This file was created by scanning the printed publication. Errors identified by the software have been corrected; however, some errors may remain. United States Department of Agriculture Management Recommendations Forest Service Rocky Mountain for the Northern Goshawk Forest and Range Experiment Station in the Southwestern United States Fort Collins, Colorado 80526 General Technical Report RM-217 Reynolds, Richard T.; Graham, Russell T.; Reiser, M. Hildegard; and others. 1992. Management recommendations for the northern goshawk in the southwestern United States. Gen. Tech. Rep. RM-217, Ft. Collins, CO: U.S. Department of Agriculture, Forest Service, Rocky Mountain Forest and Range Experiment Station. 90 p. Present forest conditions – loss of a herbaceous and shrubby understory, reductions in the amount of older forests, and increased areas of dense tree regeneration – reflect the extent of human influence on these forests. These changes may also be affecting goshawk populations. Information on goshawk nesting habitat and foraging behavior, and the food and habitats of selected goshawk prey, was therefore synthesized to develop a set of management objectives, desired forest conditions, and management recommendations. Key objectives of the guidelines are to provide (1) nesting, post-fledging, and foraging areas for goshawks, and (2) habitat to support abundant populations of 14 primary goshawk prey. Thinning trees in the understory, creating small openings in the forest, and prescribed fires should help produce and maintain the desired forest conditions. Other habitat elements critical for maintaining both goshawk and prey populations include abundant snags and large downed logs, woody debris, interspersion of different tree sizes across the landscape, and the majority of a goshawk’s home range in older-aged forests. These guidelines should also benefit forest health, soil productivity, and the habitats of other old-growth- dependent plants and animals. USDA Forest Service August, 1992 General Technical Report RM-217 Management Recommendations for the Northern Goshawk in the Southwestern United States Richard T. Reynolds1, Russell T. Graham, M. Hildegard Reiser, Richard L. Bassett, Patricia L. Kennedy, Douglas A. Boyce, Jr., Greg Goodwin, Randall Smith, and E. Leon Fisher Rocky Mountain Forest and Range Experiment Station and Southwestern Region Forest Service, U.S. Department of Agriculture2 1 Author affiliations are listed in Appendix 6. 2 The Rocky Mountain Station is headquartered in Fort Collins. Colorado, in cooperation with Colorado State University; the Southwestern Region is headquartered in Albuquerque, New Mexico. Table of Contents Executive Summary. 1 Acknowledgements . ................. 33 The Northern Goshawk Scientific Committee . 1 References ......................... 35 Components of the Nesting Home Range .... 3 Goshawk Prey ......................... 4 Present Forest Conditions . 5 Appendix 1. Description of Management Recommendations . 6 ponderosa pine, mixed-species, and Related Benefits of Achieving Desired spruce-fir forest cover types .......... 49 Forest Conditions . 8 Ponderosa Pine Forest Cover Type. 49 Mixed-Species Forest Cover Type . 50 Introduction ......................... 9 Engelmann Spruce-Subalpine Fir (Spruce-fir) Forest Cover Type. 50 Background. 10 Appendix 2. Vertebrates in the diets Goshawk Populations and Prey of nesting northern goshawks from Species ........................... 11 various locations in North America .... 51 Factors Limiting Goshawk Populations:-.... 11 Diet Breadth and Population Stability ...... 12 Appendix 3. Natural history, habitat, Prey Species .......................... 12 and management recommendations for selected goshawk prey species . 53 Conservation of the Northern American Robin . 53 Goshawk: Approach. 13 Band-tailed Pigeon . 54 Nest Area ............................ 13 Blue Grouse . 56 Post-fledging Family Area (PFA) ......... 13 Chipmunks . 58 Foraging Area. 14 Cottontails . 60 Hairy Woodpecker . 62 Synthesis of Desired Forest Mantled Ground Squirrel . 64 Conditions. 15 Mourning Dove. 65 Nest Area ............................ 15 Northern Flicker. 67 Post-fledging Family Area (PFA) ......... 15 Red-Naped Sapsucker . 68 Foraging Area ....... .' . 16 Red Squirrel . 69 Steller's Jay. 72 Present Forest Conditions . 20 Tassel-Eared Squirrel . 74 Williamson's Sapsucker ................ 76 Management Recommendations for the Home Range. 21 Appendix 4. Forest Health ............ 79 Nest Area ............................ 21 Dwarf Mistletoe . 79 Post-fledging Family Area (PFA) ......... 22 Root Diseases . 79 Foraging Area. 26 Western Spruce Budworm . 79 Bark Beetles . 79 Related Benefits of Achieving Desired Forest Conditions . 