Habitat Associations of Woodpeckers at Multiple Scales in Managed Forestsof the Southern Oregon Cascades

AN ABSTRACT OF THE THESIS OF Tiffany A. Brett for the degree of Master of Science in Wildlife Science presented on July 21, 1997. Title: Habitat Associations of Woodpeckers in Managed Forests of the Southern Oregon Cascades. Abstract approved: John P. HaY(s Abstract approved: WilliamC. McComb I studied nest-site characteristics and habitat relationships for three species of primary cavity-nesting birds--hairy woodpecker (Picoides villosus), northern flicker (Colaptes auratus), and red-breasted sapsucker (Sphyrapicus ruber)-- over spatially heterogeneous landscapes in managed forests of the Southern Oregon Cascades during 1995 and 1996. The study was conducted on the Diamond Lake Ranger District of the Umpqua National Forest. I found 163 nests--68 nests of red-breasted sapsuckers, 63 of northern flickers, and 32 of hairy woodpeckers. I evaluated characteristics of nest trees, habitat within a 0.04-ha circle surrounding nest trees, and the surrounding landscape and compared these to characteristics of randomly selected plots. Analysis revealed statistically significant differences between nest trees and random trees among species. Variables significantly influencing the probability of use of a tree were state of decay, diameter at breast height, and tree top condition (broken or intact). Red-breasted sapsucker nests were associated with large diameter (mean80.5 cm) trees with broken tops. Hairy woodpeckers used large diameter (mean80.4 cm) trees in decay class 3 for nesting. Northern flickers were associated with large diameter trees (mean =77.7cm) with broken tops. I investigated habitat associations at the landscape level using GIS coverages and FRAGSTATS spatial analysis to generate indices quantifying landscape structure for each study site. Higher numbers of woodpecker nests were found in landscapes with lower proportions of mature closed-canopy forest (trees> 53 cm, canopy closure >40%),and possessing greater overall habitat complexity. I also detected a significant association between all three species of woodpecker and proximity to edge. Red-breasted sapsuckers exhibited the most dramatic affinity for edge habitat, choosing to use nest trees located on a habitat edge more often than would be expected if selection was due to chance alone (P <5 x1(f9). Nests of northern flickers and hairy woodpeckers were also significantly associated with habitat edges (P <0.004 and P <0.04 respectively). When managing for woodpeckers within managed forest landscapes, large snags (>80 cm) should be retained. Woodpecker needs for nesting habitat may not be met if retained snags do not represent a diversity of decay classes. Snags representing a variety of tree species and decay classes should be left following management activity. Additionally, management plans should incorporate the use of a variety of methods for stand regeneration. Using prescriptions such as shelterwoods, commercial thinning, and partial cuts, overall landscape diversity will increase, enhancing habitat conditions for nesting woodpeckers. Habitat Associations of Woodpeckers at Multiple Scales in Managed Forestsof the Southern Oregon Cascades by Tiffany A. Brett A THESIS submitted to Oregon State University in partial fulfillment of the requirements for the degree of Master of Science Presented July 21, 1997 Commencement June, 1998 Master of Science thesis of Tiffany A. Brett presented on July 21, 1997 APPROVED: Co-Major representing Wildlife Science I understand that my thesis will become part of the permanent collection of Oregon State University libraries. My signature below authorizes release of my thesis to any reader upon Tiffany A. Brett, Author -Acknowledgements My thesis work was funded by DEMO (Demonstration of Ecosystem Management Options), a cooperative research project initiated in Oregon and Washington in 1994. I am grateful to the organizers of the project, and most especially the technical support from the Diamond Lake Ranger District. This thesis was inspired and encouraged by many, I could not possibly mention them all here. To my major advisors Bill McComb and John Hayes, I offer my sincere thanks in allowing me to 'explore' while keeping me on track with their timely encouragement and advice. I am especially grateful to John for his patient guidance throughout the analysis and writing of the thesis, his thoughtful advice and support were invaluable.I would like to thank the other members of my committee as well; Dan Edge for his tireless cheer, and Susan Stafford, not only for her statistical advice, but also for her encouraging words. I thank Sandy Lewis for her tireless attention to bureaucratic details, and her constant smile. I am grateful to Logan Norris, department head and supporter, for