Marc Dupuis-Desormeaux | York University (original) (raw)

Talks by Marc Dupuis-Desormeaux

Road Traffic Limits Home Ranges of Urban Raccoons (Procyon lotor) The behavior of urban-living... more Road Traffic Limits Home Ranges of Urban Raccoons (Procyon lotor)

The behavior of urban-living raccoons has not been systematically investigated at a fine-grained scale, despite the fact that raccoons co-exists closely with humans in cities across North America and can transmit deadly parasites and viruses. The purpose of this pilot study was to assess the feasibility of gathering fine-grained GPS data in an urban setting and to analyze the behavior and movement patterns of urban raccoons. We fitted five GPS and VHS tracking collars on raccoons in three different urban residential areas of the City of Toronto, Ontario, Canada. We programmed the collars to collect GPS coordinates every 5 to 20 minutes during peak activity cycles for a six-week period in August and early September of 2010. The GPS collars allowed us to obtain a large number of sample points from each animal (up to 1400 positions per animal), which gave us a detailed look at their home-range use. We know of no other raccoon study that has attempted this level of granularity. We found that home ranges during these six weeks were smaller than expected in relation to previously published data. We also found that road traffic patterns were a strong predictor of the borders of home ranges suggesting that raccoons prefer not to cross busy roads and that even minor arteries can act as hard borders. We discuss the challenges of collecting GPS data in an urban setting and the feasibility for a broader study.

Papers by Marc Dupuis-Desormeaux

Facets, 2024

In late 2020, a private volunteer group operating through a Facebook group approached Toronto and... more In late 2020, a private volunteer group operating through a Facebook group approached Toronto and Region Conservation Authority (TRCA) with an interest in participating in the Citizen Science Nest Protection and Monitoring Volunteer Program. During the 2021 season, TRCA staff virtually trained volunteers in turtle nest detection, protection, and monitoring due to COVID-19 social constraints, and provided necessary supplies and equipment. In 2021 volunteers and staff detected 181 turtle nests and were able to protect 75 nests with simple predator-exclusion devices, while in 2022, 165 nests were detected, and 155 were protected. The volunteers also collected data, including nesting location, date, and species in addition to the number of successful hatchlings (2021 only). In 2021, the 75 protected nests yielded 81 Midland Painted Turtle and 665 Snapping Turtle hatchlings. Five Midland Painted Turtle's eggs were also recovered from an injured turtle, and 44 Snapping Turtle eggs were recovered from a partially predated nest, transported to the Ontario Turtle Conservation Centre, incubated, hatched, and overwintered, and then released back into the local wetlands. The partnership with a local community group proved effective, and we would recommend this practice to other conservation organizations interested in turtle nest protection.

Canadian Field-Naturalist, Jun 21, 2023

Red-eared Slider (Trachemys scripta elegans) is a non-native turtle found in abundance in Toronto... more Red-eared Slider (Trachemys scripta elegans) is a non-native turtle found in abundance in Toronto’s wetlands as a result of pet releases. Although this species is known to reproduce successfully in southwestern Ontario, Canada, there is yet no evidence to suggest successful reproduction in the Greater Toronto Area (GTA). As part of a native turtle nest protection program, volunteers inadvertently placed nest protector boxes over four slider nests in 2021 and 10 nests in 2022. This gave us the opportunity to determine whether nests produced viable offspring and whether these hatchlings would emerge in the fall. The exact nesting date for each nest was recorded. In 2021, eight of the 41 eggs from the slider nests showed very late-stage arrested embryonic development. In 2022, one of the nests had four hatchlings out of their eggshells but still inside the nest cavity. It is unclear whether the hatchlings would emerge later in the fall or overwinter in the nest cavity and emerge the following spring. If the small population sampled accurately reflects what occurs in the GTA, complete egg development may be possible for this species in some years, in some locations, with the right local micro-climate and micro-habitat. We discuss implications for turtle nest protection in Toronto.

This dissertation examines how various anthropogenic barriers affect wildlife movement, and in pa... more This dissertation examines how various anthropogenic barriers affect wildlife movement, and in particular, how fencing affects movement and behavior of both migratory prey and predators in semi-porous environments. I chose to examine this subject as our planet's last remaining ecosystems are threatened by human encroachment due to population pressure, agriculture, and a myriad of other ecological stressors. In order to mitigate the encroachment, conservation fencing is rapidly becoming the norm even though constraining wildlife movement is fraught with ecological issues. My interest in conservation fencing was to examine the potentially hidden or understudied consequences Thanks to Geoffrey Chege, Mary Mwololo, Edwin Kisio, and all of the rest of the conservation research staff at the Lewa Wildlife Conservancy for their invaluable help with data collection. Thanks to Mike Watson and Jonathan Moss, CEOs of the Lewa Wildllife Conservancy during the time of my Ph.D. studies for proving the invaluable management support structure necessary for a Canadian to do research in Kenya. It is because of forward thinking wildlife managers that this research could happen. Thanks to Mirka Ondrack and Dr. Georges Monette of the Institute for Social Research Statistical Consulting Services at York University for the many hours of help with data analysis. Thanks to Dr. Tarmo Remmel of the York University Department of Geography for helpful suggestions pertaining to the spatial analysis.

