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Anatomy And Physiology Of Giant Neurons In The Antenniform Leg Of The Amblypygid Phrynus Marginemaculatus, A. J. Spence, Eileen Hebets Jan 2006

Anatomy And Physiology Of Giant Neurons In The Antenniform Leg Of The Amblypygid Phrynus Marginemaculatus, A. J. Spence, Eileen Hebets

Eileen Hebets Publications

Amblypygids have modified front legs that are not used for locomotion, but rather to probe the environment in the manner of antennae. These elongate, motile sense organs are referred to as antenniform legs. We have found remarkable replication in structure and function of giant neurons in the antenniform leg of the amblypygid Phrynus marginemaculatus C.L. Koch 1841 when compared with other amblypygids. These neurons have such large diameter axons (several μm) that their action potentials can be recorded outside the cuticle. Their cell bodies are found in the periphery, in the distal-most segments of the antenniform leg, centimeters away from …


Regional Seismic Song Differences In Sky Island Populations Of The Jumping Spider Harbonattus Pugillis Griswold (Araneae, Salticidae), Damian O. Elias, Eileen Hebets, Ronald R. Hoy, Wayne P. Maddison, Andrew C. Mason Jan 2006

Regional Seismic Song Differences In Sky Island Populations Of The Jumping Spider Harbonattus Pugillis Griswold (Araneae, Salticidae), Damian O. Elias, Eileen Hebets, Ronald R. Hoy, Wayne P. Maddison, Andrew C. Mason

Eileen Hebets Publications

Jumping spiders have long been used as model organisms to study visual communication. However, recent studies documenting the presence of intricate multicomponent seismic songs during courtship displays suggest an important role of seismic communication as well. Given the relatively recent focus on seismic communication, the extent to which seismic songs vary among jumping spider species or even among populations remains poorly understood. Here, we use the extensively studied Habronattus pugillis Griswold 1987 complex to explore putative seismic song diversity among males from isolated populations. H. pugillis populations have been studied extensively because of the tremendous diversification of male visual secondary …


Hyla Squirella (Squirrel Treefrog): Refugia., Louis A. Somma, David Serrano Jan 2006

Hyla Squirella (Squirrel Treefrog): Refugia., Louis A. Somma, David Serrano

Papers in Herpetology

HYLA SQUiREUA (Squirrel Treefrog). REFUGIA. Entomologists commonly use trap-nests to monitor cavity-nesting Hymenoptera. These trap-nests consist of 5 x 10 cm pine timber cut into 12-cm lengths. Five lengths are then stacked and strapped together. Each pIece of timber is predrilled in each side to have either a 3.2, 4.8, 6.4, 7.9, or 12.7 Iiundiameterhole, 8 cmindepth. Thus, each trap-nest consisted of five pieces of wood containing 2 holes of each diameter. They are suspended with wire from tree trunks and branches. We set these wooden traps (N = 10) at Devil's Millhopper Geological State Park, Gainesville, Alachua Co., Florida, …


Parelaphostrongylus Odocoilei In Columbia Black-Tailed Deer From Oregon, Jack A. Mortenson, Arthur Abrams, Benjamin M. Rosenthal, Detiger Dunams, Eric P. Hoberg, Robert J. Bildfell, Richard L. Green Jan 2006

Parelaphostrongylus Odocoilei In Columbia Black-Tailed Deer From Oregon, Jack A. Mortenson, Arthur Abrams, Benjamin M. Rosenthal, Detiger Dunams, Eric P. Hoberg, Robert J. Bildfell, Richard L. Green

Harold W. Manter Laboratory of Parasitology: Faculty Publications

Documenting the occurrence of Parelaphostrongylus odocoilei has historically relied on the morphological examination of adult worms collected from the skeletal muscle of definitive hosts, including deer. Recent advances in the knowledge of protostrongylid genetic sequences now permit larvae to be identified. Dorsal-spined larvae (DSLs) collected in 2003–2004 from the lung and feces of six Columbian black-tailed deer (Odocoileus hemionus columbianus) from Oregon were characterized genetically. The sequences from unknown DSLs were compared to those from morphologically validated adults and larvae of P. odocoilei at both the second internal transcribed spacer (ITS-2) of ribosomal DNA and the mitochondrial cytochrome …


