Student Award Recipients - Poster

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Year Recipient Title and Abstract
2005 Paula Duarte

University of Ottawa

Title: Early exposure to 17±-ethinylestradiol alters sex ratios and gonadal morphology of developing leopard frogs (Rana pipiens).

Authors: Paula Duarte, Natacha Hogan, Bruce Pauli, Michael Wade, David R. S. Lean, Vance L. Trudeau

Abstract: Environmental estrogens have been shown to alter gonad development, causing sex reversal, feminization or the intersex condition in some amphibian species. Our objective was to (1) examine normal sexual differentiation during tadpole development and metamorphosis in R. pipiens and (2) determine if the contraceptive ethinylestradiol (EE2) can have long-term effects on gonad morphology and sex ratios at metamorphosis. Control tadpoles were exposed to acetone (0.004%) vehicle throughout the experiment. Exposure to EE2 (5nM) in water began at Gosner stage 26(hind limb bud development). After an early, short-term exposure (STE; approximately 3 weeks) until stage 30, a subset of tadpoles was transferred to control water while a chronic exposure (CE) continued until both groups reached metamorphic climax (stage 42). Histological analysis of the gonads at stage 42 revealed that the sex ratio in the control group was 1:1 (female:male). STE shifted the sex ratio towards females and increased the incidence of intersex individuals; the female:male:intersex ratio was 1:0.1:0.2. For CE, the sex ratio was 1:0.6:0.7 which suggests that the timing and length of estrogen exposure can influence the resulting sex ratios. These results indicate that a short exposure to waterborne EE2 during the critical period of gonadal development can permanently alter sex ratios and induce intersex in a native Canadian amphibian. Supported by U-Ottawa, NSERC, Environment Canada

2006 Isabelle Deguise

University of British Columbia

Title: Movement patterns of adult western toads, Bufo boreas, in fragmented landscapes


Abstract: In fragmented landscapes, dispersal ability and movement behaviour are critical factors determining the persistence of a threatened species. I used radio-telemetry to follow the movement patterns of adult western toads in a fragmented landscape. Toads were experimentally translocated into either forest patches or clear-cut patches, and their movements followed on a daily basis. Preliminary results and conclusions will be shown.

2007 Anita H. Melnyk

Queen's University

Title: The influence of data partitioning on Bayesian phylogenetic inference of the Lithobates catesbeianus species group.

Authors: Anita H. Melnyk* and Stephen C. Lougheed

Abstract: Although many phylogenetic studies routinely employ Bayesian inference, few have examined the effects of different partitioning strategies on tree topology and posterior probability support. Partitioned Bayesian analyses of 1175 bps of mitochondrial DNA sequence were used to investigate the evolutionary affinities of the Lithobates catesbeiana species group of frogs. Fragments of mitochondrial 16S, tRNAleu and ND1 from 14 individuals encompassing all seven species were used in analysis with four different partitioning strategies (1. all data combined; 2. RNA and protein coding genes; 3. each gene separately; 4. stems and loops in RNA coding genes, ND1 3rd codon, ND1 1st and 2nd positions). Comparison of Bayes factors showed that no partitioning strategy was significantly better than any other although different strategies did yield trees with slightly different topologies and varied support values. This result is potentially due to the incorporation of random error associated with the small partition sizes of more complex partitioning strategies. Six of the seven species form an unresolved basal polytomy in the tree determined by the best partitioning strategy. To increase resolution of the phylogeny additional data need to be included. While there remain many areas of exploration in Bayesian analysis, including evaluation of the effects of partitioning and model choice, this study points to how more sophisticated analyses can more fully capture how evolution proceeds for phylogenetically-informative markers.

2008 Nicholas Cairns

Brandon University

Title: The Smooth Green Snake and the Northern Red-bellied Snake: A comparison of the ecology of two small, terrestrial, northern snakes.

