published about the biology of this species. Passmore & Carruthers (1979) reported …


Leptodactylus Mystacinus, M. M. Heyer, W. R. Heyer, Rafael O. De Sá Jan 2003

Leptodactylus Mystacinus, M. M. Heyer, W. R. Heyer, Rafael O. De Sá

Biology Faculty Publications

Adult Leptodactylus mystacinus are of moderate size, the head is as wide as long, and the hind limbs are moderately short (see Table; Heyer and Thompson 2000 provided definitions of adult size and leg length categories for Leptodactylus). Male vocal sacs are not visible externally or at best are weakly expanded laterally and slightly darker than female throats. Male snouts are more spatulate than those of females. Male forearms are not hypertrophied. Males lack asperities on the thumbs and chest. One or two pairs of dorsolateral folds (indicated by dark/light outlining in indifferently preserved specimens) are present: one …


Individual, Temporal, And Seasonal Variation In Sperm Concentration In Tree Swallows, Michael P. Lombardo, Armetris N. Forman, Matthew R. Czarnowski, Patrick A. Thorpe Nov 2002

Individual, Temporal, And Seasonal Variation In Sperm Concentration In Tree Swallows, Michael P. Lombardo, Armetris N. Forman, Matthew R. Czarnowski, Patrick A. Thorpe

Peer Reviewed Publications

We determined sperm concentrations in Tree Swallows (Tachycineta bicolor) by manually expressing semen samples from males during prelaying, egg-laying, incubation, and nestling periods. Sperm concentrations varied by orders of magnitude (0-109 sperm mL-1) among males. Sperm concentrations were highest during the incubation period and lowest during the prelaying period. None of the samples collected during the prelaying, egg-laying, and incubation periods were devoid of sperm. In contrast, 45% of samples collected during the nestling period lacked sperm. Sperm concentrations (1) did not vary over the course of the morning during prelaying, egg-laying, and incubation periods …


Contributions To The Mammalogy Of Mongolia, With A Checklist Of The Species Of The Country, David S. Tinnin, Jon L. Dunnum, Jorge A. Salazar-Bravo, Nyamsuren Batsaikhan, M. Scott Burt, Scott Lyell Gardner, Terry L. Yates Oct 2002

Contributions To The Mammalogy Of Mongolia, With A Checklist Of The Species Of The Country, David S. Tinnin, Jon L. Dunnum, Jorge A. Salazar-Bravo, Nyamsuren Batsaikhan, M. Scott Burt, Scott Lyell Gardner, Terry L. Yates

Harold W. Manter Laboratory of Parasitology: Faculty Publications

We present accounts for 40 species of mammals collected from 15 localities in the Mongolian People's Republic. Accounts include taxonomic, morphometric, reproductive and ecological information, as well as trap effort and success. In addition, we include a brief history of mammalogical work within Mongolia, a taxonomically updated species list for the country, and a list of institutions with holdings of Mongolian mammals.


The Mayfly Newsletter, Peter M. Grant Feb 2002

The Mayfly Newsletter, Peter M. Grant

The Mayfly Newsletter

The Mayfly Newsletter is the official newsletter of the Permanent Committee of the International Conferences on Ephemeroptera.


Leptodactylus Silvanimbus, W. R. Heyer, Rafael O. De Sá, Sarah Muller Jan 2002

Leptodactylus Silvanimbus, W. R. Heyer, Rafael O. De Sá, Sarah Muller

Biology Faculty Publications

Adult Leptodactylus silvanimhus are of moderate sized, the head is about as wide as long, and the hind limbs are moderate in length (see Table; also see Heyer and Thompson 2000 for definitions of adult size and leg length categories for Leptodacrylus). The male vocal sac is single and internal. Male forearms are hypertrophied in larger individuals. Adult males have two black thumb spines on each hand and lack chest spines. Individuals lack dorsolateral folds. The toe tips are narrow, not expanded. Females have weakly developed lateral toe fringes and males either have lateral toe ridges or weakly developed fringes. …


Mammals Of Fort A. P. Hill, Caroline County, Virginia And Vicinity, A. Scott Bellows, Joseph C. Mitchell, John F. Pagels, Heather N. Mansfield Oct 2001

Mammals Of Fort A. P. Hill, Caroline County, Virginia And Vicinity, A. Scott Bellows, Joseph C. Mitchell, John F. Pagels, Heather N. Mansfield

Virginia Journal of Science

Fort A.P. Hill (APH) is a 30,329 ha military training installation (U.S. Army) located in the upper Coastal Plain of Caroline County, Virginia. It was formed in 1941 and named in honor of Civil War Confederate Lt. General Ambrose Powell Hill. The current landscape includes a mosaic of habitats that range from old fields to hardwood forests. Forty species of mammals are known to exist on or near the installation. These include one marsupial, five insectivores, 9 chiropterans, one lagomorph, 12 rodents, 10 carnivores, and one cervid. We have studied many of the species on APH since 1997. In this …


The Mayfly Newsletter, Peter M. Grant Jun 2001

The Mayfly Newsletter, Peter M. Grant

The Mayfly Newsletter

The Mayfly Newsletter is the official newsletter of the Permanent Committee of the International Conferences on Ephemeroptera.


