United States Department of Conservation Agriculture Forest Service Assessment—Henslow’s North Central Sparrow Ammodramus Research Station General Technical henslowii Report NC-226 Dirk E. Burhans The U.S. Department of Agriculture (USDA) prohibits discrimination in all its programs and activities on the basis of race, color, national origin, sex, religion, age, disability, political beliefs, sexual orientation, and marital or family status. (Not all prohibited bases apply to all programs.) Persons with disabilities who require alternative means for communication of program information (Braille, large print, audiotape, etc.) should contact USDA’s TARGET Center at (202) 720-2600 (voice and TDD). To file a complaint of discrimination, write USDA, Director, Office of Civil Rights, Room 326-W, Whitten Building, 1400 Independence Avenue, SW, Washington, DC 20250-9410 or call (202) 720-5964 (voice and TDD). USDA is an equal opportunity provider and employer. Front cover Henslow’s Sparrow photograph: ©Doug Wechsler/VIREO. Published by: North Central Research Station Forest Service U.S. Department of Agriculture 1992 Folwell Avenue St. Paul, MN 55108 2002 Web site: www.ncrs.fs.fed.us TABLE OF CONTENTS Page SUMMARY ............................................................................................................................................. 1 INTRODUCTION AND BACKGROUND ............................................................................................... 3 TAXONOMY.......................................................................................................................................... 5 DESCRIPTION ...................................................................................................................................... 6 RANGE ............................................................................................................................................... 7 Breeding Distribution ..................................................................................................................... 7 Non-breeding Range ....................................................................................................................... 7 BIOLOGY/NATURAL HISTORY ............................................................................................................. 8 Reproductive Biology and Phenology ..............................................................................................8 Territories and Nests ....................................................................................................................... 8 Number of Broods .......................................................................................................................... 9 Clutch Size ..................................................................................................................................... 9 Incubation and Nestling Period ...................................................................................................... 9 Nesting Success .............................................................................................................................. 9 Mortality and Predation Factors ...................................................................................................... 9 Longevity...................................................................................................................................... 10 Banding Data ................................................................................................................................ 10 Site Fidelity .................................................................................................................................. 10 Migration ...................................................................................................................................... 11 Food Habits .................................................................................................................................. 11 HABITAT ............................................................................................................................................. 12 Breeding Season............................................................................................................................ 12 Breeding Microhabitat .................................................................................................................. 13 Winter Habitats ............................................................................................................................ 13 Migration Stopover Habitats ......................................................................................................... 14 POPULATION TRENDS AND ESTIMATES .......................................................................................... 15 Breeding Bird Census .................................................................................................................... 16 Christmas Bird Count ................................................................................................................... 16 Breeding Bird Atlases .................................................................................................................... 16 State Summaries ........................................................................................................................... 17 Illinois .......................................................................................................................................... 17 Indiana ......................................................................................................................................... 18 Missouri ....................................................................................................................................... 18 New York...................................................................................................................................... 19 Ohio ............................................................................................................................................. 20 Vermont........................................................................................................................................ 20 THREATS ............................................................................................................................................. 22 Present or Threatened Destruction, Modification, or Curtailment of Species’ Habitat or Range ..... 22 Threats to Wintering Grounds ...................................................................................................... 22 Present and Historical Breeding Habitat Loss ................................................................................ 22 Present and Potential Non-breeding Habitat Loss ......................................................................... 22 Overuse for Commercial, Recreational, Scientific, or Educational Purposes .................................. 23 Disease or Predation ..................................................................................................................... 23 Inadequacy of Existing Regulatory Mechanisms ............................................................................ 23 Habitat Fragmentation .................................................................................................................. 25 Page SUMMARY OF LAND OWNERSHIP AND EXISTING HABITAT PROTECTION FOR POPULATIONS.................................................................................................................................... 26 Illinois .......................................................................................................................................... 26 Indiana ......................................................................................................................................... 26 Missouri ....................................................................................................................................... 26 New York...................................................................................................................................... 27 Ohio ............................................................................................................................................. 27 Vermont........................................................................................................................................ 27 MANAGEMENT ACTIVITIES .............................................................................................................. 28 General Management Approach .................................................................................................... 28 Breeding Habitat ........................................................................................................................... 28 Winter Habitat Management ......................................................................................................... 30 Other Management Considerations and Opportunities ................................................................. 31 Monitoring Effects of Management Activities ................................................................................ 32 PAST AND CURRENT CONSERVATION ACTIVITIES UNDERTAKEN TO BENEFIT THE SPECIES .....................................................................................................................................