Journal of Great Lakes Research, Apr 1, 2021

The aim of this study was to provide a baseline assessment of the turtle community in the coastal... more The aim of this study was to provide a baseline assessment of the turtle community in the coastal wetlands of the Greater Toronto Area. We documented turtle species diversity, abundance, reproductive classes, sex-ratios, and evidence of inter-wetland movement. Our study consisted of a series of markrecapture surveys across eleven Lake Ontario coastal wetland complexes of the Greater Toronto Area performed between 2016 and 2019. We captured and marked 532 individual turtles of four native species (298 midland painted, Chrysemys picta marginata; 180 snapping, Chelydra serpentina; 7 Blanding's, Emydoidea blandingii, and 5 map, Graptemys geographica) and three non-native species (40 red-eared slider, Trachemys scripta elegans; 1 false map, Graptemys pseudogeographica, and 1 Chinese softshell, Pelodiscus sinensis). Of note was the capture of an exceptionally large male snapping turtle, one of the largest recorded in Canada for both length and mass. The age classes of both snapping and midland painted species presented large proportions of breeding-sized adults, yet midland painted turtles showed a potential low recruitment with an underrepresentation of non-reproductive females. The sex ratios of both midland painted and snapping turtles across the whole waterfront did not differ from the expected 1:1 ratio. We also recaptured 198 turtles (135 midland painted, 53 snapping, 6 Blanding's and 12 redeared Sliders). The recaptured turtles revealed inter-wetland movements of 12 km over a two-year span for a midland painted turtle and an 8 km journey for a snapping turtle, potentially demonstrating some connectivity between geographically separate wetland complexes.

PeerJ, Aug 8, 2018

Conservation authorities invest heavily in the restoration and/or creation of wetlands to counter... more Conservation authorities invest heavily in the restoration and/or creation of wetlands to counteract the destruction of habitat caused by urbanization. Monitoring the colonization of these new wetlands is critical to an adaptive management process. We conducted a turtle mark-recapture survey in a 250 ha artificially created wetland complex in a large North American city (Toronto, Ontario). We found that two of Ontario's eight native turtle species (Snapping turtle (SN), Chelydra serpentina, and Midland Painted (MP) turtle, Chrysemys picta marginata) were abundant and both were confirmed nesting. The Blanding's turtle (Emydoidea blandingii) was present but not well established. Species richness and turtle density were not equally distributed throughout the wetland complex. We noted SN almost exclusively populated one water body, while other areas of the wetland had a varying representation of both species. The sex ratios of both SN and MP turtles were 1:1. We tracked the movement of Snapping and Blanding's turtles and found that most turtles explored at least two water bodies in the park, that females explored more water bodies than males, and that 95% of turtles showed fidelity to individual overwintering wetlands. We performed DNA analysis of two Blanding's turtles found in the created wetlands and could not assign these turtles to any known profiled populations. The genetic data suggest that the turtles probably belong to a remnant local population. We discuss the implications of our results for connectivity of artificial wetlands and the importance of the whole wetland complex to this turtle assemblage.

Canadian Field-Naturalist, Jun 21, 2023

Turtles in northern latitudes are at the limit of their ranges and display various strategies for... more Turtles in northern latitudes are at the limit of their ranges and display various strategies for surviving the winter, including moving under the ice and out of water. Anthropogenic disturbances are often at the root of local habitat changes that can cause turtles to move from underwater refugia onto land, sometimes resulting in freezing and death. Turtles may also leave the water under natural freeze–thaw cycles, with early exits potentially maladaptive and lethal. We document cases of freshwater turtles freezing out of water at all life stages. We give a brief description of the circumstances surrounding the discovery of freeze-dried carcasses and highlight some of the climatic challenges facing overwintering turtles in southern Ontario.

Journal of Wildlife Diseases, Apr 21, 2022

Abstract: Between 2011 and 2020, the Ontario Turtle Conservation Centre's veterinary hospital... more Abstract: Between 2011 and 2020, the Ontario Turtle Conservation Centre's veterinary hospital admitted 6,335 turtles of eight different species, with 3,246 being midland painted turtles (Chrysemys picta marginata). At the time of admission from the wild, aural abscesses were present in 26 of the painted turtles (0.8%). Aural abscesses were never observed in juvenile turtles and were not found in any other species of turtle admitted to the hospital. An equal number of males and females were affected. All cases showed signs of chronicity. Abscesses alone did not appear to affect the overall health of turtles regardless of clinical signs. All turtles with abscesses as the sole cause for admission were released after successful treatment.

