Pub Date : 2022-03-11DOI: 10.1898/1051-1733-103.1.63
Destiny M. Mims, Sophie A Yasuda, M. J. Jordan
Abstract As urbanization increases, impacts on urban wildlife behavior are becoming more apparent. Using camera traps, we compared activity times of Raccoons (Procyon lotor) with those of Virginia Opossums (Didelphis virginiana) in natural areas of Seattle, Washington. Previous studies found that Virginia Opossums and Raccoons are significantly more active at night than at any other time. However, these studies occurred exclusively in forested or agricultural landscapes. We deployed motion-triggered camera traps in greenspaces of Seattle to test the hypothesis that Raccoons and Virginia Opossums are both primarily active at night in an urban environment. Our results demonstrated a statistically significant difference in activity time distributions between the species. Virginia Opossums were exclusively nocturnal, whereas Raccoons allocated their activity between nocturnal and crepuscular periods. This study provides a snapshot of mesopredator behavior in an environment heavily influenced by humans and informs the effective management of Raccoons in urban areas.
{"title":"CONTRASTING ACTIVITY TIMES BETWEEN RACCOONS (PROCYON LOTOR) AND VIRGINIA OPOSSUMS (DIDELPHIS VIRGINIANA) IN URBAN GREEN SPACES","authors":"Destiny M. Mims, Sophie A Yasuda, M. J. Jordan","doi":"10.1898/1051-1733-103.1.63","DOIUrl":"https://doi.org/10.1898/1051-1733-103.1.63","url":null,"abstract":"Abstract As urbanization increases, impacts on urban wildlife behavior are becoming more apparent. Using camera traps, we compared activity times of Raccoons (Procyon lotor) with those of Virginia Opossums (Didelphis virginiana) in natural areas of Seattle, Washington. Previous studies found that Virginia Opossums and Raccoons are significantly more active at night than at any other time. However, these studies occurred exclusively in forested or agricultural landscapes. We deployed motion-triggered camera traps in greenspaces of Seattle to test the hypothesis that Raccoons and Virginia Opossums are both primarily active at night in an urban environment. Our results demonstrated a statistically significant difference in activity time distributions between the species. Virginia Opossums were exclusively nocturnal, whereas Raccoons allocated their activity between nocturnal and crepuscular periods. This study provides a snapshot of mesopredator behavior in an environment heavily influenced by humans and informs the effective management of Raccoons in urban areas.","PeriodicalId":142406,"journal":{"name":"Northwestern Naturalist","volume":"72 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-03-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122793977","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 : 2022-03-11DOI: 10.1898/1051-1733-103.1.20
C. Loehle, Jake Verschuyl, Kevin A. Solarik
Abstract The Marbled Murrelet (Brachyramphus marmoratus) is a small seabird found on the western coast of North America, listed as federally threatened in the US. It has been in decline for a prolonged period over most of its range. To better understand this population trend, we analyzed relative abundance from at-sea survey transects of Marbled Murrelets throughout the California, Oregon, and Washington region, 2001–2017. We assessed the consistency of trends at different spatial extents, evidence of among-region movements, and consistency between long-term trends and published estimates of demographic parameters. Yearly changes in population survey estimates in Oregon and northern California versus Washington were negatively correlated, suggesting significant bird movement between the 2 regions. Observed declines in the north and gains in the south may be due to Marbled Murrelet movements rather than differing regional demographics. Annual fluctuations were, in some cases, greater than what observed at-sea recruitment rates would allow for the species, especially at the state and zone scales, and were more variable by year in smaller regions. Trends for smaller spatial extents did not align with the 3-state stable trend estimate, suggesting that larger survey regions may be more reliable. The lifespan/recruitment rate scenarios that would allow persistence (λ=1) were also evaluated. Recruitment levels of 0.06/y require a longevity of 16.7 y for population stability, whereas a 0.1/y recruitment only requires a 10-y lifespan. Better resolution of Marbled Murrelet movement and vital rates is needed to resolve the contradiction between demographic analyses that project population declines and the observed stability of Marbled Murrelets quantified through the 3-state at-sea survey transects.
