New England Cottontail (Sylvilagus transitionalis) Assessment 2004 John A. Litvaitis Department of Natural Resources University of New Hampshire Durham, New Hampshire 03824 and Walter J. Jakubas Maine Department of Inland Fisheries and Wildlife Wildlife Resource Assessment Section Bangor, Maine 04401 NEW ENGLAND COTTONTAIL ASSESSMENT TABLE OF CONTENTS Page INTRODUCTION...................................................................................................5 NATURAL HISTORY.............................................................................................6 Description..................................................................................................6 Population Densities...................................................................................9 Home Range and Dispersal .......................................................................9 Food Habits ..............................................................................................10 Cover Requirements.................................................................................12 Reproduction ............................................................................................13 Mortality....................................................................................................15 Diseases...................................................................................................16 Interactions with other species .................................................................18 MANAGEMENT ..................................................................................................21 Regulatory Authority .................................................................................21 Past Goals and Objectives .......................................................................21 Past Management ....................................................................................21 Current Management................................................................................24 HABITAT ASSESSMENT....................................................................................26 Past Habitat..............................................................................................26 Current Habitat .........................................................................................27 Habitat Projections & Future Management...............................................29 POPULATION ASSESSMENT............................................................................31 Past Populations.......................................................................................31 Current Populations..................................................................................33 Population Projections & Future Management .........................................37 USE AND DEMAND ASSESSMENT ..................................................................41 Past Use and Demand .............................................................................41 Current Use and Demand.........................................................................41 Nonconsumptive Use.....................................................................41 Consumptive Use ..........................................................................42 Use and Demand Projections...................................................................42 SUMMARY AND CONCLUSIONS ......................................................................44 LITERATURE CITED ..........................................................................................47 2 NEW ENGLAND COTTONTAIL ASSESSMENT APPENDIX A .....................................................................................................55 Interactions between New England and eastern cottontail rabbits APPENDIX B .....................................................................................................59 Summary information on all sites surveyed for the presence of New England cottontails in southern Maine. APPENDIX C ....................................................................................................72 Minimum population estimate for New England cottontail in Maine LIST OF FIGURES Figure 1. Distribution of recently defined sister species of cottontails in the eastern United States (modified from Chapman et al. 1992) ...........7 Figure 2. Skull characteristics that separate New England and eastern cottontails, including the supraorbital process (a) and the nasal frontal suture (b). Adapted from Godin (1977) ................................8 Figure 3. Suggested pattern of events that influenced the abundance of early-successional habitat in New England from 1650 until present (modified from Litvaitis 1993)............................................27 Figure 4. Historic and current distributions of New England cottontails. Historic distribution is a compilation of Hall and Kelson (1959), Johnston (1972), Jackson (1973), and C. Stevens (Univ. NH, unpublished data). Current distribution is an approximation based on preliminary results of recent surveys by Walter et al. (2001) and Litvaitis et al. (2003b) ..................................................32 Figure 5. Historic (circa 1960) and current ranges of New England cottontails in Maine. Current range encompasses approximately17% of the historic range (from Litvaitis et al. 2003a)............................................................................................33 Figure 6. An illustration of a metapopulation showing patches of habitat in a fragmented landscape and how New England cottontail (NEC) might move between patches of suitable habitat. ..........................34 Figure 7. Current distribution of New England cottontails and potential areas for restoration relative to Wildlife Management Districts in southern Maine ..............................................................................40 Figure 8. Expansion of eastern cottontails into New England (from Probert and Litvaitis 1995) .............................................................56 3 NEW ENGLAND COTTONTAIL ASSESSMENT LIST OF TABLES Table 1. New England cottontail harvest estimates under hunter effort from 1935 to 1983, and harvest regulations from 1955 to 2001.....22 Table 2. Differences in landscape (L) and patch-specific (P) features associated with patches occupied by New England cottontails (NEC) versus vacant patches of habitat in southern Maine (Litvaitis et al. 2003).......................................................................28 Table 3. Percent of timberland dominated by seedling/sapling-sizes trees in six counties that approximate the historic range of New England cottontails in Maine. Data were the result of U.S.D.A. Forest Service inventories conducted in 1971 (Powell and Dickson 1984) and 1995 (Griffith and Alerich 1996) ......................29 4 NEW ENGLAND COTTONTAIL ASSESSMENT INTRODUCTION Since 1968, the Maine Department of Inland Fisheries and Wildlife (MDIFW) has aggressively pursued development and refinement of wildlife species assessments and implementation of cost-effective comprehensive programs that support selected goals and objectives for the next 15 years. Assessments are based on available information and the judgments of professional wildlife biologists responsible for individual species or groups of species. Precise data may not always be available or are too limited for meaningful statistical analysis; however, many trends and indications are sometimes clear and deserve management consideration. The assessment has been organized to group information in a user-meaningful way. The Natural History section discusses biological characteristics of the species that are important to its management. The Management section contains history of regulations and regulatory authority, past management, past goals and objectives, and current management. The Habitat and Population sections address historic, current, and projected conditions for the species and its habitat. A Summary and Conclusions section summarizes the major points of the assessment. 5 NEW ENGLAND COTTONTAIL ASSESSMENT NATURAL HISTORY Description Cottontails are true rabbits. Unlike hares, rabbits are born naked with their eyes shut, and placed in a fur-lined nest constructed by the female. Hares, on the other hand, are born covered with fur, eyes open, and the young are placed in a modest depression on the ground (Chapman 1975). Cottontails are members of the family Leporidae, which includes four North American genera: Sylvilagus, the cottontails; Lepus, the hares and jackrabbits; Brachylagus, the pygmy rabbit of the Great Basin; and Romerolagus, the volcano rabbit (R. diazi) found only on volcanic slopes in central Mexico (Chapman and Litvaitis 2003). In New England, we have two species of cottontail. The most common cottontail in southern New England is the eastern cottontail (Sylvilagus floridanus). This is the species of cottontail typically seen feeding on lawns and in other open areas. The eastern cottontail is not native to New England but was introduced by hunting clubs and natural resource agencies (Johnson 1972). Our only native cottontail is the New England cottontail (Sylvilagus transitionalis). The New England cottontail (NEC) was first described by Otram Bangs at the turn of the nineteenth century (Bangs 1895), and is recognized as a distinct species (Holden and Eabry 1970). Recently, the taxonomic status of NEC has been revised to recognize two sister species