African Journal of Ecology, Apr 20, 2023

We have been monitoring spotted hyaena dens with camera traps at our site since 2016. We describe... more We have been monitoring spotted hyaena dens with camera traps at our site since 2016. We describe a novel phenomenon: concurrent subterranean den sharing between spotted hyaenas, warthogs, and crested porcupines at a wildlife conservancy in Kenya. We discovered two different hyaena clans that occasionally shared active dens with warthogs and porcupines in 2016, 2017, 2018, and 2019 but not since. We speculate on the reasons why and how this cohabitation arrangement arose and suggest that it might be based on a ‘healthy respect’ for the threats presented by their mutually formidable weaponry. We hope this note will encourage others to describe similar behaviour.

We report on male sex bias in a population of Midland Painted Turtle (Chrysemys picta marginata) ... more We report on male sex bias in a population of Midland Painted Turtle (Chrysemys picta marginata) at a wetland near Brampton, Ontario, Canada. The wetland is bisected by a major arterial road and characterized by high traffic volume and substantial wildlife-vehicle collisions. Road mortality surveys conducted in 2011, 2013, and 2015 documented 217 dead turtles, of which 118 could positively be identified as Midland Painted Turtle. From 2014-2015, we conducted a mark-recapture survey and captured 34 individual Midland Painted Turtles. The male:female sex ratio of 21:4 is one of the most skewed sex ratios for this species on record. We attribute this skew to sex-specific road mortality amongst other possible factors such as predation and nesting conditions. This study adds to the general body of work that has found a male sex ratio bias in areas of high road mortality. Résumé.-Notre étude rapporte un biais sexuel masculin dans une population de Tortue Peinte du Centre (Chrysemys picta marginata) dans un complexe d'étangs à Brampton, Ontario, Canada. Une artère principale bissecte le complexe. Cette route se caractérise par son volume élevé de circulation véhiculaire et par les nombreuses collisions avec la faune. Les relevés de mortalité routière menés en 2001, 2013 et 2015 ont permis de documenter 217 tortues tuées, dont 118 étant des Tortues Peintes. En 2014 et en 2015, nous avons mené un recensement de la population de tortues en utilisant un protocole de marquage de la carapace. Nous avons capturé 34 Tortues Peintes du Centre. Le rapport entre le sexe masculin:féminin étant de 21:4, représentant un des rapports sexuel les plus exagérés pour une population de tortues. Nous attribuons cet écart à un risque de mortalité routière qui diffère par sexe, et possiblement autres facteurs tels la prédation et les conditions de nidification. Les résultats de cette étude s'ajoutent à plusieurs autres révélant un biais masculin du rapport des sexes relié à la mortalité routière.

African Journal of Ecology

We discuss various human‐wildlife conflicts (HWC) inherent within communities bordering a mid‐siz... more We discuss various human‐wildlife conflicts (HWC) inherent within communities bordering a mid‐sized, semi‐porous wildlife conservancy in Kenya. HWC are a growing issue as human population expands into wildlife habitat to put people and wildlife in more frequent contact and compete for scarce resources. In 2018, we surveyed the crop‐raiding and livestock depredation experiences of 918 households from 10 separate villages and asked about the experiences of the villagers with HWC over the past 3 years. These communities are protected from wildlife with two different fence designs, a standard 12‐strand electrical fence, and an upgraded predator‐proof fence design. We found that between 70% and 91% of respondents had experienced some form of HWC including 39.5% who reported threats to their person from wildlife encroachments despite electrical perimeter fencing. HWC happened more often at night and during the dry seasons. The most common encroachments were from elephants, hyenas, leopard...

The Canadian Field-Naturalist

Red-eared Slider (Trachemys scripta elegans) is a non-native turtle found in abundance in Toronto... more Red-eared Slider (Trachemys scripta elegans) is a non-native turtle found in abundance in Toronto’s wetlands as a result of pet releases. Although this species is known to reproduce successfully in southwestern Ontario, Canada, there is yet no evidence to suggest successful reproduction in the Greater Toronto Area (GTA). As part of a native turtle nest protection program, volunteers inadvertently placed nest protector boxes over four slider nests in 2021 and 10 nests in 2022. This gave us the opportunity to determine whether nests produced viable offspring and whether these hatchlings would emerge in the fall. The exact nesting date for each nest was recorded. In 2021, eight of the 41 eggs from the slider nests showed very late-stage arrested embryonic development. In 2022, one of the nests had four hatchlings out of their eggshells but still inside the nest cavity. It is unclear whether the hatchlings would emerge later in the fall or overwinter in the nest cavity and emerge the fo...

