Population Dynamics of the Florida Softshell Turtle (Apalone ferox) in a Protected Spring Ecosystem
Simple Summary
Abstract
1. Introduction
2. Materials and Methods
2.1. Study Sites
2.2. Data Collection, Capture, and Marking
2.3. Statistical Analysis
3. Results
3.1. Capture Data Summary
3.2. Schumacher–Eschmeyer Population Size Estimates
3.3. Jolly–Seber Estimates
4. Discussion
5. Conclusions
Author Contributions
Funding
Institutional Review Board Statement
Data Availability Statement
Acknowledgments
Conflicts of Interest
Abbreviations
CL | Carapace length |
CW | Carapace width |
PL | Plastron length |
PIT | Passive integrated transponder |
SH | Shell height |
SDI | Sexual dimorphism index |
WSSP | Wekiwa Springs State Park |
References
- Buhlmann, K.A.; Akre, T.S.B.; Iverson, J.B.; Karapatakis, D.; Mittermeier, R.A.; Georges, A.; Rhodin, A.G.J.; van Dijk, P.P.; Gibbons, J.W. A global analysis of tortoise and freshwater turtle distributions with identification of priority conservation areas. Chelonian Conserv. Biol. 2009, 8, 116–149. [Google Scholar] [CrossRef]
- Munscher, E.C.; Walde, A.D.; Riedle, J.D.; Hootman, T.; Weber, A.S.; Osborne, W.; Brown, J.; Ross, S.; Butterfield, B.P.; Hauge, J.B. Population metrics for two sympatric river cooter species: The Peninsular Cooter (Psuedemys floridana peninsularis) and the Florida Red-bellied Cooter (P. nelsoni) in a Florida spring ecosystem. Herpetol. Conserv. Biol. 2022, 17, 51–66. [Google Scholar]
- Congdon, J.D.; Dunham, A.E.; van Loben Sels, R.C. Delayed sexual maturity and demographics of Blanding’s turtles (Emydoidea blandingii): Implications for conservation and management of long-lived organisms. Conserv. Biol. 1993, 7, 826–833. [Google Scholar] [CrossRef]
- Gibbons, J.W.; Scott, D.E.; Ryan, T.J.; Buhlmann, K.A.; Tuberville, T.D.; Metts, B.S.; Greene, J.L.; Mills, T.; Leiden, Y.; Poppy, S.; et al. The global decline of reptiles, déjà vu amphibians. BioScience 2000, 50, 653–666. [Google Scholar] [CrossRef]
- Howell, H.J.; Howell, H.J.; Legere, R.H.; Holland, D.S.; Seigel, R.A. Long-Term Turtle Declines: Protected Is a Verb, Not an Outcome. Copeia 2019, 107, 493–501. [Google Scholar] [CrossRef]
- Lovich, J.E.; Ennen, J.R. A quantitative analysis of the state of knowledge of turtles of the United States and Canada. Amphib. Reptil. 2013, 34, 421–432. [Google Scholar] [CrossRef]
- Ernst, C.H.; Lovich, J.E. Turtles of the United States and Canada; Johns Hopkins University Press: Baltimore, MD, USA, 2009. [Google Scholar]
- Iverson, J.B. Patterns of survivorship in turtles (order Testudines). Can. J. Zool. 1991, 69, 385–391. [Google Scholar] [CrossRef]
- Rhodin, A.G.J.; Stanford, C.B.; Dijk, P.P.V.; Eisemberg, C.; Luiselli, L.; Mittermeier, R.A.; Hudson, R.; Horne, B.D.; Goode, E.V.; Kuchling, G.; et al. Global conservation status of turtles and tortoises (Order Testudines). Chelonian Conserv. Biol. 2018, 17, 135–161. [Google Scholar] [CrossRef]
