Open Access. Powered by Scholars. Published by Universities.®

Animal Sciences Commons™

Open Access. Powered by Scholars. Published by Universities.®

Ecology and Evolutionary Biology

Institution
Keyword
Publication Year
Publication
Publication Type
File Type

Articles 4621 - 4650 of 5829

Full-Text Articles in Animal Sciences

The Ecology And Natural History Of The Northern Leopard Frog, Rana Pipiens Schreber, In West Virginia, William Bradley Sutton Jan 2004

The Ecology And Natural History Of The Northern Leopard Frog, Rana Pipiens Schreber, In West Virginia, William Bradley Sutton

Theses, Dissertations and Capstones

The purpose of this study was to gather ecological and life history data for the Northern Leopard Frog, Rana pipiens Schreber, in West Virginia. In Chapter 1, natural history data, such as morphometrics (larval and adult), dorsal coloration, and emergence time were recorded. In Chapter 2, it was discovered that Aeromonas hydrophila and Pseudomonas ssp. skin infections affecting R. pipiens could be identified using BIOLOG analysis. The scope of Chapter 3 was to analyze habitat partitioning between 3 sympatric anurans (R. pipiens, R. catesbeiana, and R. clamitans melanota). The following habitat partitioning gradient was discovered. Rana …


Unusual Behavior By Bison, Bison Bison, Toward Elk, Cervus Elaphus, And Wolves, Canis Lupus, L. David Mech, Rick T. Mcintyre, Douglas W. Smith Jan 2004

Unusual Behavior By Bison, Bison Bison, Toward Elk, Cervus Elaphus, And Wolves, Canis Lupus, L. David Mech, Rick T. Mcintyre, Douglas W. Smith

United States Geological Survey, Northern Prairie Wildlife Research Center: Publications

Incidents are described of Bison (Bison bison) in Yellowstone National Park mauling and possibly killing a young Elk (Cervus elaphus) calf, chasing wolves (Canis lupus) off Elk they had just killed or were killing, and keeping the wolves away for extended periods. During one of the latter cases, the Bison knocked a wolf-wounded Elk down. Bison were also seen approaching wolves that were resting and sleeping, rousting them, following them to new resting places and repeating this behavior. These behaviors might represent some type of generalized hyper-defensiveness that functions as an anti-predator strategy.


Natural History And Sexual Dimorphism Of The Eastern Hellbender, Cryptobranchus A. Alleganiensis, Robert Makowsky Jan 2004

Natural History And Sexual Dimorphism Of The Eastern Hellbender, Cryptobranchus A. Alleganiensis, Robert Makowsky

Theses, Dissertations and Capstones

The Eastern Hellbender’s natural history and morphology was examined. Field studies were done to examine the efficacy of different techniques (focusing on capturing larva) and diet analysis. Lab studies were done to determine if any sexual dimorphism exists in hellbenders using simple measurements (and ratios) and if this dimorphism could be used to reliably determine gender. Field studies were inconclusive due to the inability to find a reliable sample because of record rainfall. Lab studies revealed that a dimorphism does exist for one ratio (TG/TL, P=.048) and for several measurements. These measurements alone were not applicable for determining gender. …


The Natural History And Morphology Of The Eastern Cricket Frog, Acris Crepitans Crepitans, In West Virginia, Kimberly Ann Bayne Jan 2004

The Natural History And Morphology Of The Eastern Cricket Frog, Acris Crepitans Crepitans, In West Virginia, Kimberly Ann Bayne

Theses, Dissertations and Capstones

Two subspecies of cricket frogs, Acris crepitans blanchardi and Acris crepitans crepitans, historically have occurred in West Virginia. The range of Acris c. blanchardi, Blanchard’s Cricket Frog, begins along the Ohio River extending into West Virginia. The Eastern Cricket Frog, Acris c. crepitans, is found in counties located in the eastern panhandle. The Eastern Cricket Frog is a species of great concern. Two sites where Acris c. crepitans historically occurred, two sites that never contained A. c. crepitans, one historical site that currently has A. c. crepitans, and two new sites that have A. c. crepitans were studied by auditory …