{"title":"POPULATION TRENDS AND VITAL RATES FOR MARBLED MURRELET (BRACHYRAMPHUS MARMORATUS) IN THE PACIFIC NORTHWEST, USA","authors":"C. Loehle, Jake Verschuyl, Kevin A. Solarik","doi":"10.1898/1051-1733-103.1.20","DOIUrl":"https://doi.org/10.1898/1051-1733-103.1.20","url":null,"abstract":"Abstract The Marbled Murrelet (Brachyramphus marmoratus) is a small seabird found on the western coast of North America, listed as federally threatened in the US. It has been in decline for a prolonged period over most of its range. To better understand this population trend, we analyzed relative abundance from at-sea survey transects of Marbled Murrelets throughout the California, Oregon, and Washington region, 2001–2017. We assessed the consistency of trends at different spatial extents, evidence of among-region movements, and consistency between long-term trends and published estimates of demographic parameters. Yearly changes in population survey estimates in Oregon and northern California versus Washington were negatively correlated, suggesting significant bird movement between the 2 regions. Observed declines in the north and gains in the south may be due to Marbled Murrelet movements rather than differing regional demographics. Annual fluctuations were, in some cases, greater than what observed at-sea recruitment rates would allow for the species, especially at the state and zone scales, and were more variable by year in smaller regions. Trends for smaller spatial extents did not align with the 3-state stable trend estimate, suggesting that larger survey regions may be more reliable. The lifespan/recruitment rate scenarios that would allow persistence (λ=1) were also evaluated. Recruitment levels of 0.06/y require a longevity of 16.7 y for population stability, whereas a 0.1/y recruitment only requires a 10-y lifespan. Better resolution of Marbled Murrelet movement and vital rates is needed to resolve the contradiction between demographic analyses that project population declines and the observed stability of Marbled Murrelets quantified through the 3-state at-sea survey transects.","PeriodicalId":142406,"journal":{"name":"Northwestern Naturalist","volume":"103 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-03-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129633157","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 : 2022-03-11DOI: 10.1898/1051-1733-103.1.30
Brett R. Andersen, Keith Geluso
Abstract Protecting day roosts is imperative to the persistence and survival of local populations of tree-roosting bats. The Pine Ridge region of Nebraska represents the largest area of coniferous forests in the state and possesses the greatest diversity of bats in Nebraska. In this study, we examined roost characteristics primarily for 4 species in need of conservation in the region: Fringed Myotis (Myotis thysanodes), Long-legged Myotis (Myotis volans), Little Brown Myotis (Myotis lucifugus), and Hoary Bat (Aeorestes cinereus). With a limited understanding of roost characteristics for other species in the region, we also collected some roost data for the Big Brown Bat (Eptesicus fuscus) and Western Small-footed Myotis (Myotis ciliolabrum). We tracked 42 bats with an emphasis on lactating females. Fringed Myotis, Big Brown Bats, and Western Small-footed Myotis typically roosted in cracks and crevices of dead trees. Long-legged Myotis roosted only in rock crevices at our western-most study site and only large, dead Ponderosa Pines (Pinus ponderosa) at our eastern-most site. Little Brown Myotis roosted in human-made structures in large colonies. Hoary Bats roosted in foliage of live hardwoods and conifers. Conservation of dead Ponderosa Pines, particularly those with large diameters and exfoliating bark, will provide roost structures for most crevice-roosting bats in the region. Our limited data for Hoary Bats suggest that roost-tree use is variable, as individuals roosted in both live hardwoods and conifers. Exclusive use of buildings throughout the region by female Little Brown Myotis implies timber harvests and wildfires might not greatly affect roosts for reproductive females. We demonstrated that roost characteristics vary among species and between nearby populations of the same species, representing important information for making informed habitat management decisions in a region with limited forests in northwestern Nebraska.
