Pub Date : 2022-04-28DOI: 10.22621/cfn.v135i4.2116
S. Ashpole, Marissa Nati
Reproductively mature larval morphs, known as paedogens, are a rare occurrence in Blotched Tiger Salamander (Ambystoma mavortium melanostictum). The Southern Mountain population of this subspecies, confined to the southern interior of British Columbia, is listed federally as Endangered and has been facing increasing pressures from anthropogenic stressors in both their aquatic and terrestrial landscapes. In 2017, we examined a subset of 36 frozen Blotched Tiger Salamander paedogens collected in September 1985 after rotenone treatment in preparation for a recreational fishery near Oliver, British Columbia. We estimated total in ovo numbers in nine gravid individuals to gain insight into paedogen reproductive condition. The number of eggs per individual averaged 227 ± 109 [SD]; range 28–421), with larger dark eggs accounting for 133 ± 69 and smaller pale eggs (possibly follicles or colour may be an artifact of storage) accounting for 94 ± 49. Salamanders were collected in September after the expected egg-laying period for the terrestrial form (early spring); thus, the reproductive stage of the eggs is unclear, but is assumed to be post-breeding and representative of developing eggs and follicles. Canadian data on in ovo counts within the body cavity have not been reported for Blotched Tiger Salamander paedogens and our study provides valuable information on the reproductive condition of paedogens. Although terrestrial forms have been observed, the presence of paedogens in the treated wetland has yet to be detected.
{"title":"Paedomorphic Blotched Tiger Salamander (Ambystoma mavortium melanostictum) in ovo counts, British Columbia, Canada","authors":"S. Ashpole, Marissa Nati","doi":"10.22621/cfn.v135i4.2116","DOIUrl":"https://doi.org/10.22621/cfn.v135i4.2116","url":null,"abstract":"Reproductively mature larval morphs, known as paedogens, are a rare occurrence in Blotched Tiger Salamander (Ambystoma mavortium melanostictum). The Southern Mountain population of this subspecies, confined to the southern interior of British Columbia, is listed federally as Endangered and has been facing increasing pressures from anthropogenic stressors in both their aquatic and terrestrial landscapes. In 2017, we examined a subset of 36 frozen Blotched Tiger Salamander paedogens collected in September 1985 after rotenone treatment in preparation for a recreational fishery near Oliver, British Columbia. We estimated total in ovo numbers in nine gravid individuals to gain insight into paedogen reproductive condition. The number of eggs per individual averaged 227 ± 109 [SD]; range 28–421), with larger dark eggs accounting for 133 ± 69 and smaller pale eggs (possibly follicles or colour may be an artifact of storage) accounting for 94 ± 49. Salamanders were collected in September after the expected egg-laying period for the terrestrial form (early spring); thus, the reproductive stage of the eggs is unclear, but is assumed to be post-breeding and representative of developing eggs and follicles. Canadian data on in ovo counts within the body cavity have not been reported for Blotched Tiger Salamander paedogens and our study provides valuable information on the reproductive condition of paedogens. Although terrestrial forms have been observed, the presence of paedogens in the treated wetland has yet to be detected.","PeriodicalId":56136,"journal":{"name":"The Canadian Field-Naturalist","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-04-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74197345","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-04-28DOI: 10.22621/cfn.v135i4.2723
Courtney Irvine, L. Patterson
Pukaskwa National Park hosts part of a disjunct population of the perennial orchid species Sparrow’s-egg Lady’s-slipper (Cypripedium passerinum) on the north shore of Lake Superior, Ontario, Canada. Monitoring of C. passerinum within Pukaskwa National Park occurred between 1979 and 2019. During that period, the total number of stalks and the number of C. passerinum colonies within the park have declined, while the proportion of flowering stalks at colonies has increased. Although the number of stalks at extant colonies is stable, this population may be suffering from lack of recruitment and is at risk of extirpation. We hypothesize that the decline and lack of recruitment are a result of changing habitat conditions due to natural and anthropogenic influence.