Our Places To Tell Stories: Making Connections With Our Audiences, Public Lands Institute Jan 2006

Our Places To Tell Stories: Making Connections With Our Audiences, Public Lands Institute

Our Places to Tell Stories

The idea for an annual Our Places Tell Stories conference was prompted by discussions that took place within a unique partnership of federal, state, university, and public organizations in southern Nevada. Members identified the need to share and learn from successful educational and interpretive strategies. Our increasingly urban surroundings and rapidly changing populations hinder personal connections between people and their natural environment. However, the right tools and techniques will help us inspire children and adults to understand, value, and take care of our shared natural places.

This first conference supports professionals in creating and evaluating effective educational programs and interpretive …


Oliver Ranch Science School Complex & Wild Horse And Burro Facility: Quarterly Progress Report, Period Ending March 31, 2006, Margaret N. Rees Jan 2006

Oliver Ranch Science School Complex & Wild Horse And Burro Facility: Quarterly Progress Report, Period Ending March 31, 2006, Margaret N. Rees

Oliver Ranch Project

Executive Summary

Activity highlights during the third quarter of Year Two include the following actions toward task agreement deliverables:

  • Agenda and minutes prepared and distributed for Core Group meetings on January 17 and March 21, 2006.
  • Cultural curriculum 100% completed
  • Night Sky curriculum 100% completed.
  • Green Building curriculum 75% completed.
  • Native American Correlations 75% completed.
  • Teacher piloting workshops held on February 23, March 18, and March 25, 2006 at Spring Mountain Ranch State Park and the Oliver Ranch site.
  • RRDLC newsletter completed.
  • Website content, navigation, and graphics updated and improved.


Red Rock Desert Learning Center Community Outreach Activities Plan, Red Rock Desert Learning Center Jan 2006

Red Rock Desert Learning Center Community Outreach Activities Plan, Red Rock Desert Learning Center

Oliver Ranch Project

The Red Rock Desert Learning Center is being designed to teach participants about the natural world through inquiry-based experiential and interdisciplinary methods in a residential outdoor setting in Red Rock Canyon National Conservation Area. The intent is for students, teachers, and researchers to gain an appreciation of desert ecosystems and to begin to apply and connect their knowledge to world ecological systems. The campus will incorporate many “green building” systems in its design and operation, and those systems will be an active part of the school’s curriculum.


Red Rock Desert Learning Center & Wild Horse And Burro Facility: Fact Sheet, Red Rock Desert Learning Center Jan 2006

Red Rock Desert Learning Center & Wild Horse And Burro Facility: Fact Sheet, Red Rock Desert Learning Center

Oliver Ranch Project

Overview and questions about Red Rock Canyon Desert Learning Center and Wild Horse and Burro Facility.


Red Rock Desert Learning Center & Wild Horse And Burro Facility: Frequently Asked Questions, Red Rock Desert Learning Center Jan 2006

Red Rock Desert Learning Center & Wild Horse And Burro Facility: Frequently Asked Questions, Red Rock Desert Learning Center

Oliver Ranch Project

The mission of the Red Rock Desert Learning Center is to instill stewardship and respect by increasing knowledge and understanding of the Mojave Desert ecosystems and cultures through a unique experiential discovery program.


Red Rock Desert Learning Center & Wild Horse And Burro Facility: Newsletter, Red Rock Desert Learning Center Jan 2006

Red Rock Desert Learning Center & Wild Horse And Burro Facility: Newsletter, Red Rock Desert Learning Center

Oliver Ranch Project

The mission of the Red Rock Desert Learning Center is to instill stewardship and respect by increasing knowledge and understanding of the Mojave Desert ecosystems
and cultures through a unique experiential discovery program.


