Abstract I report on the predatory interaction of Peregrine Falcons and flocks of European Starlings in British Columbia, and I review the literature of raptors hunting starlings at their roost sites in Europe. A video analysis of peregrines attacking roosting flocks of starlings over Rome is compared to my long-term observations of peregrines hunting passerines and sandpipers in Canada. The results suggest that the starling murmurations are an anti-predator strategy. My observations, and a review of historical notes in the Oxford English Dictionary, show that the term murmuration was originally inspired by the chorus song of breeding starlings and that today's common use of that term to describe their roost site flights is a misnomer.
{"title":"THE MURMURATIONS OF EUROPEAN STARLINGS; AN ANTI-PREDATOR STRATEGY AND A HISTORICAL MISNOMER","authors":"D. Dekker","doi":"10.1898/NWN21-09","DOIUrl":"https://doi.org/10.1898/NWN21-09","url":null,"abstract":"Abstract I report on the predatory interaction of Peregrine Falcons and flocks of European Starlings in British Columbia, and I review the literature of raptors hunting starlings at their roost sites in Europe. A video analysis of peregrines attacking roosting flocks of starlings over Rome is compared to my long-term observations of peregrines hunting passerines and sandpipers in Canada. The results suggest that the starling murmurations are an anti-predator strategy. My observations, and a review of historical notes in the Oxford English Dictionary, show that the term murmuration was originally inspired by the chorus song of breeding starlings and that today's common use of that term to describe their roost site flights is a misnomer.","PeriodicalId":142406,"journal":{"name":"Northwestern Naturalist","volume":"33 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122092400","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}
D. Holt, Matthew D. Larson, S. Hiro, M. Seidensticker
Abstract Four cases of female Boreal Owls (Aegolius funereus) recaptured within varying distances of their natal or breeding sites are reported. We considered 3 recaptures within the natal or breeding neighborhood to be philopatry (site fidelity), and 1 case as dispersal. One banded female was recaptured as a 2y old, 3.4 km from her natal box. We considered this philopatry. She was later recaptured 15.8 km from her 2nd breeding site, and we considered this breeding dispersal. She lived at least 5 y, but we did not know her whereabouts in all years. A 2nd female banded as a nestling was recaptured 2.0 km from her natal box, breeding as a yearling (11 mo). We considered this natal philopatry. A 3rd female, previously banded as a breeding adult, was recaptured 2 y later breeding 2.5 km from her initial site of banding. We considered this philopatry. She was at least 4 y old. The 4th female was recaptured 3.6 km from her initial breeding box. We considered this philopatry. She was recaptured again the following year in the same nest box as her 2nd nest site. We considered the use of this same nest site philopatry. She was in her 5th calendar year. Our records are perhaps the 1st reports of natal philopatry and age of 1st breeding for female Boreal Owls in North America, and contribute additional records of female site fidelity and dispersal.
{"title":"IS THIS PHILOPATRY OR DISPERSAL IN FEMALE BOREAL OWLS?","authors":"D. Holt, Matthew D. Larson, S. Hiro, M. Seidensticker","doi":"10.1898/NWN20-35","DOIUrl":"https://doi.org/10.1898/NWN20-35","url":null,"abstract":"Abstract Four cases of female Boreal Owls (Aegolius funereus) recaptured within varying distances of their natal or breeding sites are reported. We considered 3 recaptures within the natal or breeding neighborhood to be philopatry (site fidelity), and 1 case as dispersal. One banded female was recaptured as a 2y old, 3.4 km from her natal box. We considered this philopatry. She was later recaptured 15.8 km from her 2nd breeding site, and we considered this breeding dispersal. She lived at least 5 y, but we did not know her whereabouts in all years. A 2nd female banded as a nestling was recaptured 2.0 km from her natal box, breeding as a yearling (11 mo). We considered this natal philopatry. A 3rd female, previously banded as a breeding adult, was recaptured 2 y later breeding 2.5 km from her initial site of banding. We considered this philopatry. She was at least 4 y old. The 4th female was recaptured 3.6 km from her initial breeding box. We considered this philopatry. She was recaptured again the following year in the same nest box as her 2nd nest site. We considered the use of this same nest site philopatry. She was in her 5th calendar year. Our records are perhaps the 1st reports of natal philopatry and age of 1st breeding for female Boreal Owls in North America, and contribute additional records of female site fidelity and dispersal.","PeriodicalId":142406,"journal":{"name":"Northwestern Naturalist","volume":"38 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132639629","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}
S FROM THE 2022 WESTERN PARC EXTRAVAGANZA, VIRTUAL ANNUAL MEETING OF SW PARC AND NW PARC (PARTNERS IN AMPHIBIAN AND REPTILE CONSERVATION), HOSTED BY THE TURTLE SURVIVAL ALLIANCE (TSA), 7–9 APRIL 2022
{"title":"ABSTRACTS FROM THE 2022 WESTERN PARC EXTRAVAGANZA, VIRTUAL ANNUAL MEETING OF SW PARC AND NW PARC (PARTNERS IN AMPHIBIAN AND REPTILE CONSERVATION), HOSTED BY THE TURTLE SURVIVAL ALLIANCE (TSA), 7–9 APRIL 2022","authors":"Contributed Talks","doi":"10.1898/NWN103-2","DOIUrl":"https://doi.org/10.1898/NWN103-2","url":null,"abstract":"S FROM THE 2022 WESTERN PARC EXTRAVAGANZA, VIRTUAL ANNUAL MEETING OF SW PARC AND NW PARC (PARTNERS IN AMPHIBIAN AND REPTILE CONSERVATION), HOSTED BY THE TURTLE SURVIVAL ALLIANCE (TSA), 7–9 APRIL 2022","PeriodicalId":142406,"journal":{"name":"Northwestern Naturalist","volume":"105 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124806175","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}
