Triceratops or Turtle, You Be The Judge! - By: Nick Petrarca

Triceratops or Turtle, You Be The Judge!

Ringed Sawback Turtle – (Graptemys Oculifera)

By: Nick Petrarca

Originally Prepared by

            James H Stewart

            U.S. Fish and Wildlife Service

            For

            Southeast Region

U.S. Fish and Wildlife Service

Atlanta Georgia

Date approved: April 8, 1988

Summary 3 steps

1. Point or Condition when the species can be considered recovered?

The primary objective of the recovery plan is to provide secure habitat for the ringed sawback turtle in two stretches of the Pearl River for a total protected area of 150 River miles. These reaches must be on opposite ends of Ross Barnett Reservoir at Jackson, and contain a minimum of 30 miles in either reach.

Delisting should occur on a range wide basis when the two river reaches are protected, there is evidence of a stable or increasing population over a 10 year period, and a monitoring plan is developed and implemented to ensure a continuing stable population.

2. What must be done to reach recovery?

Determine the habitat requirements, including food sources for the various life stages of the ringed sawback turtle, and maintain at least 150 river miles of habitat that meets those requirements.

The primary steps are to characterize physical parameters of required habitat, determine reproductive requirements, food sources, population, structure, and activity periods and behavior. On the basis of this information, identify and protect the two river reaches.

Attaining recovery depends upon protection of the required habitat. The areas where the ringed sawback turtle is common are known to some extent. The population status and trends and influencing factors are not known. Regulatory agencies must provide for habitat protection in areas identified as required habitat.

3. What management/maintenance needs have been identified to keep the species recovered?

The required habitat must be protected by the appropriate regulatory agencies. A monitoring plan to track population trends and protection success is a critical element.

Date Declared Endangered:            On December 23, 1986, the U.S. fish and Wildlife Service published in the Federal Register a final rule indicating its determination that the ringed sawback turtle is a threatened species under the endangered species act of 1973.

Location: The ringed sawback is restricted to the Pearl River and one tributary, the Bogue Chitto River, in Mississippi and Louisiana.

Appearance: The ringed sawback turtle is a small turtle (adults 7.5-22cm) having a yellow ring bordered inside and outside with dark olive-brown on each shield of the upper shell (carapace) and a yellow undershell (plastron). The head has a large yellow spot behind the eye, two yellow stripes from the orbit backwards and a characteristic yellow stripe covering the whole lower jaw. Males are considerably smaller than females.

Habitat: The ringed sawback turtle is encountered most frequently in river stretches having moderate current, numerous basking logs and sand beaches for nesting. The river must be wide enough to allow sun penetration for several hours. The factors that influence the suitability of nesting sites appear to be sand particle size (prefers fine sand), elevation above the water level, cover quality and distance from the waters edge. Nests are always located above mean water level with an average elevation of 4.2m. Elevation selected for nesting appeared to be the result of how far the individual traveled inland, rather then the elevation preference. Nests are also generally 3-15m from the water’s edge.

Life History: Males mature at 3-4 years of age and the female maturation time is 6-7 years, but females grow more rapidly than males during the first five years of age and the growth of both sexes virtually ceases at maturity.

            Mating occurs in late spring and early summer, but may occur at any time of the year. Throughout the year females produce 3-4 clutches annually with an average clutch size of 5-6 eggs. A single mating may be sufficient for several fertilizations since females can apparently store viable sperm for several months or possibly years. Egg mortality exceeded 90%.

Diet: Insects, snails, clams, and mussels. Juveniles and small males fed primarily on insects while large females fed almost exclusively upon mussels and clams by crushing the shell with their powerful jaws.

Predation: Nest predation is the dominant factor inhibiting population growth. At least 95% of all nests were destroyed by predators. The primary predators are the fish crow, the raccoon and the skunk. Predators destroyed most nests 12-24 hours after the eggs have been laid.

Large gars, herons, and alligator snapping turtles feeding upon the hatchlings cause predation on hatchlings. 

The only significant predator of adult turtles is man who shoots basking turtles and collects them for the commercial turtle trade.

Limiting Factors: Very little competition seems to occur among individuals or species, due to the fact that food is generally abundant if the habitat is satisfactory. The major limiting factor is habitat availability.

Reasons for Decline and Continuing Threats: The decline of the ringed sawback turtle is primarily due to the habitat modification and water quality degradation. Construction of Ross Barnett Reservoir, modification of the west channel of the Pearl River to Bogalusa, Louisiana, and floodplain clearing at Jackson, Mississippi have impacted 21% of the historic range. The Ross Barnett Reservoir modified 30 river miles to the exclusion of the ringed sawback turtles. The channel and floodplain modifications at Bogalusa and Jackson have not eliminated this species, but apparently have caused a decline in the population. Projects planned or authorized will impact up to 28% of the remaining Peal River habitat. Flood control studies on–going or planned for the Pearl River continue to threaten this turtle.

Other threats include continued channelization in the drainage, which produces increased runoff and heavy siltation. Drainage ditches from agriculture fields may increase the amount of pesticides that reach the rivers.

A.)  Recovery Objective

a.     Protection of a total of 150 miles of the turtle’s habitat in two reaches of the Pearl River. There must be a minimum of 30 miles in either reach with a total protected area totaling 150 river miles

b.     Evidence of a stable or increasing population or at least a ten year period in these two Pearl River reaches.

c.      An established, continuing plan of periodic monitoring of population tends and habitat to ensure a stable population in these river reaches.

B.)  Step-down Outline

a.     Characterize physical parameters of habitat (1995-1999)

                                               i.     Select and characterize five reaches with vigorous ringed sawback turtle populations.

