Brad D. Steinberg

Habitat selection by Blanding's turtles (Emydoidea blandingii) in a relatively pristine landscape

Abstract: Identifying habitats in which a species is likely to be found is extremely important for understanding the life history and general ecology of the species. Studies of habitat selection by species at risk provide information for management and recovery programs on critical habitat and are essential for conservation programs to be effective. Many studies on species at risk are conducted in highly altered or degraded habitats because few areas have not experienced human impacts. We investigated habitat selection by Blandings turtles (Emydoidea blandingii) in a large protected area, Algonquin Park. Specifically, we evaluated macrohabitat selection at 2 spatial scales (home range and individual location) and microhabitat selection at one scale. Macrohabitat selection was significant at the home range scale but not at the scale of individual location, and no shift in habitat selection was detected among different seasons. Habitat ranks were ambiguous because all wetland types were preferred over lotic and upland habitats. The microhabitat selection data showed no preference for habitat features or shifts among different seasons. These data combined with those from other studies suggest that large study sites in relatively pristine areas may include a large amount of suitable high-quality habitats such that habitat selection at a fine scale may not be detected or multiple habitat types may provide the resources necessary to support populations. Nomenclature: Ernst & Lovich, 2009.

Revealing a cryptic life-history stage: differences in habitat selection and survivorship between hatchlings of two turtle species at risk (Glyptemys insculpta and Emydoidea blandingii)

Abstract Context. Turtles are one of the most imperilled taxonomic groups worldwide and information about population ecology is essential to species recovery. Although the spatial ecology and demography of adults of several turtle species have been well studied, little is known about early life stages. The small size, soft shell, and limited mobility of hatchling turtles may cause differences in survivorship and habitat selection compared with adults. Aims. We tested the hypothesis that hatchling turtles select habitat as they move away from nests, so as to reduce the risk of predation and desiccation. Methods. We examined survivorship, behaviour and habitat selection at two spatial scales in hatchling Blanding’s turtles (Emydoidea blandingii) and wood turtles (Glyptemys insculpta) in 2009 and 2010, using radio-telemetry in Algonquin Provincial Park, Ontario, Canada. In addition, temperatures of sites used by hatchlings during winter were compared with those at haphazard stations in various habitats. Key results. The mortality rate was high, with 42% of E. blandingii and 11% of G. insculpta hatchlings surviving to winter; most mortality was caused by predation. Most behavioural observations for both species were of individuals hiding under cover. Both species showed evidence of macrohabitat and microhabitat selection as they dispersed from nests towards overwintering sites, and important variables in the models differed between species. Likewise, the adult stages of these two species differ in their macrohabitat specialisation. There was also evidence that hatchlings chose overwintering sites on the basis of temperature. Conclusions. Despite significant differences in survivorship between hatchlings and adults, resource selection was similar between these two demographic stages, and conservation plans based on adult habitat use should simultaneously protect hatchlings. Implications. Understanding habitat selection by juveniles is important for testing hypotheses about ontogenetic shifts in resource selection and for protecting habitat for species at risk.

Not just any old pile of dirt: evaluating the use of artificial nesting mounds as conservation tools for freshwater turtles

The viability of freshwater turtle populations is largely dependent on the survivorship of reproducing females but females are frequently killed on roads as they move to nesting sites. Installing artificial nesting mounds may increase recruitment and decrease the risk of mortality for gravid females by enticing them to nest closer to aquatic habitats. We evaluated the effectiveness of artificial nesting mounds installed in Algonquin Park, Canada. Artificial mounds were monitored for 2 years to determine if turtles would select them for nest sites. We also simulated turtle paths from wetlands to nests to determine the probability that females would encounter the new habitat. A transplant experiment with clutches of Chrysemys picta and Chelydra serpentina eggs compared nest success and incubation conditions in the absence of predation between artificial mounds and natural sites. More turtles than expected used the artificial mounds, although mounds comprised a small proportion of the available nesting habitat and the simulations predicted that the probability of females encountering mounds was low. Hatching success was higher in nests transplanted to artificial mounds (93%) than in natural nests (56%), despite no differences in heat units. Greater use than expected, high hatching success, and healthy hatchlings emerging from nests in artificial mounds suggest promise for their use as conservation tools.