{"title":"Status and declining trend of Sparrow’s-egg Lady’s-slipper (Cypripedium passerinum) orchids in Pukaskwa National Park, Ontario, Canada","authors":"Courtney Irvine, L. Patterson","doi":"10.22621/cfn.v135i4.2723","DOIUrl":"https://doi.org/10.22621/cfn.v135i4.2723","url":null,"abstract":"Pukaskwa National Park hosts part of a disjunct population of the perennial orchid species Sparrow’s-egg Lady’s-slipper (Cypripedium passerinum) on the north shore of Lake Superior, Ontario, Canada. Monitoring of C. passerinum within Pukaskwa National Park occurred between 1979 and 2019. During that period, the total number of stalks and the number of C. passerinum colonies within the park have declined, while the proportion of flowering stalks at colonies has increased. Although the number of stalks at extant colonies is stable, this population may be suffering from lack of recruitment and is at risk of extirpation. We hypothesize that the decline and lack of recruitment are a result of changing habitat conditions due to natural and anthropogenic influence.","PeriodicalId":56136,"journal":{"name":"The Canadian Field-Naturalist","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-04-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73631272","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-04-28DOI: 10.22621/cfn.v135i4.2719
L. Arbez, A. Royer, J. Therrien, S. Montuire
The examination of raptor pellets can be used to evaluate Arctic biodiversity. We found the remains of Meadow Vole (Microtus pennsylvanicus) and Ungava Collared Lemming (Dicrostonyx hudsonius) in pellets from Snowy Owl (Bubo scandiacus) nesting in the northern part of the Ungava Peninsula. We differentiated the two species by visual identification and geometric morphometric analysis of molar shape. The results of our study combined with historical data suggest that most commonly used range maps of Meadow Vole should be revised.
{"title":"Another mention of Meadow Vole (Microtus pennsylvanicus) found in pellets of Snowy Owl (Bubo scandiacus) in northern Ungava Peninsula, Canada","authors":"L. Arbez, A. Royer, J. Therrien, S. Montuire","doi":"10.22621/cfn.v135i4.2719","DOIUrl":"https://doi.org/10.22621/cfn.v135i4.2719","url":null,"abstract":"The examination of raptor pellets can be used to evaluate Arctic biodiversity. We found the remains of Meadow Vole (Microtus pennsylvanicus) and Ungava Collared Lemming (Dicrostonyx hudsonius) in pellets from Snowy Owl (Bubo scandiacus) nesting in the northern part of the Ungava Peninsula. We differentiated the two species by visual identification and geometric morphometric analysis of molar shape. The results of our study combined with historical data suggest that most commonly used range maps of Meadow Vole should be revised.","PeriodicalId":56136,"journal":{"name":"The Canadian Field-Naturalist","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-04-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77417581","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-04-28DOI: 10.22621/cfn.v135i4.2104
Brian A. Schaffer, J. Jenks, W. Jensen, Eric S. Michel
Life-history characteristics of White-tailed Deer (Odocoileus virginianus) have been documented in areas of the Northern Great Plains, but limited information is available in grassland dominated regions. We documented migration strategy, home range use, and survival of adult female White-tailed Deer in central North Dakota. We monitored 62 radio-collared adult (>1.5 year-old) female White-tailed Deer from February 2010 to December 2012. We documented 86 summer home ranges and classified deer as resident, migratory, or exhibiting a late season movement. Mean migration distance between non-overlapping summer and winter home ranges was 11.76 km (SE 0.86, n = 21). Mean late season movements were 20.69 km (SE 2.94, n = 7) and were likely the result of deer exhausting food resources throughout winter. We also developed five competing models that represented variation in survival among time periods (e.g., pre-hunt, hunt, and post-hunt in 2010 and 2011). Our top model indicated that survival (S) was similar between hunt 2010 and post-hunt 2011 periods but was lower (S = 0.82; SE 0.04, 95% CI 0.73–0.89) than the remaining time periods (S = 0.97; SE 0.01, 95% CI 0.93–0.99). Our results suggest that deer migration strategies and survival are likely influenced by a combination of winter severity and food availability. Mortalities attributed to hunter harvest were low during our study, which may indicate that increased recreational opportunities could be made available, even after severe winters.