Use Of An Artificial Pond And Marshes By Amphibians And Reptiles In West Virginia, Vanessa A. Dozeman Jan 2004

Use Of An Artificial Pond And Marshes By Amphibians And Reptiles In West Virginia, Vanessa A. Dozeman

Theses, Dissertations and Capstones

A farm pond approximately 40 years old located in Wayne County, West Virginia was studied to determine the ingress and egress of amphibians and reptiles. In addition to the pond, 2 small marshes were also examined. The study extended from February 2003 to November 2003. The pond is approximately 36 m long and 38 m wide and is located on a south-facing hillside at 202 m in elevation. A drift fence composed of landscaping cloth was constructed to completely encircle the site. At every 5.15 m, funnel traps were positioned on both sides of the fence. Traps were checked daily …


Distribution, Habitat Use, Growth, And Condition Of A Native And An Introduced Catfish Species In The Hudson River Estuary, Stephen M. Jordan, Robert M. Neumann, Eric T. Schultz Jan 2004

Distribution, Habitat Use, Growth, And Condition Of A Native And An Introduced Catfish Species In The Hudson River Estuary, Stephen M. Jordan, Robert M. Neumann, Eric T. Schultz

EEB Articles

White catfish (Ameiurus catus) is native to the Hudson River and is now coexisting with the recently established channel catfish (Ictalurus punctatus). These species were sampled from four freshwater reaches and four habitat types of the Hudson River estuary to assess whether the two species overlapped in their habitat use, and whether any impact on the native species was evident. Catfishes were sampled in 1998 and 1999 using baited hoop nets (N = 708 net nights). Catch-per-unit-effort (CPUE, number of fish per net night; total catch = 368) of white catfish was significantly different among reaches …


Características Histológicas De La Tumefacción Frontal De Melanophryniscus (Amphibia: Anura: Bufonidae), Daniel E. Naya, José A. Langone, Rafael O. De Sá Jan 2004

Características Histológicas De La Tumefacción Frontal De Melanophryniscus (Amphibia: Anura: Bufonidae), Daniel E. Naya, José A. Langone, Rafael O. De Sá

Biology Faculty Publications

Se analizó la histología tegumentaria de la región cefálica en seis especies del género Melanophryniscus, pertenecientes a los grupos stelzneri (4) y tumifrons (2), con el objetivo de esclarecer la estructura de la tumefacción frontal y su posible función. Las características generales de la histología del grupo stelzneri, coincidieron con las descripciones tegumentarias existentes para el género. Sin embargo, la región cefálica frontal en las dos especies del grupo tumifrons muestran cambios histológicos correlacionados a la tumefacción frontal. Esta estructura presenta una organización similar a otras macroglándulas presentes en la dermis de anuros (e.g., parotoides, paracnémicas), y por tanto se …


Distribución Geográfica De La Fauna De Anfibios Del Uruguay, Diego Nuñez, Raúl Maneyro, José A. Langone, Rafael O. De Sá Jan 2004

Distribución Geográfica De La Fauna De Anfibios Del Uruguay, Diego Nuñez, Raúl Maneyro, José A. Langone, Rafael O. De Sá

Biology Faculty Publications

Datos precises sobre la distribución geográfica de los organismos de una región son necesarios y prerrequisito para entender las interrelaciones ecológicas entre las comunidades biológicas. Esta información también contribuye a entender el componente histórico de la región posibilitando la determinación de centros de origen y el establecimiento de patrones de diversidad (Ron, 2000), así mismo posibilita realizar inferencias acerca de los mecanismos de especiación en los diferentes grupos zoológicos (Bridarolli & Di Tada, 1994).

