Ecological responses by Mexican spotted owls to environmental variation in the Sacramento Mountains, New Mexico

Abstract

Understanding the influence of environmental variation on population processes is a fundamental requisite for devising strategies that conserve species. A common tactic for conserving raptor populations is to maintain or manipulate habitat conditions that maintain or increase availability of prey species. A primary purpose of this investigation was to evaluate the hypothesis that Mexican spotted owls (Strix occidentalis lucida) could be conserved by manipulating microhabitat conditions that increased abundance of one or more common prey species. I evaluated this hypothesis by (1) determining which common prey were preferred by this owl, (2) which prey species were most likely to influence the owl's reproduction, and by assessing (3) which prey species were most likely to increase in abundance following microhabitat manipulation. In addition to prey availability, I also examined the influence of two other likely sources of environmental variation, weather and macrohabitat condition, on spotted owl reproduction and common prey abundance. The investigation focused on one population of Mexican spotted owls over a six-year period (1991-1996) in the Sacramento Mountains, New Mexico; an area where vegetation communities have been modified extensively over the past 100 years.

Citation

Ward, James P., Jr. 2001. Ecological responses by Mexican spotted owls to environmental variation in the Sacramento Mountains, New Mexico. Fort Collins, CO: Colorado State University. 411 p. Dissertation.