Trevor Eldred

Date Approved

2009

Degree Type

Open Access Thesis

Degree Name

Master of Science (MS)

Department or School

Biology

Committee Member

Peter Bednekoff, PhD, Chair

Committee Member

Allen Kurta, PhD

Committee Member

Cara Shillington, PhD

Abstract

I investigated how vigilance in sandhill crane time budgets changed with behavioral, climatic, and anthropogenic factors. I measured two different postures that could be interpreted as vigilance. Cranes significantly altered the time spent in the alert investigative posture with differences in gender and modal non-vigilant behavior. They significantly altered the time spent in the tall alert posture with differences in gender, breeding status, time of day, traffic on the nearest road, and human disturbances. The southern Michigan populations of sandhill cranes nest closer to roads and houses than they have in the past and do not preferentially avoid them. They favor emergent and semi-permanently flooded wetlands and avoid forested, open water, and scrub-shrub wetlands for nesting. They do not preferentially avoid roads and houses when selecting fall staging sites. Sandhill crane vigilance is best determined by the alert investigative posture, although this posture may include other behaviors as well. Sandhill cranes adapt well to human impacts, and their population can increase with their ability to move beyond the traditional nesting and migratory staging sites. 2

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