Timber rattlesnake
Crotalus horridus
ITIS Species Code:   174306         NatureServ Element Code:   ARADE02040
NatureServe Global Rank: 
NatureServe State (NC) Rank: 
Federal Status: 
NC State Status: 
Land Unit

US Fish & Wildlife Service
US Forest Service
US National Park Service
US Department of Defense
NC State Parks
NC University System
NC Wildlife Res. Com.
NC Forest Service
NC Div. of Coastal Mgmt.
Local Governments
Non-Governmental Org.
Other Public Lands
Private Lands

GAP Status 1-2
All Protected Lands




% of Dist. on
Prot. Lands

7.0 %
47.6 %
12.0 %
12.6 %
4.5 %
2.2 %
8.1 %
1.4 %
0.7 %
2.7 %
2.7 %
0.3 %
< 0.1 %

35.4 %
% of Dist. on
All Lands

0.9 %
6.5 %
1.6 %
1.7 %
0.6 %
0.3 %
1.1 %
0.2 %
< 0.1 %
0.1 %
0.4 %
< 0.1 %
86.3 %

4.8 %

In the north, often on wooded rocky hillsides or in mature hardwood forests with many downed logs and a layer of leaves and humus. In the southern and southeastern part of the range, occurs in bottomland hardwoods and swamps not subject to winter flooding; cane thickets associated with the edges of wetlands; cedar swamps; maritime shrub thickets; hardwood hammocks; dense canopied pine flatwoods with wiregrass, saw palmetto, or gallberry understory; oak-pine woods; oak uplands; and grown-up farmlands; also coastal marsh in association with wooded corridors along watercourses or causeways; apparently requires both close canopy and open canopy within the home range (Martin, in Tyning 1992). Occurs near streams in late summer in some areas.

Upland populations hibernate commonly in burrows and crevices of rock outcroppings, often on steep slopes facing in southerly or westerly directions (Martin 1992). Lowland populations hibernate in the base of hollow trees, in stumps, in underground burrows, or in similar sites. In the New Jersey Pine Barrens, hibernated in proximity of streams in low-lying white cedar swamps (Reinert and Zappalorti 1988); coiled among tree roots in the water table; young may trail adults to hibernacula (Zappalorti and Reinert, in Tyning 1992). In New York, made nonrandom use of rock cover at denning site, and use of different outcrops varied among years; tended to be under rock ledge or in full shade when ground temperature in sun was greater than 27.8 C, in full sun when ground temperature was less than 27.2 C (Peterson 1990).

Copulation occurs near winter den. Gravid females select relatively warmer (less densely forested) habitats than do nongravid individuals (Reinert and Zappalorti 1988), and are easier to find than are nongravid individuals (Peterson 1990). In the New Jersey Pine Barrens, parturition frequently occurs in upland pine-oak forest as much a 1 km from hibernaculum (Reinert and Zappalorti 1988). In the region on northern Virginia, gravid females favor exposed rocks usually within 500 m of over- wintering dens (Martin 1992).

See also Brown (1993) for habitat information.