Authors: Nicholas Cairns, Pamela Rutherford

Abstract: The smooth green snake (Liochlorophis vernalis) and the northern red-bellied snake (Storeria occipitomaculata occipitomaculata) are small, terrestrial colubrid snakes reaching the extremes of their distributions in southwestern Manitoba. While both species are constrained by short, active seasons they differ substantially in morphology and reproductive mode (L. vernalis is oviparous and S. occipitomaculata is viviparous). The aim of this study is to compare the ecology of these two species in Manitoba by asking two specific questions. First, do these two northern snakes occupy similar ecological niches? Second, what are the local hibernation characteristics in comparison to their hibernation sites at other localities? We addressed these questions with a mark-recapture study using active searching and searching under artificial cover. Local hibernation patterns were determined using drift fences and trapping, active searching, and implantation of temperature data loggers at the hibernation sites. The study was conducted from spring 2007 to summer 2008 in southwestern Manitoba, Canada. Approximately equal numbers of both species were located, although hibernation characteristics were determined only for S. occipitomaculata. Sexual dimorphism was evident only in L. vernalis (females were larger) and gravid females of both species were last captured in mid-July. S. occipitomaculata were captured at lower temperatures and tended to be captured in habitat more closely associated with water although in the third week of June there appeared to be a pulse of activity in more xeric prairie and associated habitat. L. vernalis were almost always associated with prairie and prairie ecotone habitat types. S. occipitomaculata used abandoned ant nests for hibernation sites and were active at these sites until September 25, 2007. Hibernation site characteristics will be determined in spring 2008.

2009 Godwin Okonkwo

University of Alberta

Title: The use of small ephemeral wetlands by amphibians in the mixedwood forest of boreal Alberta.

Authors: Godwin E. Okonkwo*, Cynthia A. Paszkowski and Brian R. Eaton

Abstract: Amphibians are currently experiencing a population decline due to several factors including habitat loss. Identifying what constitutes amphibian habitat in the mixed wood forest landscape will provide a critical tool for managing populations. Most conservation plans for amphibians ignore small ephemeral watersheds because of their size and temporary nature. Furthermore, there have been limited studies on amphibian use of these habitats. We carried out a study to identify if and how amphibians use small ephemeral wetlands (< 0.1ha) on land leased by Daishowa Marubeni International Ltd. within the Peace River Forest Management Area of northwestern Alberta. Twenty-seven small ephemeral wetlands (< 0.1ha) were sampled every two weeks using time-constrained visual encounter surveys for all life stages of amphibians, from May to August, 2008. During each survey, water depth, hydroperiod, temperature, pH and canopy cover of the ponds were also measured. Amphibians were observed at the water surface, pond bottom, under submerged debris, shoreline and riparian areas. A total of 1,105 amphibians including Lithobates sylvaticus (Rana sylvatica), Anaxyrus boreas (Bufo boreas) and Pseudacris maculata were captured in 19 wetlands. Breeding was observed with egg masses and tadpoles occurring in 14 wetlands. Over 68% of the animals found were young-ofthe-year. Wetlands with amphibians were characterised by < 40% canopy cover, while > 60% canopy cover was observed at wetlands without amphibians. Temperature and pH were significantly higher in wetlands with amphibians present. Regression analysis indicated that pH, canopy cover, temperature and hydroperiod significantly influenced amphibian presence and breeding at these wetlands. Our study demonstrates that amphibians use small ephemeral wetlands at different stages of their life cycles. The value of these wetlands should not be under-estimated because of their small size, and the absence of water at the time of operational planning. Based on the use of these habitats by amphibians documented by our study, incorporating small wetlands into forestry and conservation plans will contribute to the preservation of amphibian populations.

2010 Joël Leduc

Department of Biology, Laurentian University

Title: Ecology of Herpetofaunal Populations in Tailings Wetlands in Sudbury, Ontario.