The Canadian Field-Naturalist

Turtles in northern latitudes are at the limit of their ranges and display various strategies for... more Turtles in northern latitudes are at the limit of their ranges and display various strategies for surviving the winter, including moving under the ice and out of water. Anthropogenic disturbances are often at the root of local habitat changes that can cause turtles to move from underwater refugia onto land, sometimes resulting in freezing and death. Turtles may also leave the water under natural freeze–thaw cycles, with early exits potentially maladaptive and lethal. We document cases of freshwater turtles freezing out of water at all life stages. We give a brief description of the circumstances surrounding the discovery of freeze-dried carcasses and highlight some of the climatic challenges facing overwintering turtles in southern Ontario.

Canadian Field Naturalist, 2022

Red-eared Slider (Trachemys scripta elegans) is a non-native turtle found in abundance in Toronto... more Red-eared Slider (Trachemys scripta elegans) is a non-native turtle found in abundance in Toronto's wetlands as a result of pet releases. Although this species is known to reproduce successfully in southwestern Ontario, Canada, there is yet no evidence to suggest successful reproduction in the Greater Toronto Area (GTA). As part of a native turtle nest protection program, volunteers inadvertently placed nest protector boxes over four slider nests in 2021 and 10 nests in 2022. This gave us the opportunity to determine whether nests produced viable offspring and whether these hatchlings would emerge in the fall. The exact nesting date for each nest was recorded. In 2021, eight of the 41 eggs from the slider nests showed very late-stage arrested embryonic development. In 2022, one of the nests had four hatchlings out of their eggshells but still inside the nest cavity. It is unclear whether the hatchlings would emerge later in the fall or overwinter in the nest cavity and emerge the following spring. If the small population sampled accurately reflects what occurs in the GTA, complete egg development may be possible for this species in some years, in some locations, with the right local micro-climate and micro-habitat. We discuss implications for turtle nest protection in Toronto.

Canadian Field Naturalist, 2022

Turtles in northern latitudes are at the limit of their ranges and display various strategies for... more Turtles in northern latitudes are at the limit of their ranges and display various strategies for surviving the winter, including moving under the ice and out of water. Anthropogenic disturbances are often at the root of local habitat changes that can cause turtles to move from underwater refugia onto land, sometimes resulting in freezing and death. Turtles may also leave the water under natural freeze-thaw cycles, with early exits potentially maladaptive and lethal. We document cases of freshwater turtles freezing out of water at all life stages. We give a brief description of the circumstances surrounding the discovery of freeze-dried carcasses and highlight some of the climatic challenges facing overwintering turtles in southern Ontario.

Protecting an endangered and highly poached species can conflict with providing an open and ecolo... more Protecting an endangered and highly poached species can conflict with providing an open and ecologically connected landscape for coexisting species. In Kenya, about half of the black rhino (Diceros bicornis) live in electrically fenced private conservancies. Purpose-built fence-gaps permit some landscape connectivity for elephant while restricting rhino from escaping. We monitored the usage patterns at these gaps by motion-triggered cameras and found high traffic volumes and predictable patterns of prey movement. The prey-trap hypothesis (PTH) proposes that predators exploit this predictable prey movement. We tested the PTH at two semi-porous reserves using two different methods: a spatial analysis and a temporal analysis. Using spatial analysis, we mapped the location of predation events with GPS and looked for concentration of kill sites near the gaps as well as conducting clustering and hot spot analysis to determine areas of statistically significant predation clustering. Using temporal analysis, we examined the time lapse between the passage of prey and predator and searched for evidence of active prey seeking and/or predator avoidance. We found no support for the PTH and conclude that the design of the fence-gaps is well suited to promoting connectivity in these types of conservancies.

Road Traffic Limits Home Ranges of Urban Raccoons (Procyon lotor) The behavior of urban-living... more Road Traffic Limits Home Ranges of Urban Raccoons (Procyon lotor)

The behavior of urban-living raccoons has not been systematically investigated at a fine-grained scale, despite the fact that raccoons co-exists closely with humans in cities across North America and can transmit deadly parasites and viruses. The purpose of this pilot study was to assess the feasibility of gathering fine-grained GPS data in an urban setting and to analyze the behavior and movement patterns of urban raccoons. We fitted five GPS and VHS tracking collars on raccoons in three different urban residential areas of the City of Toronto, Ontario, Canada. We programmed the collars to collect GPS coordinates every 5 to 20 minutes during peak activity cycles for a six-week period in August and early September of 2010. The GPS collars allowed us to obtain a large number of sample points from each animal (up to 1400 positions per animal), which gave us a detailed look at their home-range use. We know of no other raccoon study that has attempted this level of granularity. We found that home ranges during these six weeks were smaller than expected in relation to previously published data. We also found that road traffic patterns were a strong predictor of the borders of home ranges suggesting that raccoons prefer not to cross busy roads and that even minor arteries can act as hard borders. We discuss the challenges of collecting GPS data in an urban setting and the feasibility for a broader study.