30 Appendix 5. Vegetation structural Landscape Ecology . 30 stage determination and Species Associated with Old-Growth . 30 management options . ................ 81 Susceptibility to Catastrophic Crown Fire. 30 Vegetation Structural Stage Determination . 81 Large Snags and Downed Logs . 31 Management Options for Developing Forest Productivity ..................... 31 Vegetation Structural Stages. 81 Maintenance of Mycorrhizal Communities . 31 Forest Products ........................ 32 Forage Production . 32 Appendix 6. The Scientific Committee . .. 85 Research Needs . 32 Appendix 7. Glossary of Terms ........ 87 Northern Goshawk in the Southwestern United States Executive Summary The northern goshawk (Accipiter gentilis development of the "desired forest conditions" for atricapillus) (hereafter called the "goshawk") is the the goshawk and its prey required certain largest North American member of the genus assumptions: Accipiter, which includes both the sharp-shinned 1) goshawks and their prey populations are hawk (Accipiter striatus) and the Cooper's hawk limited by the availability of their foods (Accipiter cooperii). It breeds in coniferous, and habitats, deciduous, and mixed forests throughout much of 2) the availability of abundant, sustainable North America. prey populations reduces the probability The goshawk is a: forest habitat generalist that uses that food is limiting, a variety of forest types, forest ages, structural 3) extreme fluctuations of goshawk conditions, and successional stages. It preys on populations caused by changes in the small- to medium-sized birds and mammals (robins abundance of one or more prey will be and chipmunks to grouse and hares), which it dampened when a wider variety of prey captures on the ground, in trees, or in the air. A species are available, single goshawk rna y consume one-to-two prey per 4) the foods and habitats of goshawk prey in day. southwestern forests are similar in The principal forest types occupied by the adjacent regions, and goshawk in the Southwest are ponderosa pine, 5) the forest attributes and age-classes of mixed-species, and spruce-fir. There is a concern southwestern forests described herein that populations and reproduction of the goshawk are can be sustained with scientific declining in these forests and elsewhere in the management. western United States. These declines may be These assumptions reveal areas where research is associated with forest changes caused by timber needed on goshawk and forest ecology. harvesting. However, fire suppression, livestock The following are key concepts fundamental to the grazing, drought, and toxic chemicals may be GSC recommendations: involved. Because of the concerns over the effects of • Forests within goshawk nesting home timber harvesting, the goshawk was listed as a ranges should be an interspersed mosaic "sensitive species" by the Southwestern Region of of structural stages -- young to old forests the Forest Service, U.S. Department of Agriculture in -- to increase the diversity of habitat for 1982. goshawks and their many prey species. Six vegetation structural stages (VSS) The Northern Goshawk were used to describe regeneration, Scientific Committee growth, and development of forests in the Southwest (Fig. 1). The proportions of the VSS and their interspersion in the The Northern Goshawk Scientific Committee forest is how the GSC described the (GSC) was established by the Regional Forester of the Southwestern Region in the fall of 1990. Its forest mosaic. • The extent to which southwestern forests charter was to develop a credible management strategy to conserve the goshawk in the southwestern were modified by Native Americans United States. This report describes the process before European settlement is not well used, findings, and recommendations of the scientific known. Since European settlement, committee. In developing the recommendations, we management practices (such as timber used available information on goshawk biology, harvesting, livestock grazing, and fire behavior, diet, and habitat. Information about control) have changed the structure and goshawk foraging habitat was augmented with species composition of forests. Today, information on the habitat and foods of its main prey much forested area consists of dense species. From this the GSC developed a set of "thickets" of small-diameter trees (Fig. 2). "desired forest conditions" that, in their best Forests containing these thickets are estimate, will sustain goshawk populations in the prone to catastrophic, tree-killing fire, and Southwestern Region. insect and disease outbreaks. Because of Because information on goshawk biology is inter-tree competition for moisture, limited, and our ability to produce and sustain certain nutrients, and light, these thickets will