Abstract The Northwestern Pond Turtle (Actinemys marmorata) ranges from Washington to the southern end of the Central Valley of California. Because of the extensive latitudinal range of the species, it is expected that several life-history traits will vary across the range. Most data on population structure and growth of A. marmorata have been gathered from southern Oregon and California, and reproductive data are sparse north of the southern end of the range. These data are important to a critical understanding of the species' biology and especially for making conservation judgments for a species some consider in need of protection. Thus, we collected key life-history information at the Luckiamute State Natural Area in the mid-Willamette Valley, Oregon. We found that the population structure, adult size, and growth were similar to southern Oregon sites. Clutch size from radiographs was 6.0 ± 1.18 SE (range = 5–8), smaller than sites at the southern end of the range. The slow growth rate of Luckiamute turtles may be explained by cooler temperature in the Willamette Valley compared to more southerly sites. Still, Luckiamute adults reach a slightly larger size than most turtles in more southerly sites. It just requires many more years to reach sexual maturity and achieve larger sizes in northern areas.
{"title":"GROWTH AND REPRODUCTION OF NORTHWESTERN POND TURTLES IN THE MID-WILLAMETTE VALLEY, OREGON","authors":"D. Germano, R. Bury, G. Bury","doi":"10.1898/NWN20-21","DOIUrl":"https://doi.org/10.1898/NWN20-21","url":null,"abstract":"Abstract The Northwestern Pond Turtle (Actinemys marmorata) ranges from Washington to the southern end of the Central Valley of California. Because of the extensive latitudinal range of the species, it is expected that several life-history traits will vary across the range. Most data on population structure and growth of A. marmorata have been gathered from southern Oregon and California, and reproductive data are sparse north of the southern end of the range. These data are important to a critical understanding of the species' biology and especially for making conservation judgments for a species some consider in need of protection. Thus, we collected key life-history information at the Luckiamute State Natural Area in the mid-Willamette Valley, Oregon. We found that the population structure, adult size, and growth were similar to southern Oregon sites. Clutch size from radiographs was 6.0 ± 1.18 SE (range = 5–8), smaller than sites at the southern end of the range. The slow growth rate of Luckiamute turtles may be explained by cooler temperature in the Willamette Valley compared to more southerly sites. Still, Luckiamute adults reach a slightly larger size than most turtles in more southerly sites. It just requires many more years to reach sexual maturity and achieve larger sizes in northern areas.","PeriodicalId":142406,"journal":{"name":"Northwestern Naturalist","volume":"69 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124840998","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}
Abstract Gloger's rule is an ecogeographical pattern observed in many vertebrates whereby populations in more humid environments have darker pigmentation than populations in more arid environments. The coat color for several species of temperate bats exhibits this pattern, including the Western Long-eared Bat (Myotis evotis) in coastal versus interior populations. We tested Gloger's rule by comparing the coat of M. evotis in the mountains and prairies of Alberta, areas with similar humidity. We predicted that both sets of bats would have similar pigmentation if humidity is the main factor driving variation in coat coloration. Discriminant function analysis of color attributes readily separated M. evotis in the mountains from those in the prairies. Individuals were darker in the mountains, violating Gloger's rule. Differential selection by nocturnal predators against conspicuous coat may explain the color differences we found, and perhaps in other species of temperate bats.
{"title":"COAT COLOR OF WESTERN LONG-EARED BATS (MYOTIS EVOTIS) LIVING IN DIFFERENT ENVIRONMENTS: A TEST OF GLOGER'S RULE","authors":"D. Solick, R. Barclay","doi":"10.1898/NWN21-14","DOIUrl":"https://doi.org/10.1898/NWN21-14","url":null,"abstract":"Abstract Gloger's rule is an ecogeographical pattern observed in many vertebrates whereby populations in more humid environments have darker pigmentation than populations in more arid environments. The coat color for several species of temperate bats exhibits this pattern, including the Western Long-eared Bat (Myotis evotis) in coastal versus interior populations. We tested Gloger's rule by comparing the coat of M. evotis in the mountains and prairies of Alberta, areas with similar humidity. We predicted that both sets of bats would have similar pigmentation if humidity is the main factor driving variation in coat coloration. Discriminant function analysis of color attributes readily separated M. evotis in the mountains from those in the prairies. Individuals were darker in the mountains, violating Gloger's rule. Differential selection by nocturnal predators against conspicuous coat may explain the color differences we found, and perhaps in other species of temperate bats.","PeriodicalId":142406,"journal":{"name":"Northwestern Naturalist","volume":"70 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116281024","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}
Abstract The diet of the American Robin (Turdus migratorius) consists largely of fruit and invertebrates. Rarely, predation of small vertebrates has also been reported, including attacks on, and/or consumption of, snakes, a skink, fish, shrews, a field mouse, a salamander, and frogs. Few observations have included a prolonged interaction, leaving unanswered questions about how the prey are subdued, killed, and eaten. Here I describe an 8-min encounter between an adult male Robin and a Pacific Tree Frog (Psuedacris regilla), including plausible prey-dropping, pursuit, bill-pouncing, pecking, and beating the frog against the ground. The frog was killed, but not consumed, apparently because it was too large to swallow whole and the Robin failed to open or dismember the carcass. This marks the first reported attack by a Robin on a Pacific Tree Frog, and the first confirmed Robin kill of any frog species.
