Donini, J.T., C.J. Lechowicz, and R.A. Valverde. 2018. Comparisons of summer and winter patterns in ovarian development, plasma vitellogenin, and sex steroids in female Diamondback Terrapins (Malaclemys terrapin) in southern Florida. Chelonian Conservation and Biology 17(2):227–235.
The reproductive cycles of turtles are linked to environmental factors, such as photoperiod and temperature. Currently, the reproductive physiology of diamondback terrapins (Malaclemys terrapin) is poorly understood, especially in Gulf of Mexico. The reproductive cycles of terrapins are thought to follow typical seasonal patterns. However, latitudinal variations in temperature regimens lead to longer-lasting warm periods, which can facilitate extended reproductive periods in some turtle species. This suggests that terrapins may show a similar change in the southern parts of their range. To elucidate aspects of the terrapin reproductive cycle, we sampled during the known reproductive season of a southern population of terrapins (May–July), as well as during the winter in late December and early January. We used enzyme-linked immunosorbent assays to quantify concentrations of the plasma sex hormones estradiol and testosterone, and the egg yolk protein precursor vitellogenin. Additionally, we used radiography and ultrasonography to monitor the ovarian status and egg development in females. Follicles showed no significant difference in average diameter across sampling periods with preovulatory class follicles existing in both summer and winter. Eggs were only detected from May to July, with radiographic data showing second clutches in 4 individuals. Testosterone and estradiol showed elevated concentrations throughout the nesting season, coinciding with multiple clutches of eggs, before both showed a significant decrease in winter. Vitellogenin showed peak concentrations in June with other months showing lower but detectable concentrations. Our results suggest that in southwestern Florida, terrapins may have extended reproductive potential and continuous vitellogenic cycles given the presence of preovulatory follicles and high quantities of vitellogenin found in summer and winter. However, true continuous reproduction was not detected in this study.
Krysko, J.I., L.A. Somma, D.C. Smith, C.R. Gillette, D. Cueva, J.A. Wasilewski, K.M. Enge, S.A. Johnson, T.S. Campbell, J.R. Edwards, M.R. Rochford, R. Tompkins, J.I. Fobb, S. Mullin, C.J. Lechowicz, D. Hazelton, and A. Warren. 2016. New verified nonindigenous amphibians and reptiles of Florida through 2015, with a summary of over 152 years of introductions. IRCF Reptiles and Amphibians 23(2):110–143.
More nonindigenous species occur in Florida, USA, than any other region worldwide and may threaten many of Florida's natural resources. The frequency of new reports mandates the need for regular updates. Herein, we use photographic and specimen vouchers in addition to literature records to provide updated information on verified nonindigenous amphibians and reptiles in Florida. Between our most recent summary in 2012 and the end of 2015, 38 additional species are known to have been intercepted (n=2) or introduced (n=36). We also update the invasion stage of seven species previously reported from Florida and report that five additional taxa are now established. In total 191 independent known introductions of 180 herpetofaunal taxa led to the establishment of 63 taxa. This suggests that one in three introduced herpetofaunal species becomes established in Florida. The pet trade represents the most common introduction pathway among these species and a single animal importer in Hollywood, Broward County, is the probable source for introduction of a quarter of all herpetofauna introduced to Florida.
Godwin, J.C, J.E. Lovich, J.R. Ennen, B.R. Kreiser, B. Folt, and C.J. Lechowicz. 2014. Hybridization of two megacephalic map turtles (Testudines: Emydidae: Graptemys) in the Choctawhatchee River drainage of Alabama and Florida. Copeia 4:725–742.
Map turtles of the genus Graptemys are highly aquatic and rarely undergo terrestrial movements, and limited dispersal among drainages has been hypothesized to drive drainage-specific endemism and high species richness of this group in the southeastern United States. Until recently, two members of the megacephalic “pulchra clade,” Graptemys barbouri and Graptemys ernsti, were presumed to be allopatric with a gap in both species' ranges in the Choctawhatchee River drainage. In this paper, we analyzed variation in morphology (head and shell patterns) and genetics (mitochondrial DNA and microsatellite loci) from G. barbouri, G. ernsti, and Graptemys sp. collected from the Choctawhatchee River drainage, and we document the syntopic occurrence of those species and back-crossed individuals of mixed ancestry in the Choctawhatchee River drainage. Our results provide a first counter-example to the pattern of drainage-specific endemism in megacephalic Graptemys. Geologic events associated with Pliocene and Pleistocene sea level fluctuations and the existence of paleo-river systems appear to have allowed the invasion of the Choctawhatchee system by these species, and the subsequent introgression likely predates any potential human-mediated introduction.
Books, Reports, & Symposia
Lechowicz, C. 2019. Habitat use and island movements in the jewel of Sanibel, the Florida box turtle (Terrapene carolina bauri). Exploring Florida's Rich Turtle Diversity Symposium, Native Florida Birding and Nature Festival.
Gibson, N., C.J. Lechowicz, and E.E. Everham III. 2017. Habitat use of the Florida Box Turtle (Terrapene carolina bauri) on a barrier island: Sanibel, FL. Charlotte Harbor National Estuary Program, Fort Myers, FL. Poster Presentation.
Donini, J., C. Lechowicz, W. Selman, and R. Valverde. 2016. Reproductive physiology of diamondback terrapins (Malalclemys terrapin) at two latitudes in the Gulf of Mexico. Turtle Survival Alliance Symposium.
Lechowicz, C. 2016. Update on the recent introduction of the giant toad (Rhinella marina) on Sanibel Island, FL. CISMA Invasive Species Symposium.
Lechowicz, C. 2015. Possible introduction methods, movement patterns, and control efforts of the giant toad (Rhinella marina) on Sanibel Island, FL. CISMA Invasive Species Symposium.
LeBuff, C.A., and C.J. Lechowicz. 2014. Amphibians & Reptiles of Sanibel & Captiva Islands, FL: A Natural History. Amber Publishing. Ralph Curtis Publishing, Fort Myers, FL.
Lechowicz, C. 2014. Terrapin nesting habitat discovery using satellite telemetry. Turtle Survival Alliance Symposium.
Lechowicz, C., P. Meylan, P. Moler, T. Thomas, and W. Turner. 2011. Barbour’s Map Turtle biological status review report. Florida Fish & Wildlife Conservation Commission. Tallahassee, FL.
Lechowicz, C. 2009. Population structure and trends in Barbour's map turtles (Graptemys barbouri), Escambia map turtles (Graptemys ernsti), and the hybrid (Graptemys barbouri x ernsti) in Alabama and Florida. Turtle Survival Alliance Symposium.