ii TABLE OF CONTENTS SUMMARY........................................................ 1 TAXONOMY....................................................... 3 PHYSICAL DESCRIPTION, SONG, AND GENERAL BEHAVIOR............... 3 RANGE.......................................................... 4 HABITAT........................................................ 6 BREEDING SEASON HABITAT REQUIREMENTS ......................... 6 WINTER HABITAT REQUIREMENTS .................................. 9 BIOLOGY....................................................... 11 MIGRATION ................................................... 11 REPRODUCTION ................................................ 12 FOOD HABITS ................................................. 14 POPULATION TRENDS AND ESTIMATES............................... 15 NORTH AMERICAN BREEDING BIRD SURVEY ......................... 15 BREEDING BIRD ATLASES ....................................... 17 CHRISTMAS BIRD COUNTS ....................................... 17 STATE SUMMARIES ............................................. 18 FWS REGION 2 .............................................. 19 Oklahoma................................................. 19 Texas.................................................... 21 FWS REGION 3 .............................................. 22 Illinois................................................. 22 Indiana.................................................. 24 Iowa..................................................... 25 Michigan................................................. 26 Minnesota................................................ 27 Missouri................................................. 28 Ohio..................................................... 29 Wisconsin................................................ 30 FWS REGION 4 .............................................. 33 Alabama.................................................. 33 Arkansas................................................. 34 Florida.................................................. 34 Georgia.................................................. 35 Kentucky................................................. 36 Louisiana................................................ 37 Mississippi.............................................. 38 North Carolina........................................... 39 South Carolina........................................... 41 FWS REGION 5 .............................................. 42 Connecticut.............................................. 42 Delaware................................................. 43 Maine.................................................... 43 Maryland................................................. 44 Massachusetts............................................ 44 New Hampshire............................................ 46 New Jersey............................................... 46 iii New York................................................. 47 Pennsylvania............................................. 48 Rhode Island............................................. 49 Vermont.................................................. 50 Virginia................................................. 51 West Virginia............................................ 52 FWS REGION 6 .............................................. 53 Kansas................................................... 53 Nebraska................................................. 54 South Dakota............................................. 55 CANADA .................................................... 55 Ontario.................................................. 55 THREATS....................................................... 66 PRESENT OR THREATENED HABITAT LOSS .......................... 66 OVERUTILIZATION ............................................. 69 DISEASE OR PREDATION ........................................ 69 INADEQUACY OF EXISTING REGULATORY MECHANISMS ................ 70 OTHER NATURAL OR MANMADE FACTORS ............................ 71 MANAGEMENT.................................................... 72 BREEDING HABITAT MANAGEMENT ................................. 72 PRESCRIBED BURNING ........................................ 72 MOWING .................................................... 73 GRAZING ................................................... 74 WINTER HABITAT MANAGEMENT ................................... 75 MANAGEMENT CONSIDERATIONS AND OPPORTUNITIES ................. 76 RESEARCH AND MONITORING NEEDS................................. 79 MONITOR PERSISTENT BREEDING POPULATIONS ..................... 79 EVALUATE STATUS AND ECOLOGY ON WINTER RANGE ................. 80 OTHER RESEARCH AND MONITORING NEEDS ......................... 80 LITERATURE CITED.............................................. 81 APPENDIX I.................................................... 92 iv LIST OF TABLES AND FIGURES ══════════════════════════════════════════════════════════════════════════════ Table 1. Trends in abundance of Henslow's sparrow based on BBS data. .... 16 Table 2. Status of Henslow's sparrow in states within the species breeding range. Information in table is abbreviated from state summaries, which include citations. ................................ 58 Table 3. Status of Henslow's sparrow in states within the species winter range. Information in table is abbreviated from state summaries, which include citations. ................................ 64 Figure 1. Approximate U.S. range of the Henslow's sparrow. (Breeding range also includes extreme southern Ontario). ................. 5 v ACRONYMS USED IN THE TEXT ══════════════════════════════════════════════════════════════════════════════ American Ornithologist's Union ............................ AOU Breeding Bird Atlas ....................................... BBA Christmas Bird Count ...................................... CBC Committee on the Status of Endangered Wildlife in Canada .. COSEWIC Conservation Reserve Program .............................. CRP Department of Natural Resources ........................... DNR Migratory Bird Treaty Act of 1918 ......................... MBTA National Biological Service ............................... NBS National Environmental Policy Act of 1969 ................. NEPA National Forest ........................................... NF National Wildlife Refuge .................................. NWR North American Breeding Bird Survey ....................... BBS North American Ornithological Atlas Committee ............. NORAC Texas Bird Records Committee .............................. TBRC The Nature Conservancy .................................... TNC U.S. Army Corps of Engineers .............................. COE U.S. Fish and Wildlife Service ............................ FWS Wisconsin Grassland Bird Study ............................ WGBS 1 SUMMARY Prior to European settlement, Henslow's sparrow (Ammodramus henslowii) bred primarily in prairie habitat. With the loss of native prairie to agriculture, Henslow's sparrow adapted to breeding in secondary grassland habitats, particularly hayfields and pasture. The availability of these secondary habitats also allowed the species' range to expand to the north and the east as forests were cleared for agriculture. The species currently breeds locally across the Great Lakes region of the eastern U.S. and southern Ontario (Canada), to New York, south to Maryland, across northern Virginia, West Virginia and Kentucky, and west to eastern portions of Oklahoma and Kansas. The breeding range, particularly in the northwestern and eastern portion of the range, is contracting. The species winters in coastal areas from South Carolina, south to Florida, and west to Texas. Grasslands which provide Henslow's sparrow breeding habitat are generally characterized by tall, dense grass with a well-developed litter layer and a relatively high coverage of standing dead vegetation. The grasslands frequently support sparse woody vegetation, but extensive woody invasion will eventually preclude use by Henslow's sparrow. Habitat area is considered a limiting factor for Henslow's sparrow; only large grasslands support persistent populations. Winter habitats of Henslow's sparrow are similar to breeding habitats, in that they are dominated by dense groundcover. Either pine forests or open prairies are suitable winter habitat, provided that dense groundcover is present. The winter habitat requirements have not been rigorously studied until recently; 3 ongoing studies represent the first systematic research on wintering Henslow's sparrows. The scientific community has expressed concern regarding Henslow's sparrow populations for decades, but it has been difficult to document population trends. North American Breeding Bird Survey (BBS) data clearly indicate a significant population decline for this species (since 1966) which is fairly consistent throughout its breeding range. Christmas Bird Count data indicate that the species' population is also declining on winter range. The distribution of Henslow's sparrow is scattered and localized throughout its current range. In 1987, the U.S. Fish and Wildlife Service identified Henslow's sparrow as one of 30 "migratory nongame birds of management concern in the United States" due to the species' widespread population decline and need for restricted/vulnerable habitats. Henslow's sparrow is listed as endangered, threatened, or a species of special concern in 16 states and was designated as endangered in Canada in 1993. This status assessment includes summaries of