Critical Life History Parameters of the Texas Diamond-backed Terrapin, Malaclemys terrapin littoralis

Purpose/Objectives

The objectives of this study are to 1) develop estimates of local population abundance and density of Texas diamond-backed terrapin; 2) estimate various demographic and population parameters including relative age, size, sex distributions and somatic growth, total and natural mortality and birth rates; 3) evaluate habitat preferences including physical and biological foraging and nesting attributes; and 4) estimate crab trap bycatch mortality rates for Texas diamond-backed terrapin.

Study Area

Coastal Texas (with focus on Galveston Bay)

Project Period

2007 – Present

Description

The diamond-backed terrapin is the only turtle species to live exclusively in brackish water. Due to their limited distribution and unique life history, little information has been gathered on the numbers or health of terrapin state-wide. This research will build upon previous research conducted by EIH on the population of the Texas diamond-backed terrapin.

Publications and Presentations

Gordon, M., Guillen, G.J., Franklin, C.J., and Ricardez, V. 2021. Malaclemys terrapin littoralis (Texas diamond-backed terrapin). Malocclusion (prognathism). Herpetological Review 52(4):847-848.

Gordon, M., Oakley, J.W., and Guillen, G.J. 2019. Staying close to home: seasonality and site fidelity of an insular population of Texas diamondback terrapins as determined by acoustic telemetry. 8th Triennial Meeting of the Diamondback Terrapin Working Group, Wilmington, NC. Presentation.

Alleman, B.J. and Guillen, G. 2017. Prey availability and diet analysis of Texas diamond-backed terrapin (Malaclemys terrapin littoralis). Chelonian Conservation and Biology 16.1:52–61.

Alleman, B.J. and Guillen, G.J. 2016. Malaclemys terrapin littoralis (Texas diamond-backed terrapin). Herpetological Review 47:286.

Alleman, B.J. 2015. Diet Analysis and Assessment of Habitat and Prey Availability Associated with Texas Diamond-backed Terrapin (Malaclemys terrapin littoralis). University of Houston-Clear Lake, Houston.

Alleman, B. and Guillen, G. 2015. Assessment of Habitat and Prey Availability Associated with the Distribution of Texas Diamond-backed Terrapin (Malaclemys terrapin littoralis). Texas Bays and Estuaries Meeting, Port Aransas, TX. Presentation.

Alleman, B. and Guillen, G. 2015. Diet of Texas Diamondback Terrapin (Malaclemys terrapin littoralis). Texas Academy of Science Meeting, San Antonio, TX. Presentation.

Clarkson, E. and Guillen, G. 2015. Malaclemys terrapin littoralis (Texas diamond-backed terrapin). Herpetological Review 46.1:83.

Guillen, G., Gordon, M.L., Oakley, J., Mokrech, M., Alleman, B., George, R., and Bush, D. 2015. Population survey of the Texas diamondback terrapin, Malaclemys terrapin littoralis, in San Antonio Bay, Matagorda Bay, and Sabine Lake. EIH Report 15-001, 194 pp.

Alleman, B. and Guillen, G. 2014. Characterization of Prey Availability Between Texas Diamondback Terrapin (Malaclemys terrapin littoralis) Capture Sites and Background Wetland Densities. Texas Academy of Science Meeting, Galveston, TX. Poster.

George, R.R. 2014. Nesting Ecology of the Texas Diamondback Terrapin (Malaclemys terrapin littoralis). University of Houston-Clear Lake, Houston.

Moss, M. and Guillen, G. 2014. Mid-upper Coast Surveys of Texas Diamondback Terrapin. 1st Meeting of the Texas Diamondback Terrapin Working Group, Port Aransas, TX. Presentation.

Moss, M., Guillen, G., Alleman, B., and George, R. 2014. Population Survey of the Texas Diamondback Terrapin in San Antonio Bay, Matagorda Bay, and Sabine Lake: Preliminary Results. Mission-Aransas National Wildlife Refuge Research Symp., Port Aransas,TX. Presentation.

Glenos, S.M. 2013. A Comparative Assessment of Genetic Variation of Diamondback Terrapin (Malaclemys terrapin) in Galveston Bay, Texas in Relation to Other Northern Gulf Coast Populations. University of Houston-Clear Lake, Houston. Thesis.

Guillen, G. and Oakley, J.W. 2013. Bycatch Mortality and Critical Life History Parameters of the Texas Diamondback Terrapin. EIH Technical Report 13-004:151.

Clarkson, E. 2012. Short Term Temporal Trends in Activity and Habitat Selection of the Texas Diamondback Terrapin. University of Houston-Clear Lake, Houston. Thesis.

Clarkson, E. and Guillen, G. 2011. Small-scale Habitat Selection and Activity Trends of the Diamondback Terrapin in West Galveston Bay, Texas as Determined by Acoustic Telemetry. In American Society of Ichthyologists and Herpetologists, Minneapolis, MN. Poster.

Guillen, G., Clarkson, E., and Oakley, J.W. 2011. Mid-Texas Coast Complex Texas Diamondback Terrapin (Malaclemys terrapin littoralis) Ecology Project. EIH Technical Report 12-004:33.

Haskett, K. 2011. Abundance and Movement of the Texas Diamondback Terrapin in the Deer Island Complex, Galveston, Texas. University of Houston-Clear Lake, Houston. Thesis.

Marlow, A. and Guillen, G. 2011. Injury Rates of Diamondback Terrapin (Malaclemys terrapin) in Galveston Bay, Texas. In Diamondback Terrapin Working Group. Poster.

Wrast, J., Guillen, G., Mokrech, M., and McCarthy, E. 2011. Development of a Habitat Suitability Index for the Texas Diamondback Terrapin, Malaclemys terrapin littoralis. In Restore America's Estuaries, Galveston, TX. Poster.

Clarkson, E., Marlow, A., and Guillen, G. 2010. Site Fidelity and Range of an Island Population of Diamondback Terrapin (Malaclemys terrapin) in West Galveston Bay, Texas. In Diamondback Terrapin Working Group. Poster.

Haskett, K. and Guillen, G. 2010. Population Characteristics of Diamondback Terrapin at the Deer Island Complex; Galveston Texas During 2008. EIH Technical Report 10-017:37.

Project Sponsors

• Texas Parks & Wildlife

Related links

• Video: Texas Diamondback Terrapin - Environmental Institute of Houston
• Video: Rookery Island Erosion, A New North Deer - Texas Parks & Wildlife [Official]