- Schradin, C.; Schradin, C.; Hayes, L.D. A synopsis of long-term field studies of mammals: Achievements, future directions, and some advice. J. Mammal. 2017, 98, 670–677. [Google Scholar] [CrossRef]
- Meylan, P.A.; Moler, P.E. Apalone ferox–Florida Softshell Turtle. In Biology and Conservation of Florida Turtles; Meylan, P.A., Ed.; Chelonian Research Monographs No. 3; Chelonian Research Foundation: Arlington, VT, USA, 2006; pp. 160–168. [Google Scholar]
- Aresco, M.J. Environmental correlates of the abundances of three species of freshwater turtles in lakes of northern Florida. Copeia 2009, 3, 545–555. [Google Scholar] [CrossRef]
- Munscher, E.C.; Walde, A.D.; Riedle, D.A.; Kuhns, E.H.; Weber, A.S.; Hauge, J.B. Population structure of the Florida Softshell Turtle (Apalone ferox Schneider) in a protected ecosystem, Wekiwa Springs State Park. Chelonian Conserv. Biol. 2015, 14, 34–42. [Google Scholar] [CrossRef]
- Munscher, E.C.; Siders, Z.A.; Skibsted, M.; Letcher, S.; Morrison, M.; Walde, A.D. Multivariate sexual size dimorphism in the Florida Softshell Turtle (Apalone ferox). Hydrobiologia 2025, in press.
- van Dijk, P.P.; Stuart, B.L.; Rhodin, A.G.J. Asian turtle trade: Proceedings of a workshop on conservation and trade of freshwater turtles and tortoises in Asia. In Proceedings of the Asian Turtle Trade: Proceedings of a Workshop on Conservation and Trade of Freshwater Turtles and Tortoises in Asia, Phnom Penh, Cambodia, 1–4 December 1999; Chelonian Research Foundation: Arlington, VT, USA, 2000. [Google Scholar]
- Turtle Taxonomy Working Group (TTWG). Turtles of the World Annotated Checklist and Atlas of Taxonomy, Synonymy, Distribution, and Conservation Status, 9th ed.; Chelonian Research Monographs, Number 8; Chelonian Research Foundation: Arlington, VT, USA, 2021; pp. 1–472. [Google Scholar] [CrossRef]
- Munscher, E.C.; Morrison, M.; Siders, Z.; Weber, A.S.; Walde, A.D. 2025. Apalone ferox. The IUCN Red List of Threatened Species 2025: e.T165597A251135698. Available online: https://www.iucnredlist.org/species/165597/251135698 (accessed on 14 January 2024).
- Munscher, E.C.; Walde, A.D.; Riedle, J.D.; Hootman, T.; Weber, A.S.; Osborne, W.; Brown, J.; Butterfield, B.P.; Hauge, J.B. Demographics of sympatric musk turtles: The loggerhead musk turtle (Sternotherus minor) and the eastern musk turtle (Sternotherus odoratus) in a Florida spring ecosystem. Chelonian Conserv. Biol. 2020, 19, 36–47. [Google Scholar] [CrossRef]
- Hubbs, C. Springs and spring runs as unique aquatic systems. Copeia 1995, 4, 989–991. [Google Scholar] [CrossRef]
- Scott, T.M.; Means, G.H.; Meegan, R.P.; Means, R.C.; Upchurch, S.B.; Copeland, R.E.; Jones, J.; Roberts, T.; Willet, A. Springs of Florida. Fla. Geol. Surv. Bull. 2004, 66, 1–377. [Google Scholar]
- Walsh, S.J.; Knowles, L.; Katz, B.G.; Strom, D.G. Hydrology, Water Quality, and Aquatic Communities of Selected Springs in the St. Johns River Water Management District, Florida; Report No.: 2009–0546; U.S. Geological Survey: Reston, VA, USA, 2009.
