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Full-Text Articles in Life Sciences

Forest Regeneration On The Osa Peninsula, Costa Rica, Manette E. Sandor Dec 2012

Forest Regeneration On The Osa Peninsula, Costa Rica, Manette E. Sandor

Master's Theses

Woody species diversity of secondary forest has the potential to converge with that found in old growth forest. This study is the first to examine multiple aspects of species and reproductive trait diversity, and their relationship to each other, across a successional chronosequence. Species richness and species diversity increases with increasing age of forest. Diaspore size and diversity as well as fruit size generally increased with increasing age of forest, but fruit size diversity did not. Abundance of animal-dispersed species increased whereas wind-dispersed species decreased in abundance over succession. Insect-pollinated individuals were most abundant overall. Diaspore diversity, pollination diversity, and …


Seasonal Food Habits Of Burrowing Owls (Athene Cunicularia) In Human-Altered Landscapes, Carie Marie Wingert Jun 2012

Seasonal Food Habits Of Burrowing Owls (Athene Cunicularia) In Human-Altered Landscapes, Carie Marie Wingert

Master's Theses

In 2004, I initiated a year-long study to investigate the food habits of burrowing owls (Athene cunicularia). Burrowing owls have been found in a variety of human-altered landscapes; however, little is known about burrowing owl food habits in urban landscapes. Burrowing owl food habits during the non-breeding season are also largely undocumented, despite increasing concern over the survival of overwintering burrowing owls. Differences in prey consumption between reproductive and non-reproductive owls during the breeding season have not yet been examined. I collected pellets over a 12 month period at four study sites affected by different levels of human …


An Approach For Use Of Dual Frequency Identification Sonar (Didson) To Quantify Behavioral Aspects Of Piscivory At Ecologically Relevant Time And Space Scales, Victoria E. Price May 2012

An Approach For Use Of Dual Frequency Identification Sonar (Didson) To Quantify Behavioral Aspects Of Piscivory At Ecologically Relevant Time And Space Scales, Victoria E. Price

Master's Theses

Predator-prey interactions of large vagile fishes are difficult to study in the ocean due to limitations in the space and time requirements for observations. Small-scale direct underwater observations by divers (<10m >radius) and large-scale hydroacoustic surveys (10s - 100s km2) are traditional approaches. However, large piscivorous predators identify and attack prey at the scale of meters to tens of meters. Dual- Frequency Identification Sonar, or DIDSON, is a high-resolution acoustic camera operating in the MHz range that provides detailed continuous video-like imaging of objects out to 30 m range. This technology can be used to observe predator-prey interactions at ecologically …


American Pika (Ochotona Princeps): Persistence And Activity Patterns In A Changing Climate, Cody P. Massing May 2012

American Pika (Ochotona Princeps): Persistence And Activity Patterns In A Changing Climate, Cody P. Massing

Master's Theses

An increasing amount of evidence suggests that as temperatures increase, montane animals are moving upward in elevation (IPCC 2007, Parmesan and Yohe 2003). As suitable habitats rise in elevation and then disappear altogether, these animals could be pushed to extinction. The American pika, Ochotona princeps, is a montane mammal that lives in western North America, usually at elevations above 1500 m (Smith and Weston 1990). Recent evidence suggests that pika population numbers are dropping in response to rising temperatures (Beever et al. 2010). The pika is a small herbivorous lagomorph, a relative of hares and rabbits. Its habitat is …