白尾鹿(Odocoileus virginianus)的生活史特征在北部大平原地区有文献记载，但在草原为主的地区资料有限。我们记录了北达科他州中部成年雌性白尾鹿的迁徙策略、栖息地利用和存活率。2010年2月至2012年12月，对62只带无线电项圈(>1.5岁)成年雌白尾鹿进行了监测。我们记录了86个夏季家园范围，并将鹿分类为居住，迁徙或表现出晚季运动。夏季和冬季非重叠栖息地之间的平均迁徙距离为11.76 km (SE 0.86, n = 21)。季节后期平均移动20.69 km (SE 2.94, n = 7)，可能是鹿在整个冬季耗尽食物资源的结果。我们还开发了五个相互竞争的模型，代表不同时期(例如，2010年和2011年的狩猎前、狩猎后和狩猎后)的生存变化。我们的顶级模型显示，2010年狩猎和2011年后狩猎期间的存活率(S)相似，但较低(S = 0.82;SE 0.04, 95% CI 0.73-0.89)高于其余时间段(S = 0.97;Se 0.01, 95% ci 0.93-0.99)。我们的研究结果表明，鹿的迁徙策略和生存可能受到冬季严酷程度和食物供应的共同影响。在我们的研究中，由于猎人的收获而导致的死亡率很低，这可能表明即使在严冬之后，也可以提供更多的娱乐机会。
{"title":"Assessing migration strategies and cause specific mortality of adult female White-tailed Deer (Odocoileus virginianus) in North Dakota, USA","authors":"Brian A. Schaffer, J. Jenks, W. Jensen, Eric S. Michel","doi":"10.22621/cfn.v135i4.2104","DOIUrl":"https://doi.org/10.22621/cfn.v135i4.2104","url":null,"abstract":"Life-history characteristics of White-tailed Deer (Odocoileus virginianus) have been documented in areas of the Northern Great Plains, but limited information is available in grassland dominated regions. We documented migration strategy, home range use, and survival of adult female White-tailed Deer in central North Dakota. We monitored 62 radio-collared adult (>1.5 year-old) female White-tailed Deer from February 2010 to December 2012. We documented 86 summer home ranges and classified deer as resident, migratory, or exhibiting a late season movement. Mean migration distance between non-overlapping summer and winter home ranges was 11.76 km (SE 0.86, n = 21). Mean late season movements were 20.69 km (SE 2.94, n = 7) and were likely the result of deer exhausting food resources throughout winter. We also developed five competing models that represented variation in survival among time periods (e.g., pre-hunt, hunt, and post-hunt in 2010 and 2011). Our top model indicated that survival (S) was similar between hunt 2010 and post-hunt 2011 periods but was lower (S = 0.82; SE 0.04, 95% CI 0.73–0.89) than the remaining time periods (S = 0.97; SE 0.01, 95% CI 0.93–0.99). Our results suggest that deer migration strategies and survival are likely influenced by a combination of winter severity and food availability. Mortalities attributed to hunter harvest were low during our study, which may indicate that increased recreational opportunities could be made available, even after severe winters.","PeriodicalId":56136,"journal":{"name":"The Canadian Field-Naturalist","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-04-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82625114","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-04-28DOI: 10.22621/cfn.v135i4.2725
T. Jung, B. Slough
Several species of martens (Martes spp.) are reported to use buildings as resting or den sites. However, such behaviour has not been attributed to American Marten (Martes americana). We report American Marten using occupied buildings and evidence of suspected use of an abandoned cabin, as resting sites in southern Yukon, Canada. These observations further highlight the behavioural flexibility of North American species of Martes with regard to using novel structures as resting sites.
{"title":"Gimme shelter: anthropogenic structures as resting sites for American Marten (Martes americana)","authors":"T. Jung, B. Slough","doi":"10.22621/cfn.v135i4.2725","DOIUrl":"https://doi.org/10.22621/cfn.v135i4.2725","url":null,"abstract":"Several species of martens (Martes spp.) are reported to use buildings as resting or den sites. However, such behaviour has not been attributed to American Marten (Martes americana). We report American Marten using occupied buildings and evidence of suspected use of an abandoned cabin, as resting sites in southern Yukon, Canada. These observations further highlight the behavioural flexibility of North American species of Martes with regard to using novel structures as resting sites.","PeriodicalId":56136,"journal":{"name":"The Canadian Field-Naturalist","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-04-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83908581","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-04-28DOI: 10.22621/cfn.v135i4.2445
Madison Reynolds, J. Shook, G. Breed, K. Kielland
We studied the diet and reproductive success of Great Horned Owl (Bubo virginianus) at its northern range limit during an apparent high in the Snowshoe Hare (Lepus americanus) population. We performed diet analyses using images from fixed motion sensor cameras and pellet and prey remains collected at active nests, and gathered data on breeding success through camera and visual observations. Pellet data at 14 nests produced 1277 prey records consisting of 65–95% Snowshoe Hare biomass. Great Horned Owls ate 18 different prey types, with overall biomass consisting of 93% mammal, 7% bird, and less than 1% insects, frogs, and fish. The mean prey mass of 714 g (± 34 SE) was 2–25 times the mean prey mass of studies of this species at more southerly latitudes. Camera observations showed that Great Horned Owls delivered an average of 459 g/chick/d (± 75) throughout nesting. This was significantly (P = 0.005) higher than observations from Alberta, at 328–411 g/chick/d. Pellet/prey remains data showed that Great Horned Owls delivering a higher proportion of hares to their nestlings successfully raised more chicks (χ21 = 6.3, P = 0.012), highlighting the importance of this prey in the population dynamics of Great Horned Owl. In addition, we observed Snowshoe Hare removing pellets beneath nest sites, revealing an apparently undocumented bias to the use of pellet analysis.