Leptodactylus Fragilis (Brocchi): White-Lipped Thin-Toed Frog, Miriam M. Heyer, W. Ronald Heyer, Rafael O. De Sá Jan 2006

Leptodactylus Fragilis (Brocchi): White-Lipped Thin-Toed Frog, Miriam M. Heyer, W. Ronald Heyer, Rafael O. De Sá

Biology Faculty Publications

Adult Leptodactylus fragilis are small. The head is longer than wide, and the hind limbs are moderately long (Table 1; Heyer and Thompson 2000 provided definitions of adult size and leg length categories for Leptodactylus). Male vocal sacs are laterally expanded and range from lightly gray speckled to darkly pigmented. Male snout is spatulate; female snout is rounded. Male forearms are not hypertrophied and males lack asperities on the thumbs and chest. The dorsum is spotted or blotched with dark markings, which are often chevron-shaped and sometimes confluent. The supratympanic fold is dark brown. A pair of dorsolateral folds …


Neoteny And The Plesiomorphic Condition Of The Plesiosaur Basicranium, F. Robin O’Keefe Jan 2006

Neoteny And The Plesiomorphic Condition Of The Plesiosaur Basicranium, F. Robin O’Keefe

Biological Sciences Faculty Research

The purpose of this paper is to describe the condition of the braincase in stratigraphically early and morphologically primitive plesiosaurs. Information on the braincase of plesiomorphic taxa is important because it establishes the polarity of characters occurring in more derived plesiosaurs. This paper begins with a short review of braincase anatomy in stem-group sauropterygians. Data on braincase morphology of the plesiomorphic plesiosaur genera Thalassiodracon and Eurycleidus are then presented and interpreted via comparison with other plesiosaurs, stemgroup sauropterygians, and stem diapsids (Araeoscelis). Early diapsids are relevant because plesiosaur skulls more closely resemble early diapsids than stem-group sauropterygians in several key …


Moral Implications Of Darwinian Evolution For Human Reference Based In Christian Ethics: A Critical Analysis And Response To The "Moral Individualism" Of James Rachels, Stephen Bauer Jan 2006

Moral Implications Of Darwinian Evolution For Human Reference Based In Christian Ethics: A Critical Analysis And Response To The "Moral Individualism" Of James Rachels, Stephen Bauer

Dissertations

The topic. This dissertation explores and analyzes James Rachels's efforts to prove that Darwin's theory of evolution has catastrophic implications for traditional Christian ethics.

The purpose. The purpose of this dissertation is to explore and evaluate the question of whether or not protology affects ethics. In particular, I propose to distill the implications of evolutionary views of origins for ethics, mainly in reference to the issue of human preference over nature in ethics. I propose to disclose Rachels's understanding of the implications of evolution on human preference (greater protections for human beings over non-humans) in ethics (such as biblical-Christian ethics), …


A Switch From Polyandry To Serial Monogamy: Results From A Three Year Tagging Study Of Horseshoe Crabs In Long Island Sound, Jennifer Mattei Ph.D., Paul Goodell, Christine Depierro, Meghann Burke Jan 2006

A Switch From Polyandry To Serial Monogamy: Results From A Three Year Tagging Study Of Horseshoe Crabs In Long Island Sound, Jennifer Mattei Ph.D., Paul Goodell, Christine Depierro, Meghann Burke

Biology Faculty Publications

Part of an ongoing population study of the North American Horseshoe Crab, Limulus polyphemus, in Long Island Sound was completed during the 2003 – 2005 spawning seasons at Milford Point, in Milford, CT. Horseshoe crabs range more widely throughout Long Island Sound than expected and exhibit weak site fidelity. Animals originally tagged in Milford were found as far west as Stamford and as far east as Clinton, CT. during the 3 year study. Out of 522 female horseshoe crabs tagged in 2004 only 4 came back to spawn again at Milford Pt. in 2005. The sex ratios of tagged and …