Authors: Joël C. Leduc*, Kristen J. Kozlowicz, Jacqueline D. Litzgus et David Lesbarrés

Abstract: Since the 1920's, Sudbury, Ontario has emerged into one of the world's largest metal producers. The mining and smelting industries have left a devastating ecological footprint on the Sudbury landscape with metal-contaminated substrates and acidified waters near the smelting facilities and tailings wetlands. We tested the hypothesis that the perturbations caused by smelting activities have a negative effect on ecological aspects of amphibian and reptile populations on the tailings wetlands of Xstrata Nickel. We examined the differences in herpetofaunal amphibian and reptile abundance, diversity, biomass, body length and reproduction among three impacted wetlands situated at Xstrata Nickel, Falconbridge, Ontario in comparison with a non-tailings wetland located at the Laurentian Conservation Area, Sudbury, Ontario. Day and night field surveying and sampling were performed two to three times per week for an entire breeding season (22 May - 24 September, 2009). We found significant differences in abundance, biomass, and reproduction, but no differences in species richness or body size in a target species, the green frog (Lithobates clamitans), among sites. The three impacted sites demonstrated lower abundance and biomass than the control site, and fewer species were reproductively active. Our findings indicate that the tailings wetlands may not be able to sustain the large dynamic communities present at non-tailings wetlands, and that herpetofaunal communities may be negatively impacted within the tailings wetlands.

2011 Julia L. Riley

Laurentian University

Pamela Rutherford with Julia
Title: Should i stay or should i go? The influence of environmental factors on Chrysemys picta hatchling overwintering strategy.

Authors: Julia L. Riley, Glenn Tattersall, and Jacqueline D. Litzgus

Abstract: In northern temperate areas, Chrysemys picta hatchlings spend their first winter either submerged in water after fall nest emergence, or within their natal nest chamber. The occurrence of these two strategies varies among populations throughout the species' range, and temporally within the same population; however, the natural factors that determine the strategy employed by a given clutch are not well understood. Subzero nest temperatures above -4°C can be survived by hatchlings using freeze-tolerance, but low nest temperatures like those found in the temperate north can only be survived in a supercooled state. If overwintering strategy maximizes winter survival and is cued by environmental factors, then northern hatchlings should remain in nests when the environment promotes supercooling. Clutches that overwinter in-nest should experience lower fall nest temperatures, soil moisture and vegetation cover, higher nest soil organic content, and smaller nest soil particle size than clutches that experience fall nest emergence. We are testing this hypothesis over two field seasons in Algonquin Park, Ontario. In summer 2010, 26 C. picta nests were caged and a data logger was placed in each to record temperature. Soil texture was quantified for each nest. Nest microhabitat variables were recorded at oviposition and monthly during incubation. In the fall of 2010, 12% of the nests emerged. From April to May 2011, spring emergence was monitored and overwinter survival was 41% (N = 18). None of the environmental factors examined to date appear to influence overwintering strategy; however, additional environmental factors, such as percent oxygen, are currently being monitored, and 27 caged nests will be followed over the 2011-12 winter. Knowledge of hatchling C. picta overwintering strategies is predominately based on laboratory studies; our study will contribute to understanding this phenomenon in nature.

2012 James Baxter-Glibert

Laurentian University

Title: On The Road Again: Measuring the Effectiveness of Mitigation Structures for Reducing Reptile Road Mortality

Authors: James Baxter-Gilbert, Dr. David Lesbarreres, and Dr. Jacqueline Litzgus

Abstract: Many reptile populations are negatively impacted by roads, especially because seasonal migratory movements increase individual encounters with traffic. The Highway 69/400 corridor, connecting southern and northern Ontario, runs along the eastern Georgian Bay Coast, one of Canada's richest areas of reptile biodiversity. A section of new 4-lane highway has been designed to include mitigation structures (e.g., eco-passages, fences) intended to lessen the detrimental effects this major roadway poses to numerous Species-at-Risk (SAR) reptiles. Using a Before-After-Control-Impact-Paired (BACIP) study design, we will quantify reptile road mortality present on the existing, non-mitigated 2-lane highway (in spring and summer 2012) and compare it to mortality on the new, mitigated 4-lane highway (in spring and summer 2013). In both years of the study, a control site without any mitigation measures will also be monitored. If the exclusion structures (e.g., fences) of the new highway are effective, animals should be prevented from accessing the road and we should therefore observe a reduction in road mortality. Radio telemetry, automated PIT tag readers, and wildlife cameras will be used to monitor reptile movements around and under the road via population connectivity structures (e.g., eco-passages). Additionally, a "willingness to utilize" experiment will be conducted, which will assess turtle behaviour in response to the eco-passage. If the population connectivity measures are effective, movements between habitats on either side of road, and use of the eco-passages are expected. Conclusions drawn from our study will allow development of recommendations for future road mitigation structures to reduce road mortality, and counteract the decline of reptile biodiversity.