{"title":"Diet and reproductive success of Great Horned Owl (Bubo virginianus) at its northern breeding limit","authors":"Madison Reynolds, J. Shook, G. Breed, K. Kielland","doi":"10.22621/cfn.v135i4.2445","DOIUrl":"https://doi.org/10.22621/cfn.v135i4.2445","url":null,"abstract":"We studied the diet and reproductive success of Great Horned Owl (Bubo virginianus) at its northern range limit during an apparent high in the Snowshoe Hare (Lepus americanus) population. We performed diet analyses using images from fixed motion sensor cameras and pellet and prey remains collected at active nests, and gathered data on breeding success through camera and visual observations. Pellet data at 14 nests produced 1277 prey records consisting of 65–95% Snowshoe Hare biomass. Great Horned Owls ate 18 different prey types, with overall biomass consisting of 93% mammal, 7% bird, and less than 1% insects, frogs, and fish. The mean prey mass of 714 g (± 34 SE) was 2–25 times the mean prey mass of studies of this species at more southerly latitudes. Camera observations showed that Great Horned Owls delivered an average of 459 g/chick/d (± 75) throughout nesting. This was significantly (P = 0.005) higher than observations from Alberta, at 328–411 g/chick/d. Pellet/prey remains data showed that Great Horned Owls delivering a higher proportion of hares to their nestlings successfully raised more chicks (χ21 = 6.3, P = 0.012), highlighting the importance of this prey in the population dynamics of Great Horned Owl. In addition, we observed Snowshoe Hare removing pellets beneath nest sites, revealing an apparently undocumented bias to the use of pellet analysis.","PeriodicalId":56136,"journal":{"name":"The Canadian Field-Naturalist","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-04-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86052697","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-04-28DOI: 10.22621/cfn.v135i4.2975
W. Halliday
{"title":"\"We Are All Whalers: the Plight of Whales and our Responsibility\" by Michael J. Moore, 2021 [book review]","authors":"W. Halliday","doi":"10.22621/cfn.v135i4.2975","DOIUrl":"https://doi.org/10.22621/cfn.v135i4.2975","url":null,"abstract":"","PeriodicalId":56136,"journal":{"name":"The Canadian Field-Naturalist","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-04-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75940603","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-04-28DOI: 10.22621/cfn.v135i4.2793
B. Thompson
At the time of European settlement, an extensive graminoid wetland existed at the confluence of the East and West Holland Rivers at the southern end of Lake Simcoe, Ontario. However, by 1925, clearing and draining of the marsh for specialty agriculture (i.e., market gardens) had begun and, by the 1940s, ~46% of the wetland had been cleared and another 13% was lost before 2016. Concurrent with marsh conversion has been an increase in Narrow-leaved Cattail (Typha angustifolia) in the remnant wetland. This study documents the change in the Holland Marsh wetland by delineating boundaries between marsh, fen, and shrub communities on aerial photographs taken at ~10-year intervals between 1946 and 2015 and documenting vegetation change along transects running perpendicular to tributaries bisecting the wetland. The extent of fen habitat within the Holland Marsh has been decreasing since 1946 at an average rate of 0.24 ha/year because of increases in both shrub and marsh (i.e., T. angustifolia) communities. Typha angustifolia expansion has been predominantly from along the margins of the Holland River where soil phosphorus concentration is significantly higher than in the core of the fen. Beyond 30 m from the river, vegetation dominance shifts from T. angustifolia to sedges (Cyperaceae). Managing phosphorus loading from upstream land uses will be of critical importance in protecting this habitat, which is rare in southern Ontario.