The Influence Of Seabird-Derived Nutrients On Island Ecosystems In The Oligotrophic Marine Waters Of South-Western Australia, Sofie A. Harrison Jan 2006

The Influence Of Seabird-Derived Nutrients On Island Ecosystems In The Oligotrophic Marine Waters Of South-Western Australia, Sofie A. Harrison

Theses: Doctorates and Masters

Nutrient inputs from productive marine environments have been shown to directly and indirectly subsidise primary producers and consumers in terrestrial ecosystems (e.g. Polis and Hurd 1995; 1996; Anderson and Polis 1998; 1999). But does this theory hold true on islands surrounded by oligotrophic waters, which account for a significant proportion of the marine environment? The aim of the present study was to examine the applicability of the spatial subsidisation hypotheses proposed by Polis and his co-authors to an oligotrophic system in south-western region of Western Australia. These aims were achieved by comparing soil and plant nutrients, and the nitrogen stable …


The Ecology And Behaviour Of Varanus Mertensi (Reptilia: Varanidae), Phillip J. Mayes Jan 2006

The Ecology And Behaviour Of Varanus Mertensi (Reptilia: Varanidae), Phillip J. Mayes

Theses: Doctorates and Masters

This study examines numerous aspects of the ecology and behaviour of Merten's Water Monitor, Varanus mertensi (Reptilia: Varanidae) including; daily behaviour, diet, foraging behaviour, reproductive seasonality and daily and long-term movements. Findings from over two years of field study of V. mertensi found in waterbodies of both the Ord River Irrigation Scheme and surrounding East Kimberley/Victoria River Downs bioregion of Western Australia are presented. This study simultaneously broadens our understanding of the family Varanidae and provides insight into the life of a semi-aquatic faunal species found in waterbodies of the Ord River Irrigation Scheme.


Reintroduction Ecology Of Mala (Lagorchestes Hirsutus) And Merrnine (Lagostrophus Fasciatus) At Shark Bay, Western Australia, Blair Hardman Jan 2006

Reintroduction Ecology Of Mala (Lagorchestes Hirsutus) And Merrnine (Lagostrophus Fasciatus) At Shark Bay, Western Australia, Blair Hardman

Theses: Doctorates and Masters

The transfer of threatened animals from one location to another in order to benefit the species is a technique frequently used by animal conservation managers. However, very few of these relocations have experimentally assessed the relative merits and disadvantages of commonly used release techniques. Two species of hare-wallaby, mala (Lagorchestes hirsutus) and merrnine (Lagostrophus fasciatus), were reintroduced in August 2001 onto Peron Peninsula in Western Australia. These threatened species were reintroduced using two release strategies (soft versus hard release), and their subsequent movements and body condition were monitored using radio-telemetry and trapping.


Movement Patterns And Habitat Usage Of Shark Bay Dugongs, David K. Holley Jan 2006

Movement Patterns And Habitat Usage Of Shark Bay Dugongs, David K. Holley

Theses: Doctorates and Masters

In order to define small and large scale spatial and temporal individual movement patterns of dugongs (Dugong dugon) within the Shark Bay World Heritage Property (SBWHP) a total of 19 dugongs were fitted with remote location recording and transmitting devices. Combined locations from all units totalled over 10,000 locations. This spatial and temporal data was used to define movement patterns of dugongs within Shark Bay as well as areas of high use deemed to be indicative of foraging activity. Platform Transmitting Terminals (PTT?s) using the ARGOS location collection system tracked animals over large temporal scales with 4 animals tracked up …


An Examination Of Seasonal Growth And Survivorship Of Sigmodon Hispidus In Southeastern Virginia, Heather Alyssa Green Jan 2006

An Examination Of Seasonal Growth And Survivorship Of Sigmodon Hispidus In Southeastern Virginia, Heather Alyssa Green

