Alabama Red-bellied Turtle
Why has nothing been done to solve the road mortality problem of the Federally
Endangered Alabama red-bellied turtle?
Matthew J. Aresco, Ph.D.
Director, Nokuse Plantation
13292 Co. Hwy 3280
Bruce, FL 32455
The Alabama red-bellied turtle (Pseudemys alabamensis) is a large emydid turtle that only occurs in streams and embayments in the lower part of the Mobile Bay Drainage System in Mobile and Baldwin Counties in Alabama. This species was listed as Endangered by the U.S. Fish and Wildlife Service in 1987 and became the Official State Reptile of Alabama in 1990. Human predation on adults and eggs was a significant cause of the historic decline of this species. Presently, road mortality is the most significant problem facing the long-term survival and recovery of this species.
The Mobile Causeway (US 90/98) between Spanish Fort and Mobile, AL was built across islands and bays on the deltas of the Apalachee, Tensaw and Blakeley Rivers. These sandy islands are key nesting sites for the Alabama red bellied turtle. Each year, gravid females come on shore to lay eggs along US 90. Many of these females and hatchlings are killed on the highway. For example, in 2001-2002, 131 individuals (hatchlings and adult females) were reported as killed by vehicles by Dr. David Nelson of the University of South Alabama. In 1992-1993, a mark-recapture study by Dr. James Dobie of Auburn University estimated a population size of only 209 adults in a study area that included Chocalata Bay, Apalachee River, and Minette Bay. A total of 82 adult females were trapped in 1992-1993. During the same period, 20 gravid female Alabama red-bellied turtles were found road-killed on the Mobile Causeway. The annual losses of 15-20 reproductive females (that require 12-15 years to reach maturity) in such a small population may have significant population viability implications and may result in a long-term population decline.
The road mortality problem of Pseudemys alabamensis could be easily solved by the construction of a low barrier fence along 3.4 miles of the Causeway. Although there are several driveways that enter private properties along the highway, installation of this fencing would probably reduce road kills by at least 95%. The U.S. Fish and Wildlife Service had hoped that the project could be paid for by mitigation funds from the future widening of nearby Interstate 10 but this has not happened. FHWA has now recommended the use of Federal Transportation Enhancement (TE) funds for this project and I estimate the cost at $300,000 - $400,000. The USFWS would be the logical project sponsor, but would be required to obtain the matching funds for the project (ca. 20% of the total cost). Cooperation between USFWS, Alabama DOT, and FHWA will be required to implement this project, but so far these agencies have not made a serious effort to solve this problem. Temporary measures should be taken immediately by these agencies until the funding for a permanent barrier is in place. Because the road mortality problem of Pseudemys alabamensis has long been documented, continued mortality is unauthorized take under Section 7 of the Endangered Species Act and leaves open a legal challenge against any agency with jurisdiction.