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Ecology and Vulnerability Smooth Green Snake
Ecology and Vulnerability
Smooth Green Snake
The green snake ranges from Nova Scotia and southern Ontario, throughout most of New England into the Appalachian Mountains of Virginia, and west into Minnesota... Read More
The green snake ranges from Nova Scotia and southern Ontario, throughout most of New England into the Appalachian Mountains of Virginia, and west into Minnesota. Life history information is sparse for this species 6. Green snakes are grassland dependent, and tend to reside in open upland areas with thick cover, such as fields, wet meadows, bogs, open aspen stands, sphagnum bogs, marshes, shrublands with thick vines and brambles, and open hardwood stands 3,7.
Green snakes emerge in April or May, and lay 1-2 egg clutches that are highly variable in size (2-18 eggs) in June to September 3,6. Females may encourage egg hatching by incubating eggs internally before laying them in rodent burrows, sawdust piles, sandy soils, rotting logs, or even occasionally in trees 4,6. Communal nesting and denning is common in this species 6. Green snakes are active during the day, and feed primarily on arthropods (insects) 7. They hibernate over the late fall and winter, and may use linear riparian habitat features to migrate to and from denning sites and populations 6. The green snake does not, however, appear to move large distances, and so may be vulnerable to habitat fragmentation 6. Habitat loss has been a primary cause of green snake decline throughout their range. Other important sources of mortality include pesticides and road mortality 6. These snakes have a conservation status (endangered, threatened, or a species of Greatest Conservation Need) in several states 6.
A few studies indicate that climate change impacts, such as extreme precipitation events could negatively affect snakes in the Northeast and Midwest. For example, after a year with exceptionally high summer rainfall, a skin infection caused significant declines in New Hampshire’s timber rattlesnake (Crotalus horridus) population 1. Likewise, extreme fluctuations of the water table, especially near hibernation sites, caused demographic stress in populations of Eastern Massasauga rattlesnakes (Sistrurus catenatus catenatus); this trend will likely be exacerbated in the future 5. Flooding of communal denning sites has been known to cause mass mortality in green snakes 6. In addition, green snakes are thought to be vulnerable to reductions in invertebrate prey due to extreme climate events, drought (as has been seen in the rough green snake (Opheodrys aestivus)), and extremely low temperatures 6. On the other hand, higher temperatures can increase the activity patterns, and perhaps the survival rates, of ectotherms (animals that need heat external from their body) such as snakes 2. Finally, because green snakes appear to not travel far, are very localized and clustered in their distribution, are relatively short lived, and have low to moderate reproductive output, they are likely to be adversely affected by extreme or random disturbances related to climate change (even if they are only short in duration). These snakes will unlikely be able to recolonize into neighboring populations after such events 6.
1. Clark, R.W., M.N. Marchand, B.J. Clifford, R. Stechert, and S. Stephens. 2011. Decline of an isolated timber rattlesnake (Crotalus horridus) population: Interactions between climate change, disease, and loss of genetic diversity. Biological Conservation 144: 886–891.
2. Cox, W.A., F.R. Thompson, and J. Faaborg. 2012. Species and Temporal Factors Affect Predator-Specific Rates of Nest Predation for Forest Songbirds in the Midwest. The Auk 129: 147–155.
3. DeGraaf, R.M., and D.D. Rudis. 1986. New England Wildlife: Habitat, Natural History, and Distribution. Forest Service Northeast Forest Experiment Station General Technical Report NE - 108.
4. Hughes, D.F. 2015. Opheodrys vernalis (Smooth Greensnake). Nest Selection. Herpetological Review 46: 453.
5. Pomara, L.Y., B. Zuckerberg, O. LeDee, and K.J. Martin. 2014. A Climate Change Vulnerability Assessment for the Eastern Massasauga Rattlesnake an Endemic of the Upper Midwest and Great Lakes Region.
6. Redder, A.J., B.E. Smith, and D.A. Keinath. 2006. Smooth green snake (Opheodrys vernalis): a technical conservation assessment. USDA Forest Service, Rocky Mountain Region Available: http://www.fs.fed.us/r2/ Projects/scp/assessments/smoothgreensnake.pdf.
7. Sacerdote-Velat, A.B., J.M. Earnhardt, D. Mulkerin, D. Boehm, and G. Glowacki. 2014. Evaluation of headstarting and release techniques for population augmentation and reintroduction of the smooth green snake. Animal Conservation 17: 65–73.
Hoving, C. L., Y. M. Lee, P. J. Badra, and B. J. Klatt. 2013. Changing climate, changing wildlife: a vulnerability assessment of 400 Species of Greatest Conservation Need and game species in Michigan. Wildlife Division Report #3564. Michigan Department of Natural Resources, Lansing, MI.
Related Adaptation Strategies and Actions
Related Habitats (detailed)
Related Species Groups
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