An integrative approach to regional mapping of suitable habitat for the Blanding’s turtle (Emydoidea blandingii) on islands in Georgian Bay, Lake Huron

Mapping suitable habitat for a species at risk is one of the first steps in a conservation plan. Creating habitat suitability maps can be very challenging when the area of interest is large and located in remote areas where field excursions can be difficult to implement. Such is the case for the Blanding’s turtle, a threatened species in Ontario, that live on the Georgian Bay archipelago. With increasing anthropogenic pressures, maps indicating suitable habitat can aid management decisions and prioritize areas for protection. We apply an interdisciplinary approach using traditional field data and generalized linear models to produce high resolution, regional maps which identify suitable habitat for Blanding’s turtles throughout the archipelago. We assessed the accuracy of our models using an independent survey dataset of 16 island sites distributed throughout the archipelago, and evaluated models using a reference island as a threshold for determining suitability of survey sites. Islands with higher proportions of wetlands and vernal pools were generally considered to be suitable for Blanding’s turtles compared to those with lower proportions. Our findings highlight the importance of both permanent and temporary wet habitats for Blanding’s turtles. Based on our final model, approximately 64% of evaluated islands support habitat for Blanding’s turtles. Our study is the first to produce detailed habitat suitability maps for Blanding’s turtles on the Georgian Bay archipelago. We recommend an integrative approach be applied to create habitat suitability maps for other species at risk in Georgian Bay

Land-cover trends over 85 years in Point Pelee National Park.

<p>(a) Marsh habitats, excluding 1990. (b) Upland habitats. (c) Shoreline, beach and anthropogenic classes. Habitat types comprising < 0.5% of the park are not shown.</p

Image data processed for change-detection analyses in Point Pelee National Park (PPNP).

<p>Image data processed for change-detection analyses in Point Pelee National Park (PPNP).</p

Habitat composition throughout the sampling period (1931 to 2015) in Point Pelee National Park.

<p>The quality of the 1990 image did not permit classification of marsh ecosites/vegetation types (i.e., common reed, cattail organic shallow marsh, graminoid organic shallow marsh, forb organic shallow marsh) and is only presented at the community level (marsh). Habitat types comprising < 0.5% of the park are not shown.</p

Habitat types classified in image data for Point Pelee National Park.

<p>Habitat types classified in image data for Point Pelee National Park.</p

Change in marsh habitat in Point Pelee National Park between 1959 and 2015.

<p>(a) and (b) indicate hotspots of major habitat change and infilling within the marsh (solid-lined boxes). (c), (d), and (e) indicate hotspots of invasive common reed (dashed-lined boxes).</p

Metrics used to describe habitat changes in Point Pelee National Park at the landscape and class scale.

<p>Metrics used to describe habitat changes in Point Pelee National Park at the landscape and class scale.</p