A key step in generating effective recovery strategies for species at risk is to identify habitat used under a variety of geographic settings. In part attributable to habitat loss and degradation, the Blanding's turtle (Emydoidea blandingii) is considered at risk across most of its range. Because little information for this species exists for the many islands of Georgian Bay, the world's largest freshwater archipelago, we conducted an intensive study on the habitat use of 12 turtles (6 males, 6 females) on a protected island. We used a combination of radio tracking and GPS loggers to determine habitat use during the active seasons of 2011 and 2012. We used aerial imagery to quantify available habitat and used compositional analyses to determine habitat selection. Both sexes used vernal pools and wet forest to move between habitat patches. Females used inland wetlands early in the year and coastal wetlands during the nesting season, whereas males maintained extensive use of inland wetlands during the entire active season. An effective conservation strategy for Blanding's turtles in Georgian Bay must include protection of inland and coastal wetlands, in addition to the surrounding upland matrix and connecting corridors.
One of the deadliest roads in North America for species at risk fragments a marsh-lake ecosystem. To reduce road mortality, stakeholders installed >5 km of exclusion fencing along a southwestern Ontario, Canada, causeway in 2008. Between 2012 culverts were installed to provide safe crossings. We evaluated the success of these mitigation strategies by 1) comparing results of road surveys conducted 5 years before and 5 years after fencing installation; and 2) monitoring use of culverts by turtles using motion-activated cameras at culvert openings and stationary antennas placed to detect movements of passive integrated transponder (PIT)-tagged turtles (68 Blanding's turtles [Emydoidea blandingii] and 30 spotted turtles [Clemmys guttata]). We also radio-tracked 30 Blanding's turtles to measure culvert use in relation to home ranges. Turtle and snake abundance was 89% and 53% lower, respectively, in completely fenced road sections than in unfenced sections; abundance was 6% and 10% higher, respectively, between partially fenced and unfenced sections. After mitigation, locations where we found reptiles on the road were associated with fence ends, underscoring the importance of fence integrity and ineffectiveness of partial fencing as a mitigation strategy. We confirmed use of culverts by Blanding's turtles, northern map turtles (Graptemys geographica), snapping turtles (Chelydra serpentina), and midland painted turtles (Chrysemys picta). Through radio-tracking, we determined that male and female Blanding's turtles home ranges overlapped with different segments of the causeway. We recommend that stakeholders emphasize ensuring fence integrity and continuity, limiting impact of edge effects, and conducting a comprehensive monitoring program. Ó 2017 The Wildlife Society.
We used a multi-rotor (Phantom 2 Vision+, DJI) and a fixed-wing (eBee, senseFly) unmanned aerial vehicle (UAV) to acquire high-spatial-resolution composite photos of an impounded freshwater marsh during late summer in 2014 and 2015. Dominant type and percent cover of three vegetation classes (submerged aquatic, floating or emergent vegetation) were identified and compared against field data collected in 176 (2 m × 2 m) quadrats during summer 2014. We also compared these data against the most recently available digital aerial true colour, high-resolution photographs provided by the government of Ontario (Southwestern Ontario Orthophotography Project (SWOOP), May 2010), which are free to researchers but taken every 5 years in leaf-off spring conditions. The eBee system produced the most effective data for determining percent cover of floating and emergent vegetation (58% and 64% overall accuracy, respectively). Both the eBee and the Phantom were comparable in their ability to determine dominant habitat types (moderate kappa agreement) and were superior to SWOOP in this respect (poor kappa agreement). UAVs can provide a time-sensitive, flexible, and affordable option to capture dynamic seasonal changes in wetlands, information that ecologists often require to study how species at risk use their habitat.
Point Pelee National Park, located at the southern-most tip of Canada’s mainland, historically supported a large number of herpetofauna species; however, despite nearly a century of protection, six snake and five amphibian species have disappeared, and remaining species-at-risk populations are thought to be in decline. We hypothesized that long-term changes in availability and distribution of critical habitat types may have contributed to the disappearance of herpetofauna. To track habitat changes we used aerial image data spanning 85 years (1931–2015) and manually digitized and classified image data using a standardized framework. Change-detection analyses were used to evaluate the relative importance of proportionate loss and fragmentation of 17 habitat types. Marsh habitat diversity and aquatic connectivity has declined since 1931. The marsh matrix transitioned from a graminoid and forb shallow marsh interspersed with water to a cattail dominated marsh, altering critical breeding, foraging, and overwintering habitat. Reduced diversity of marsh habitats appears to be linked to the expansion of invasive Phragmites australis, which invaded prior to 2000. Loss of open habitats such as savanna and meadow has reduced availability of high quality thermoregulation habitat for reptiles. Restoration of the northwestern region and tip of Point Pelee National Park to a mixed landscape of shallow wetlands (cattail, graminoid, forb, open water) and eradication of dense Phragmites stands should improve habitat diversity. Our results suggest that long-term landscape changes resulting from habitat succession and invasive species can negatively affect habitat suitability for herpetofauna and protection of land alone does not necessarily equate to protection of sensitive herpetofauna.
With recent advances in technology, personal aerial imagery acquired with unmanned aerial vehicles (UAVs) has transformed the way ecologists can map seasonal changes in wetland habitat. Here, we use a multi-rotor (consumer quad-copter, the DJI Phantom 2 Vision+) UAV to acquire a high-resolution (< 8 cm) composite photo of a coastal wetland in summer 2014. Using validation data collected in the field, we determine if a UAV image and SWOOP (Southwestern Ontario Orthoimagery Project) image (collected in spring 2010) differ in their classification of type of dominant vegetation type and percent cover of three plant classes: submerged aquatic vegetation, floating aquatic vegetation, and emergent vegetation. The UAV imagery was more accurate than available SWOOP imagery for mapping percent cover of submergent and floating vegetation categories, but both were able to accurately determine the dominant vegetation type and percent cover of emergent vegetation. Our results underscore the value and potential for affordable UAVs (complete quad-copter system < $3,000 CAD) to revolutionize the way ecologists obtain imagery and conduct field research. In Canada, new UAV regulations make this an easy and affordable way to obtain multiple high-resolution images of small (< 1.0 km<sup>2</sup>) wetlands, or portions of larger wetlands throughout a year.
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