Natural History And Roosting Ecology Of The Eastern Pipistrelle, Pipistrellus Subflavus, Jacques Pierre Veilleux May 2001

Natural History And Roosting Ecology Of The Eastern Pipistrelle, Pipistrellus Subflavus, Jacques Pierre Veilleux

All-Inclusive List of Electronic Theses and Dissertations

A study concerning the natural history and roosting ecology of the eastern pipistrelle, Pipistrellus subtlavus, was conducted from 1997 to 2000, in southern Vigo County, Indiana. 111 Females began forming pre-maternity colonies during early May, and parturition began during late June. Pre-maternity colonies averaged 3.7 ± 1.9 individuals, and maternity colonies averaged 4.4 ± 2.4 individuals. Young pipistrelles first became volant during the third and fourth weeks of July. Pipistrelles were located in 59 roost trees. All roosts were located in foliage, either in clusters of dead leaves (n = 40) or in live foliage (n = 19). Oaks (Ouercus …


Determining Differences In The Spatial Distribution Of Forest Structure On The Kaibab Plateau: Implications For Forest Management And The Northern Goshawk, Ryan S. Miller Apr 2001

Determining Differences In The Spatial Distribution Of Forest Structure On The Kaibab Plateau: Implications For Forest Management And The Northern Goshawk, Ryan S. Miller

Other Publications in Wildlife Management

The Kaibab Plateau, in North Central Arizona, has undergone extensive change in the last 100 years due to land management practices such as logging, road building, and fire suppression. The northern goshawk (Accipiter gentilis) has been a center of controversy, due to the potential effects of silvicultural practices on goshawk breeding habitat (Reynolds-1983, Bloom et al 1986, Kennedy 1989, Crocker-Bedford 1990). Current and past research efforts on the Kaibab Plateau have mapped Goshawk nesting territories and temporal change in nesting behavior and success. However, these research efforts have not determined how long-term spatial changes in land-use activities that have influenced …


Rare, Threatened And Endangered Plants And Animals Of Oregon (2001), James S. Kagan, Sue Vrilakas, Eleanor P. Gaines, Cliff Alton, Ken Popper, Mark A. Stern, Eric Scheuering, John A. Christy, Mary Finnerty, Jon Hak, Anthony A. Tovar, Michael Murray, Claudine Tobalske, Oregon Natural Heritage Program Feb 2001

Rare, Threatened And Endangered Plants And Animals Of Oregon (2001), James S. Kagan, Sue Vrilakas, Eleanor P. Gaines, Cliff Alton, Ken Popper, Mark A. Stern, Eric Scheuering, John A. Christy, Mary Finnerty, Jon Hak, Anthony A. Tovar, Michael Murray, Claudine Tobalske, Oregon Natural Heritage Program

Institute for Natural Resources Publications

Extinction is a natural process. Today, however, plant and animal species are disappearing world-wide at an accelerated pace. Based on current trends, half of the species on earth will be extinct within the next 100 years. The major cause of this phenomenon is large-scale destruction of native habitats, which has increased since European settlement began in the mid 1800's - in Oregon and throughout the New World.

Once lost, a species can never be recovered, and there is no way of knowing how useful it may have been. We do know that human beings and many of their industries depend …


Effects Of Hydroperiod On Metamorphosis In Rana Sphenocephala, Travis J. Ryan, Christopher T. Winne Jan 2001

Effects Of Hydroperiod On Metamorphosis In Rana Sphenocephala, Travis J. Ryan, Christopher T. Winne

Scholarship and Professional Work - LAS

Hydroperiod, the time a temporary pond holds water, is an important factor influencing recruitment in amphibian populations and structuring amphibian communities. We conducted an experiment to test the effect of hydroperiod on metamorphic traits of the southern leopard frog (Rana sphenocephala), a common amphibian in the southeastern United States. We reared larval R. sphenocephala in artificial ponds at a density of 32 larvae per tank (initial volume = approximately 650 liter). We dried the tanks according to natural patterns, using three different hydroperiods (60, 75 and 90 d). Experimental hydroperiods had a significant effect on the number of …


The Mayfly Newsletter, Peter M. Grant Dec 2000

The Mayfly Newsletter, Peter M. Grant

The Mayfly Newsletter

The Mayfly Newsletter is the official newsletter of the Permanent Committee of the International Conferences on Ephemeroptera.


