20 research outputs found

    Noise levels and sources in the Stellwagen Bank National Marine Sanctuary and the St. Lawrence River Estuary

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    Although ambient (background) noise in the ocean is a topic that has been widely studied since pre-World War II, the effects of noise on marine organisms has only been a focus of concern for the last 25 years. The main point of concern has been the potential of noise to affect the health and behavior of marine mammals. The Stellwagen Bank National Marine Sanctuary (SBNMS) is a site where the degradation of habitat due to increasing noise levels is a concern because it is a feeding ground and summer haven for numerous species of marine mammals. Ambient noise in the ocean is defined as “the part of the total noise background observed with an omnidirectional hydrophone.” It is an inherent characteristic of the medium having no specific point source. Ambient noise is comprised of a number of components that contribute to the “noise level” in varying degrees depending on where the noise is being measured. This report describes the current understanding of ambient noise and existing levels in the Stellwagen Bank National Marine Sanctuary. (PDF contains 32 pages.

    Bulletin 2220: Best Management Practices for Small Scale Poultry Producers in Maine

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    Written for small-scale poultry producers. University specialists, Extension educators, and agriculture service providers from New England and New York developed this list of Best Management Practices to assist small-scale poultry growers to provide the best of care for their birds, minimize losses due to disease and predation, as well as minimizing the impact on the environment while assuring a high quality, wholesome product for their family and customers.https://digitalcommons.library.umaine.edu/extension_ag/1004/thumbnail.jp

    A Framework for Bioacoustic Vocalization Analysis Using Hidden Markov Models

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    Using Hidden Markov Models (HMMs) as a recognition framework for automatic classification of animal vocalizations has a number of benefits, including the ability to handle duration variability through nonlinear time alignment, the ability to incorporate complex language or recognition constraints, and easy extendibility to continuous recognition and detection domains. In this work, we apply HMMs to several different species and bioacoustic tasks using generalized spectral features that can be easily adjusted across species and HMM network topologies suited to each task. This experimental work includes a simple call type classification task using one HMM per vocalization for repertoire analysis of Asian elephants, a language-constrained song recognition task using syllable models as base units for ortolan bunting vocalizations, and a stress stimulus differentiation task in poultry vocalizations using a non-sequential model via a one-state HMM with Gaussian mixtures. Results show strong performance across all tasks and illustrate the flexibility of the HMM framework for a variety of species, vocalization types, and analysis tasks

    A Framework for Bioacoustic Vocalization Analysis Using Hidden Markov Models

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    Using Hidden Markov Models (HMMs) as a recognition framework for automatic classification of animal vocalizations has a number of benefits, including the ability to handle duration variability through nonlinear time alignment, the ability to incorporate complex language or recognition constraints, and easy extendibility to continuous recognition and detection domains. In this work, we apply HMMs to several different species and bioacoustic tasks using generalized spectral features that can be easily adjusted across species and HMM network topologies suited to each task. This experimental work includes a simple call type classification task using one HMM per vocalization for repertoire analysis of Asian elephants, a language-constrained song recognition task using syllable models as base units for ortolan bunting vocalizations, and a stress stimulus differentiation task in poultry vocalizations using a non-sequential model via a one-state HMM with Gaussian mixtures. Results show strong performance across all tasks and illustrate the flexibility of the HMM framework for a variety of species, vocalization types, and analysis tasks

    The Cardiovascular Responses of Domestic Fowl to Elevated Ambient Temperatures

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    203 p.Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 1981.A series of experiments were performed to study cardiovascular and thermoregulatory responses of chickens during an acute heat challenge at 35(DEGREES)C ambient temperature (T(,a)). In the first experiment eight mature Single Comb White Leghorn hens, maintained at 25(DEGREES)C T(,a), were subjU of I OnlyRestricted to the U of I community idenfinitely during batch ingest of legacy ETD

    Marine trophic niche-use and life history diversity among Arctic charr Salvelinus alpinus in southwestern Greenland

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    Life history strategies and potential marine niche use of Arctic charr Salvelinus alpinus (n = 237, 84–652 mm, total body length, LT) were determined during the ice‐free season (2012) at three different watercourses in south‐western Greenland. All Arctic charr were collected from freshwater habitats. Based on stable isotopes of δ34S, the Arctic charr were categorized as either marine‐ or freshwater‐dependent feeders. The use of time‐integrated trophic tracers (stable isotopes of δ13C, δ15N, δ34S) suggested that several trophic groups of Arctic charr operate alongside within each fjord system. The groups suggested were one group that specialized in the marine habitat, in addition to two freshwater resident morphs (small‐sized resident and/or large‐growing cannibalistic individuals). Stomach contents consisted entirely of freshwater and terrestrial prey (i.e., insects), indicating that marine‐dependent feeders also fed in freshwater habitats after return from their marine migration. Growth and maturity patterns further supported variable life history strategies within each watercourse. The life history strategy patterns and marine trophic niche use were consistent across the watercourses along several hundred kilometres of coastline. This study represents the first ecological baseline for partially anadromous populations of Greenland Arctic charr
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