{"title":"ROOST CHARACTERISTICS OF BATS IN THE PINE RIDGE REGION OF NEBRASKA","authors":"Brett R. Andersen, Keith Geluso","doi":"10.1898/1051-1733-103.1.30","DOIUrl":"https://doi.org/10.1898/1051-1733-103.1.30","url":null,"abstract":"Abstract Protecting day roosts is imperative to the persistence and survival of local populations of tree-roosting bats. The Pine Ridge region of Nebraska represents the largest area of coniferous forests in the state and possesses the greatest diversity of bats in Nebraska. In this study, we examined roost characteristics primarily for 4 species in need of conservation in the region: Fringed Myotis (Myotis thysanodes), Long-legged Myotis (Myotis volans), Little Brown Myotis (Myotis lucifugus), and Hoary Bat (Aeorestes cinereus). With a limited understanding of roost characteristics for other species in the region, we also collected some roost data for the Big Brown Bat (Eptesicus fuscus) and Western Small-footed Myotis (Myotis ciliolabrum). We tracked 42 bats with an emphasis on lactating females. Fringed Myotis, Big Brown Bats, and Western Small-footed Myotis typically roosted in cracks and crevices of dead trees. Long-legged Myotis roosted only in rock crevices at our western-most study site and only large, dead Ponderosa Pines (Pinus ponderosa) at our eastern-most site. Little Brown Myotis roosted in human-made structures in large colonies. Hoary Bats roosted in foliage of live hardwoods and conifers. Conservation of dead Ponderosa Pines, particularly those with large diameters and exfoliating bark, will provide roost structures for most crevice-roosting bats in the region. Our limited data for Hoary Bats suggest that roost-tree use is variable, as individuals roosted in both live hardwoods and conifers. Exclusive use of buildings throughout the region by female Little Brown Myotis implies timber harvests and wildfires might not greatly affect roosts for reproductive females. We demonstrated that roost characteristics vary among species and between nearby populations of the same species, representing important information for making informed habitat management decisions in a region with limited forests in northwestern Nebraska.","PeriodicalId":142406,"journal":{"name":"Northwestern Naturalist","volume":"35 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-03-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131050195","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 : 2022-03-11DOI: 10.1898/1051-1733-103.1.11
B. Clucas, Zephan Atkins
Abstract Developing methods to effectively survey small, nocturnal mammals is important for conservation and management, as they are prey for many other species, including those of conservation concern, and may be threatened or endangered themselves. The Humboldt's Flying Squirrel (Glaucomys oregonensis), previously thought to be part of the Northern Flying Squirrel species (Glaucomys sabrinus), was recently discovered to be a separate species. The ability to effectively and efficiently survey for this species will be essential to evaluating its conservation status. Here we test a non-invasive method to survey for Humboldt's Flying Squirrels by using baited camera traps in old-growth and second-growth Coastal Redwood (Sequoia sempervirens) forests in northwestern California. We found that the camera trap method was successful at detecting flying squirrels in both stand types; however, the number of detections and activity levels were greater in the old-growth forest. Humboldt's Flying Squirrels may prefer old-growth forest when it is available, but still appear to utilize some second-growth forest stands. Camera traps can be used instead of live trapping when researchers or land managers are interested in determining the presence or absence of Humboldt's Flying Squirrels in forested habitat.