Biological Sciences Theses & Dissertations

A reexamination of specific population dynamic aspects of Sigmodon hispidus, the hispid cotton rat, is necessary in order to gain additional knowledge and perspective on this species in its northernmost distribution on the east coast of the United States. Previous studies of Virginia cotton rats were based on data from necropsies, which do not allow for the determination of certain population characteristics, such as density, growth, and survival. General population trends and rates of growth and survival in males and females throughout the seasons in Virginia will also provide a basis for comparison with populations of cotton rats in …


The Dynamics Of Bay Anchovy In The Hudson River Estuary: Process-Oriented Studies And Long-Term Changes, Eric T. Schultz, Kamazima M. M. Lwiza, John R. Young, Kyle J. Hartman, R. C. Tipton Dec 2005

The Dynamics Of Bay Anchovy In The Hudson River Estuary: Process-Oriented Studies And Long-Term Changes, Eric T. Schultz, Kamazima M. M. Lwiza, John R. Young, Kyle J. Hartman, R. C. Tipton

EEB Articles

We review three areas of recent research on Hudson River bay anchovy. One focus has been the along-estuary movement of early life stages. A cohort analysis of samples collected in a spatiotemporally extensive monitoring program has confirmed that early-stage anchovy migrate up-estuary, at an estimated rate of 0.6 km/d. Complementary fine-scale field sampling was designed to clarify behaviors that effect the migration. This work found that early-stage anchovy can show preferences for depth and can conduct periodic vertical migration. To determine whether these behaviors were sufficient to produce up-estuary migration, larval flux and velocity were estimated. These estimates were consistent …


Lake Mead National Recreation Area Sensitive Wildlife Species Monitoring And Analysis: Quarterly Progress Report, Period Ending December 31, 2005, Margaret N. Rees Dec 2005

Lake Mead National Recreation Area Sensitive Wildlife Species Monitoring And Analysis: Quarterly Progress Report, Period Ending December 31, 2005, Margaret N. Rees

Wildlife Monitoring

  • Topsoil replacement monitored at Willow Beach Wastewater Rehabilitation Project
  • Desert tortoise surveys and monitoring conducted for Northshore Road reconstruction projects, and desert tortoise training provided to 9 construction contractors.
  • Field work associated with the project to remove desert tortoise radio transmitters from animals on Mormon Mesa completed.
  • Weekly data processing for Desert Bighorn Sheep monitoring associated with the Hoover Dam Bypass Project continued.
  • Fall field surveys for relict leopard frogs completed (11 sites surveyed); last of this year’s head-started animals released; RLFCT meeting held.
  • Work started on a digital database (GIS) of Peregrine falcon observations.
  • Monthly shorebird surveys conducted (22 …


Assessment Of Anti-Poaching Effort In Ruaha National Park, Tanzania, C. L. Nahonyo Dec 2005

Assessment Of Anti-Poaching Effort In Ruaha National Park, Tanzania, C. L. Nahonyo

Tanzania Journal of Science

Anti-poaching effort in Ruaha National Park for the period between January 1996 to June 1999 was evaluated in terms of strength, frequency and duration of patrols, area covered and success of patrols. It was found that the park spent 72.4 US$ km-2 year-1 on law enforcement. There were 72 rangers each required to patrol on the average 143 km2. A total of 1,255 patrols were conducted; patrols ranged from 14 to 43 trips per month and each lasted between 1 to 25 days and most were foot and vehicle patrols. Patrol units had 2 to 11 rangers while the average …


Results Of The Alcoa Foundation-Suriname Expeditions. Xiv. Mammals Of Brownsberg Nature Park, Suriname, Burton K. Lim, Mark D. Engstrom, Hugh H. Genoways, François M. Catzeflis, Kelly A. Fitzgerald, Sandra L. Peters, Marijem Djosetro, Sandra Brandon, Sutrisno Mitro Dec 2005

