Assessment of critical habitat for common snapping turtles (Chelydra serpentina) in an urbanized coastal wetland
Critical habitats such as nesting areas and overwintering sites are specific areas used by organisms to carry out important life functions. In many urbanized centers, critical habitats of at-risk species have often become degraded and/or fragmented because of human activities. Such is the case for the population of common snapping turtles (Chelydra serpentina) in Cootes Paradise Marsh, a highly urbanized ecosystem located at the western tip of Lake Ontario. In addition to these threats, mortality from collisions with cars on a four-lane highway at the western end of the marsh has greatly reduced wildlife populations. Here, we examine long-term changes in critical habitat distribution that has accompanied urbanization of Cootes Paradise Marsh from 1934 to 2010. We delineated potential nesting habitat for snapping turtles in 7 digitized aerial photos, using literature information and 2017 nesting surveys as guides. Between 1934 and 2010, total area of potential nesting habitat decreased by almost 50%. Nesting surveys confirmed that snapping turtles were disproportionately using created nesting mounds and this suggests that availability of natural nesting habitat is limited. We also radio tracked 11 snapping turtles to identify use of overwintering habitat. Temperature loggers monitored in-situ water temperatures at each turtle’s location and other unconfirmed habitats. The snapping turtle population overwintered in a wide range of upland terrestrial habitats and we found consistent characteristics regarding water temperature across both confirmed and unconfirmed sites, therefore suggesting overwintering habitat may not be limiting within the marsh.
KeywordsSnapping turtle Chelydra serpentina Urban impacts Critical habitat Overwintering Nesting
All field work was conducted respectful of approved McMaster University animal use protocols (No. 17-01-05) and site-specific permits (Hamilton Conservation Authority land access, Wildlife Scientific Collector’s Authorization No. 1084392 and Royal Botanical Gardens No. 2016-07). Thank you to the students of the Chow-Fraser lab and to Jacqueline Garnett for assisting with data collection. Thanks to Dylan Melmer for his insight and help with analysis. We also like to thank the Hamilton Conservation Authority and Royal Botanical Gardens.
This project was funded by the Natural Sciences and Engineering Research Council of Canada.
Compliance with ethical standards
Conflict of interest
The authors declare that they have no conflict of interest.
This article does not contain any studies with human participants or animals performed by any of the authors.
- Aresco MJ, Gunzberger MS (2007) Ecology and Morphology of Chelydra serpentina in Northwestern Florida. Southeastern Naturalist 6:435-448Google Scholar
- Bobyn ML, Brooks RJ (1993) Incubation conditions as potential factors limiting the northern distribution of snapping turtle, Chelydra serpentina Can J Zool 72:28–37Google Scholar
- Buhlmann KA, Gibbons JW (2001) Terrestrial habitat use by aquatic turtles from a seasonally fluctuating wetland: implications for wetland conservation boundaries. Intern J Turt Tortoise Res 4(1):115–127Google Scholar
- Carr AF (1952) Handbook of turtles – the turtles of the United States, Canada, and Baja California. Ithaca, New YorkGoogle Scholar
- City of Hamilton, Information Technology Services, GIS Services (2002)Digital orthoimagery of the City of Hamilton. Spring 2002. Accessed as a web map tile serviceGoogle Scholar
- Committee on the Status of Endangered Wildlife in Canada [COSEWIC] (2008) COSEWIC assessment and update status report on the snapping turtle Chelydra serpentina in Canada. Committee on the status of endangered wildlife in Canada, Ottawa, CanadaGoogle Scholar
- Congdon JD, Breitenbach GL, van Loben Sels RC, Tinkle DW (1987) Reproduction and nesting ecology of snapping turtles (Chelydra serpentina) in southeastern Michigan. Herptologica 43(1):39–54Google Scholar
- Dekker CD (2015) Population and status assessment of the snapping turtle Chelydra serpentina in North Dakota. Dissertation, University of IdahoGoogle Scholar
- Environment and Climate Change Canada (2016) Management plan for the snapping turtle (Chelydra serpentina) in Canada. Species at risk act management plan series. Environment and climate change CanadaGoogle Scholar
