Population features of invasive turtle species and European pond turtle in Holt-Maros
Abstract
Surveys of pond turtle population were performed between June and September 2017 in the locally protected backwater of Maros River, Szeged, Hungary. During the visual observation along the backwater, species and positions of basking specimens were recorded. In addition, basking traps were placed at 6 points of the backwater. Carapax and plastron size and body weight were measured, and injuries and anomalies were recorded for each individual captured. All captured pond turtles were individually marked and released. During visual observation of basking individuals, 59 pond turtles and 65 invasive turtles were recorded. With basking traps, 75 pond turtles and 69 invasive turtles were captured during the 2,5 month collecting period. Three invasive species were found in the study area: majority of invasives was common slider (Trachemys scripta – including all the three subspecies), and 1-1 specimen of map turtle (Graptemys sp.) and chinese stripe-necked turtle (Mauremys sinensis) were captured, respectively. Regarding the sex ratio of common sliders and pond turtles, females dominated in both species (female/male: 2,0 and 1,46, repectively). Size difference between the two species is known but also size-distributions were different. Larger size classes of females dominated in common slider population but among pond turtle females usually the medium-sized individuals dominated. Number of injured individuals was higher among pond turtles (20%) then among common sliders (11,9%). Injuries were more common among females: 31,7% of captured female pond turtles were injured. Comparison of data from visual observation of basking individuals and from trapping resulted in different spatial distribution. This is probably due to different basking opportunities at different sections of the backwater
References
"1143/2014/EU" rendelet (2014): Az Európai Parlament és a Tanács 1143/2014/EU rendelete (2014. október 22.) az idegenhonos inváziós fajok betelepítésének vagy behurcolásának és terjedésének megelőzéséről és kezeléséről.
Arena, P. C., Steedman, C. & Warwick, C. (2012): Amphibian and reptile pet markets in the EU: An investigation and assessment. – Animal Protection Agency, 52 p.
Cadi, A. & Joly, P. (2003): Competition for basking places between the endangered European pond turtle (Emys orbicularis) and the introduced red-eared slider (Trachemys scripta elegans). – Can. J. Zool. 81: 1392–1398. doi: https://doi.org/10.1139/z03-108
Cadi, A. & Joly, P. (2004): Impact of the introduction of the red-eared slider (Trachemys scripta elegans) on survival rates of the European pond turtle (Emys orbicularis). – Biodivers. Conserv. 13: 2511–2518. doi: https://doi.org/10.1023/B:BIOC.0000048451.07820.9c
Farkas, B., Halpern, B., Agócs, P., Dankovics, R., Földi, A., Gulácsi, E., Györffy, Gy., Kalmár, Zs., Kiss, I., Kovács, T., Lovász, Zs. E., Molnár, L., Molnár, T. G., Péchy, T., Somlai, T. & Torvaji, L. (2013): Conservation activities for European pond turtles (Emys orbicularis) in Hungary. – Herpetol. Notes 6: 107–110.
Huxel, G. R. (1999): Rapid displacement of native species by invasive species: effects of hybridization. – Biol. Conserv. 89: 143–152. doi: https://doi.org/10.1016/S0006-3207(98)00153-0
Kovács, T., Anthony, B., Farkas, B. & Bera, M. (2004): Preliminary results of a long-term conservation project on Emys orbicularis in an urban lake in Budapest, Hungary. – Turtle and Tortoise Newsletter 7: 14–17.
Lowe, S., Browne, M., Boudjelas, S. & de Poorter, M. (2000): 100 of the world’s worst invasive alien species. A selection from the global invasive species database. – Hollands Printing Ltd, New Zealand, 12 p.
Mali, I., Wang, H-H., Grant, W. E., Feldman, M. & Forstner, M. R. J. (2015): Modeling commercial freshwater turtle production on US Farms for pet and meat markets. – PLoS ONE 10: e0139053. doi: https://doi.org/10.1371/journal.pone.0139053.s001
Mooney, H. A. & Cleland, E. (2001): The evolutionary impact of invasive species. – Proc. Natl. Acad. Sci. 98: 446–451. doi: https://doi.org/10.1073/pnas.091093398
Perez-Santigosa, N., Díaz-Paniauga, C. & Hidalgo-Vila, J. (2008): The reproductive ecology of exotic Trachemys scriptaelegans in an invaded area of southern Europe. – Aquatic Conserv: Mar. Freshw. Ecosyst. 18: 1302–1310. doi: https://doi.org/10.1002/aqc.974
Sancho, V. & Lacomba, J. I. (2016): Expansion of Trachemys scripta in the Valencian Community (Eastern Spain). – Proc. Int. Symp. Fresh Turtles Conserv. 1: 41–49.
Shea, K. & Chesson, P. (2002): Community ecology theory as a framework for biological invasions. – Trends Ecol. Evol. 17: 170–176. doi: https://doi.org/10.1016/S0169-5347(02)02495-3
Valdeón, A. Crespo-Diaz, A., Egaña-Callejo, A. & Gosá, A. (2010): Update of the pond slider Trachemys scripta (Schoepff, 1792) records in Navarre (Northern Spain), and presentation of the Aranzadi Turtle Trap for its population control. – Aquat. Invasions 5: 297–302. doi: http://dx.doi.org/10.3391/ai.2010.5.3.07
Vitousek, P. M., Mooney, H. A., Lubchenco, J. & Melillo, J. M. (1997): Human domination of earth’s ecosystems. – Science 277: 494–499. doi: http://doi.org/10.1126/science.277.5325.494