La distribución geográfica de los anfibios en Uruguay ha sido parcialmente reportada (Achaval & Olmos, 1997; Langone, 1995; Maneyro et al, 1995; Maneyro & Langone, 2001). …


The Effects Of Environmentally Relevant Doses Of Perchlorate (Clo4-) On Rana Pipiens Metamorphosis And Development, Andrea N. Golli Jan 2004

The Effects Of Environmentally Relevant Doses Of Perchlorate (Clo4-) On Rana Pipiens Metamorphosis And Development, Andrea N. Golli

UNLV Theses, Dissertations, Professional Papers, and Capstones

The purpose of this study was to assess the effects of environmentally relevant concentrations of perchlorate on the development and growth of Rana pipiens. Ammonium perchlorate is a rocket fuel oxidizer that is known to interfere with the function of the thyroid gland and some of the highest United States surface water concentration exists in the Las Vegas Wash, NV. Perchlorate not only blocks the body’s ability to incorporate iodine into T3 and T4 hormones through the sodium iodine symporter system, but also depletes the thyroid glands’ internal stores of iodine. Many of the steps that regulate metamorphosis in amphibians …


On The Engimatic Distribution Of The Honduran Endemic Leptodactylus Silvanimbus (Amphibia: Anura: Leptodactylidae), W. R. Heyer, Rafael O. De Sá, Sarah Muller Jan 2004

On The Engimatic Distribution Of The Honduran Endemic Leptodactylus Silvanimbus (Amphibia: Anura: Leptodactylidae), W. R. Heyer, Rafael O. De Sá, Sarah Muller

Biology Faculty Publications

Most species of the frog genus Leptodactylus occur in South America, and all authors who have treated the zoogeography of the genus have concluded that it originated somewhere in South America (e.g., Savage 1982). Savage (1982, 518) summarized the historical herpetofaunal units of the Neotropics as follows: "All evidence points to an ancient contiguity and essential similarity of a generalized tropical herpetofauna that ranged over tropical North, Middle, and most of South America in Cretaceous-Paleocene times. Descendents of this fauna are represented today by the South and Middle American tracks (Elements). To the north of this fauna ranged a subtropical-temperate …


On The Cranial Anatomy Of The Polycotylid Plesiosaurs, Including New Material Of Polycotylus Latipinnis, Cope, From Alabama, F. Robin O’Keefe Jan 2004

On The Cranial Anatomy Of The Polycotylid Plesiosaurs, Including New Material Of Polycotylus Latipinnis, Cope, From Alabama, F. Robin O’Keefe

Biological Sciences Faculty Research

The cranial anatomy of plesiosaurs in the family Polycotylidae (Reptilia: Sauropterygia) has received renewed attention recently because various skull characters are thought to indicate plesiosauroid, rather than pliosauroid, affinities for this family. New data on the cranial anatomy of polycotylid plesiosaurs is presented, and is shown to compare closely to the structure of cryptocleidoid plesiosaurs. The morphology of known polycotylid taxa is reported and discussed, and a preliminary phylogenetic analysis is used to establish ingroup relationships of the Cryptocleidoidea. This study also presents new material referable to Polycotylus latipinnis from the Mooreville Chalk Formation of Alabama. This skeleton is largely …


The Effect Of Size-Limited Brood Capacity On Brood Size In A Freshwater Bivalve, Mark Beekey Jan 2004

The Effect Of Size-Limited Brood Capacity On Brood Size In A Freshwater Bivalve, Mark Beekey

Biology Faculty Publications

Size limited brood capacity is common among species with hard exoskeletons or shells. In these species, brood size is limited by the physical capacity to hold offspring. Here we present evidence that brood size is limited by physical constraints in Sphaerium striatinum , a small brooding bivalve. Sphaerium striatinum is a sequential brooder and produces offspring throughout the year. Offspring are brooded in marsupial sacs located on the inner demibranch. In an unconstrained brooder one would predict that brood size would increase as a function of adult length cubed, a volumetric relationship. In S. striatinum, brood size increases as less …


The Role Of Farm Dams As Refugia For Aquatic Invertebrates In A Salinised Landscape, South Western Australia, Jean-Michel Benier Jan 2004