Results Of The Alcoa Foundation-Suriname Expeditions. Xiv. Mammals Of Brownsberg Nature Park, Suriname, Burton K. Lim, Mark D. Engstrom, Hugh H. Genoways, François M. Catzeflis, Kelly A. Fitzgerald, Sandra L. Peters, Marijem Djosetro, Sandra Brandon, Sutrisno Mitro

University of Nebraska State Museum: Mammalogy Papers

An inventory of mammals in the vicinity of Brownsberg Nature Park, Suriname, incorporated a number of different sampling methods including examining museum voucher specimens, an animal-rescue operation, transect surveys, camera photo-traps, and interviews with local inhabitants. We document a total of 125 mammal species present in the Park. These include ten opossums, five pilosans, four armadillos, 58 bats, eight monkeys, 13 carnivores, one tapir, four artiodactyls, and 22 rodents. Nine of these species are reported for the first time from Suriname: one mouse opossum (Marmosops pinheiroi); one naked-backed moustached bat (Pteronotus gymnonotus); four fruit-eating bats ( …


Fisheries Research Report No. 151 - Biology And Stock Assessment Of The Thickskin (Sandbar) Shark, Carcharhinus Plumbeus, In Western Australia And Further Refinement Of The Dusky Shark, Carcharhinus Obscurus, Stock Assessment., Rory Mcauley, R Lenanton, J. Chidlow, R. Allison, E. Heist Dec 2005

Fisheries Research Report No. 151 - Biology And Stock Assessment Of The Thickskin (Sandbar) Shark, Carcharhinus Plumbeus, In Western Australia And Further Refinement Of The Dusky Shark, Carcharhinus Obscurus, Stock Assessment., Rory Mcauley, R Lenanton, J. Chidlow, R. Allison, E. Heist

Fisheries Research Reports

Final FRDC Report - Project 2000/134

The purpose of this project was to collect the biological and fishery information necessary to conduct a stock assessment of the sandbar (known locally as ‘thickskin’) shark, Carcharhinus plumbeus and to improve and update the existing stock assessment for the dusky shark, Carcharhinus obscurus. Results from this project have already been used by the Western Australian Department of Fisheries to determine appropriate management arrangements for the State’s shark fisheries to ensure the sustainable exploitation of these species. Results have also assisted the WA target-shark fisheries in conducting Ecologically Sustainable Development (ESD) assessment in order …


Comparing Immune Responses Of Juvenile And Adult Northern Fence Lizards, Sceloporus Undulatus, Zaïna Sandrine Kabange Dec 2005

Comparing Immune Responses Of Juvenile And Adult Northern Fence Lizards, Sceloporus Undulatus, Zaïna Sandrine Kabange

All-Inclusive List of Electronic Theses and Dissertations

Sex steroid hormones affect behavior and morphological traits important in sexual selection. Steroid hormones also play a role in the development and functioning of immune system components. The immunocompetence handicap hypothesis (Folstad and Karter, 1992) proposes that tradeoffs, mediated by plasma levels of testosterone, exist between the immune system and elaboration of secondary sexual traits. Endocrine-immune interactions are well documented in birds and mammals, and steroid hormones can be immunoenhancing or immunosuppressive. Relatively little work has examined the ontogeny of immune function, and the interactions between steroid hormones and the immune system in reptiles. The first experiment addressed the question …


Cortical Complexity In Cetacean Brains, Patrick R. Hof, Rebecca Chanis, Lori Marino Nov 2005

Cortical Complexity In Cetacean Brains, Patrick R. Hof, Rebecca Chanis, Lori Marino

Veterinary Science and Medicine Collection

Cetaceans (dolphins, whales, and porpoises) have a long, dramatically divergent evolutionary history compared with terrestrial mammals. Throughout their 55–60 million years of evolution, cetaceans acquired a compelling set of characteristics that include echolocation ability (in odontocetes), complex auditory and communicative capacities, and complex social organization. Moreover, although cetaceans have not shared a common ancestor with primates for over 90 million years, they possess a set of cognitive attributes that are strikingly convergent with those of many primates, including great apes and humans. In contrast, cetaceans have evolved a highly unusual combination of neurobiological features different from that of primates. As …


