The Significance of “Good Years”: Using Demographic Modeling to Predict Recruitment Rates for a Threatened Turtle Species Nathan W.
1,2 Byer ,
Craig
3 Nein ,
Scott A.
4 Smith ,
and Richard A.
1 Seigel
1: Department of Biological Sciences, Towson University, Towson, MD ; 2: Present Address: Department of Forestry and Wildlife Ecology, University of Wisconsin – Madison, Madison, WI (contact:
[email protected]); 3:Johnson, Mirmiran and Thompson, Inc., Sparks, MD; 4: MD DNR – Wildlife and Heritage Service, Wye Mills Field Office, Wye Mills, MD
Introduction • Turtles are one of the most threatened taxonomic groups – as of 2012, 228 out of 322 turtles are listed on the IUCN Red List • Field studies suggest that turtles experience high rates of egg and nest depredation – often close to 100% • Most studies are of short duration - may miss years where nest failure is less severe • Failing to take into account undetected variation in recruitment rates may lead to inaccurate population assessments
The Bog Turtle
Results and Discussion
• Habitat specialist – requires wet meadows and bogs • Low reproductive output (1-5 eggs) • Small population sizes
Figure 1: Photograph of a (often