Los Anfibios Del Monumento Natural Barro Colorado, Parque Nacional Soberania Y Areas Adyacentes, Rafael O. De Sá Sep 2000

Los Anfibios Del Monumento Natural Barro Colorado, Parque Nacional Soberania Y Areas Adyacentes, Rafael O. De Sá

Biology Faculty Publications

This book focuses on the batrachofauna of Barro Colorado Nature Monument. Soberania National Park and adjacent areas. It complements other recent publications on Neotropical amphibians such as those by Rodriguez and Duellman ( 1994) on Peru, Achaval and Olmos (1995) on Uruguay, and Meyer and Foster (1996) on Belize. The goal of these books is to reach a wider audience than the more technical batrachofaunal summaries-e.g., Frogs of Boracéia (Heyer 1990). Amphibians of Argentina (Cei 1985), and Frogs of the Genus Eleutherodactylus in Western Ecuador (Lynch and Duellman 1997). These geographically focused guides are especially useful to students, amateur biologists, …


The Mayfly Newsletter, Peter M. Grant Jun 2000

The Mayfly Newsletter, Peter M. Grant

The Mayfly Newsletter

The Mayfly Newsletter is the official newsletter of the Permanent Committee of the International Conferences on Ephemeroptera.


Los Coquís De Puerto Rico: Su Historia Natural Y Conservación, Rafael O. De Sá Mar 2000

Los Coquís De Puerto Rico: Su Historia Natural Y Conservación, Rafael O. De Sá

Biology Faculty Publications

As the title indicates, this well-illustrated (115 photographs and 76 illustrations) book summarizes the current knowledge about the natural history of the 16 species of Eleutherodactylus inhabiting Puerto Rico. The book consists of eight chapters (including the epilogue) and it is clearly stated that it was written to serve both the scientific community and the nonspecialist reader. The goal of bridging these two audiences is ambitious and usually difficult; however, the book has probably accomplished this goal. The technical reader, i.e., students and professional herpetologists, will find a good summary of data and enough information to continue reading with interest. …


The Global Decline Of Reptiles, Deja’ Vu Amphibians, J. Whitfield Gibbons, David E. Scott, Travis J. Ryan, Kurt A. Buhlmann, Tracey D. Tiuberville, Brian S. Metts, Judith L. Greene, Tony Mills, Yale Leiden, Sean Poppy, Christopher T. Winne Jan 2000

The Global Decline Of Reptiles, Deja’ Vu Amphibians, J. Whitfield Gibbons, David E. Scott, Travis J. Ryan, Kurt A. Buhlmann, Tracey D. Tiuberville, Brian S. Metts, Judith L. Greene, Tony Mills, Yale Leiden, Sean Poppy, Christopher T. Winne

Scholarship and Professional Work - LAS

Reptile species are declining on a global scale. Six significant threats to reptile populations are habitat loss and degradation, introduced invasive species, environmental pollution, disease, unsustainable use, and global climate change.


The Mayfly Newsletter, Peter M. Grant Jan 2000

The Mayfly Newsletter, Peter M. Grant

The Mayfly Newsletter

The Mayfly Newsletter is the official newsletter of the Permanent Committee of the International Conferences on Ephemeroptera.


Black-Tailed Deer Habitat Changes In A Portion Of The Mount St. Helens Blast Zone, Ronald W. Davis Dec 1999

Black-Tailed Deer Habitat Changes In A Portion Of The Mount St. Helens Blast Zone, Ronald W. Davis

All-Inclusive List of Electronic Theses and Dissertations

This study utilized Landsat TM imagery to evaluate black-tailed deer habitat changes in a portion of the Mount Saint Helens blast zone in western Washington. The purpose of this study was to compare the post eruption vegetation changes with population trends for black tailed deer. The 55,000-acre study area comprises a Washington Department of Game Management unit (GMU 524) located to the northnorthwest of Mount St. Helens. Approximately 80% ofthe mostly forested study area was affected by lateral blast from the 1980 eruption. The area is predominantly private land managed for timber production but a small portion falls within the …


Comparing The Tadpoles Of Hyla Geographica And Hyla Semilineata, Anne D'Heursel, Rafael O. De Sá Sep 1999

Comparing The Tadpoles Of Hyla Geographica And Hyla Semilineata, Anne D'Heursel, Rafael O. De Sá