1.     The ringed sawback turtle continues to exist in good numbers in an approximate 50 mile reach upstream of Ratliff’s Ferry and in a 120 mile reach from near Georgetown, Mississippi. Five reaches of at least 3 miles each will be selected to characterize the parameters in a. These reaches will be in the vicinity of the Highway 35 bridge at Carthage, below the highway 25 bridge, and near Monticello, Columbia, and Sandy Hook, Mississippi. Within each selected reach, at least 10 sample stations will be defined to aid in statistical comparisons.

                                              ii.     Select and characterize five reaches that don not support vigorous ringed sawback turtle populations.

1.     These reaches will be: between Ross Barnet Reservoir and Lakeland Ave., Jackson; between the Jackson metropolitan area and Georgetown; downstream of Bogalusa; and near Walkiah Bluff Water Park above Picayune, Mississippi.

                                            iii.     Copmare data and determine potentially limiting factors.

b.     Determine reproductively requirements

                                               i.     Determine nesting locations and prepare physical description of site. (1995-1999)

1.     In at least two study areas, determine the characteristics of nest cavity, substrate type, location of nest relative to water, vegetation, and debris, length of exposure per day of nest site to direct sun, temperature of nest substrate and other parameters necessary to determining the suitability of a nesting site.

                                              ii.     Determine nesting requirements. (1995-1999)

1.     Determine dates of nesting, period of greatest nesting activity, extreme nesting dates, incubation period, clutch size, frequency of nesting description of eggs.

                                            iii.     Determine effects of environmental changes and of predation on reproductive success. (1995-2010)

1.     The length of time an egg or embryo can be submerged before dying is crucial in predicting certain environmental impacts to population trends. We must know the impact of nest predation on the ringed sawback turtle.

                                            iv.     Determine where most of the successful reproduction occurs and the influencing factors. (partially complete 1995-2010)

1.     This task will seek to determine if nest temperatures influence sex determination and, if so, could bank clearing have enough effect on nest temperature to result in a skewed sex ratio.

c.      Determine food sources

                                               i.     Determine the food requirements at the various life stages and seasons. (not started)

1.     This task will seek to determine the groups or species utilized as food by examining fecal samples from captured turtles and from stomach content analysis of any turtles that may be sacrificed for other purposes or from stomach pumping of live turtles.

                                              ii.     Determine physical requirements of the major prey species (not started)

1.     This task will seek to determine the factors that influence the food source found from c.i regarding their abundance and availability.

                                            iii.     Determine how distribution and abundance of the major prey species correlates with the vigorous turtle populations. (not started)

1.     There may be a direct correlation between the presence and abundance of food and turtle populations.

d.     Determine population structure

                                               i.     Determine sex ratio, size and age at maturity, and age structure. (partially complete 1995-2020)

1.     If early nesting is lost due to flooding or some other factor, the increased temperatures of late nesting could skew the sex ratio.

                                              ii.     Estimate number of ringed sawback turtles per mile in each of the study reaches (partially complete 1995-2020)

1.     This task will provide baseline data to determine population trends. For three years turtles will be captured and marked to ensure accurate population counting.

e.     Determine activity periods and behavior (partially complete 1995-2020)

                                               i.     Determine seasonal activity

1.     Studies have shown that feeding activity ceases in the late fall with turtles entering a period of low activity. This task will seek to identify where turtles go during this phase of low activity.

                                              ii.     Determine daily activity

1.     Age and sex classes under varying environmental conditions will determine daily activity.

                                            iii.     Determine if the species moves any distance during its lifetime and barriers to such movement, if any.

1.     This task will determine if river reaches that support low population levels are dependent upon emigration from other river reaches and if there are barriers to such movement.

f.      From the information gathered, determine and protect at least two river reaches critical to maintain a stable population.

                                               i.     Protect these two river reaches from activities that would cause a decline of this species’ population. (partially complete 1995-2020)

1.     This task will develop the actions necessary to protect the identified habitat and seek to protect it by implementing those actions.

                                              ii.     Develop and implement a monitoring plan to evaluate effectiveness of protective measures and to track population plans. (ongoing current 1995-2020)

1.     Using the baseline data gathered in this plan, develop a monitoring plan to evaluate the protective measures, track population trends, and take corrective action as necessary. Population monitoring including age classes, sex ratio, nesting success, food availability, and number of turtles per mile will be conducted at three year intervals in the protected river regions.

Bibliography

Environmental Conservation Online System

"Recovery Plan Action Status." Recovery Plan Action Status. U.S. Fish & Wildlife Service, n.d. Web. 09 Mar. 2015.

Facts

"Graptemys Oculifera." (Ringed Map Turtle, Ringed Sawback). N.p., n.d. Web. 09 Mar. 2015. <http://www.iucnredlist.org/details/9499/0>.

PDF article

920, Konica Minolta. "Ringed Sawback Turtle Recovery Plan." (n.d.): n. pag. Environmental Conservation Online System. U.S. Fish and Wildlife Service. Web. 9 Mar. 2015.

A Map of Species Locations:

Ecos.fws.gov,. 'Species Profile For Ringed Map Turtle (Graptemys Oculifera)'. N.p., 2015. Web. 9 Mar. 2015.

<http://ecos.fws.gov/speciesProfile/profile/speciesProfile.action?spcode=C022>

Images

"Ringed Map Turtle Photo." - Graptemys Oculifera. N.p., n.d. Web. 09 Mar. 2015. <


http://www.arkive.org/ringed-map-turtle/graptemys-oculifera/image-G75594.html>.