{"title":"USING CAMERA TRAPS TO SURVEY HUMBOLDT'S FLYING SQUIRRELS IN OLD- AND SECOND-GROWTH REDWOOD FORESTS","authors":"B. Clucas, Zephan Atkins","doi":"10.1898/1051-1733-103.1.11","DOIUrl":"https://doi.org/10.1898/1051-1733-103.1.11","url":null,"abstract":"Abstract Developing methods to effectively survey small, nocturnal mammals is important for conservation and management, as they are prey for many other species, including those of conservation concern, and may be threatened or endangered themselves. The Humboldt's Flying Squirrel (Glaucomys oregonensis), previously thought to be part of the Northern Flying Squirrel species (Glaucomys sabrinus), was recently discovered to be a separate species. The ability to effectively and efficiently survey for this species will be essential to evaluating its conservation status. Here we test a non-invasive method to survey for Humboldt's Flying Squirrels by using baited camera traps in old-growth and second-growth Coastal Redwood (Sequoia sempervirens) forests in northwestern California. We found that the camera trap method was successful at detecting flying squirrels in both stand types; however, the number of detections and activity levels were greater in the old-growth forest. Humboldt's Flying Squirrels may prefer old-growth forest when it is available, but still appear to utilize some second-growth forest stands. Camera traps can be used instead of live trapping when researchers or land managers are interested in determining the presence or absence of Humboldt's Flying Squirrels in forested habitat.","PeriodicalId":142406,"journal":{"name":"Northwestern Naturalist","volume":"6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-03-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132754294","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 : 2022-03-11DOI: 10.1898/1051-1733-103.1.51
Kiana B. Young, T. Lewis, L. Prugh
Abstract Many avian and mammalian predators are facultative scavengers and will opportunistically forage from carcasses. A food source as large as a whale carcass could be valuable to wildlife because of its size and high lipid content. Large carcasses can elicit unique behaviors and interactions in wildlife, but because whale beachings are relatively uncommon, little research has examined the scavenging dynamics at whale carcasses. Here, we used a remote camera to investigate the composition and interactions of scavengers at a Humpback Whale (Megaptera novaeangliae) carcass that washed ashore in Glacier Bay National Park, Alaska, in 2016. We split the consumption process into 3 stages based on how much soft tissue remained. Bald Eagles (Haliaeetus leucocephalus) were the first to feed on the carcass and appeared to dominate the food source, preventing many smaller birds from feeding. Gray Wolves (Canis lupus), corvids (Corvus spp.), and gulls (Larus spp.) were also regularly detected. Scavenger numbers remained high during the first 2 stages of carcass consumption and declined by the 3rd stage. Most interactions observed were between individual Bald Eagles and occurred during the 1st stage. Following the eagles' departure after the 1st stage, interactions between individuals were far less common. These results suggest that a carcass of this size in the intertidal zone is utilized primarily by avian scavengers and that interactions between individuals decrease as the food resource declines. These findings help advance our understanding of scavenger dynamics and the general ecology of coastal Pacific Northwest ecosystems.
{"title":"THE COMPOSITION AND INTERACTIONS OF SCAVENGERS ON A HUMPBACK WHALE CARCASS IN ALASKA","authors":"Kiana B. Young, T. Lewis, L. Prugh","doi":"10.1898/1051-1733-103.1.51","DOIUrl":"https://doi.org/10.1898/1051-1733-103.1.51","url":null,"abstract":"Abstract Many avian and mammalian predators are facultative scavengers and will opportunistically forage from carcasses. A food source as large as a whale carcass could be valuable to wildlife because of its size and high lipid content. Large carcasses can elicit unique behaviors and interactions in wildlife, but because whale beachings are relatively uncommon, little research has examined the scavenging dynamics at whale carcasses. Here, we used a remote camera to investigate the composition and interactions of scavengers at a Humpback Whale (Megaptera novaeangliae) carcass that washed ashore in Glacier Bay National Park, Alaska, in 2016. We split the consumption process into 3 stages based on how much soft tissue remained. Bald Eagles (Haliaeetus leucocephalus) were the first to feed on the carcass and appeared to dominate the food source, preventing many smaller birds from feeding. Gray Wolves (Canis lupus), corvids (Corvus spp.), and gulls (Larus spp.) were also regularly detected. Scavenger numbers remained high during the first 2 stages of carcass consumption and declined by the 3rd stage. Most interactions observed were between individual Bald Eagles and occurred during the 1st stage. Following the eagles' departure after the 1st stage, interactions between individuals were far less common. These results suggest that a carcass of this size in the intertidal zone is utilized primarily by avian scavengers and that interactions between individuals decrease as the food resource declines. These findings help advance our understanding of scavenger dynamics and the general ecology of coastal Pacific Northwest ecosystems.","PeriodicalId":142406,"journal":{"name":"Northwestern Naturalist","volume":"102 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-03-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115354686","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 : 2022-03-11DOI: 10.1898/1051-1733-103.1.81