The Role Of Farm Dams As Refugia For Aquatic Invertebrates In A Salinised Landscape, South Western Australia, Jean-Michel Benier

Theses: Doctorates and Masters

In a salinised landscape farm dams may represent the last truly freshwater surface resource, and therefore provide refuge habitats for the biota of wetlands affected by increasing salinity. One wetland threatened by increased salinity in south-west Western Australia is Lake Toolibin. It is listed as a Wetland of International Importance under the Ramsar Convention in recognition of its high conservation value, and remediation actions to halt (and possibly reverse) further increases in salinity are being undertaken at this wetland. Farm dams act as aquatic refugia if they convey resistance and/or resilience to the biotic communities of a disturbed habitat. This …


Record High Wolf, Canis Lupus, Pack Density, L. David Mech, Shawn Tracy Jan 2004

Record High Wolf, Canis Lupus, Pack Density, L. David Mech, Shawn Tracy

United States Geological Survey, Northern Prairie Wildlife Research Center: Publications

This report documents a year-around Wolf (Canis lupus) density of 18.2/100 km2 and a summer density of 30.8/100 km2, in a northeastern Minnesota Wolf pack. The previous record was a summer density of 14.1/100 km2, for a Wolf pack on Vancouver Island, British Columbia, Canada.


Metabolic Rate Models And The Substitutability Of Predator Populations, David R. Chalcraft, William J. Resetarits Jr. Jan 2004

Metabolic Rate Models And The Substitutability Of Predator Populations, David R. Chalcraft, William J. Resetarits Jr.

Biological Sciences Faculty Publications

1. Much of the debate surrounding the consequences of biodiversity loss centres around the issue of whether different species are functionally similar in their effects on ecological processes. In this study, we examined whether populations consisting of smaller, more abundant individuals are functionally similar to populations of the same species with larger, fewer individuals.
2. We manipulated the biomass and density of banded sunfish (Enneacanthus obesus) and measured their impact on populations of Southern leopard frog (Rana sphenocephala) larvae. We also evaluated the ability of models relating metabolic rate to body size to predict the relative …


The Translocation Of Golden Perch, Murray Cod And Australian Bass, Into And Within Western Australia, For The Purposes Of Recreational Stocking, Domestic Stocking And Commercial And Non-Commercial Aquaculture. A Discussion Paper., Department Of Fisheries Dec 2003

The Translocation Of Golden Perch, Murray Cod And Australian Bass, Into And Within Western Australia, For The Purposes Of Recreational Stocking, Domestic Stocking And Commercial And Non-Commercial Aquaculture. A Discussion Paper., Department Of Fisheries

Fisheries Management Papers

This discussion paper has been prepared to provide information to assist in assessment of the possible impact of the translocation of golden perch (Macquaria ambigua), Murray cod (Maccullochella peelii peelii) and Australian bass (Macquaria novemaculeata) into and within Western Australia, for the purposes of recreational stocking, domestic stocking, commercial and non-commercial aquaculture. In assessing the translocation of any aquatic species, economic and social benefits must be balanced with biological and environmental risks.


Body Mass Of Late Quaternary Mammals (Data Set), Felisa A. Smith, S. Kathleen Lyons, S.K. Morgan Ernest, Kate E. Jones, Kansas State University, Tamar Dayan, Pablo A. Marquet, James H. Brown, John P. Haskell Dec 2003

Body Mass Of Late Quaternary Mammals (Data Set), Felisa A. Smith, S. Kathleen Lyons, S.K. Morgan Ernest, Kate E. Jones, Kansas State University, Tamar Dayan, Pablo A. Marquet, James H. Brown, John P. Haskell

School of Biological Sciences: Faculty Publications

The purpose of this data set was to compile body mass information for all mammals on Earth so that we could investigate the patterns of body mass seen across geographic and taxonomic space and evolutionary time. We were interested in the heritability of body size across taxonomic groups (How conserved is body mass within a genus, family, and order?), in the overall pattern of body mass across continents (Do the moments and other descriptive statistics remain the same across geographic space?), and over evolutionary time (How quickly did body mass patterns iterate on the patterns seen today? Were the Pleistocene …