his unending optimism with regards to the DEMO project. I would be remiss without thanking Carol Chambers, who had enough faith in me to choose me as a research assistant on the DEMO project in 1994. Carol was always there to offer professional and personal advice whenever it was needed. Gody Spycher, database whiz and fellow lover of Rilke, was always willing to share bits of wisdom on database management, and would help out with SAS problems in a pinch. His cheery disposition got me through some of the rough spots in the analysis. I would have been lost had it not been for the GIS wizardry of George Leinkaemper. He patiently guided me through the painful introductory stages of Arc Info, and in the process turned me on to the wonders of spatial analysis with his always-present enthusiasm. Thanks also to Barbara Marks, who aided in analysis with FRAGSTATS. My work would not have been possible without the assistance of these two people. I am grateful for the support of my friends and colleagues, I would not have made it through this difficult time without their empathy and understanding. Special thanks to friends and fellow classmates Jennifer Weikel, Nobi Suzuki, and Jonathon Brooks, who gave invaluable advice along the way. Thanks to Matthew Hunter notonly for his endless enthusiasm for all creatures winged and otherwise, but also for his thoughtful comments which inspired ideas during the later writing stages. To fellow Wisconsinite Joan Hagar I am grateful, as someone with whom I could share my love for birds, and who was always willing to 'lend an ear' when I needed one. I am indebted to Louise Yount and Shelley Church, who were always there for me when the going got tough, and who have become very dear friends along the way. I would like to acknowledge and thank fellow Demo researchers Rebecca Thompson, and Jeff Feen, with whom I shared the joys and frustrations of field work. Jeff, despite being a 'mammal guy' has become a dear friend during the last two years (even though he remains a staunch advocate of Fords and flying squirrels). I would like to thank those who have worked hard to help me collect the data during the past two years; including Wayne Harris, Sue Danver, and the Swift sisters Roberta and Stephanie. Thanks to Lyndia Hammer for her endless enthusiasm and to Anthony Floyd for his loyalty and hard work. I owe a great deal to Anthony, who not only shared my love of feathered critters, but also stuck out two field seasons, putting up with the hard work and delightful spring weather of the Oregon Cascades-cheerfully for the most part. I owe gratitude to many forest service employees at the Diamond Lake Ranger District who generously provided technical support throughout the duration of my study. To Rick Abbott, die-hard supporter of DEMO, I thank for accommodating all DEMO researchers, and dealing with problems we encountered along the way. I am grateful to Kim Vieira, GIS guru on the district, for her patient direction in my explorations of GIS and Arc-Info. I am grateful to friends and a fellow bird-enthusiasts Keith and Mary Graves. Keith, as district recreation specialist/biologist, gave freely of his advice and support throughout the study. I am most grateful to my parents Frank and Chris Church, who encouraged me in all of my explorations. Thanks to my father, for cultivating in me a love and respect for nature as a young girl, and for sharing his awe and wonder in things natural, wild, and free. He is responsible for 'planting the seed' that blossomed into my passion (some might call it obsession) for birds.I will always be grateful to my mother for helping me to see beauty in all things, and for her tireless support and undying faithin me. Finally, I would like to thank my husband Joe, who besides being wonderfully supportive throughout, also gave freely of his time to instruct me in the use of the GPS satellite equipment, and helped me to create the map coverages I needed for analysis. I especially thank Joe for his constant love and patience, and for sharing his love and knowledge of the Diamond Lake area with me. TABLE OF CONTENTS Page CHAPTER 1- HABITAT ASSOCIATIONS OF WOODPECKERS AT MULTIPLE SCALES IN MANAGED FORESTS OF TIlE SOUTHERN OREGON CASCADES CONCEPTUAL BACKGROUND 1 RESEARCH NEED AND JUSTIFICATION 5 SnagManagement 7 Woodpeckers of the Southern Oregon Cascades 7 OBJECTiVES 8 LITERATURE CITED 9 CHAPTER 2- NEST-SITE CHARACTERISTICS OF WOODPECKERS IN MANAGED FORESTS OF THE SOUTHERN OREGON CASCADES 13 INTRODUCTION 13 STUDY AREA 15 METHODS 19 Study-Site Selection 19 Bird Sampling and Nest Searches 19 Habitat Sampling 20 Data Analysis 22 RESULTS 23 Characteristics of Nest Trees 24 Multivariate analysis 26 DISCUSSION 32 Diameter 32 Tree Condition and Decay 34 Tree Species 34 CONCLUSION 35 LITERATURE CITED 36 TABLE OF CONTENTS

Load more