HOTSPOTS: BIRD SURVEY OF MENDENHALL WETLANDS APRIL 2002 to MAY 2003 Photo 1 Long-billed Dowitcher.jpg Robert H. Armstrong, Richard L. Carstensen, and Mary F. Willson Juneau Audubon Society and Taku Conservation Society 2004 Some of the data for this paper were gathered by the authors under a contract between Discovery Southeast and the U.S. Fish and Wildlife Service (FWS), and were provided to FWS in a report entitled “Bird use of the Mendenhall Wetlands April 2002 to May 2003.” The authors have included data from that report in this paper, along with additional information they have collected. Any conclusions and recommendations presented herein are the authors’ personal views, and have not been endorsed by Discovery Southeast. The Juneau Audubon Society and Taku Conservation Society provided financial support for the printing and distribution of this report. All recommendations in this report are those of the authors and have not been officially endorsed by the Juneau Audubon Society. Contents Introduction ..................................................................................................... 2 1 Methods ...................................................................................................... 2 Study site and field methods for hotspots ..................................................... 2 GIS mapping of data .................................................................................... 3 Phenology .................................................................................................... 3 Connections ................................................................................................. 4 2 Overview of diversity and abundance on the wetlands .......................... 4 3 Summary maps and charts........................................................................ 5 4 Glacial rebound, vegetation and birds ................................................... 10 5 Hotspot descriptions ............................................................................... 17 Mendenhall River mouth (r05) .................................................................... 17 Fritz Cove (r06) .......................................................................................... 18 Western mudflat sand lance area (r08) ...................................................... 19 Lower Fish Creek estuary (f08) .................................................................. 20 Upper Fish Creek estuary (f01) .................................................................. 21 Salmon Creek estuary (s01)....................................................................... 22 Otter Pond (a01) ........................................................................................ 23 Sedge flats west of Otter Pond (a08) ......................................................... 24 ERA heliport (e02) ...................................................................................... 25 Western Channel (f09) ............................................................................... 26 Upper Mendenhall River (r02, 13, 03, 07 and 04) ..................................... 27 Wigeon Ponds (p02) .................................................................................. 28 Phalarope Slough (a10) ............................................................................. 29 Junk Car Slough (a02) ............................................................................... 30 Miller-Honsinger Pond (a04) ...................................................................... 31 Float Plane Basin Finger Ponds (a03) ....................................................... 32 Auke Lake (x01) ......................................................................................... 33 Twin Lakes (t02) ......................................................................................... 34 6 Comparisons with Cain et al. 1988 ......................................................... 35 7 Phenology and distribution ..................................................................... 36 8 Connections with the rest of the world .................................................. 44 9 Animal food resources on the wetlands ................................................ 45 Fish ............................................................................................................ 45 Mammals .................................................................................................... 48 Invertebrates .............................................................................................. 48 10 Synthesis and recommendations ......................................................... 51 Shorebirds .................................................................................................. 51 Past and pending habitat loss .................................................................... 53 Birds and airplane safety ............................................................................ 53 Dogs and birds ...........................................................................................56 Hunting .......................................................................................................57 Infrequently surveyed areas of the wetlands .............................................58 Further research needs ..............................................................................59 Acknowledgments ........................................................................................ 59 Literature Cited ............................................................................................. 59 Appendices ................................................................................................... 61 Appendix A Common and scientific names ............................................... 61 Appendix B Species distribution maps ...................................................... 62 Appendix C Phenology tables for all refuge species ................................. 65 1 HOTSPOTS: BIRD SURVEY OF MENDENHALL WETLANDS, APRIL 2002 to MAY 2003 Robert H. Armstrong, Richard L. Carstensen, and Mary F. Willson Introduction For 14 months we conducted bird surveys on the Birding Association’s publication titled North American Mendenhall Wetlands State Game Refuge. The principal Birds and the existing Mendenhall Wetlands bird list goal of this survey was to document areas of the wetlands (Armstrong and Gordon 2002): that hosted large concentrations of birds at various Fall (August-November) seasons; these areas were called ‘hotspots’ of bird activity. Winter (December-February) A secondary goal was a rough comparison of present bird Spring (March-May) abundances with those recorded by Cain et al. (1988), Summer (June–July). using different methods. A third goal, which emerged as we were conducting the bird surveys, was a synopsis of Table 1.1. Dates of full surveys of the wetland. April and bird phenology on the wetlands, showing seasonal patterns early May surveys were done in both 2002 and 2003. of use. Season Dates Number/season Spring 2002 April 2-5 5 April 11-14 1 Methods April 27 Study site and field methods for hotspots. May 3-5 We surveyed most of the wetlands between the end May 14 Summer 2002 June 13 2 of the Mendenhall Peninsula and Fritz Cove and the July 1-2 southeastern edge of the Salmon Creek delta (Map 1.1). Fall 2002 August 12-15 5 Primary survey areas are those visited on all full surveys September 3 of the wetlands. Secondary survey areas were visited September 22-25 occasionally. One section of the wetlands north of Johnson October 24-25 Creek was not covered, because of poor access (Map November 29-30 10.4). For place names used in the text, see orthophoto on Winter 2003-03 December 14 3 back cover. January 21 Eighteen full surveys were completed between April February 18 Spring 2003 March 20 3 2002 and May 2003 (Table 1.1), unequally distributed April 23 among seasons. Seasons were defined as in the American May 5 Map 1.1 Location of primary survey areas (z) on 9 subunits of Mendenhall Wetlands. p = peninsula; r = river; f = fish; a = airport; n = ninemile; k = king’s; L = lemon; e = era; t = twin lakes; s = salmon. = secondary survey areas 2 Surveys were conducted by observers on foot, using all observations for Canada Goose involving resting binoculars and spotting scopes. We recorded all bird groups of more than 100 birds, then compare that to all concentrations we saw, with notes on tide, weather, feeding observations for groups of similar size. All dots location, number of individuals, habitat and activity. (survey areas) satisfying the query change color. Species present in smaller numbers were also recorded in To compare our observations to those of Cain et al. order to build a record of species diversity for each survey (1988) we also entered 422 of their largest counts (biggest area. All full surveys included each of the 42 primary bird concentrations - equivalent to our hotspot records) survey areas, timed to center around low tides in daylight into ArcView. In that study, counts were listed for 32 hours. Hotspot analyses used only these full-survey separate units of the refuge, a slightly different approach records, and omitted observations of single or small bird than in our hotspot study, which was more focused on key groups. This basic data set comprised 794 records. concentration areas. Still, the two ArcView projects make it In addition to the 18 full surveys, 41 “ancillary possible to detect changes