Author: Kristin Brunk

Publisher:

Published: 2021

Total Pages: 0

ISBN-13:

The Marbled Murrelet (Brachyramphus marmoratus) is a small, federally threatened seabird native to the western coast of North America that ranges from the Aleutians to central California. Murrelets are old-growth forest specialists during the breeding portion of their life history, and historic loss of old-growth forest throughout much of the murrelet's range has resulted in greatly reduced murrelet populations, especially in the southern-most extent of the murrelet's range. In central California, approximately 85% of old-growth forests have been lost due to timber harvest of economically valuable old-growth trees. Much of the remaining old-growth forest is either on private property, where murrelets are at the mercy of local forest management strategies, or protected in national and state parks. Additionally, in the fragmented old-growth that remains, murrelets often experience elevated rates of nest predation, largely by corvids such as Common Ravens (Corvus corax) and Steller's Jays (Cyanocitta stelleri). Indeed, low reproductive success has been implicated in the ongoing decline of murrelet populations, even though much of their remaining nesting habitat has been protected. Habitat protected for murrelet breeding, such as state parks, is also often important for human recreation. Human use of these protected areas has led to increased densities of corvids that take advantage of readily available human food subsidies. Abundant human food subsidies potentially put murrelets at greater risk of nest predation and also affect the ecology and behavior of corvids. The first two-thirds of this dissertation examines the effectiveness of conservation measures to protect nesting habitat for marbled murrelets and to control populations of overabundant murrelet nest predators. The last third focuses on understanding how human food subsidies affect the behavioral ecology of subsidized nest predators.