Biology Faculty Publications

External morphology, internal oral anatomy, and chondrocranial anatomy were examined for tadpoles of Hyla geographica from the Amazon rainforest, Brazil, and Hyla semilineata from the Atlantic rainforest, Brazil. Here, we provide morphological larval data to help diagnose these closely related species. Scanning electron microscopy analysis of buccal morphology showed the most distinctive features between these species: the distance between the lingual papillae in the buccal floor of H. geographica is three times greater than that distance in H. semilineata, and the relative size of the lingual papillae in H. geographica is less than half their size in H. semilineata. Although …


Avian Communities Of Large Reclaimed Mine Grasslands In Southwestern Indiana, Travis L. Devault Aug 1999

Avian Communities Of Large Reclaimed Mine Grasslands In Southwestern Indiana, Travis L. Devault

All-Inclusive List of Electronic Theses and Dissertations

Many bird species native to the tallgrnss prairie region oCthc central U.S. have declined drastically since European settlement due lo the destruction and alteration of grassland habitat. In this study, the breeding bird communities or 21 large reclaimed surface coal mine grasslands in a seven-county area or southwestern Indiana were examined with respect to species and guild composition, density, variation among sites, and grassland size. In addition, the vegetation characteristics of nine large mine grasslands were described and related to the presence and abundance or eight grasslund bird species common to the study areas. The immense size of mine grasslands …


Estructura Del Condrocráneo Y Esqueleto Visceral De Larvas De Pseudis Minuta (Anura, Pseudidae, E. O. Lavilla, Rafael O. De Sá Jun 1999

Estructura Del Condrocráneo Y Esqueleto Visceral De Larvas De Pseudis Minuta (Anura, Pseudidae, E. O. Lavilla, Rafael O. De Sá

Biology Faculty Publications

The chondrocranium and visceral skeleton of Pseudis minuta tadpoles are described, based on a series of five larvae in stages 31 - 35 of Gosner (1960). Among their striking characters are the presence of peculiar articular surfaces between cornua trabeculae and suprarostral cartilage, the incomplete development of the orbital cartilage, the high fenestration of the floor of the cavum cranii, the fusion of posterior foramina, and the fusion of spicules 3 and 4 in the hyobranchial skeleton.


The Mayfly Newsletter, Peter M. Grant Jun 1999

The Mayfly Newsletter, Peter M. Grant

The Mayfly Newsletter

The Mayfly Newsletter is the official newsletter of the Permanent Committee of the International Conferences on Ephemeroptera.


The Timing And Pattern Of Myogenesis In Hymenochirus Boettgeri, Matthew T. Smetanick, Rafael O. De Sá, Gary P. Radice Jun 1999

The Timing And Pattern Of Myogenesis In Hymenochirus Boettgeri, Matthew T. Smetanick, Rafael O. De Sá, Gary P. Radice

Biology Faculty Publications

Differences in the relative timing of homologous developmental events among closely related species, known as heterochronies, may provide valuable clues in understanding evolutionary relationships (McKinney, 1988; McNamara, 1995). Examining the timing of myogenic events is a relatively easy and effective method for finding heterochronic events. For example, whether muscle proteins and myofibrils appear before or after multinucleation can be determined through histological techniciques (Kielbowna, 1981). Simple observations of live specimens can pinpoint functional landmarks such as first twitch (spontaneous or due to external stimuli) and first heartbeat.


Ecology Of The Malay Civet (Viverra Tangalunga) In A Logged And An Unlogged Forest In Sabah, East Malaysia, Christina P. Colon May 1999

Ecology Of The Malay Civet (Viverra Tangalunga) In A Logged And An Unlogged Forest In Sabah, East Malaysia, Christina P. Colon

Publications and Research

Malay civets in a dipterocarp rain forest were studied from December, 1995, through June, 1997, in the Ulu Segama Forest Reserve in Sabah, East Malaysia. To investigate the basic ecology of this species and explore the potential impact of selective logging, data on home range, activity and diet were collected on study animals in an unlogged and a selectively logged forest, and comparisons made.

Density in the unlogged forest was 1/0.46 km2 , and 1/1.07 km2 in the logged forest. Mean home range size based on a 95% minimum convex polygon was 110 ha. and did not differ …


Analysis Of Intraguild Predation With A Consideration Of Adaptive Foraging, Toshinori Okuyama May 1999

Analysis Of Intraguild Predation With A Consideration Of Adaptive Foraging, Toshinori Okuyama

School of Biological Sciences: Dissertations, Theses, and Student Research

Identification of interactive units in food webs is particularly important in population and community ecology. Intraguild predation has gained much attention recently with the recognition of its prevalence in the field, although its significance has not been fully studied. Nature contains much more complex interactions than a simple food chain. Yet, much theory still focuses on the trophic levels connected in a single linear chain. In this thesis, I study intraguild predation including the consideration of animal behavior whose importance is also often neglected in population and community ecology.

First, the concepts of intraguild predation and animal behavior are introduced. …