Fisheries Occasional Publication No. 29 - Western Rock Lobster Fishery Effects Of Fishing On The Ecosystem - Scientific Reference Group (Chairman's Report No. 3, February 2005), Department Of Fisheries, Western Australia Nov 2005

Fisheries Occasional Publication No. 29 - Western Rock Lobster Fishery Effects Of Fishing On The Ecosystem - Scientific Reference Group (Chairman's Report No. 3, February 2005), Department Of Fisheries, Western Australia

Fisheries Occasional Publications

The Western Rock Lobster Effects of Fishing on the Ecosystem Scientific Reference Group (the SRG) was convened jointly by the Department of Fisheries and the WA Fishing Industry Council (WAFIC). The SRG met on Tuesday 1 February 2005 at the Fremantle Sailing Club, and this document is the official report from that meeting.


Development Of Biological Reference Conditions Of Wadeable Streams In The Major Ecoregions And Subecoregions Of Georgia, Duncan L. Hughes Nov 2005

Development Of Biological Reference Conditions Of Wadeable Streams In The Major Ecoregions And Subecoregions Of Georgia, Duncan L. Hughes

Theses and Dissertations

One bioassessment tool available to resource managers to indicate NPS impairment of wadeable streams and rivers are multi-metric invertebrate indices. Such indices are assembled from metrics in broad categories that represent different aspects of community structure and function (e.g. richness, composition, tolerance/intolerance, feeding group, and habit). Indices must incorporate suites of metrics that are ecologically relevant, quantifiable, non-redundant, and that best individually discriminate between reference sites and impaired sites. More than 240 wadeable streams in Georgia were sampled during the September thru February index period using RBP protocols during three successive sample seasons (1999-2003). Ecoregional reference (minimally impaired) sites, as …


Ecological Costs And Benefits Of Defenses In Nectar, Lynn S. Adler, Rebecca E. Irwin Nov 2005

Ecological Costs And Benefits Of Defenses In Nectar, Lynn S. Adler, Rebecca E. Irwin

Dartmouth Scholarship

The nectar of many plant species contains defensive compounds that have been hypothesized to benefit plants through a variety of mechanisms. However, the relationship between nectar defenses and plant fitness has not been established for any species. We experimentally manipulated gelsemine, the principal alkaloid of Carolina jessamine (Gelsemium sempervirens), in nectar to determine its effect on pollinator visitation, nectar robber visitation, and male and female plant reproduction. We found that nectar robbers and most pollinators probed fewer flowers and spent less time per flower on plants with high compared to low nectar alkaloids. High alkaloids decreased the donation of fluorescent …


Impact Of Bythotrephes Invasion On Zooplankton Communities In Acid-Damaged And Recovered Lakes On The Boreal Shield, Angela L. Strecker, Shelley E. Arnott Oct 2005

Impact Of Bythotrephes Invasion On Zooplankton Communities In Acid-Damaged And Recovered Lakes On The Boreal Shield, Angela L. Strecker, Shelley E. Arnott

Environmental Science and Management Faculty Publications and Presentations

Invasive species introductions into freshwater ecosystems have had a multitude of effects on aquatic communities. Few studies, however, have directly compared the impact of an invader on communities with contrasting structure. Historically high levels and subsequent reductions of acid deposition have produced landscapes of lakes of varying acidity and zooplankton communitystructure. We conducted a 30-day enclosure experiment in Killarney Provincial Park, Ontario, Canada, to test the effects ofBythotrephes longimanus, an invasive invertebrate predator, on two contrasting zooplankton communities at different stages of recovery from acidification: recovered and acid damaged. Bythotrephes significantly decreased zooplankton biomass and abundance in both communities but …