Facets, 2024

In late 2020, a private volunteer group operating through a Facebook group approached Toronto and... more In late 2020, a private volunteer group operating through a Facebook group approached Toronto and Region Conservation Authority (TRCA) with an interest in participating in the Citizen Science Nest Protection and Monitoring Volunteer Program. During the 2021 season, TRCA staff virtually trained volunteers in turtle nest detection, protection, and monitoring due to COVID-19 social constraints, and provided necessary supplies and equipment. In 2021 volunteers and staff detected 181 turtle nests and were able to protect 75 nests with simple predator-exclusion devices, while in 2022, 165 nests were detected, and 155 were protected. The volunteers also collected data, including nesting location, date, and species in addition to the number of successful hatchlings (2021 only). In 2021, the 75 protected nests yielded 81 Midland Painted Turtle and 665 Snapping Turtle hatchlings. Five Midland Painted Turtle's eggs were also recovered from an injured turtle, and 44 Snapping Turtle eggs were recovered from a partially predated nest, transported to the Ontario Turtle Conservation Centre, incubated, hatched, and overwintered, and then released back into the local wetlands. The partnership with a local community group proved effective, and we would recommend this practice to other conservation organizations interested in turtle nest protection.

Canadian Field-Naturalist, Jun 21, 2023

Red-eared Slider (Trachemys scripta elegans) is a non-native turtle found in abundance in Toronto... more Red-eared Slider (Trachemys scripta elegans) is a non-native turtle found in abundance in Toronto’s wetlands as a result of pet releases. Although this species is known to reproduce successfully in southwestern Ontario, Canada, there is yet no evidence to suggest successful reproduction in the Greater Toronto Area (GTA). As part of a native turtle nest protection program, volunteers inadvertently placed nest protector boxes over four slider nests in 2021 and 10 nests in 2022. This gave us the opportunity to determine whether nests produced viable offspring and whether these hatchlings would emerge in the fall. The exact nesting date for each nest was recorded. In 2021, eight of the 41 eggs from the slider nests showed very late-stage arrested embryonic development. In 2022, one of the nests had four hatchlings out of their eggshells but still inside the nest cavity. It is unclear whether the hatchlings would emerge later in the fall or overwinter in the nest cavity and emerge the following spring. If the small population sampled accurately reflects what occurs in the GTA, complete egg development may be possible for this species in some years, in some locations, with the right local micro-climate and micro-habitat. We discuss implications for turtle nest protection in Toronto.

This dissertation examines how various anthropogenic barriers affect wildlife movement, and in pa... more This dissertation examines how various anthropogenic barriers affect wildlife movement, and in particular, how fencing affects movement and behavior of both migratory prey and predators in semi-porous environments. I chose to examine this subject as our planet's last remaining ecosystems are threatened by human encroachment due to population pressure, agriculture, and a myriad of other ecological stressors. In order to mitigate the encroachment, conservation fencing is rapidly becoming the norm even though constraining wildlife movement is fraught with ecological issues. My interest in conservation fencing was to examine the potentially hidden or understudied consequences Thanks to Geoffrey Chege, Mary Mwololo, Edwin Kisio, and all of the rest of the conservation research staff at the Lewa Wildlife Conservancy for their invaluable help with data collection. Thanks to Mike Watson and Jonathan Moss, CEOs of the Lewa Wildllife Conservancy during the time of my Ph.D. studies for proving the invaluable management support structure necessary for a Canadian to do research in Kenya. It is because of forward thinking wildlife managers that this research could happen. Thanks to Mirka Ondrack and Dr. Georges Monette of the Institute for Social Research Statistical Consulting Services at York University for the many hours of help with data analysis. Thanks to Dr. Tarmo Remmel of the York University Department of Geography for helpful suggestions pertaining to the spatial analysis.