- Moler, P.E.; Berish, J.E. Impact of Commercial Exploitation on Softshell Turtle Populations; Final Report; Florida Game and Fresh Water Fish Commission: Tallahassee, FL, USA, 1995; p. 18. [Google Scholar]
- Weber, S.A.; Munscher, E.C.; Brown, J.; Cox, C.; Hauge, J.B. Using tattoos to mark turtles for individual recognition. Herpetol. Rev. 2011, 4, 530–532. [Google Scholar]
- Runyan, A.L.; Meylan, P.A. PIT tag retention in Trachemys and Pseudemys. Herpetol. Rev. 2005, 36, 45–47. [Google Scholar]
- Schumacher, F.; Eschmeyer, R. The recapture and distribution of tagged bass in Norris Reservoir, Tennessee. J. Tenn. Acad. Sci. 1943, 17, 228–249. [Google Scholar]
- Seber, G.A.F. The Estimation of Animal Abundance and Related Parameters, 2nd ed.; Charles Griffin: London, UK, 1982. [Google Scholar]
- Krebs, C.J. Estimating abundance and density: Mark-recapture techniques. In Ecological Methodology, 2nd ed.; Benjamin Cummings: Menlo Park, CA, USA, 1999; pp. 24–83. [Google Scholar]
- Royle, J.A.; Dorazio, R.M. Parameter-expanded data augmentation for Bayesian analysis of capture–recapture models. J. Ornithol. 2012, 152, 521–537. [Google Scholar] [CrossRef]
- Royle, J.A.; Dorazio, R.M. Hierarchical Modeling and Inference in Ecology: The Analysis of Data from Populations, Metapopulations and Communities; Academic Press: San Diego, CA, USA, 2008. [Google Scholar] [CrossRef]
- Kéry, M.; Schaub, M. Bayesian Population Analysis Using WinBUGS: A Hierarchical Perspective; Academic Press: Oxford, UK, 2011. [Google Scholar]
- Then, A.Y.; Hoenig, J.M.; Hall, N.G.; Hewitt, D.A. Evaluating the predictive performance of empirical estimators of natural mortality rate using information on over 200 fish species. ICES J. Mar. Sci. 2015, 72, 82–92. [Google Scholar] [CrossRef]
- Saracco, J.F.; Yackulic, C.B. Fast and flexible Bayesian Jolly Seber models and application to populations with transients. bioRxiv 2023. [Google Scholar] [CrossRef]
- Yackulic, C.B.; Dodrill, M.; Dzul, M.; Sanderlin, J.S.; Reid, J.A. A need for speed in Bayesian population models: A practical guide to marginalizing and recovering discrete latent states. Ecol. Appl. 2020, 30, e02112. [Google Scholar] [CrossRef] [PubMed]
- Stan Development Team. Stan Reference Manual, Version 2.36. 2025. Available online: https://mc-stan.org/docs/reference-manual/ (accessed on 14 January 2024).
- Gabry, J.; Češnovar, R.; Johnson, A.; Bronder, S. cmdstanr: R Interface to “CmdStan”. Version 0.8.1. 2024. Available online: https://mc-stan.org/cmdstanr/ (accessed on 14 January 2024).