2013 Camille Tremblay-Beaulieu

Laurentian University

Title: Effects of mining on the physiological ecology and morphology of herpetofauna in Sudbury, Ontario

Authors: Camille Tremblay-Beaulieu, Kiyoshi Sasaki, David Lesbarrères, Glen Watson and Jacqueline Litzgus

Abstract: A century of Sudbury's mining operations has created barren landscapes with high levels of heavy metals and acidity. While much effort has been made to assess the impacts of mining on water and soil quality, and the vegetation component of ecosystems, effects on most fauna, including herpetofauna, remain largely uninvestigated. In 2012 we undertook a population-level study and found that severely affected sites (barren), despite their superficial recovery in vegetation cover, had reduced numbers of species and abundances as compared to reference sites. Because inferences based on population-level data need to be supplemented with studies at the individual level to avoid drawing spurious conclusions, our current study focuses on the physical functions and conditions of individuals, including assessments of body condition, bilateral asymmetry in scute number in turtles, scalation in snakes, limb length in frogs, and metabolic rate in snakes. We predicted that animals from the barren sites would display poorer body condition, higher levels of asymmetry, and elevated metabolic rates as compared to animals from reference sites. Preliminary results will be presented, with a focus on snake scalation and metabolic rate. These findings have important consequences because they shed light on the mechanisms underlying impacts at population- and community-levels and will thus help to develop more targeted restoration strategies.

2014 Michael Colley

Laurentian University

Title: Preparing for the future: a hot spot analysis of reptile road mortality in Killbear Provincial Park

Authors: Michael Colley, Stephen C Lougheed, Kenton Otterbein and Jacqueline D Litzgus

Abstract: Scientists are increasingly concerned over global declines in reptile populations. These declines have been attributed to multiple causes including habitat fragmentation and loss, climate change, persecution, and road mortality. Roads cause diminution in population size through direct mortality caused by vehicles. Wildlife barriers and ecopassages recently have been used in many locations in an attempt to reduce the threat of reptile road mortality. Killbear Provincial Park in Ontario hosts a variety of reptile species, many of which are in decline, in part, because of road mortality. The park currently has 3.5 km of wildlife barrier fencing and 4 ecopassages, thus potentially mitigating road mortality on 2.5 km of park roads; however, road mortality still occurs in places lacking mitigation measures. Our goal is to identify and quantify the locations of high road mortality ("hot spots") and potential future mitigation sites. In 2013 and 2014 park roads were monitored twice daily on bicycles, and again at night by car to document locations of both living and dead snakes and turtles. Prior to 2013, park staff opportunistically monitored park roads by car for Massasauga Rattlesnakes and Eastern Foxsnakes. Road surveys in 2013 indicated over 190 dead-on-road reptiles and identified three sites on park roads that may need mitigation. Road surveys to date in 2014 have documented over 90 dead-on-road reptiles; data from the 2014 field season are still being collected and will augment the final analyses. We will use approaches encoded in SIRIEMA and Circuitscape software to identify specific hot spots that require mitigation. Determining the locations of such hot spots is essential for directing effective future mitigation on roadways. The outreach completed as a component of this project will help inform key stakeholders and the public of the negative effects that roads have on reptiles and measures that can counter them.