Journal of Great Lakes Research, Apr 1, 2021

The aim of this study was to provide a baseline assessment of the turtle community in the coastal... more The aim of this study was to provide a baseline assessment of the turtle community in the coastal wetlands of the Greater Toronto Area. We documented turtle species diversity, abundance, reproductive classes, sex-ratios, and evidence of inter-wetland movement. Our study consisted of a series of markrecapture surveys across eleven Lake Ontario coastal wetland complexes of the Greater Toronto Area performed between 2016 and 2019. We captured and marked 532 individual turtles of four native species (298 midland painted, Chrysemys picta marginata; 180 snapping, Chelydra serpentina; 7 Blanding's, Emydoidea blandingii, and 5 map, Graptemys geographica) and three non-native species (40 red-eared slider, Trachemys scripta elegans; 1 false map, Graptemys pseudogeographica, and 1 Chinese softshell, Pelodiscus sinensis). Of note was the capture of an exceptionally large male snapping turtle, one of the largest recorded in Canada for both length and mass. The age classes of both snapping and midland painted species presented large proportions of breeding-sized adults, yet midland painted turtles showed a potential low recruitment with an underrepresentation of non-reproductive females. The sex ratios of both midland painted and snapping turtles across the whole waterfront did not differ from the expected 1:1 ratio. We also recaptured 198 turtles (135 midland painted, 53 snapping, 6 Blanding's and 12 redeared Sliders). The recaptured turtles revealed inter-wetland movements of 12 km over a two-year span for a midland painted turtle and an 8 km journey for a snapping turtle, potentially demonstrating some connectivity between geographically separate wetland complexes.

PeerJ, Aug 8, 2018

Conservation authorities invest heavily in the restoration and/or creation of wetlands to counter... more Conservation authorities invest heavily in the restoration and/or creation of wetlands to counteract the destruction of habitat caused by urbanization. Monitoring the colonization of these new wetlands is critical to an adaptive management process. We conducted a turtle mark-recapture survey in a 250 ha artificially created wetland complex in a large North American city (Toronto, Ontario). We found that two of Ontario's eight native turtle species (Snapping turtle (SN), Chelydra serpentina, and Midland Painted (MP) turtle, Chrysemys picta marginata) were abundant and both were confirmed nesting. The Blanding's turtle (Emydoidea blandingii) was present but not well established. Species richness and turtle density were not equally distributed throughout the wetland complex. We noted SN almost exclusively populated one water body, while other areas of the wetland had a varying representation of both species. The sex ratios of both SN and MP turtles were 1:1. We tracked the movement of Snapping and Blanding's turtles and found that most turtles explored at least two water bodies in the park, that females explored more water bodies than males, and that 95% of turtles showed fidelity to individual overwintering wetlands. We performed DNA analysis of two Blanding's turtles found in the created wetlands and could not assign these turtles to any known profiled populations. The genetic data suggest that the turtles probably belong to a remnant local population. We discuss the implications of our results for connectivity of artificial wetlands and the importance of the whole wetland complex to this turtle assemblage.

Canadian Field-Naturalist, Jun 21, 2023

Turtles in northern latitudes are at the limit of their ranges and display various strategies for... more Turtles in northern latitudes are at the limit of their ranges and display various strategies for surviving the winter, including moving under the ice and out of water. Anthropogenic disturbances are often at the root of local habitat changes that can cause turtles to move from underwater refugia onto land, sometimes resulting in freezing and death. Turtles may also leave the water under natural freeze–thaw cycles, with early exits potentially maladaptive and lethal. We document cases of freshwater turtles freezing out of water at all life stages. We give a brief description of the circumstances surrounding the discovery of freeze-dried carcasses and highlight some of the climatic challenges facing overwintering turtles in southern Ontario.

Journal of Wildlife Diseases, Apr 21, 2022

Abstract: Between 2011 and 2020, the Ontario Turtle Conservation Centre's veterinary hospital... more Abstract: Between 2011 and 2020, the Ontario Turtle Conservation Centre's veterinary hospital admitted 6,335 turtles of eight different species, with 3,246 being midland painted turtles (Chrysemys picta marginata). At the time of admission from the wild, aural abscesses were present in 26 of the painted turtles (0.8%). Aural abscesses were never observed in juvenile turtles and were not found in any other species of turtle admitted to the hospital. An equal number of males and females were affected. All cases showed signs of chronicity. Abscesses alone did not appear to affect the overall health of turtles regardless of clinical signs. All turtles with abscesses as the sole cause for admission were released after successful treatment.

African Journal of Ecology, Apr 20, 2023

We have been monitoring spotted hyaena dens with camera traps at our site since 2016. We describe... more We have been monitoring spotted hyaena dens with camera traps at our site since 2016. We describe a novel phenomenon: concurrent subterranean den sharing between spotted hyaenas, warthogs, and crested porcupines at a wildlife conservancy in Kenya. We discovered two different hyaena clans that occasionally shared active dens with warthogs and porcupines in 2016, 2017, 2018, and 2019 but not since. We speculate on the reasons why and how this cohabitation arrangement arose and suggest that it might be based on a ‘healthy respect’ for the threats presented by their mutually formidable weaponry. We hope this note will encourage others to describe similar behaviour.

