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A Comparison Of Drone Imagery And Groundbased Methods For Estimating The Extent Of Habitat Destruction By Lesser Snow Geese (Anser Caerulescens Caerulescens) In La Pérouse Bay, Andrew F. Barnas, Brian J. Darby, Gregory S. Vandeberg, Robert F. Rockwell, Susan N. Ellis-Felege Aug 2019

A Comparison Of Drone Imagery And Groundbased Methods For Estimating The Extent Of Habitat Destruction By Lesser Snow Geese (Anser Caerulescens Caerulescens) In La Pérouse Bay, Andrew F. Barnas, Brian J. Darby, Gregory S. Vandeberg, Robert F. Rockwell, Susan N. Ellis-Felege

Biology Faculty Publications

Lesser snow goose (Anser caerulescens caerulescens) populations have dramatically altered vegetation communities through increased foraging pressure. In remote regions, regular habitat assessments are logistically challenging and time consuming. Drones are increasingly being used by ecologists to conduct habitat assessments, but reliance on georeferenced data as ground truth may not always be feasible. We estimated goose habitat degradation using photointerpretation of drone imagery and compared estimates to those made with ground-based linear transects. In July 2016, we surveyed five study plots in La Pérouse Bay, Manitoba, to evaluate the effectiveness of a fixed-wing drone with simple Red Green Blue …


On Estimating The Exponent Of Power-Law Frequency Distributions, Ethan P. White, B. J. Enquist, J. L. Green Jan 2008

On Estimating The Exponent Of Power-Law Frequency Distributions, Ethan P. White, B. J. Enquist, J. L. Green

Biology Faculty Publications

Power-law frequency distributions characterize a wide array of natural phenomena. In ecology, biology, and many physical and social sciences, the exponents of these power-laws are estimated to draw inference about the processes underlying the phenomenon, to test theoretical models, and to scale up from local observations to global patterns. Therefore, it is essential that these exponents be estimated accurately. Unfortunately, the binning-based methods traditionally utilized in ecology and other disciplines perform quite poorly. Here we discuss more sophisticated methods for fitting these exponents based on cumulative distribution functions and maximum likelihood estimation. We illustrate their superior performance at estimating known …


A Critical Evaluation Of Research Techniques In Animal Ecology, Michelle A. Baker Jan 2001

A Critical Evaluation Of Research Techniques In Animal Ecology, Michelle A. Baker

Biology Faculty Publications

No abstract provided.


Foraging Ecology Of Temperate-Zone And Tropical Woodpeckers, Robert A. Askins Aug 1983

Foraging Ecology Of Temperate-Zone And Tropical Woodpeckers, Robert A. Askins

Biology Faculty Publications

The foraging behavior of 11 species of woodpeckers in Guatemala, Maryland, and Minnesota was studied in order to test the seasonal stability hypothesis. This hypothesis predicts that specialization and species richness should be no greater for tropical wood-excavators than for those in the temperate zone because wood-excavators in both regions are buffered against seasonal change. Niche breadth values for six variables that describe foraging methods and perches were calculated by two methods. Unweighted niche breadth values were similar for tropical and temperate woodpeckers for all variables except foraging techniques; in this case the temperate species are more specialized. With weighted …