Life Sciences Commons^™

Diel And Tidal Rhythms Of Emercenge Events Based On Acousitc Observations In A Shallow Estuary, Mei Sato

Electronic Theses and Dissertations

Field observations of emergence events by epibenthic animals were conducted with two Tracor Acoustic Profiling Systems (TAPS) in the Damariscotta River estuary, Maine, in fall 2005 and summer 2006. Spectral analysis revealed that periodic temporal variability of the acoustic signals was concentrated at four periods. One was the solar day (24 h) and the other three were lunar tidal periods of 25.82 (diurnal or Oi), 12.42 (semidiurnal or M2) and 6.21 h (half the semidiurnal period). The mysid Neomysis americana showed strong nocturnal migration patterns of water-column activity during its peak summer emergence season, regulated by the diel cycle. Toward …

Seasonal Territoriality In The Carolina Wren, Thryothorus Ludovicianus, To Visual And Vocal Stimuli., Mark Allen Dunaway

Electronic Theses and Dissertations

Carolina Wrens, Thryothorus ludovicianus, are permanent residents throughout their range. They form pair bonds at a young age, maintain these bonds for multiple years, and defend feeding/breeding territories year round. Male Carolina Wrens use songs in territorial defense and have been shown to countersing regularly to both neighbors and intruders. They use various song characteristics to determine the location of another bird and whether its territory has been invaded.

Wrens often approach playbacks silently in apparent searching behavior. In some cases, birds will investigate the playback but fail to countersing. I wanted to determine whether or not wrens would …

Modeling Large Whale Entanglement Injuries: An Experimental Analysis Of The Influence Of Tissue Compliance, Line Tension, And Draw-Length On Epidermal Abrasion Resistance, Jeremy Paul Winn

Electronic Theses and Dissertations

Two test systems were developed to evaluate the influence of draw-length and tissue compliance on entanglement-induced epidermal abrasion in humpback (Megaptera novaeangliae) and right whale (Eubalaena glacialis) tissue samples. Under straight pull abrasion tests an adult right whale fluke required 3.7 times the load and 15 times the draw-length of a right whale calf flipper to induce epidermal failure while a humpback fluke was intermediate between these extremes. Epidermal thickness did not appear to be the cause of this difference in abrasion resistance. Epidermal thickness averaged 8.0k0.2 mm for the calf flipper, 4.9k0.4 rnrn for the humpback fluke, and 5.1k0.1 …

Ecological Relationships Among Partial Harvesting, Vegetation, Snowshoe Hares, And Canada Lynx In Maine, Laura Robinson

Electronic Theses and Dissertations

Understanding the ecological factors affecting habitat use by the Canada lynx (Lynx canadensis) and its primary prey, the snowshoe hare (Lepus americanus), could help formulate conservation strategies for this carnivore, which is federally listed as threatened and occurs in only four regions of the U.S.A. I measured vegetation characteristics and snowshoe hare densities in 15 regenerating conifer clearcuts and 21 partially harvested stands in northern Maine during the leaf-off seasons, 2005 and 2006; and the leaf-on season, 2005. Regenerating clearcut stands had been harvested between 1974 and 1985 and were subsequently treated with an aerial application …

Physical And Behavioral Development Of Nursing Harbor Seal (Phoca Vitulina) Pups In Maine, John P. Skinner

Electronic Theses and Dissertations

Compared to other phocids seals, the maternal investment strategy of the small bodied female harbor seal (Phoca vitulina) is complex. Females are unable to fast for the entire duration of pup rearing and are therefore reliant on resources in the vicinity of the pupping aggregation to continue provisioning their pup by mid-lactation. At the same time, harbor seal pups are highly active during lactation which increases energetic costs to the female but also offers an opportunity for females to influence the behavioral development of her pup. To understand how females maximize their pup's survival it is important to …

The Effects Of Serotonin On The Courtship Behavior Of Drosophilia Melanogaster, Nicholas James Brandmeir

Electronic Theses and Dissertations

In Drosophila, the male courtship ritual is stereotyped and under the control of several genes including fruitless. In previous studies, it has been show that various fruitless alleles cause phenotypic abnormalities in the D. melanogaster courtship ritual. It is also known that there is a high level of co-expression of both the fruitless gene product and serotonin in specific neurons of the Drosophila CNS. This study examines the role of serotonin in the Drosophila male courtship ritual by using a mutant strain, Ddc^ts1,in which the production of serotonin is blocked above 30°C. In this study an increase in temperature caused …

Phenotypic Divergence Of Indigenous And Translocated Arctic Charr (Salvelinus Alpinus) Populations In Maine, Wendy K. Michaud

Electronic Theses and Dissertations

Selection on traits related to trophic ecology is recognized as an important contributing factor in adaptive divergence and speciation. For several freshwater fish species, including Arctic charr (Salvelinus alpinus), such selection is commonly reflected in relationships between diet, habitat use and phenotypic divergence. Trophic specializations that emerge have been extensively studied among sympatric forms, but much less is known of the extent of this type of divergence in allopatry. Trait differences among these forms are also thought to reflect thousands of years of evolution, making it difficult to examine root causes of such divergence in natural populations. Here, I address …

Molecular Population Genetics Of The Atlantic Sand Fiddler Crab, Uca Pugilator, Along The Atlantic Coast, David A. Weese

Electronic Theses and Dissertations

Author's abstract: The Atlantic sand fiddler crab, Uca pugilator, is an extremely abundant fiddler crab found along the eastern and Gulf coast of the United States. Fiddler crabs have a life cycle with an obligatory planktonic larval phase of 30-90 days, which might be expected to lead to widespread larval dispersal and consequent genetic homogeneity over considerable distances. However a large amount of morphological and behavioral variation is found between northern and southern populations along the eastern coast. This study was undertaken to determine the population genetic structure of U. pugilator and to determine whether these differences may have a …

Sexual Dimorphic Social Development And Female Intrasexual Chemical Signaling Of African Elephants (Loxodonta Africana), Jordana M. Meyer

Electronic Theses and Dissertations

Author's abstract: African elephants are a polygynous species in which males and females carry out dimorphic lifestyles. Males search and compete for reproductively active females, while females care for offspring and facilitate group cohesion. The objectives of this study was a) to compare the development of sexually dimorphic behaviors and developmental trends between young male and female wild African elephants and b) to determine the ability of captive female African elephants to discern between the follicular and luteal phase of conspecifics through trunk-tip contacts and the investigation of urine, and whether the reproductive phase of the receiver affected the response …

The Winter Ecology Of The Piping Plover (Charadrius Melodus) In Coastal Georgia, Brandon Lennon Noel

Electronic Theses and Dissertations

Author's abstract: The Piping Plover (Charadrius melodus) is a federally listed species with three distinct breeding populations, including Great Plains (threatened), Great Lakes (endangered), and Atlantic Coast (threatened), all of which winter along the Atlnatic and Gulf coasts of the United States. I studied the winter ecology of the Piping Plovers on Little St. Simons Island (LSSI), Georgia, from 2003-2006, with emphasis on the conservation significance of this site for the endangered Great Lakes population. During 2003-2004 and 2004-2005, LSSI supported up to 100 Piping Plovers during peak migration, and approximately 40 birds wintered at this site. All populations had …