Occupied Landcover Map Units:
Code NameDescription NC Natural Heritage Program Equivalent
75 Tidal Swamp Forest Swamp tupelo dominated forest with or without black tupelo and/or cypress trees. Restricted to the tidal zones in the coastal plain. May have inclusions of coastal red cedar woodlands. Tidal cypress - gum swamp
121 Maritime Pinelands Loblolly forests and woodlands of the outer coastal plain. Estuarine Fringe Loblolly Pine Forest
17 Maritime Forests and Hammocks Maritime forests and woodlands dominated by live or sand laurel oak. Estuarine Fringe forests dominated by loblolly pine. Coastal Fringe Evergreen Forest, Maritime Deciduous Forest, Maritime Deciduous Forest
126 Interdune Wooded Depression Swamp Includes swamps dominated by sweetbay and swampbay or dogwood dominated forests. Maritime Shrub Swamp, Maritime Swamp Forest
173 Coastal Plain Riverbank Shrubs Shrub dominated riverbanks, commonly dominated by willows and/or alders. Sand and Mud Bar
50 Coastal Plain Mixed Bottomland Forests Includes forests dominated by a variety of hardwood species, including sweetgum, cottonwood, red maple. Coastal Plain Bottomland Hardwood (in part), Coastal Plain Levee Forest
49 Coastal Plain Oak Bottomland Forest Bottomland forests dominated by deciduous oak alliances. Oaks represented can include swamp chestnut, cherrybark, willow, and/or overcup oak. Inclusions of loblolly pine temporarily flooded forests occur in patches. Hydrology is temporarily to seasonally flooded. Coastal Plain Bottomland Hardwoods (in part) blackwater subtype, brownwater subtype
158 Coastal Plain Nonriverine Wet Flat Forests Loblolly pine - Atlantic white-cedar - red maple - swamp tupelo saturated forests as well as forests dominated by loblolly, sweetgum, and red maple in non-riverine flats. Non-riverine Wet Hardwood Forest
15 Seepage and Streamhead Swamps Includes extensive peat flats in the coastal plain, dominated by swamp tupelo, maples, and Atlantic white cedar alliances. In the sandhills includes streamhead pond pine and bay forests alliances. Saturated hydrology. Bay Forest, Small Depression Pocosin, Streamhead Atlantic White Cedar Forest, Streamhead Pocosins
30 Cypress-Gum Floodplain Forests Swamps dominated by black or swamp tupelo with or without Taxodium. Seasonally to semi-permanently flooded hydrology. Cypress-Gum Swamps
78 Pond-Cypress - Gum Swamps, Savannas and Lakeshores Cypress dominated swamps and lakeshores. Can include bays dominated by pond cypress or shorelines of coastal plain lakes with a narrow band of cypress. Non-riverine Swamp Forest, Natural Lakeshores (in part)
385 Oak Bottomland Forest and Swamp Forest The swamp chestnut oak, cherrybark oak, shumard oak and sweetgum alliance is one representative. Other alliances are dominated by water, willow, and overcup oaks. Swamp forests can be dominated by sweetgum, red maple, and black gum being dominant. Loblolly can occur in combination with sweetgum and red maple, or with tulip poplar. Includes saturated and semi- to permanently flooded forests in the mountains. Piedmont/Mountain Bottomland Forest, Piedmont/Mountain Swamp Forest
67 Wet Longleaf or Slash Pine Savanna Wet flatwoods and pine savannas, typically dominated by longleaf pines, but slash or pond pines may be the dominant pines. Wet Pine Flatwoods
97 Mesic Longleaf Pine Longleaf pine woodlands without a major scrub oak component. Slash or loblolly pines may be present as well. Mesic Pine Flatwoods
42 Xeric Longleaf Pine Sandhills including a range of longleaf pine density from predominantly wiregrass, scrub oak dominated to true longleaf pine woodland. This does not include mesic or saturated flatwood types. Xeric Sandhill Scrub, Pine/Scrub Oak Sandhill, Coastal Fringe Sandhill
46 Xeric Oak - Pine Forests Mixed forest dominated by yellow pines with white or northern red oaks co-dominating. Pine Oak Heath
232 Xeric Pine-Hardwood Woodlands and Forests Mixed forest dominated by yellow pines with drier oaks including southern red, post, and chestnut oaks. Dry Oak Hickory Forest
384 Piedmont/Mountain Mixed Bottomland Hardwood Forests Includes temporarily to seasonally forests dominated by hardwood species. Hardwoods include sweetgum, red maple, sycamore which co-occur in a mosaic of bottomland and levee positions. Includes alluvial hardwood forests in the mountains. Hemlock and white pine may occur as inclusions, but are generally mapped separately. Piedmont/Mountain Alluvial Forest, Piedmont/Mountain Levee Forest
383 Piedmont Mixed Successional Forest Generally loblolly mixed with successional hardwoods. Sweetgum, tulip poplar and red maple are common co-dominants in these successional forests. No equivalent
228 Piedmont Dry-Mesic Oak and Hardwood Forests Primarily oak dominated forests, white oak is often dominant, with co-dominants including . Also represented by sweetgum and tulip poplar dominated forests. Dry Mesic Oak Hickory Forest, Basic Oak Hickory Forest, Dry Oak Hickory Forest
222 Piedmont Dry-Mesic Pine Forests Loblolly dominated forests resulting from succession following clearing. This type occurs on all moisture regimes following disturbance with the exception of the extremely xeric sites. No equivalent
382 Dry Mesic Oak Pine Forests Mixed forests of the coastal plain and piedmont. Includes loblolly pine with white, southern red and/or post oak and loblolly with water oak. On basic sites of the piedmont, eastern red cedar may co-occur with post, black, and blackjack oaks. Dry Mesic Oak Hickory Forest, Xeric Hard Pan Forest, Chestnut Oak Forest, Dry Mesic Oak Hickory Forest, Dry Oak Hickory Forest
220 Piedmont Xeric Pine Forests Dry to xeric pine forests dominated by Virginia pine, shortleaf pine or Eastern Red Cedar. Pine Oak Heath
226 Piedmont Xeric Woodlands Generally post and blackjack oak dominated woodlands. White ash and pignut hickory can be found in combination with Eastern red cedar on glades. Xeric Hardpan Forest
20 Coniferous Regeneration Regenerating pine stands. Predominantly loblolly pine, but slash and longleaf stands occur as well. No equivalent
21 Coniferous Cultivated Plantation (natural / planted) Managed pine plantations, densely planted. Most planted stands are loblolly, but slash and longleaf occur as well. No equivalent
51 Deciduous Cultivated Plantation Planted deciduous trees. Includes sweetgum and sycamore plantations. No equivalent
36 Successional Deciduous Forests Regenerating deciduous trees with a shrub stature. Commonly dominated by sweetgum, tulip poplars and maples. No equivalent
202 Residential Urban Includes vegetation interspersed in residential areas. Includes lawns, mixed species woodlots, and horticultural shrubs. Vegetation accounts for between 20 - 70% of the cover. No equivalent
203 Urban Low-Intensity Developed Highly developed areas with vegetation accounting for < 20% of the cover. No equivalent
522 Northern Hardwoods High Elevation forests including yellow birch, American beech, and yellow buckeye. Includes forests with Hemlock and Yellow Birch. Northern Hardwoods Forest, Boulderfield Forest
525 Appalachian Oak Forest A variety of oak forest types including Black, White, Scarlet Oaks in dry to mesic situations. Includes forests historically co-dominated by American Chestnut. High Elevation Red Oak Forest, Montane White Oak Forest
526 Appalachian Cove Forest Mixed Mesophytic forests of the mountains. Includes tuliptree, basswood, yellow buckeye and surgar maple. This class is mapped to include cove forests dominated or co-dominated by hemlock. Rich Cove Forest, Acidic Cove Forest
527 Appalachian Hemlock Upland hemlock forests of the moutains region. Vary from side slopes to steep slope positions. Canada Hemlock Forest
528 Appalachian Xeric Pine Forest Pine forests and woodlands on xeric sites. A variety of pines, including Virginia, Shortleaf, Eastern White Pine, Table Mountain and Pitch pine. Often small areas of dense pine within a matrix of Xeric Oak-Pine Forests. Pine Oak Heath
529 Appalachian Xeric Mixed Forest Mixed forests with Virginia, Shortleaf, Eastern White Pine, Table Mountain and Pitch pines in combination with xeric oak species. Oaks include, white, Southern Red, black, and rock chestnut. Pine Oak Heath
530 Appalachian Xeric Deciduous Forest Deciduous forests in the mountains dominated by Xeric Oak species. Species include, white, Southern red, black, and rock chestnut. High Elevation Red Oak Forest, Montane White Oak Forest
View Entire Landcover Legend
Additional Spatial Constraints:
Exclude all area outside of known range.
Collins, J. T. and J. L. Knight. 1980. CROTALUS HORRIDUS. Catologue of American Amphibians and Reptiles. SSAR NO. 47:1-2.