Out of the Woods: Mitigating Negative Impacts of Unused Forest Roads on Amphibians with Woody Debris

Out of the Woods: Mitigating Negative Impacts of Unused Forest Roads on Amphibians with Woody Debris Habitat loss and fragmentation are among the most serious threats facing amphibians. While less noticeable than highways and with typically little vehicle traffic, extensive networks of logging roads also fragment habitats and some species avoid crossing these roads. Woody debris is an important habitat feature for many amphibians providing refuges and foraging opportunities for species sheltering underneath. In an attempt to mitigate the negative impacts of habitat fragmentation by logging roads in Algonquin Provincial Park, Canada, we sampled amphibians crossing an unused logging road using pitfall traps and tested several types of woody debris treatments. Using the ‘before’ and ‘after’, ‘control’ and ‘impact’ (BACI) model, we compared captures of Red-backed Salamanders (Plethodon cinereus), Red Efts (Notophthalmus viridescens) and Green Frogs (Lithobates clamitans) in 2010 (pre-treatment) and 2011 (post-treatment); the treatments consisted of either hardwood mulch, conifer brush, timbers and a control with no woody debris. Our results with pitfall traps indicated specific responses to mitigation with Green Frogs showing positive responses to the brush and timber treatments, while both salamander species showed little response.

Middle of the road: enhanced habitat for salamanders on unused logging roads

Abstract Context. Amphibians are particularly susceptible to the effects of habitat loss and fragmentation. The construction and use of roads is among the most common sources of habitat fragmentation and can lead to serious population declines. Unused resource access roads, such as those formerly used for logging, can still negatively impact salamanders and reduce habitat quality through edge effects. Unfortunately, habitat rehabilitation and enhancement is rarely attempted on unused forest roads. Aims. Our aim was to elaborate on a previous study that tested several types of woody debris to mitigate the negative impacts of forest roads by creating a novel habitat on an unused forest road in Algonquin Provincial Park. Here we focus solely on the use of large, squared timbers and their use by salamanders. Methods. We tested the application of coarse woody debris (CWD) to the surface of an unused forest road. CWD were sampled for salamanders seven times during the 2011 field season. Local climatic variables were tested against salamander captures, and CWD size preferences and patterns of salamander aggregation under CWD were assessed. Key results. We observed five salamander species and 415 individuals under timbers in the 2011 field season. Larger timbers (>1 m3) were preferred by all species observed and a significant proportion of animals were found in groups of two or more under larger timbers. High ambient temperature and low relative humidity negatively affected the number and species composition observed under timbers, suggesting that the efficiency of CWD as a survey method and enhanced habitat is season dependent. Implications. Large timbers placed on unused forest roads may provide suitable refuges for migrating or dispersing forest salamanders while they attempt to cross the road. The tendency of salamanders to aggregate under CWD allows individual red efts to reduce water loss; however, red-backed salamanders are territorial and may drive off conspecifics. The use of large CWD may be an effective and low-cost method to rehabilitate unused forest roads and can be used to promote habitat connectivity for salamanders in targeted habitats, such as near wetlands, or for other species of concern.

Big enough for bears? American black bears at heightened risk of mortality during seasonal forays outside Algonquin Provincial Park, Ontario

Abstract:  Protected areas may provide insufficient protection for carnivores such as bears (Ursidae) with large home ranges and extensive seasonal movements. Even in protected areas, harvest can be the main cause of mortality if parks are small or individuals live close to the boundary. At >7,600 km2, Algonquin Provincial Park (APP) is the largest protected area in southern Ontario, Canada, yet wolves (Canis lycaon c.f.) experienced increased mortality when leaving APP to hunt white-tailed deer (Odocoileus virginianus). American black bears (Ursus americanus; hereafter, bears) also undertake seasonal movements, and may incur increased risk of harvest related mortality if they leave the park. We fitted 72 bears with Global Positioning System or Very High Frequency radiocollars during 2006–2014 to determine overall and cause-specific mortality rates, and whether risk of mortality changed when bears left APP or during years of low natural food availability. Further, we compared the abundance of resident bears with harvest rates in Wildlife Management Units (WMUs) surrounding APP to determine whether harvest was higher in areas surrounding the park compared with WMUs farther from the park boundary. Hazard analysis showed annual mortality for radiocollared bears in APP was 15%. Harvest mortality was double that of all other causes combined. Bears were 7 times more likely to die outside the park. Years of lower natural food availability inside the park, or higher red oak (Quercus rubra) availability outside the park did not significantly alter the risk of mortality. Male bears were 6 times more likely to be harvested than females, and 4 times more likely to die from other causes. High harvests of bears in WMUs near APP contrasted with low abundance of resident bears, suggesting that APP acts as a source population for harvest that occurs near park boundaries. Meaningful maintenance of the integrity of bear populations in protected areas should be undertaken at the landscape scale.