Oliver Freni, Joseph L Freni, Christopher D. Anderson, Lisa A. Hallock, M. Lambert, Nicholas Van Gilder, D. Wake, E. Jockusch
Abstract Human activities are increasingly responsible for moving organisms far beyond natural dispersal distances and range boundaries. Here we describe the 1st documented instance of a slender salamander (genus Batrachoseps; B. attenuatus specifically) in Washington State, in the Seattle suburb of Kirkland. We molecularly identified this individual as belonging to a B. attenuatus clade in San Francisco, California. Beyond representing the 1st Batrachoseps in Washington, this is the 1st record of B. attenuatus introduced beyond its range limits in central and northern California, and the 1st record of the entire genus far beyond its geographic range. This specimen is also noteworthy because it was a gravid female that was exceptionally large, suggesting it could found a population on its own if one does not already exist, and that habitat conditions in a suburban region of the Pacific Northwest are suitable for this species. The Pacific Northwest is expected to be particularly suitable for the establishment of a diversity of introduced salamander species, and our work highlights the importance of proactive research and management to address species introductions.
{"title":"FIRST RECORD OF A SLENDER SALAMANDER (GENUS BATRACHOSEPS) INTRODUCED TO WASHINGTON STATE AND MOLECULAR SOURCE IDENTIFICATION FROM SAN FRANCISCO, CALIFORNIA","authors":"Oliver Freni, Joseph L Freni, Christopher D. Anderson, Lisa A. Hallock, M. Lambert, Nicholas Van Gilder, D. Wake, E. Jockusch","doi":"10.1898/1051-1733-103.1.81","DOIUrl":"https://doi.org/10.1898/1051-1733-103.1.81","url":null,"abstract":"Abstract Human activities are increasingly responsible for moving organisms far beyond natural dispersal distances and range boundaries. Here we describe the 1st documented instance of a slender salamander (genus Batrachoseps; B. attenuatus specifically) in Washington State, in the Seattle suburb of Kirkland. We molecularly identified this individual as belonging to a B. attenuatus clade in San Francisco, California. Beyond representing the 1st Batrachoseps in Washington, this is the 1st record of B. attenuatus introduced beyond its range limits in central and northern California, and the 1st record of the entire genus far beyond its geographic range. This specimen is also noteworthy because it was a gravid female that was exceptionally large, suggesting it could found a population on its own if one does not already exist, and that habitat conditions in a suburban region of the Pacific Northwest are suitable for this species. The Pacific Northwest is expected to be particularly suitable for the establishment of a diversity of introduced salamander species, and our work highlights the importance of proactive research and management to address species introductions.","PeriodicalId":142406,"journal":{"name":"Northwestern Naturalist","volume":"4 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-03-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115362502","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 : 2022-03-11DOI: 10.1898/1051-1733-103.1.42
Emily Buckner, P. Chittaro, Frances Wood, T. Klinger
Abstract We investigated dietary preferences in Pigeon Guillemot (Cepphus columba) across different breeding stages in Puget Sound, WA. Observations of prey delivered to chicks were conducted during the breeding season (June–September) at 28 colonies on Whidbey Island over a 12-y period (2008–2019). We conducted stable isotope analysis on discarded eggshells collected below active Pigeon Guillemot burrows distributed across 9 colonies on Whidbey Island during the 2019 breeding season. We estimated the relative percent contribution of fish and invertebrates to the diet of pre-laying adult Pigeon Guillemot using the δ15N and δ13C in eggshell membrane tissue. Results of our mixing model showed that adults derive nearly 75% of their energy and nutrients from demersal fish species (rockfish, gunnel, and sculpin) during the pre-laying period, and prey-delivery observations showed that Pigeon Guillemot preferentially deliver gunnel (Pholidae) to chicks. These results demonstrate a consistent foraging pattern and dietary preference in this population over the course of 2 different stages during the breeding season.
