ORGANIZATION OF A PLANT-POLLINATOR COMMUNITY IN A SEASONAL HABITAT (BEES, SOCIALITY, FORAGING). Item Type text; Dissertation-Reproduction (electronic) Authors Anderson, Linda Susan Publisher The University of Arizona. Rights Copyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author. Download date 30/09/2021 14:15:40 Link to Item http://hdl.handle.net/10150/187851 INFORMATION TO USERS This reproduction was made from a copy of a document sent to us for microfilming. While the most advanced technology has been used to photograph and reproduce this document, the quality of the reproduction is heavily dependent upon the quality of the material submitted. 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Zeeb Road Ann Arbor, MI48106 II 8504746 Anderson, Linda Susan ORGANIZATION OF A PLANT· POLLINATOR COMMUNITY IN A SEASONAL HABITAT The University of Arizona PH.D. 1984 University Microfilms International 300 N. Zeeb Road, Ann Arbor, MI48106 ORGANIZATION OF A PLANT-POLLINATOR COMMUNITY IN A SEASONAL HABITAT by Linda Susan Anderson A Dissertation Submitted to the Faculty of the DEPARTMENT OF ECOLOGY AND EVOLUTIONARY BIOLOGY In Partial Fulfillment of the Requirements for the Degree of DOCTOR OF PHILOSOPHY In the Graduate College THE UNIVERSITY OF ARIZONA 1 9 8 4 TaE UNIVERSITY OF ARIZONA GRADU~TE COLLEGE As members of the Final Examination Committee, we certify that we have read the dissertation prepared by Linda Sus~n Anderson entitled Organization of a Plant-Pollinator Community in a Seasonal Habitat and recommend that it be accepted as fulfilling the dissertation requirement for the Degree of Date - Date I ; . J~~l7Yf Date Final approval and acceptance of this dissertation is contingent upon the candidate's submission of the final copy of the dissertation to the Graduate College. Date J / STATEMENT OF AUTHOR This dissertation has been submitted in partial fulfillment of requirements for an advanced degree at The University of Arizona and is deposited in the University Library to be made available to bor­ rowers under rules of the Library. Brief quotations from this dissertation are allowable without special permission, provided that accurate acknowledgment of source is made. Requests for permission for extended quotation from or repro­ duction of this manuscript in whole or in part may be granted by the head of the major department or the Dean of the Graduate College when in his or her judgement the proposed use of the material is in the interests of scholarship. In all other instances, however, permission must be obtained from the author. ACKNOHLEDGMENTS This dissertation would never have been completed without the encouragement and support of many people. First, I would like to thank Peter \~arren, my husband, friend and colleague for his unwavering and loving encouragement through good and bad times. I also thank my family, Ursula, Ed, Erich, Hendy and Mort for always believing in me. The creative, critical, but always supportive atmosphere of the EEB Department was another important factor in completing this dissert8tion. I thank my committee members, Astrid Kodric-Brown, Charles Lowe, Bob Smith, and Steve Buchmann for their guidance and constructive criticism. Jim Brown, my advisor, provided creative inspiration and encouragment while allowing me to pursue my Ol.,n course. I am grateful to the Eebie graduate students for their companionship, critical inspiration, and support, expecially Bob Frye, Dave Gori, Bob Holmes, Katrina Mangin, Marie McGee, David McDonald, and Yvonne Maluf. Peter Harren, Michael Bowers, Dave Gori, and Bob Holmes made constructive comments on earlier drafts of this work and Linda Delph and Peter Harren drafted the figures. I would like to thank the staff and researchers of the Rocky Mountain Biological Lab for their friendship and support especially Cindy Carey, who gave me a home for two summers, billy barr, Kevin Donavan, Nancy Huntly, and Bobbie Peckarsky. I thank G. E. Bohart, G. C. Eickwort and Frank Parker for identifying bees. iii iv This research was supported in part by grants from the National Academy of Science O. C. Marsh Fund, Sigma Xi, the University of Arizona Graduate Student Development Fund, and the Anderson/Kantor Foundation. TABLE OF CONTENTS Page LIST OF TABLES . • vi LIST OF ILLUSTRATIONS viii ABSTRACT ix CHAPTER 1. FORAGING BEHAVIOR AND SOCIALITY IN A NATIVE ROCKY MOUNTAIN BEE COMMUNITY 1 Introduction • 1 Methods • • • • • 5 Study Area 5 Plants 5 Bees 6 Results • • . • • 8 Discussion 21 2. FLOWERING PHENOLOGY IN A SUBALPINE ROCKY MOUNTIAN MEADOW: RESPONSE OF BEE POLLINATORS TO VARYING RESOURCES 29 Introduction • • 29 Methods • • . • 31 Study Area 31 Plants 32 Bees 33 Results ••• 36 Discussion 50 APPENDIX A: SEASONAL RELATIVE ABUNDANCE OF FLo\.JERS 59 APPENDIX B: POLLEN PREFERENCES OF SOLITARY AND PRIMITIVELY SOCIAL BEES DETERMINED FROM SCOPAL LOADS 60 LITERATURE CITED . • . • . • . • . • • . • •. 63 v LIST OF TABLES Table Page 1. Proportional use of different pollen. plants from scopal loads of specialist and generalist solitary and primitively social bees • • • • . • • . • 11 2. Foraging behavior of solitary and primitively social bees in 1977 • • . • . • • • • • • • . • . • . • 13 3. Foraging behavior of solitary and primitively social bees in 1978 . 14 4. Foraging behavior of solitary and primitively social bees in 1981 • • • • • • • • 15 5. Mean values of species niche breadth (SNB) and average individual niche breadth (INB) for specialists and generalists • • . • • • • • . • 17 6. Proportion of specialist and generalist foragers at Brush Creek • • • •• • • • • • . • • • • 17 7. Generalist bee species that switched foraging prefer- ences (most preferred pollen species) between years 19 8. Seasonal activity periods for bees at Brush Creek 20 9. Average activity periods in days for bee species • • 21 10. Characteristics of the blooming season at Brush Creek for four years • • . • • • • . •• 37 11. Weather characteristics from the Crested Butte weather station near Brush Creek for four years 38 12. Relationship between community-wide phenological patterns and selected climatic factors . • 39 13. The number of days from June 1st to the peak of the bloom for the thirteen most common flower species at Brush Creek • • • •• •• • • • • • • • 42 14. Floral density summed over the blooming season • 45 1~. The number and relative proportion of flower visits by solitary and primitively social bees . • . • . • • .• 47 vi vii LIST OF TABLES--Continued Table Page 16. Average floral preference (ratio of relative bee visitation to relative plant abundance) over the blooming season and the proportion of the blooming period during which a species was preferred • • • . • . • . • 48 17. Relative abundance of preferred and non-preferred plant species • • • • • • • • • • • . • 51 18. Correlations between bee visitation and average flower density and yearly variation in flower density • • •• 51 LIST OF ILLUSTRATIONS Figure Page 1. Frequency distribution of the proportion of the most preferred pollen in scopal loads from bee species with sample size greater than three 9 2. The flower density at Brush Creek for four years 41 3. Blooming periods of the 13 most common flowering plants at Brush Creek • • • • • • • • • • • • 44 viii ABSTRACT The foraging behavior of native solitary and primitively social bees was analyzed by identifying scopal pollen loads. In all species individual bees specislized on one pollen type during single foraging bouts. Generalized foraging behavior at the species level may result from switching pollens on sequential foraging bouts in individuals or from the individuals of a colony simultaneously gather­