- Gelman, A.; Rubin, D.B. Inference from iterative simulation using multiple sequences. Stat. Sci. 1992, 17, 457–472. [Google Scholar] [CrossRef]
- Bürkner, P.C. brms: An R package for Bayesian multilevel models using Stan. J. Stat. Softw. 2017, 80, 1–28. [Google Scholar] [CrossRef]
- Schwarz, C.J.; Arnason, A.N. A General Methodology for the Analysis of Capture-Recapture Experiments in Open Populations. Biometrics 1996, 52, 860. [Google Scholar] [CrossRef]
- Makowski, D.; Ben-Shachar, M.S.; Lüdecke, D. bayestestR: Describing effects and their uncertainty, existence and significance within the bayesian framework. J. Open Source Softw. 2019, 4, 1541. [Google Scholar] [CrossRef]
- Barko, V.A.; Briggler, J.T. Midland smooth softshell (Apalone mutica) and spiny softshell (Apalone spinifera) turtles in the Middle Mississippi River: Habitat associations, population structure, and implications for conservation. Chelonian Conserv. Biol. 2006, 5, 225–231. [Google Scholar] [CrossRef]
- Plummer, M.V. Habitat and population structure in the turtle Trionyx muticus. Copeia 1977, 3, 431–440. [Google Scholar] [CrossRef]
- Plummer, M.V.; Mills, N.E. Structure of an urban population of softshell turtles (Apalone spinifera) before and after severe stream alteration. Herpetol. Conserv. 2008, 3, 95–105. [Google Scholar]
- Glorioso, B.M.; Vaughn, A.J.; Waddle, J.H. The aquatic turtle assemblage inhabiting a highly altered landscape in southwest Missouri. J. Fish Wildl. Manag. 2010, 1, 161–168. [Google Scholar] [CrossRef]
- Iverson, J.B. Biomass in turtle populations—A neglected subject. Oecologia 1982, 55, 69–76. [Google Scholar] [CrossRef]
- Munscher, E.C.; Kuhns, E.H.; Cox, C.A.; Butler, J.A. Decreased nest mortality for the Carolina Diamondback terrapin (Malaclemys terrapin centrata) following removal of raccoons (Procyon lotor) from a nesting beach in Northeastern Florida. Herpetol. Conserv. Biol. 2012, 7, 176–184. [Google Scholar]
- Iverson, J.B.; Moler, P.E. The female reproductive cycle of the Florida softshell turtle (Apalone Ferox). J. Herpetol. 1997, 31, 399–409. [Google Scholar] [CrossRef]
- Enge, K.M. Herptile Use and Trade in Florida; Nongame Wildlife Program Final Report; Florida Game and Freshwater Fish Commission: Tallahassee, FL, USA, 1993. [Google Scholar]
- Scheffers, B.R.; Oliveira, B.F.; Lamb, I.; Edwards, D.P. Global wildlife trade across the tree of life. Science 2021, 366, 71–78. [Google Scholar] [CrossRef] [PubMed]
- Lindsey, P.; Allan, J.; Brehony, P.; Dickman, A.; Robson, A.; Begg, C.; Flyman, M. Conserving Africa’s wildlife and wildlands through the COVID-19 crisis and beyond. Nat. Ecol. Evol. 2020, 4, 1300–1310. [Google Scholar] [CrossRef] [PubMed]
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Munscher, E.C.; Siders, Z.A.; Weber, A.S.; Munscher, J.; Morrison, M.; Osborne, W.; Letcher, S.; Butterfield, B.P.; Skibsted, M.; Walde, A.D. Population Dynamics of the Florida Softshell Turtle (Apalone ferox) in a Protected Spring Ecosystem. Biology 2025, 14, 1018. https://doi.org/10.3390/biology14081018
Munscher EC, Siders ZA, Weber AS, Munscher J, Morrison M, Osborne W, Letcher S, Butterfield BP, Skibsted M, Walde AD. Population Dynamics of the Florida Softshell Turtle (Apalone ferox) in a Protected Spring Ecosystem. Biology. 2025; 14(8):1018. https://doi.org/10.3390/biology14081018
Chicago/Turabian StyleMunscher, Eric C., Zachary A. Siders, Andrew S. Weber, Jessica Munscher, Madeleine Morrison, Wayne Osborne, Shannon Letcher, Brian P. Butterfield, Michael Skibsted, and Andrew D. Walde. 2025. "Population Dynamics of the Florida Softshell Turtle (Apalone ferox) in a Protected Spring Ecosystem" Biology 14, no. 8: 1018. https://doi.org/10.3390/biology14081018
APA StyleMunscher, E. C., Siders, Z. A., Weber, A. S., Munscher, J., Morrison, M., Osborne, W., Letcher, S., Butterfield, B. P., Skibsted, M., & Walde, A. D. (2025). Population Dynamics of the Florida Softshell Turtle (Apalone ferox) in a Protected Spring Ecosystem. Biology, 14(8), 1018. https://doi.org/10.3390/biology14081018