December 16, 2017

TurtlePop Project

Contact: David Bowne, Elizabethtown College,

Initiated: 2011


Researchers find skewed age and sex ratios in freshwater turtle species and these findings are often attributed to anthropogenic changes in the landscape. A high concentration of roads near turtle nesting sites may, for example, selectively increase mortality of adult females, leading to a male-skewed population. Increased predation of nests caused by a high density of predators that flourish in human-dominated landscapes (e.g. raccoons, opposums) may reduce juvenile recruitment and cause an adult-skewed population.  As of now, each of these statements has not been rigorously tested due in part to the spatial restrictions of the few studies that have been conducted.  In the TurtlePop project, members of EREN will conduct turtle sampling in lentic habitats on or near campus in order to determine the population structure of turtles across an urbanization gradient.

We will test the following primary hypotheses:

  1. The secondary sex ratio of turtles will be more male-biased as urbanization increases. Urbanization will be measured by road density, human population density, and habitat types within an area scaled to the movement range of the turtle species.
  2. The population age distribution will be more biased towards adults as urbanization increases.


The turtle species that we study in this project may serve as model species for the conservation of other freshwater turtles. Worldwide, roughly 45% of freshwater turtle taxa are listed as threatened in the 2000 IUCN Red List of Threatened Species. By better understanding how common freshwater turtles respond to changes along an urbanization gradient, one can devise improved conservation strategies for the many imperiled freshwater turtle species.

TurtlePop Curriculum-2012

Guidelines for the use of live amphibians and reptiles in field research

Animal Protocol

TurtlePop Protocol

View the TurtlePop Participants

View the Map of the Participating Institutions

EREN Turtlepop Facebook Page

Helpful Turtlepop Youtube Videos

TurtlePOP Poster at the Ecological Society of America Meetings 2013

2012 Data

Project Timeline [coming soon]
Images [coming soon]

For more information contact:
David Bowne– Elizabethtown College