Browsing by Subject "behaviors"
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Item Reproductive strategies of Weddell seals in McMurdo Sound, Antarctica: relationship among vocalizations, behaviors, and social interactions(Texas A&M University, 2007-09-17) Rousseau, Ludivine BlandinePhocid seals (true seals, Order Carnivora, Family Phocidae) use a diverse array of breeding habitats and strategies, and produce many vocalizations. Therefore, phocids are well suited as subjects for study of reproductive strategies and the role of vocalizations in species mating at sea. However, the amount of information is still limited for aquatically breeding pinnipeds. Using underwater audio and video recordings of Weddell seals (Leptonychotes weddellii) interacting in McMurdo Sound, I compared the frequencies of vocalizations and behaviors of males and females during the mating season. I also investigated differences in these frequencies based on the social context. Finally, I identified patterns of vocalizations and behaviors to help determine the behavioral context of calls and used this information as a basis for considering the degree of ritualization in Weddell seal displays. Mews, growls, knocks, and trills were found to be almost exclusively male-specific. The territorial male produced chirps more often when another male was present in its territory; whereas, mews and growls were more frequent when one or more free-ranging females were present. Several vocal and behavioral padeparture of the territorial male into or from the breathing hole. In the context of an evolutionary-based model of communication, these findings suggest that low-frequency vocalizations and stereotyped displays produced by territorial males may have been favored by sexual selection: they may provide reliable information to females about the fitness of the signaler and influence their choice of mate. They may also help in limiting conflicts between the territorial male and females over access to the breathing hole.Item Spatial Ecology of and Public Attitudes toward Monk Parakeets Nesting on Electric Utility Structures in Dallas and Tarrant Counties, Texas(2014-07-29) Reed, Janet ElaineMonk parakeets (Myiopsitta monachus) were introduced to the United States (US) where they established naturalized populations. They often build their bulky twig nests on electric utility structures, causing economic damage. From May 2010?February 2013, we examined the spatial ecology of and public attitudes toward monk parakeets nesting on electric utility structures in Dallas and Tarrant counties, Texas, US. As nest sites, monk parakeets selected electric switchyards and substations constructed with multiple flat surfaces and acute-angles, within small fenced areas, with large canopy trees and taller anthropogenic structures within 100 m. Multi-scale analysis of urban land use-land cover (LULC) suggested the surrounding landscape had little impact on nest-site selection. Monk parakeets used canopy LULC more often than pavement, grass, buildings, or water. They traveled farthest from their nests during winter. Flock sizes were highly variable, yet largest during nonbreeding season. They foraged on a broad range of native vegetation and exhibited a diverse diet of flowers, fruits, acorns, grass blades, wild dry seeds, leaf buds, insect larvae, and commercial bird seed. We evaluated sociological variables as predictors of opposition to managing monk parakeets nesting on electric utility structures. Most survey participants were affluent, well-educated, older Caucasians who were unknowledgeable about, inexperienced with, and unsure about the impacts of monk parakeets. They indicated least opposition to nest removal and structural modification. When opposing, they would most likely do so socially and through petitions. Participants were influenced by their desire for monk parakeets to feed at their bird feeders or nest in their yard, people and groups important to them, and their perceived ease of opposing. Our results suggest LULC manipulation and food-based strategies are not reasonable for controlling urban monk parakeets. We recommend an outreach program explaining monk parakeet biology and the impacts of their nesting habits. We suggest targeting affluent areas adjacent to electric structures with nests and the predictors driving participants? behaviors. To provoke least opposition, we advise nest removal and structural modification. We recommend electric companies conduct cost-benefit analyses exploring feasibility of modifying construction elements preferred by monk parakeets and redesigning new construction to reduce risk of future nesting on electric utility structures.