2015 Geoffrey Hughes

Laurentian University

Title: The thermal landscape as a predictor of Wood Turtle (Glyptemys insculpta) nest-site selection

Authors: Geoffrey N. Hughes and Jacqueline D. Litzgus

Abstract: For oviparous species with no parental care, like wood turtles (Glyptemys insculpta), nest-site selection represents the only point at which a mother may behaviourally invest in her offspring. Previous studies in the Sudbury District determined that wood turtle females select nest sites for high-but-variable nest temperatures; lab studies have shown that variable incubation temperatures speed development of wood turtle embryos. By studying both the thermal and physical properties of known nesting beaches at the study site, and comparing them to the specific thermal and physical selections made by nesting wood turtle females, we will determine whether wood turtles navigate a thermal landscape on the microhabitat scale, and if this thermal landscape is more important in determining their behaviour than the physical landscape. Thermal imaging cameras will be placed on three known nesting beaches to measure their thermal characteristics. These beaches will be divided into 1m2 grids; soil samples will be collected from each grid prior to the commencement of nesting activity to measure soil organic content and grain size distribution, to measure the physical characteristics of the beaches; we will also take daily soil moisture measurements during the nesting period. When we observe a female nesting on a beach, we will compare the thermal and physical characteristics to assess relative importance in the female's nest-site selection. This study will improve our knowledge of the surface cues used by female wood turtles in nest-site selection, and can lead to new techniques for surveying nesting habitat. Preliminary data will be presented.

2016 Shannon Ritchie

University of Toronto Scarborough / the Toronto Zoo

Title: Overwintering ecology of head-started Blanding's Turtles (Emydoidea blandingii) in a restored wetland

Authors: Shannon D. Ritchie, Nicholas E. Mandrak, Marc W. Cadotte and Andrew M. Lentini

Abstract: The Blanding's turtle (Emydoidea blandingii) is a Threatened species in Ontario, and without mitigation is expected to become extirpated in urban environments, such as the Greater Toronto Area. For three years, the Toronto Zoo's Adopt-A-Pond Wetland Conservation Programme has been supplementing the Blanding's turtle population in Rouge National Urban Park (RNUP) with captive-raised, two-year old juvenile turtles, "head-starts", in conjunction with habitat restoration work. The Rouge River in RNUP has tributaries, which act as movement corridors for a small, local, population of Blanding's turtles. However, the availability of wetland habitat is minimal and mainly composed of restored or artificial wetlands. Environmental variables directly influence the physiological conditions and survival of overwintering turtles. The selection and availability of appropriate overwintering sites can minimize threats to mortality, such as acidosis and tissue freezing. This research project is examining the location and ecology of successful overwintering sites used by head-started Blanding's turtles living in a restored wetland. The relationship between site selection, survival and environmental conditions such as temperature, dissolved oxygen content, vegetation, substrate, and water depth is being evaluated. The results of this research will provide important insight for future wetland restoration design and turtle population supplementing programs around the Great Lakes basin.

2018 Ying Chen

Queen’s University

Title: Understanding Variation in Male Advertisement Calls in Spring Peepers (Pseudacris crucifer)

Authors: Ying Chen, Amanda S. Cicchino and Stephen C. Lougheed

Abstract: The mate recognition system is the foundation of biological speciation in anurans. Sexual selection has been suggested to cause males call evolution. It is generally assumed that a significant fraction of variation in male call has an underlying genetic basis and that there is some link between call attributes and fitness, yet there are largely unproved assertions with many other factors contributing to diversity of calls within a male chorus. Anurans advertisement calls are important in studies in sexual selection, speciation as well as phenological studies. In all of these understanding, heritability is prerequisite to understanding evolutionary patterns and potential responses to selection. However, very few studies have examined the heritability of advertisement calls in anurans. In general, we know that key aspects of anuran calls, including both temporal and spatial attributes, vary with morphology such as body size, ontogeny such as age, abiotic factors such as temperature and habitat types, as well as biotic interactions like inter-male competition. In this study, I hope to quantify the genetic-basis of anuran call variation within a calling assemblage of a temperate treefrog, Pseudacris crucifer, and disentangle the relative contributions of different factors: body size, age, calling temperature and genetics. I hope to use single nucleotide polymorphisms (SNPs) to estimate the relatedness of calling males and use animal model to incorporate influential factors. By investigating the genetic basis as well as environmental components of advertisement call attributes, we will gain a better understanding of call evolution and the potential for sexual selection to drive divergence.