Left-Sided Directional Bias Of Cloacal Contacts During House Sparrow Copulations, Karen B. Nyland, Michael P. Lombardo, Patrick A. Thorpe Dec 2003

Left-Sided Directional Bias Of Cloacal Contacts During House Sparrow Copulations, Karen B. Nyland, Michael P. Lombardo, Patrick A. Thorpe

Peer Reviewed Publications

Most female birds have only a left ovary and associated oviduct. The entry to the oviduct is on the left side of the urodeum of the cloaca. This arrangement may favor males that mount females from the left during copulation if it results in sperm being placed closer to the opening of the oviduct. Therefore, we predicted a left-sided directional bias of cloacal contacts during House Sparrow (Passer domesticus) copulations. Cloacal contacts from the left outnumbered those from the right 74 to 25 (3:1) during 25 bouts of copulation at 11 House Sparrow nests. While this pattern suggests …


Breeding Distribution And Habitat Use Of Audubon's Oriole In The Lower Rio Grande Valley Of Texas, Steven Gerald Monk Dec 2003

Breeding Distribution And Habitat Use Of Audubon's Oriole In The Lower Rio Grande Valley Of Texas, Steven Gerald Monk

Theses and Dissertations - UTB/UTPA

Audubon's Oriole ( Icterus graduacauda ) was known historically throughout the Lower Rio Grande Valley (LRGV) of Texas, but its breeding range has now declined to mainly riparian habitat in Starr County. Habitat loss, degradation, and fragmentation, and brood parasitism by Bronzed Cowbirds ( Molothrus aeneus ) are likely causes of this decline. Habitat patches where Audubon's Orioles were present were larger, with a larger vertical range of canopy, greater vegetation volume, greater richness of bird and woody plant species, less local deforestation, and less local habitat fragmentation than where Audubon's Orioles were absent. Bronzed Cowbirds showed no numeric correlation …


The Role Of Facial Pits In The Thermoregulatory Behavior Of Pitvipers (Viperidae: Crotalinae) Behavioral, Ecological And Phylogenetic Perspectives, Aaron R. Krochmal Dec 2003

The Role Of Facial Pits In The Thermoregulatory Behavior Of Pitvipers (Viperidae: Crotalinae) Behavioral, Ecological And Phylogenetic Perspectives, Aaron R. Krochmal

All-Inclusive List of Electronic Theses and Dissertations

Pitvipers (Viperidae: Crotalinae) possess unique sensory organs, the facial pits, capable of sensing subtle fluctuations in thermal radiation. Prey acquisition has long been regarded as the sole function of the facial pits. However, the ability to sense thermal radiation could also direct thermoregulatory behavior by remotely sensing nearby surface temperatures. Using a series ofbehavioral arenas of varying spatial complexity and ecological relevance, I surveyed the ability of western diamondback rattlesnakes (Crotalus atrox) to direct successful thermoregulatory movements with either functional or disabled facial pits. I found that western diamondback rattlesnakes could base thermoregulatory decisions on thermal radiation cues when their …


Inventory Of The Land Conservation Values Of The Houtman Abrolhos Islands., Department Of Fisheries. Western Australia Oct 2003

Inventory Of The Land Conservation Values Of The Houtman Abrolhos Islands., Department Of Fisheries. Western Australia

Fisheries Management Papers

There is growing pressure for increased development on the Houtman Abrolhos Islands (Abrolhos Islands). Much work on the natural, historical and cultural values of the islands has been undertaken. This document is a review of this work, which provides an overview of the conservation values of the islands, and should prove useful in considering the selection, design and evaluation of proposed developments at the Abrolhos Islands. Based on existing information, the purpose of the Review of the Land Conservation Values of the Houtman Abrolhos Islands is to: • identify and map areas of conservation value (natural, historical and cultural); and …


Effects Of Management Practices On Grassland Birds: Greater Prairie-Chicken, W. D. Svedarsky, J. E. Toepfer, R. L. Westemeier, R. J. Robel Sep 2003

