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Population Dynamics and Biology of the California Sea Otter (Enhydra Lutris Nereis) at the Southern End of Its Range

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Population Dynamics and Biology of the California Sea Otter (Enhydra Lutris Nereis) at the Southern End of Its Range OCS Study • MMS 2006-007 Population Dynamics and Biology of the California Sea Otter (Enhydra lutris nereis) at the Southern End of its Range Final Technical Summary Final Study Report U.S. Department of the Interior Minerals Management Service Pacific OCS Region OCS Study MMS 2006-007 Population Dynamics and Biology of the California Sea Otter (Enhydra lutris nereis) at the Southern End of its Range Final Technical Summary Final Study Report Editors M. Tim Tinker James A. Estes Katherine Ralls Terrie M. Williams Dave Jessup Daniel P. Costa Principal Investigators James A. Estes Katherine Ralls Terrie M. Williams Daniel P. Costa Prepared under MMS Cooperative Agreement No. 14-35-0001-31063 by Coastal Marine Institute Marine Science Institute University of California Santa Barbara, CA 93106-6150 U.S. Department of the Interior Minerals Management Service Camarillo Pacific OCS Region May 2006 Disclaimer This report has been reviewed by the Pacific Outer Continental Shelf Region, Minerals Management Service, U.S. Department of the Interior and approved for publication. The opinions, findings, conclusions, or recommendations in this report are those of the authors, and do not necessarily reflect the views and policies of the Minerals Management Service. Mention of trade names or commercial products does not constitute an endorsement or recommendation for use. This report has not been edited for conformity with Minerals Management Service editorial standards. Availability of Report Extra copies of the report may be obtained from: U.S. Dept. of the Interior Minerals Management Service Pacific OCS Region 770 Paseo Camarillo Camarillo, CA 93010 Phone: 805-389-7621 A PDF file of this report is available at: http://www.coastalresearchcenter.ucsb.edu/CMI/ Suggested Citation The suggested citation for this report is: Tinker, M.T. et al. Population Dynamics and Biology of the California Sea Otter (Enhydra lutris nereis) at the Southern End of its Range. MMS OCS Study 2006-007. Coastal Research Center, Marine Science Institute, University of California, Santa Barbara, California. MMS Cooperative Agreement Number 14-35-0001-31063. 253 pages. Table of Contents FINAL TECHNICAL SUMMARY ...................................................................................... 1 FINAL STUDY REPORT...................................................................................................... 9 CHAPTER 1. Introduction ............................................................................................. 9 Ralls, K., M. Tinker, J. Estes CHAPTER 2. Spatial and temporal variation in sea otter demography.................. 12 Tinker, M., D. Doak, J. Estes, B. Hatfield, M. Steadler, J. Bodkin Abstract ........................................................................................................................ 12 Introduction.................................................................................................................... 13 Methods ........................................................................................................................ 15 Part 1: Estimating past demographic rates ........................................................... 15 Field data........................................................................................................ 15 Overview of modeling approach.................................................................... 16 Formulating age, sex, time, and location-dependent demographic rates ....... 16 Matrix projection............................................................................................ 22 Maximum likelihood analysis........................................................................ 24 Incorporating model uncertainty.................................................................... 25 Part 2: Estimating recent demographic rates ........................................................ 29 Results............................................................................................................................ 31 Part 1: Past demographic rates.............................................................................. 31 Part 2: Recent demographic rates ......................................................................... 36 Discussion...................................................................................................................... 39 CHAPTER 3. Temporal and spatial variation in movement patterns ..................... 43 Kage, A., J. Estes, M. Tinker, D. Doak, P. Raimondi Abstract.......................................................................................................................... 43 Introduction.................................................................................................................... 44 Analysis of animal movement .............................................................................. 45 Home range estimation......................................................................................... 46 Methods......................................................................................................................... 47 Data collection...................................................................................................... 47 Data analysis......................................................................................................... 51 Statistical analysis.................................................................................................52 Results............................................................................................................................ 53 Move lengths........................................................................................................ 53 Home range........................................................................................................... 57 Correlated random walk....................................................................................... 60 Discussion...................................................................................................................... 63 Movement patterns: age and sex class over time ................................................. 65 Spatial variation in movement patterns ................................................................ 66 Temporal changes in movement patterns ............................................................. 69 Home range: age and sex class............................................................................. 69 Spatial variation – home range area ..................................................................... 70 Temporal variation – home range area................................................................. 71 Variation in home range morphology................................................................... 73 Spatial variation using correlated random walk ................................................... 76 Temporal variation using correlated random walk............................................... 78 Conclusions.................................................................................................................... 79 CHAPTER 4. Spatially explicit simulation model to predict range expansion ....... 81 Tinker, M., D. Doak, J. Estes, A. Kage Abstract.......................................................................................................................... 81 Introduction.................................................................................................................... 82 Methods......................................................................................................................... 84 Matrix structure.................................................................................................... 84 Simulating range expansion.................................................................................. 88 Model parameterization........................................................................................ 88 Running simulations............................................................................................. 92 Results............................................................................................................................ 94 Discussion.................................................................................................................... 101 CHAPTER 5. Foraging ecology.................................................................................. 103 Tinker, M., J. Estes, M. Steadler, J. Bodkin Abstract........................................................................................................................ 103 Introduction.................................................................................................................. 104 Methods....................................................................................................................... 105 Data collection.................................................................................................... 105 Data analysis....................................................................................................... 107 Results.......................................................................................................................... 115 Discussion.................................................................................................................... 125 CHAPTER 6. Dive behavior and activity
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