We report on male sex bias in a population of Midland Painted Turtle (Chrysemys picta marginata) ... more We report on male sex bias in a population of Midland Painted Turtle (Chrysemys picta marginata) at a wetland near Brampton, Ontario, Canada. The wetland is bisected by a major arterial road and characterized by high traffic volume and substantial wildlife-vehicle collisions. Road mortality surveys conducted in 2011, 2013, and 2015 documented 217 dead turtles, of which 118 could positively be identified as Midland Painted Turtle. From 2014-2015, we conducted a mark-recapture survey and captured 34 individual Midland Painted Turtles. The male:female sex ratio of 21:4 is one of the most skewed sex ratios for this species on record. We attribute this skew to sex-specific road mortality amongst other possible factors such as predation and nesting conditions. This study adds to the general body of work that has found a male sex ratio bias in areas of high road mortality. Résumé.-Notre étude rapporte un biais sexuel masculin dans une population de Tortue Peinte du Centre (Chrysemys picta marginata) dans un complexe d'étangs à Brampton, Ontario, Canada. Une artère principale bissecte le complexe. Cette route se caractérise par son volume élevé de circulation véhiculaire et par les nombreuses collisions avec la faune. Les relevés de mortalité routière menés en 2001, 2013 et 2015 ont permis de documenter 217 tortues tuées, dont 118 étant des Tortues Peintes. En 2014 et en 2015, nous avons mené un recensement de la population de tortues en utilisant un protocole de marquage de la carapace. Nous avons capturé 34 Tortues Peintes du Centre. Le rapport entre le sexe masculin:féminin étant de 21:4, représentant un des rapports sexuel les plus exagérés pour une population de tortues. Nous attribuons cet écart à un risque de mortalité routière qui diffère par sexe, et possiblement autres facteurs tels la prédation et les conditions de nidification. Les résultats de cette étude s'ajoutent à plusieurs autres révélant un biais masculin du rapport des sexes relié à la mortalité routière.

African Journal of Ecology

We discuss various human‐wildlife conflicts (HWC) inherent within communities bordering a mid‐siz... more We discuss various human‐wildlife conflicts (HWC) inherent within communities bordering a mid‐sized, semi‐porous wildlife conservancy in Kenya. HWC are a growing issue as human population expands into wildlife habitat to put people and wildlife in more frequent contact and compete for scarce resources. In 2018, we surveyed the crop‐raiding and livestock depredation experiences of 918 households from 10 separate villages and asked about the experiences of the villagers with HWC over the past 3 years. These communities are protected from wildlife with two different fence designs, a standard 12‐strand electrical fence, and an upgraded predator‐proof fence design. We found that between 70% and 91% of respondents had experienced some form of HWC including 39.5% who reported threats to their person from wildlife encroachments despite electrical perimeter fencing. HWC happened more often at night and during the dry seasons. The most common encroachments were from elephants, hyenas, leopard...

The Canadian Field-Naturalist

Red-eared Slider (Trachemys scripta elegans) is a non-native turtle found in abundance in Toronto... more Red-eared Slider (Trachemys scripta elegans) is a non-native turtle found in abundance in Toronto’s wetlands as a result of pet releases. Although this species is known to reproduce successfully in southwestern Ontario, Canada, there is yet no evidence to suggest successful reproduction in the Greater Toronto Area (GTA). As part of a native turtle nest protection program, volunteers inadvertently placed nest protector boxes over four slider nests in 2021 and 10 nests in 2022. This gave us the opportunity to determine whether nests produced viable offspring and whether these hatchlings would emerge in the fall. The exact nesting date for each nest was recorded. In 2021, eight of the 41 eggs from the slider nests showed very late-stage arrested embryonic development. In 2022, one of the nests had four hatchlings out of their eggshells but still inside the nest cavity. It is unclear whether the hatchlings would emerge later in the fall or overwinter in the nest cavity and emerge the fo...

The Canadian Field-Naturalist

Turtles in northern latitudes are at the limit of their ranges and display various strategies for... more Turtles in northern latitudes are at the limit of their ranges and display various strategies for surviving the winter, including moving under the ice and out of water. Anthropogenic disturbances are often at the root of local habitat changes that can cause turtles to move from underwater refugia onto land, sometimes resulting in freezing and death. Turtles may also leave the water under natural freeze–thaw cycles, with early exits potentially maladaptive and lethal. We document cases of freshwater turtles freezing out of water at all life stages. We give a brief description of the circumstances surrounding the discovery of freeze-dried carcasses and highlight some of the climatic challenges facing overwintering turtles in southern Ontario.