Effects Of Management Practices On Grassland Birds: Greater Prairie-Chicken, W. D. Svedarsky, J. E. Toepfer, R. L. Westemeier, R. J. Robel

United States Geological Survey: Effects of Management Practices on Grassland Birds

Information on the habitat requirements and effects of habitat management on grassland birds were summarized from information in more than 5,500 published and unpublished papers. A range map is provided to indicate the breeding distribution of Greater Prairie-Chicken in the United States and southern Canada. Although birds frequently are observed outside the breeding range indicated, the maps are intended to show areas where managers might concentrate their attention. It may be ineffectual to manage habitat at a site for a species that rarely occurs in an area. The species account begins with a brief capsule statement, which provides the fundamental …


Draft Plan Of Management For The Proposed Point Quobba Fish Habitat Protection Area., Department Of Fisheries Aug 2003

Draft Plan Of Management For The Proposed Point Quobba Fish Habitat Protection Area., Department Of Fisheries

Fisheries Management Papers

Point Quobba is a popular site for locals and tourists for beach activities, fishing and snorkelling, and as a place for children to learn to swim and gain an awareness of the marine environment. The marine life and habitats of the area are of considerable scientific and recreational interest and are highly valued in the local community. However, they are at risk from their high level of use and from conflict between users due to their proximity to popular tourism, boat ramp, camping and settlement areas on-shore.


Fisheries Occasional Publication No. 8 - Department Of Fisheries Stakeholder Survey 2002, Tara Baharthah, Neil R. Sumner Jul 2003

Fisheries Occasional Publication No. 8 - Department Of Fisheries Stakeholder Survey 2002, Tara Baharthah, Neil R. Sumner

Fisheries Occasional Publications

A telephone survey of Department of Fisheries' stakeholders was conducted in November 2002 in order to evaluate their perception of the Department's management of commercial and recreational fishing, pearling and aquaculture, and fish and fish habitat protection. The survey also assessed satisfaction with the level of service provided to stakeholders and their involvement in the decision making process.

The sample comprised of 149 interviews - 40 representing the commercial fishing sector, 40 representing the recreational fishing sector, 40 representing fish and fish habitat protection, and 29 representing aquaculture and pearling.

In general, the stakeholders gave positive responses regarding the Department …


Preliminary Report On The Osteology And Relationships Of A New Aberrant Cryptocleidoid Plesiosaur From The Sundance Formation, Wyoming, F. Robin O’Keefe, William Wahl Jr. Jul 2003

Preliminary Report On The Osteology And Relationships Of A New Aberrant Cryptocleidoid Plesiosaur From The Sundance Formation, Wyoming, F. Robin O’Keefe, William Wahl Jr.

Biological Sciences Faculty Research

The cryptocleidoid plesiosaur Tatenectes laramiensis, new genus, is described from the Redwater Shale Member of the Sundance Formation, Narrona County, Wyoming. The holotype of this species was a partial skeleton that has since been lost. A neotype is designated that preserves the same elements present in the holotype. A second specimen is referred to the taxon, and this specimen includes cranial material. The preserved cranial elements are the left squamosal, a partial right frontal, several isolated teeth, the parasphenoid, and large portions of the left and right pterygoids. The skull shares many traits with that of Kimmerosaurus, a cryptocleidoid plesiosaur …


Geographic Variation In The Morphology Of Crotalus Horridus (Serpentes: Viperidae), John Robert Allsteadt Jul 2003

Geographic Variation In The Morphology Of Crotalus Horridus (Serpentes: Viperidae), John Robert Allsteadt

Biological Sciences Theses & Dissertations

The Timber Rattlesnake (Crotalus horridus) occurs in discontinuous populations throughout the eastern and central United States. The species exhibits high levels of polymorphism in morphological traits, especially in coloration and pattern. Previous studies recognized either distinct northern and southern subspecies or three regional morphs (northern, southern, and western), but conflicting data sets and limited geographic sampling of previous studies have left the relationships among those regional variants unclear. In this study, univariate and multivariate statistics, together with a geographic information system, were used to analyze geographic variation in 36 morphological characters recorded from 2,420 specimens of C. horridus …