- Ernst CH, Lovich JE (2009) Turtles of the United States and Canada. Smithsonian Institution Press, WashingtonGoogle Scholar
- Fitch HS (1956) Temperature responses in free-living amphibians and reptiles of northeastern Kansas. University of Kansas Publications of the Museum of Natural History 8:417–476Google Scholar
- Government of Canada (2009) Species at risk public registry. Available from http://www.sararegistry.gc.ca/sar/index/default_e.cfm. Accessed 21 Aug 2018
- Haxton T (2000) Road mortality of snapping turtles, Chelydra serpentina, in Central Ontario during their nesting period. Can Field-Nat 114(1):106–110Google Scholar
- International Joint Commission (1961) Water levels of lake Ontario: report to the government of Canada and the government of the United StatesGoogle Scholar
- Lesbarrères D, Ashpole SL, Bishop CA, Blouin-Demers G, Brooks RJ, Echaubard P, Govindarajulu P, Green DM, Hecnar SJ, Herman T, Houlahan J, Litzgus JD, Mazerolle MJ, Paszkowski CA, Rutherford P, Schock DM, Storey KB, Lougheed SC (2014) Conservation of herpetofauna in northern landscapes: threats and challenges. Biol Conserv 170:48–55CrossRefGoogle Scholar
- Lockwood Survey Corporation ltd. [Hamilton Area, 1972] : [C5383-72-Photo 16]. Scale [1:12,000 approximately]. C5383-72. [Place of publication unknown]: [Publisher unknown], 1972Google Scholar
- Markle CE, Chow-Fraser P (2017) Thermal characteristics of overwintering habitats for the Blanding’s turtle (Emydoidea blandingii) across three study areas in Ontario, Canada. Herpetol Conserv Biol 12:241–251Google Scholar
- National Air Photo Library (1934) [Greater Hamilton Area, from Caledonia to Vineland, 1934-11-03]: [A4871-Photo 10]. Scale [1:20,000]. A4871. [Place of publication unknown]: [Publisher unknown]Google Scholar
- North West Geomatics Canada Inc. (1999) [West Hamilton, 1999]: [GTA004-Photo 56]. Scale 1:20,000. GTA004. [Place of publication unknown]: [Publisher unknown]Google Scholar
- Obbard ME, Brooks RJ (1980) Nesting migrations in the common snapping turtle (Chelydra serpentina). Herptologica 36:158–162Google Scholar
- Obbard ME, Brooks RJ (1981) Fate of overwintered clutches of the common snapping turtle (Chelydra serpentina) in Algonquin Park, Ontario. Can Field-Nat 95(3):350–352Google Scholar
- Ontario Ministry of Natural Resources (1978) [Regional municipality of Hamilton-Wentworth and surrounding Area, 1978] : [4319–63-Photo 224]. Scale [1:10,000]. 4319–63. [Place of publication unknown]: [Publisher unknown], 1978Google Scholar
- Pappas MJ, Congdon JD, Brecke BJ, Freedberg S (2013) Orientation of freshwater hatchling Blanding's (Emydoiea blandingii) and snapping turtles (Chelydra serpentina) dispersing from experimental nests in agricultural fields. Herpetol Conserv Biol 8:385–399Google Scholar
- Pettit KE, Bishop CA, Brooks RJ (1995) Home range and movements of the common snapping turtle, Chelydra serpentina serpentina, in a coastal wetland of Hamilton harbour, Lake Ontario, Canada. Can Field-Nat 109:192–200Google Scholar
- R Core Team (2018) R: A language and environment for statistical computing. R Foundation for Statistical Computing, Vienna, AustriaGoogle Scholar
- Spartan Air Services Ltd. (1959) [Golden Horseshoe Area, 1959-11-09] : [A16883-Photo 16]. Scale [1:30,000 approximately]. A16883. [Ottawa, Ont.]: [Spartan Air Services Ltd.], 1959–1962Google Scholar
- Steyermark AC, Finkler MS, Brooks RJ (2008) Biology of the snapping turtle (Chelydra serpentina). Baltimore, MarylandGoogle Scholar
- SWOOP (2010) Lidar [computer file]. Land Information Ontario, Ontario Ministry of Natural Resources and ForestryGoogle Scholar
- Thompson MM, Coe BH, Congdon JD, Stauffer DF, Hopkins WA (2017) Nesting ecology and habitat use of Chelydra serpentina in an area modified by agricultural and industrial activity. Herpetol Conserv Biol 12:292–306Google Scholar
- Toronto and Region Conservation Authority [TRCA]. (2018). Reptiles and amphibians of Tommy Thompson Park. Available from: https://tommythompsonpark.ca/park-species/herpetofauna/. Accessed 29 July 2018
- Ultsch GR, Lee D (1983) Radiotelemetric observations of wintering snapping turtles (Chelydra serpentina) in Rhode Island. J Ala Acad Sci 54:200–206Google Scholar
- Urbanek RE, Glowacki GA, Nielsen CK (2016) Effect of raccoon (Procyon lotor) reduction on Blanding’s turtle (Emydoidea blandingii) nest success. Journal N Am Herpetol 1:39–44Google Scholar