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Spatial ecology of adélie penguin breeding colonies : the effects of landscape, environmental variability and human activities


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Bricher, Phillippa Kate 2007 , 'Spatial ecology of adélie penguin breeding colonies : the effects of landscape, environmental variability and human activities', Unspecified thesis, University of Tasmania.

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Adelie penguins have been widely studied as an "indicator" species for the health of the Southern
Ocean ecosystem. However, the effects of climatic variability and human activities on Adelie
penguin populations are poorly understood. As many of the Adelie penguin colonies used for longterm
demographic studies are located near research stations, there is a need to be able to disentangle
the effects of human activities and environmental variability on Adelie penguin populations. This
study investigates the landscape properties that drive the locations of Adelie penguin colonies in the
Windmill Is, East Antarctica. It also examines whether potential changes in snow cover and/or
proximity to human activities best explain the varying population trends of colonies in two breeding
localities. While some colonies have been abandoned, or have undergone strong population
decreases, the populations of others have grown by more than 1000% in the past 38 years.
This study uses Geographic Information Systems to generate spatial data of landscape, snow
accumulation patterns and proximity to human activity parameters. Landscape parameters are
derived from fine-scale digital elevation models (DEMs) and snow accumulation patterns are
modelled using a complex physically-based GIS model. The parameters are then combined into
multivariate statistical models to generate predictions of habitat suitability.
Individually, the landscape attributes, such as elevation, slope, solar radiation, and wetness index,
have little power to predict the distribution of colonies within a breeding locality. On the• other
hand, multivariate models (discriminant analysis and decision tree) derived from these landscape
attributes predict the presence or absence of colonies in test grid cells with up to 78.9% accuracy.
General rules to describe the distribution of Adelie penguin colonies are not easily derived, as
habitat suitability appears to be driven by complex interactions between landscape attributes.
At Whitney Pt, the study site farthest from Casey, modelled snow accumulation parameters explain
most of the variation in population trends among colonies (up to 83.7% accuracy, for five classes).
At Shirley I, 500 m from Casey, models derived from proximity to human activity parameters
correctly predict the trend classes for up to 83.8% of test cells, while models derived from snow
accumulation parameters correctly classify up to 57.8% of test cells. This suggests that while snow
accumulation patterns are a primary driver of variation in population trends among colonies, the
effect of snow accumulation is outweighed by the effects of human activities near Casey.

Item Type: Thesis - Unspecified
Authors/Creators:Bricher, Phillippa Kate
Keywords: Adelie penguin
Copyright Holders: The Author
Additional Information:

Available for library use only and copying in accordance with the Copyright Act 1968, as amended. Thesis (MEnvMgt)--University of Tasmania, 2007. Includes bibliographical references

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