Fisheries Research Contract Report No. 2 - Towards An Assessment Of Natural And Human Use Impacts On The Marine Environment Of The Abrolhos Islands (Phase 1 : Data Consolidation And Scoping - Final Report For Frdc Project 2000/1 66), C. F. Chubb, K. Nardi Jul 2003

Fisheries Research Contract Report No. 2 - Towards An Assessment Of Natural And Human Use Impacts On The Marine Environment Of The Abrolhos Islands (Phase 1 : Data Consolidation And Scoping - Final Report For Frdc Project 2000/1 66), C. F. Chubb, K. Nardi

Fisheries Research Contract Reports

This project has drawn together existing research data relating to natural and human impacts on the Abrolhos Islands marine habitats. It has surveyed current uses of these habitats and placed anthropogenic impacts within the context of natural perturbations. Through public forum presentation and debate, this work has allowed real issues, not perceptions, to surface and be addressed properly. This was achieved by defining a strategic programme of research through a scientific workshop process involving all community stakeholders. A two volume Fisheries Research Report (WA) summarizes current knowledge and details the workshop proceedings and strategic research plan.


Mechanical Properties Of The Integument Of The Common Gartersnake, Thamnophis Sirtalis (Serpentes: Colubridae), Gabriel Rivera Jul 2003

Mechanical Properties Of The Integument Of The Common Gartersnake, Thamnophis Sirtalis (Serpentes: Colubridae), Gabriel Rivera

Biological Sciences Theses & Dissertations

The evolution of the ophidian feeding mechanism has involved substantial morphological restructuring associated with the ability to ingest relatively large prey. Previous studies examining the morphological consequences of macrophagy have concentrated on modifications of the skull and cephalic musculature. Although it is evident that macrophagy requires highly compliant skin, the mechanical properties of the ophidian integument have received limited attention, particularly in the context of feeding. I examined mechanical properties of skin along the body axis in male Thamnophis sirtalis (Colubridae). From each of 11 specimens, I examined nine circumferential strips of skin, each spanning 10 ventral scales, spaced at …


Reconstructing Cetacean Brain Evolution Using Computed Tomography, Lori Marino, Mark D. Uhen, Nicholas D. Pyenson, Bruno Frohlich May 2003

Reconstructing Cetacean Brain Evolution Using Computed Tomography, Lori Marino, Mark D. Uhen, Nicholas D. Pyenson, Bruno Frohlich

Veterinary Science and Medicine Collection

Until recently, there have been relatively few studies of brain mass and morphology in fossil cetaceans (dolphins, whales, and porpoises) because of difficulty accessing the matrix that fills the endocranial cavity of fossil cetacean skulls. As a result, our knowledge about cetacean brain evolution has been quite limited. By applying the noninvasive technique of computed tomography (CT) to visualize, measure, and reconstruct the endocranial morphology of fossil cetacean skulls, we can gain vastly more information at an unprecedented rate about cetacean brain evolution. Here, we discuss our method and demonstrate it with several examples from our fossil cetacean database. This …


Breeding Bird Communities Of Major Mainland Rivers Of Southeastern Alaska, Jim A. Johnson May 2003

Breeding Bird Communities Of Major Mainland Rivers Of Southeastern Alaska, Jim A. Johnson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Because of the scarcity of information for bird communities at the major mainland rivers of southeastern Alaska, the main objective of this study was to provide baseline information including distribution, status, and habitat associations of breeding birds.

I conducted a meta-analysis of all known reports (including the current study) conducted at major mainland rivers during the breeding season. I described bird species composition, distribution, abundance estimates, status, habitat associations, and guild membership for all birds recorded at 11 major mainland rivers. Based on incidental observations, 170 species were recorded by all studies. Of these, 134 species were known or suspected …