Canadian Field Naturalist, 2022

Red-eared Slider (Trachemys scripta elegans) is a non-native turtle found in abundance in Toronto... more Red-eared Slider (Trachemys scripta elegans) is a non-native turtle found in abundance in Toronto's wetlands as a result of pet releases. Although this species is known to reproduce successfully in southwestern Ontario, Canada, there is yet no evidence to suggest successful reproduction in the Greater Toronto Area (GTA). As part of a native turtle nest protection program, volunteers inadvertently placed nest protector boxes over four slider nests in 2021 and 10 nests in 2022. This gave us the opportunity to determine whether nests produced viable offspring and whether these hatchlings would emerge in the fall. The exact nesting date for each nest was recorded. In 2021, eight of the 41 eggs from the slider nests showed very late-stage arrested embryonic development. In 2022, one of the nests had four hatchlings out of their eggshells but still inside the nest cavity. It is unclear whether the hatchlings would emerge later in the fall or overwinter in the nest cavity and emerge the following spring. If the small population sampled accurately reflects what occurs in the GTA, complete egg development may be possible for this species in some years, in some locations, with the right local micro-climate and micro-habitat. We discuss implications for turtle nest protection in Toronto.

Canadian Field Naturalist, 2022

Turtles in northern latitudes are at the limit of their ranges and display various strategies for... more Turtles in northern latitudes are at the limit of their ranges and display various strategies for surviving the winter, including moving under the ice and out of water. Anthropogenic disturbances are often at the root of local habitat changes that can cause turtles to move from underwater refugia onto land, sometimes resulting in freezing and death. Turtles may also leave the water under natural freeze-thaw cycles, with early exits potentially maladaptive and lethal. We document cases of freshwater turtles freezing out of water at all life stages. We give a brief description of the circumstances surrounding the discovery of freeze-dried carcasses and highlight some of the climatic challenges facing overwintering turtles in southern Ontario.

Protecting an endangered and highly poached species can conflict with providing an open and ecolo... more Protecting an endangered and highly poached species can conflict with providing an open and ecologically connected landscape for coexisting species. In Kenya, about half of the black rhino (Diceros bicornis) live in electrically fenced private conservancies. Purpose-built fence-gaps permit some landscape connectivity for elephant while restricting rhino from escaping. We monitored the usage patterns at these gaps by motion-triggered cameras and found high traffic volumes and predictable patterns of prey movement. The prey-trap hypothesis (PTH) proposes that predators exploit this predictable prey movement. We tested the PTH at two semi-porous reserves using two different methods: a spatial analysis and a temporal analysis. Using spatial analysis, we mapped the location of predation events with GPS and looked for concentration of kill sites near the gaps as well as conducting clustering and hot spot analysis to determine areas of statistically significant predation clustering. Using temporal analysis, we examined the time lapse between the passage of prey and predator and searched for evidence of active prey seeking and/or predator avoidance. We found no support for the PTH and conclude that the design of the fence-gaps is well suited to promoting connectivity in these types of conservancies.

GPS location of kill site

We investigated the effectiveness of a potential elephant attractant to influence elephant 36 mov... more We investigated the effectiveness of a potential elephant attractant to influence elephant 36 movement patterns and reduce human-elephant conflict. We conducted a three-phase study on 37 wild elephants in northern Kenya during an extended drought. In the first phase, a food 38 preference study found that elephants preferred Fever tree to other available food sources. In the 39 second phase, we added vanilla extract to the possible choices and found that all elephants 40 showed consistent interest in this novel scent. In the third phase, we field tested various vanilla-41 scented items and found that elephants showed interest in all of them. We discuss the next steps 42 of this on-going study and the implications for elephant management and the use of vanilla 43 extract as a tool in leading elephants through a narrow migratory corridor. 44 45 KEY WORDS attractant, vanilla, elephant, food preference, scent. 46 47 48

The purpose of this study was to investigate urban movement patterns of the 25 raccoon. We fitted... more The purpose of this study was to investigate urban movement patterns of the 25 raccoon. We fitted five raccoons with GPS tracking collars in a major urban 26 metropolis. We collected coordinates at short regular intervals during a five--week 27 period. The data yielded large number of sample points for each animal (up to 1500 28 positions per animal), giving us an unprecedented detailed look at home--range 29 usage. We found that raccoon territories were between 6 and 16 hectares, smaller 30 than previously reported, and did not need to encompass a permanent source of 31 water, although each site had a latrine in close proximity.. Urban road traffic 32 patterns seemed to delimit the boundaries of the territories. Raccoons used a 33 variety of natural and anthropogenic structures as sleeping or denning sites, and 34 each raccoon used many different sites within its territory during the study period. 35 Our results illustrate the particular movement patterns of urban--living animals and 36 can be used to manage this ubiquitous synanthropic species. 37 38 39 40 Introduction: 40 Although raccoons (Procyon lotor) are ubiquitous in large cities around North 41 America, there is limited knowledge of their movement patterns in urban 42