2017 Steven Kell

Laurentian University

Title: Causes and benefits of high density nesting in Painted Turtles

Authors: Steven J. Kell, Ronald J. Brooks and Jacqueline D. Litzgus

Abstract: Nesting is a costly time for female turtles, both energetically and from threat of predation. Although predation rates of eggs and juveniles are often high, ensuring maximum survival of offspring is crucial for population stability and individual fitness. Therefore, females should try to maximize offspring fitness while also minimizing risk to themselves. Our past observations indicate that female painted turtles at our study site in Algonquin Park are nesting at higher densities than random, suggesting some benefit to themselves and/or their offspring. Our goals are to determine if females are choosing to nest at high densities, what cues they use to locate nest sites, and what benefits the offspring might accrue from incubating at high nest densities. We will use ArcGIS to perform a spatial analysis on nest locations using data from 2015–2017 to determine if nest density is non-random or a product of abiotic nesting conditions. Why a female may choose a nesting location will be determined based on olfaction and visual cues provided by other females. Artificial nests scented with either turtle urine or water will be randomly distributed across the nesting site, allowing females to potentially choose to nest near or avoid other nests. Turtle models will be placed at the nest site in 3 densities, rotating locations each day to determine if nest site choice and nest density are driven by visual cues. Nests will be caged to prevent predation and spatial analyses conducted using ArcGIS to determine if incubation duration differs based on nearest neighbor distances. Our study will expand the knowledge of turtle reproductive biology and will also help in conservation as this information could be used to make artificial nesting mounds more attractive to female turtles.

2019 Morgan Skinner

Wilfrid Laurier University

Title: Individual differences in sociability and boldness in Eastern Garter Snakes

Authors: Morgan Skinner and Noam Miller

Abstract: There is little research on individual differences, sometimes called ‘personality’, in snakes. We measured sociability and boldness of juvenile Eastern Garter Snakes in both an individual and a group environment. To individually test sociability, we measured a snake’s attraction to a social shelter (scented with conspecific skin lipids), compared to a control shelter. To measure boldness, we examined the time to emerge from a shelter and the time spent exploring an arena. We then examined the consistency of these behaviors when the snakes were moved into a group environment, by placing groups of ten snakes in a square enclosure that had four hides. We recorded positions of all the snakes every 5 seconds for 8 days. We constructed social networks of the snakes’ interactions and examined the effects of individual differences in sociability and boldness on their aggregation tendencies. We found that social preferences within the group context were consistent across days and between the individual and group scenarios. Additionally, we found significant changes in boldness across contexts. Not only is this the first study to demonstrate individual differences in sociability in snakes, it is also the first study to examine the effects of snake ‘personality’ in a group context.

2021 Briar Hunter

Laurentian University

Title: Investigating genetic health in captive and wild Oregon Spotted Frogs (Rana pretiosa) in Canada

Authors: Briar Hunter, David Lesbarrères and Gabriela F. Mastromonaco

Abstract: The Oregon Spotted Frog (Rana pretiosa) is the most endangered amphibian in Canada and captive programs are in place to support its recovery. Unfortunately, all face challenges of poor reproductive performance, low egg fertility and high incidence of egg binding in females. While these issues are physiological in nature, they may have a genetic basis. Yet the level of genetic diversity in this species, whose populations have disappeared from up to 90% of its historical range, is currently unknown. In order to better understand its reproductive challenges and determine if differences exist between the remaining 6 wild populations and 3 captive populations, this study is investigating their genetic make-up. DNA has been collected by buccal swabbing both captive and wild frogs to measure genetic variability and inbreeding coefficients. We suspect inbreeding is already present in the small, fragmented wild populations and even more prevalent in the further restricted captive populations. Determining genetic variability holds implications not only for the adaptive potential of captive-bred frogs reintroduced to the wild, but also for the long-term sustainability of these programs. Results are still pending, but overall, my work will improve the cohesiveness of current Oregon Spotted Frog recovery efforts across Canada, ensuring all time, effort and resources make a lasting impact on our most endangered amphibian species.

