United States Department of Agriculture Conservation Assessment Forest Service Rocky of the Pygmy Nuthatch in Mountain Region Black Hills the Black Hills National National Forest Custer, Forest, South Dakota and South Dakota May 2003 Wyoming Cameron Ghalambor Conservation Assessment of the Pygmy Nuthatch in the Black Hills National Forest, South Dakota and Wyoming Cameron Ghalambor Department of Biology University of California – Riverside Riverside, CA 92521 Under a personal services contract with: USDA Forest Service Black Hills National Forest Cameron Ghalambor is currently a postdoctoral research biologist at the University of California at Riverside. He received his B. A. from University of California at Los Angeles and his Ph.D. from the University of Montana at Missoula. His Ph.D. and subsequent research has focused in part on the comparative reproductive biology of Pygmy, Red-breasted, and White-breasted Nuthatches. His work on nuthatches and related species has investigated such questions as 1) the ecological and evolutionary determinants that shape different incubation strategies, 2) the role of life histories in determining parental investment strategies, and 3) the adaptive significance of conifer resin use at Red-breasted Nuthatch nests. His current address is: Department of Biology, University of California - Riverside, Riverside, CA 92521. Table of Contents INTRODUCTION.......................................................................................................................................... 1 CURRENT MANAGEMENT SITUATION ................................................................................................. 2 Management Status.................................................................................................................................... 2 Existing Management Plans, Assessments, Or Conservation Strategies ................................................... 3 REVIEW OF TECHNICAL KNOWLEDGE ................................................................................................ 3 Systematics ................................................................................................................................................ 3 Distribution And Abundance..................................................................................................................... 5 Distribution Recognized In Primary Literature..................................................................................... 5 Populations Within The United States And Canada......................................................................... 5 Populations Within Mainland Mexico ............................................................................................. 6 Additional Information From Federal, State, And Other Records ........................................................ 7 Estimates Of Local Abundance............................................................................................................. 7 Population Trend ....................................................................................................................................... 8 Broad Scale Movement Patterns................................................................................................................ 8 Habitat Characteristics............................................................................................................................... 9 Foraging Habitat ................................................................................................................................. 10 Food Items Consumed.................................................................................................................... 11 Nesting Habitat ................................................................................................................................... 12 Nest Tree........................................................................................................................................ 12 Characteristics Of Nest Tree .......................................................................................................... 13 Tree Height .................................................................................................................................... 14 Diameter Of Nest Tree................................................................................................................... 14 Height Of Nest Cavity In The Tree................................................................................................ 14 Habitat Surrounding Nest Tree ...................................................................................................... 14 Condition Of Nest Tree:................................................................................................................. 14 Communal Roost Cavities .................................................................................................................. 14 Landscape Context Review................................................................................................................. 15 Movements.......................................................................................................................................... 15 Breeding Biology..................................................................................................................................... 16 Phenology Of Courtship And Breeding .............................................................................................. 16 Courtship Characteristics .................................................................................................................... 16 Nest Site Characteristics ..................................................................................................................... 17 Cavity Dimensions......................................................................................................................... 18 Cavity Microclimate....................................................................................................................... 18 Maintenance Or Reuse Of Nests, Alternate Nests.......................................................................... 18 Clutch Initiation And Size .................................................................................................................. 19 Egg Shape ...................................................................................................................................... 19 Clutch Size ..................................................................................................................................... 20 Parental Care....................................................................................................................................... 21 Incubation....................................................................................................................................... 21 Brooding......................................................................................................................................... 22 Feeding Nestlings........................................................................................................................... 22 Nest Sanitation ............................................................................................................................... 23 Demography ............................................................................................................................................ 23 Life History Characteristics ................................................................................................................ 23 Survival And Reproduction ................................................................................................................ 23 Survival .......................................................................................................................................... 23 Reproduction.................................................................................................................................. 24 Factors Influencing Species Density................................................................................................... 24 Breeding Season............................................................................................................................. 25 Non-Breeding Season..................................................................................................................... 25 Local Density Estimates ..................................................................................................................... 26 Limiting Factors.................................................................................................................................. 26 i Nest Site Availability ..................................................................................................................... 26 Roost Site Availability ................................................................................................................... 26 Availability Of Foraging Substrate ................................................................................................ 26 Patterns Of Dispersal .......................................................................................................................... 27 Initial Dispersal From Natal Site...................................................................................................