Status and Distribution of Marine Birds and Mammals in the Fraser River Estuary, British Columbia 2016-2017 1 1 2 2 Robert W. Butler , Rod MacVicar , Andrew R. Couturier , Sonya Richmond , and Holly A. 3 Middleton 1 2 3 Pacific WildLife Foundation , Bird Studies Canada and Middleton Ecological Consulting Recommended citation: Butler, R.W., R. MacVicar, A. R. Couturier, S. Richmond, and H. A. Middleton. 2018. Status and Distribution of Marine Birds and Mammals in the Fraser River Estuary, British Columbia. Pacific WildLife Foundation and Bird Studies Canada. Unpublished Report. Port Moody, BC and Port Rowan, Ontario. The data from this survey are publicly available for download at www.naturecounts.ca 1 - Pacific Wildlife Foundation, Box 1-12, Reed Point Marina, 850 Barnet Highway, Port Moody, British Columbia, Canada, V3H 1V6. www.pwlf.org 2 - Bird Studies Canada, P.O. Box 160, 115 Front Street, Port Rowan, Ontario, Canada, N0E 1M0. www.birdscanada.org 3 - Middleton Ecological Consulting, 8-3563 Oak Street, Vancouver, British Columbia, Canada, V6H 2M1. www.middletonecological.ca Butler, MacVicar, Couturier, Richmond, and Middleton 2018 | i Contents Executive Summary ........................................................................................................................ 1 1. Introduction ............................................................................................................................... 2 1.1 Background and context ....................................................................................................... 2 1.2 Previous studies .................................................................................................................... 3 2. Study Area and Methods ............................................................................................................. 4 2.1 Study Area ............................................................................................................................ 4 2.2 Transect Route and Field Protocol ........................................................................................ 5 2.3 Kernel and Cluster Mapping Techniques ............................................................................. 5 2.3.1 Kernel Analysis .............................................................................................................. 5 2.4 Other Observations ............................................................................................................... 6 3. Results ....................................................................................................................................... 6 3.1 English Bay Records ............................................................................................................. 6 3.2 Summary of Monthly Surveys .............................................................................................. 7 3.3 General finding for species of conservation concern ............................................................ 9 4. Discussion ............................................................................................................................... 10 4.1 Precision of Estimates ......................................................................................................... 11 4.2 Conservation Priority Species ............................................................................................. 11 4.3. Habitat Recommendations ................................................................................................. 11 Acknowledgements ....................................................................................................................... 12 References ..................................................................................................................................... 13 Appendix 1. Species Accounts ..................................................................................................... 21 BIRDS ....................................................................................................................................... 21 Canada Goose Branta canadensis ......................................................................................... 22 Pacific Black Brant Branta bernicla ..................................................................................... 23 Northern Pintail Anas acuta .................................................................................................. 24 White-winged Scoter Melanitta deglandi ............................................................................. 26 Surf Scoter Melanitta perspicillata ...................................................................................... 28 Red-breasted Merganser Mergus serrator ............................................................................ 30 Pacific Loon Gavia pacifica .................................................................................................. 31 Red-throated Loon Gavia stellata ....................................................................................... 32 Western Grebe Aechmophorus occidentalis ....................................................................... 34 Fork-tailed Storm-petrel Oceanodroma furcata ................................................................... 36 Butler, MacVicar, Couturier, Richmond, and Middleton 2018 | ii Brandt’s Cormorant Phalacrocorax penicillatus ................................................................... 37 Double-crested Cormorant Phalacrocorax auritus auritus .................................................. 38 Pelagic Cormorant Phalacrocorax pelagicus ...................................................................... 40 Bald Eagle Haliaeetus leucocephalus ................................................................................. 42 Dunlin Calidris alpina ........................................................................................................... 43 Bonaparte’s Gull Chroicocephalus philadelphia .................................................................. 45 Mew Gull Larus canus .......................................................................................................... 47 California Gull Larus californicus ...................................................................................... 49 Herring Gull Larus argentatus.............................................................................................. 51 Iceland (Thayer’s) Gull Larus islandica thayeri .................................................................. 52 Glaucous-winged Gull Larus glaucescens .......................................................................... 53 Caspian Tern Hydroprogne caspia ..................................................................................... 55 Parasitic Jaeger Stercorarius parasiticus .............................................................................. 56 Pomarine Jaeger Stercorarius pomarinus ............................................................................. 57 Common Murre Uria aalge .................................................................................................. 58 Ancient Murrelet Synthliboramphus antiquus ...................................................................... 60 Pigeon Guillemot Cepphus columba .................................................................................. 61 Marbled Murrelet Brachyramphus marmoratus ................................................................... 63 Rhinoceros Auklet Cerorhinca monocerata ......................................................................... 65 MAMMALS ............................................................................................................................. 66 Harbour Porpoise Phocoena phocoena ................................................................................. 66 Dall’s Porpoise Phocoenoides dalli ...................................................................................... 68 Harbour Seal Phoca vitulina ................................................................................................. 70 Killer Whale (“Bigg’s” Transient) Orcinus orca.................................................................. 72 Butler, MacVicar, Couturier, Richmond, and Middleton 2018 | iii List of Tables Table 1. Regularly occurring marine bird and mammal species of conservation priority in the Fraser estuary........................................................................................................3 Table 2. Number of birds and marine mammals seen each month in transit through English Bay between First Narrows and Point Grey bell buoy. Dates correspond with transect survey dates...........................................................................................7 Table 3. Number of marine birds and mammals counted during 12 line transect surveys (within 100 meters either side of survey vessel) in the Fraser estuary, British Columbia, 2016-2017. Annual total is the sum of November 2016 to October 2017 (shaded) columns.................................................................................................8 List of Figures Fig. 1 Fraser River estuary study area..........................................................................................4 Fig. 2 Primary, secondary and tertiary areas for all federal and provincial marine bird and mammal Species at Risk along the transect route in the Fraser