Brown, W. S., D. W. Pyle, K. R. Greene, and J. B. Friedland-er. 1982. Movements and temperature relationships of tim- ber rattlesnakes (Crotalus horridus) in northeastern New York. J. Herpetol. 16:151-161.

Peterson, A. 1990. Ecology and management of a timber rattlesnake (CROTALUS HORRIDUS L.) population in south-central New York. Pages 255-261 in Mitchell et al., eds. Ecosystem management:rare species and significant habitats. New York State Mus. Bull. 471

Martin, W. H. 1993. Reproduction of the timber rattlesnake (CROTALUS HORRIDUS) in the Appalachian Mountains. J. Herpetol. 27:133-143.

Conant, R. and J. T. Collins. 1991. A field guide to reptiles and amphibians:eastern and central North America. Third edition. Houghton Mifflin Co., Boston, Massachusetts. 450 pp.

Gibbons, J. W., and R. D. Semlitsch. 1991. Guide to the reptiles and amphibians of the Savannah River Site. Univ. of Georgia Press, Athens. xii + 131 pp.

Campbell, J. A., and E. D. Brodie, Jr., editors. Biology of the pit vipers. Selva, Tyler, Texas.

Ernst, C. H. 1992. Venomous reptiles of North America. Smithsonian Inst. Press, Washington, D.C. ix + 236 pp.