{"title":"Continuing expansion of Narrow-leaved Cattail (Typha angustifolia) and decline of a provincially rare fen in the Holland Marsh, Ontario","authors":"B. Thompson","doi":"10.22621/cfn.v135i4.2793","DOIUrl":"https://doi.org/10.22621/cfn.v135i4.2793","url":null,"abstract":"At the time of European settlement, an extensive graminoid wetland existed at the confluence of the East and West Holland Rivers at the southern end of Lake Simcoe, Ontario. However, by 1925, clearing and draining of the marsh for specialty agriculture (i.e., market gardens) had begun and, by the 1940s, ~46% of the wetland had been cleared and another 13% was lost before 2016. Concurrent with marsh conversion has been an increase in Narrow-leaved Cattail (Typha angustifolia) in the remnant wetland. This study documents the change in the Holland Marsh wetland by delineating boundaries between marsh, fen, and shrub communities on aerial photographs taken at ~10-year intervals between 1946 and 2015 and documenting vegetation change along transects running perpendicular to tributaries bisecting the wetland. The extent of fen habitat within the Holland Marsh has been decreasing since 1946 at an average rate of 0.24 ha/year because of increases in both shrub and marsh (i.e., T. angustifolia) communities. Typha angustifolia expansion has been predominantly from along the margins of the Holland River where soil phosphorus concentration is significantly higher than in the core of the fen. Beyond 30 m from the river, vegetation dominance shifts from T. angustifolia to sedges (Cyperaceae). Managing phosphorus loading from upstream land uses will be of critical importance in protecting this habitat, which is rare in southern Ontario.","PeriodicalId":56136,"journal":{"name":"The Canadian Field-Naturalist","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-04-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86581777","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-04-28DOI: 10.22621/cfn.v135i4.2709
David C. Seburn, M. Burns, Iyanuoluwa Akinrinola, Sara Cecile, T. Farquharson, Charlotte Hung, Payton McIntyre
Around the margin of an artificial pond in Ottawa, Ontario, we found 25 Painted Turtles (Chrysemys picta) that appeared to have died over the course of two winters (17 during the first winter and eight during the second). We examined meteorological data to try to determine the cause of the mortality. Summer and fall rains were only slightly below normal in both years, suggesting water levels should have been close to normal. The winter air temperature was warmer than normal and winter snowfall was slightly above normal in both years. Unseasonable weather does not appear to be responsible for the winter mortality and the pond’s maximum depth of 1.7 m should prevent freezing to the bottom. It is possible that the artificial nature of the pond creates suboptimal overwintering habitat, rendering the site an ecological trap; however, there is no direct evidence to support this theory. It is also possible that winter mortality of turtles is widespread at temperate wetlands, but that dead turtles were more detectable at this site because of the bare shoreline around the pond. Winter mass mortality events, if common, may represent an additional threat to turtle populations, which are declining from various anthropogenic threats.
{"title":"Apparent winterkill of Painted Turtle (Chrysemys picta)","authors":"David C. Seburn, M. Burns, Iyanuoluwa Akinrinola, Sara Cecile, T. Farquharson, Charlotte Hung, Payton McIntyre","doi":"10.22621/cfn.v135i4.2709","DOIUrl":"https://doi.org/10.22621/cfn.v135i4.2709","url":null,"abstract":"Around the margin of an artificial pond in Ottawa, Ontario, we found 25 Painted Turtles (Chrysemys picta) that appeared to have died over the course of two winters (17 during the first winter and eight during the second). We examined meteorological data to try to determine the cause of the mortality. Summer and fall rains were only slightly below normal in both years, suggesting water levels should have been close to normal. The winter air temperature was warmer than normal and winter snowfall was slightly above normal in both years. Unseasonable weather does not appear to be responsible for the winter mortality and the pond’s maximum depth of 1.7 m should prevent freezing to the bottom. It is possible that the artificial nature of the pond creates suboptimal overwintering habitat, rendering the site an ecological trap; however, there is no direct evidence to support this theory. It is also possible that winter mortality of turtles is widespread at temperate wetlands, but that dead turtles were more detectable at this site because of the bare shoreline around the pond. Winter mass mortality events, if common, may represent an additional threat to turtle populations, which are declining from various anthropogenic threats.","PeriodicalId":56136,"journal":{"name":"The Canadian Field-Naturalist","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-04-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80441574","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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