{"title":"IDENTIFYING DIETARY PREFERENCES IN BREEDING PIGEON GUILLEMOT (CEPPHUS COLUMBA) USING DIFFERENT METHODS","authors":"Emily Buckner, P. Chittaro, Frances Wood, T. Klinger","doi":"10.1898/1051-1733-103.1.42","DOIUrl":"https://doi.org/10.1898/1051-1733-103.1.42","url":null,"abstract":"Abstract We investigated dietary preferences in Pigeon Guillemot (Cepphus columba) across different breeding stages in Puget Sound, WA. Observations of prey delivered to chicks were conducted during the breeding season (June–September) at 28 colonies on Whidbey Island over a 12-y period (2008–2019). We conducted stable isotope analysis on discarded eggshells collected below active Pigeon Guillemot burrows distributed across 9 colonies on Whidbey Island during the 2019 breeding season. We estimated the relative percent contribution of fish and invertebrates to the diet of pre-laying adult Pigeon Guillemot using the δ15N and δ13C in eggshell membrane tissue. Results of our mixing model showed that adults derive nearly 75% of their energy and nutrients from demersal fish species (rockfish, gunnel, and sculpin) during the pre-laying period, and prey-delivery observations showed that Pigeon Guillemot preferentially deliver gunnel (Pholidae) to chicks. These results demonstrate a consistent foraging pattern and dietary preference in this population over the course of 2 different stages during the breeding season.","PeriodicalId":142406,"journal":{"name":"Northwestern Naturalist","volume":"14 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-03-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130352512","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 : 2022-03-11DOI: 10.1898/1051-1733-103.1.76
P. Hendricks, Lisa M. Hendricks
Abstract On 12 April 2021, we observed a Black-billed Magpie (Pica hudsonia) kill an apparently-healthy adult female Cassin's Finch (Haemorhous cassinii) in an urban backyard near a feeding station in Missoula, Montana. The magpie landed on a chain-link fence above the finch before dropping to the ground 1–2 s later where it grabbed the finch with its bill and pinned it to the ground with a foot, then delivered several blows of the bill to the finch's neck, back, and breast. The entire attack, from arrival of the magpie to its departure with the apparently-dead finch held in its bill, lasted no more than 60 s. We found only 2 prior reports of Black-billed Magpies capturing adult birds, and none for the Yellow-billed Magpie (Pica nuttalli). There are several published cases of the closely-related Eurasian Magpie (Pica pica) attacking and killing adult birds, indicating that magpies are quite capable of subduing birds if so motivated when given the opportunity. Black-billed Magpies and Eurasian Magpies tended to attack adult birds during winter through spring (non-breeding season), and most often in urban environments where small birds aggregate near concentrations of food or potential roost and nest sites, resources also attractive to magpies. These circumstances may afford magpies more close encounters with potential adult avian prey than might occur in rural locations, and may encourage them to hunt adult birds more frequently.