Tyning, T. F., editor. 1992. Conservation of the timber rattlesnake in the northeast. Massachusetts Audubon Society, Lincoln, Massachusetts.

Brown, W. S. 1993. Biology, status, and management of the timber rattlesnake (CROTALUS HORRIDUS):a guide for conservation. SSAR Herp. Circ. No. 22. vi + 78 pp.

Fraser, D. F., and R. W. Fritsch, II. 1991. The status of the timber rattlesnake in east Glastonbury, Connecticut 1985-1990. Report submitted to Connecticut Department of Environmental Protection, Wildlife Bureau. 41 pp.

Reinert, H. K., and R. T. Zappalorti. 1988. Timber rattlesnakes (CROTALUS HORRIDUS) of the Pine Barrens:their movement patterns and habitat preference. Copeia 1988:964-978.

Reinert, H. K., and R. T. Zappalorti. 1988. Field observation of the association of adult and neonatal timber rattlesnakes, CROTALUS HORRIDUS, with possible evidence for conspecific trailing. Copeia 1988:1057-1059.

Smith, P. W. 1961. The amphibians and reptiles of Illinois. Illinois Natural History Survey 28:1-298.

Webb, R. G. 1970. Reptiles of Oklahoma. University of Oklahoma Press, Norman. 370 pp.

Barbour, R. W. 1971. Amphibians and reptiles of Kentucky. Univ. Press of Kentucky, Lexington. x + 334 pp.

Klauber, L. M. 1972. Rattlesnakes:their habits, life histories, and influence on mankind. Second edition. Two volumes. Univ. California Press, Berkeley.

Minton, S. A., Jr. 1972. Amphibians and reptiles of Indiana. Indiana Academy Science Monographs 3. v + 346 pp.

Conant, R. 1975. A Field Guide to Reptiles and Amphibians of Eastern and Central North America. Second Edition. Houghton Mifflin Company, Boston, Massachusetts. xvii + 429 pp.

Mount, R. H. 1975. The Reptiles and Amphibians of Alabama. Auburn University Agricultural Experiment Station, Auburn, Alabama. vii + 347 pp.

Reinert, H. K., D. Cundall, and L. M. Bushar. 1984. Foraging behavior of the timber rattlesnake, CROTALUS HORRIDUS. Copeia 1984:976-981.

Behler, J. L., and F. W. King. 1979. The Audubon Society field guide to North American reptiles and amphibians. Alfred A. Knopf, New York. 719 pp.

Martof, B. S., W. M. Palmer, J. R. Bailey, and J. R. Harrison, III. 1980. Amphibians and reptiles of the Carolinas and Virginia. University of North Carolina Press, Chapel Hill, North Carolina. 264 pp.

Vogt, R. G. 1981. Natural history of amphibians and reptiles of Wisconsin. Milwaukee Public Museum. 205 pp.

Collins, J. T. 1982. Amphibians and reptiles in Kansas. Second edition. Univ. Kansas Mus. Nat. Hist., Pub. Ed. Ser. 8. xiii + 356 pp.

Brown, C. W., and C. H. Ernst. 1986. A study of variation in eastern timber rattlesnakes, CROTALUS HORRIDUS Linnae (Serpentes:Viperidae). Brimleyana 12:57-74.

DeGraaf, R. M., and D. D. Rudis. 1983. Amphibians and reptiles of New England. Habitats and natural history. Univ. Massachusetts Press. vii + 83 pp.

Tennant, A. 1984. The Snakes of Texas. Texas Monthly Press, Austin, Texas. 561 pp.

Brown, W. S. 1987. Hidden life of the timber rattler. National Geographic 172:128-138.

Green, N. B., and T. K. Pauley. 1987. Amphibians and reptiles in West Virginia. University of Pittsburg Press, Pittsburg, Pennsylvania. xi + 241 pp.

Johnson, T. R. 1987. The amphibians and reptiles of Missouri. Missouri Department of Conservation, Jefferson City. 368 pp.

Brown, W. S. 1991. Female reproductive ecology in a northern population of the timber rattlesnake, CROTALUS HORRIDUS. Herpetologica 47:101-115.

Dundee, H. A., and D. A. Rossman. 1989. The amphibians and reptiles of Louisiana. Louisiana State Univ. Press, Baton Rouge.

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10 March 2005
This data was compiled and/or developed by the North Carolina GAP Analysis Project.

For more information please contact them at:
NC-GAP Analysis Project
Dept. of Zoology, NCSU
Campus Box 7617
Raleigh, NC 27695-7617
(919) 513-2853