2022 Jeanne Dudemaine

Université Laval

Title: Survival of chorus frogs in natural and restored environments

Authors: Jeanne Dudemaine, Marc J. Mazerolle, Vance L. Trudeau, Aurore Fayard, Emiko Wong, Odile Colin, Lyne Bouthillier, Catherine Doucet, and Sophie Tessier

Abstract: Several amphibian species have experienced population declines in recent decades. The Great Lakes, St-Lawrence, Canadian shield populations of the western chorus frog (Pseudacris triseriata) has suffered reductions in its distribution. Wetland habitat loss following urban expansion is one reason of the decline in the Montérégie area of southern Quebec. Different tools have been considered to promote the conservation of the species, including releasing individuals in restored environments. Our project aims to evaluate the persistence of chorus frog populations following reintroduction in restored habitat. The project has three objectives: (1) to assess the abundance and survival of individuals in reintroduced populations and compare them to natural populations, (2) to determine the impact of larval density in mesocosms on short term and long-term survival, (3) to evaluate the use of environmental DNA to estimate the abundance of individuals. In 2021, we released 732 metamorphs in two constructed ponds in Parc national du Mont-Saint-Bruno. We conducted a capture-mark-recapture study in three natural ponds and three constructed ponds during the 2022 breeding season. One of the three natural populations became extinct, whereas the two other natural populations had a low number of adults captured (12-20 individuals). At the ponds constructed for chorus frog reintroduction, we captured adults released the year before as metamorphs, although captures were low (5-10 individuals). We reared a total of 1191 individuals in mesocosms during the summer 2022, distributed along six larval densities. A total of 583 individuals reached metamorphosis. Preliminary results show that individuals reached metamorphosis at a lower size and weight when reared at higher density. The metamorphs were marked with Visible Implant Elastomer and released in two constructed ponds. The results obtained from this project will allow us to better orient reintroduction efforts to promote the persistence of introduced populations.

2023 Joshua Christiansen

Mount Allison University

Title: City slicker salamanders: Examining the behaviour of a widespread Plethodontid salamander across a gradient of urbanization

Authors: Joshua J.A. Christiansen and Julia L. Riley

Abstract: In our modern era, there are a suite of environmental changes, like urbanisation, that challenge our planet’s ecosystems. However, wildlife can persist and adapt to changes associated with urban expansion. For example, urban wildlife may exhibit different behavioural characteristics than non-urban conspecifics. Eastern Red-backed Salamanders (Plethodon cinereus) occur widely in Eastern North American forests across a gradient from highly urban to pristine natural areas. Plethodon cinereus are also behaviourally complex and the successful survival and persistence of urban populations may be due to adaptative behavioural change. We are studying whether the behaviour of P. cinereus differs between urban and natural forests by conducting repeated behavioural assays in the field to quantify three behavioural traits: tendency to explore a novel environment, boldness, and aggression toward a conspecific model. We are also collecting environmental data (e.g., temperature, relative humidity, etc.) to help us explore potential causes of behavioural differences between urban and natural populations. Fieldwork is on-going and we will present preliminary results whether salamander behavioural traits and their expression (e.g., repeatability) differ between habitat types. This work will add to our knowledge of how urban evolution is impacting amphibians. In addition, P. cinereus is a well-known indicator of forest health and understanding how anthropogenic activity influences their biology will also inform whether and how urbanization is impacting forest ecosystems. As the rate of urbanization continues to increase in Canada, this is critical information about how wildlife may adapt to and persist in our ever-changing world.