{"title":"PREDATORY ATTACKS BY BLACK-BILLED MAGPIES (PICA HUDSONIA) ON CASSIN'S FINCH (HAEMORHOUS CASSINII) AND OTHER ADULT BIRDS","authors":"P. Hendricks, Lisa M. Hendricks","doi":"10.1898/1051-1733-103.1.76","DOIUrl":"https://doi.org/10.1898/1051-1733-103.1.76","url":null,"abstract":"Abstract On 12 April 2021, we observed a Black-billed Magpie (Pica hudsonia) kill an apparently-healthy adult female Cassin's Finch (Haemorhous cassinii) in an urban backyard near a feeding station in Missoula, Montana. The magpie landed on a chain-link fence above the finch before dropping to the ground 1–2 s later where it grabbed the finch with its bill and pinned it to the ground with a foot, then delivered several blows of the bill to the finch's neck, back, and breast. The entire attack, from arrival of the magpie to its departure with the apparently-dead finch held in its bill, lasted no more than 60 s. We found only 2 prior reports of Black-billed Magpies capturing adult birds, and none for the Yellow-billed Magpie (Pica nuttalli). There are several published cases of the closely-related Eurasian Magpie (Pica pica) attacking and killing adult birds, indicating that magpies are quite capable of subduing birds if so motivated when given the opportunity. Black-billed Magpies and Eurasian Magpies tended to attack adult birds during winter through spring (non-breeding season), and most often in urban environments where small birds aggregate near concentrations of food or potential roost and nest sites, resources also attractive to magpies. These circumstances may afford magpies more close encounters with potential adult avian prey than might occur in rural locations, and may encourage them to hunt adult birds more frequently.","PeriodicalId":142406,"journal":{"name":"Northwestern Naturalist","volume":"7 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-03-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128278328","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 : 2022-03-11DOI: 10.1898/1051-1733-103.1.88
M. D. Thompson, Ron Clark
Abstract A case of predation by a Belted Kingfisher (Megaceryle alcyon) on adult Long-toed Salamanders (Ambystoma macrodactylum) and a Northern Red-legged Frog (Rana aurora) is reported. This general note provides a description of the predation events with photographs of the amphibians being devoured. Additional photographs showing scars in long-toed salamanders are presented and considered in review of types of predatory attacks and defensive strategies. A literature review was completed to identify reported cases of predation on these two amphibian species. We discuss what is known about their anti-predator defensive strategies and what species are involved in the ecological and evolutionary dynamics at play. Traits exhibited by these amphibians are discussed as anti-predator adaptations that include warning colorations, defensive postures, tail dropping, crypsis, and glandular skin secretions that can be adhesive, unpalatable, or toxic. A potentially significant role of avian predators is considered in light of the evidence presented.
{"title":"PREDATION ON ADULT LONG-TOED SALAMANDERS AND A NORTHERN RED-LEGGED FROG BY A BELTED KINGFISHER ON VANCOUVER ISLAND, BRITISH COLUMBIA: A REVIEW OF DEFENSIVE STRATEGY ADAPTATIONS","authors":"M. D. Thompson, Ron Clark","doi":"10.1898/1051-1733-103.1.88","DOIUrl":"https://doi.org/10.1898/1051-1733-103.1.88","url":null,"abstract":"Abstract A case of predation by a Belted Kingfisher (Megaceryle alcyon) on adult Long-toed Salamanders (Ambystoma macrodactylum) and a Northern Red-legged Frog (Rana aurora) is reported. This general note provides a description of the predation events with photographs of the amphibians being devoured. Additional photographs showing scars in long-toed salamanders are presented and considered in review of types of predatory attacks and defensive strategies. A literature review was completed to identify reported cases of predation on these two amphibian species. We discuss what is known about their anti-predator defensive strategies and what species are involved in the ecological and evolutionary dynamics at play. Traits exhibited by these amphibians are discussed as anti-predator adaptations that include warning colorations, defensive postures, tail dropping, crypsis, and glandular skin secretions that can be adhesive, unpalatable, or toxic. A potentially significant role of avian predators is considered in light of the evidence presented.","PeriodicalId":142406,"journal":{"name":"Northwestern Naturalist","volume":"46 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-03-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124635427","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 : 2021-11-26DOI: 10.1898/1051-1733-102.3.276
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