{"title":"PREDATION OF A PACIFIC TREE FROG (PSEUDACRIS REGILLA) BY AN AMERICAN ROBIN (TURDUS MIGRATORIUS) ON SAN JUAN ISLAND, WASHINGTON","authors":"Thor R. Hanson","doi":"10.1898/NWN21-20","DOIUrl":"https://doi.org/10.1898/NWN21-20","url":null,"abstract":"Abstract The diet of the American Robin (Turdus migratorius) consists largely of fruit and invertebrates. Rarely, predation of small vertebrates has also been reported, including attacks on, and/or consumption of, snakes, a skink, fish, shrews, a field mouse, a salamander, and frogs. Few observations have included a prolonged interaction, leaving unanswered questions about how the prey are subdued, killed, and eaten. Here I describe an 8-min encounter between an adult male Robin and a Pacific Tree Frog (Psuedacris regilla), including plausible prey-dropping, pursuit, bill-pouncing, pecking, and beating the frog against the ground. The frog was killed, but not consumed, apparently because it was too large to swallow whole and the Robin failed to open or dismember the carcass. This marks the first reported attack by a Robin on a Pacific Tree Frog, and the first confirmed Robin kill of any frog species.","PeriodicalId":142406,"journal":{"name":"Northwestern Naturalist","volume":"176 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134285372","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}
K. Lomac-MacNair, Sheyna S. Wisdom, José Pedro de Andrade, J. Stepanuk, Maren Anderson, Ann Zoidis, E. Esteves
Abstract With global climate change and increasing ocean-based human activities, large whales face novel challenges in the Arctic seas. Understanding and assessing large whale occurrence and the links between occurrence and environmental variables in this region is a key issue in current management and conservation strategies for Arctic marine mammal species. During the Chukchi Sea Environmental Studies Program, large whale occurrence data were collected from vessel surveys during >56,909 km of observation effort in summer and autumn, 2008 to 2014, in the northeastern Chukchi, southern Beaufort, and Bering Seas. The most-recorded species were the Bowhead (Balaena mysticetus) and Gray (Eschrichtius robustus) Whales. Subarctic species recorded included the Humpback Whale (Megaptera novaeangliae), Fin Whale (Balaenoptera physalus), and Minke Whale (Balaenoptera acutorostrata). Sightings data were analyzed with respect to environmental variables: sea-surface temperature (SST), depth (m), and distance from shore (km), by month and year. Investigating occurrence associations with environmental parameters is a key element for predicting large whale trends in these Arctic seas and for understanding marine mammals as sentinels of oceanic shifts.
{"title":"LARGE WHALE OCCURRENCE IN NORTHEASTERN CHUKCHI AND SOUTHERN BEAUFORT SEAS FROM VESSEL SURVEYS, 2008–2014","authors":"K. Lomac-MacNair, Sheyna S. Wisdom, José Pedro de Andrade, J. Stepanuk, Maren Anderson, Ann Zoidis, E. Esteves","doi":"10.1898/NWN21-11","DOIUrl":"https://doi.org/10.1898/NWN21-11","url":null,"abstract":"Abstract With global climate change and increasing ocean-based human activities, large whales face novel challenges in the Arctic seas. Understanding and assessing large whale occurrence and the links between occurrence and environmental variables in this region is a key issue in current management and conservation strategies for Arctic marine mammal species. During the Chukchi Sea Environmental Studies Program, large whale occurrence data were collected from vessel surveys during >56,909 km of observation effort in summer and autumn, 2008 to 2014, in the northeastern Chukchi, southern Beaufort, and Bering Seas. The most-recorded species were the Bowhead (Balaena mysticetus) and Gray (Eschrichtius robustus) Whales. Subarctic species recorded included the Humpback Whale (Megaptera novaeangliae), Fin Whale (Balaenoptera physalus), and Minke Whale (Balaenoptera acutorostrata). Sightings data were analyzed with respect to environmental variables: sea-surface temperature (SST), depth (m), and distance from shore (km), by month and year. Investigating occurrence associations with environmental parameters is a key element for predicting large whale trends in these Arctic seas and for understanding marine mammals as sentinels of oceanic shifts.","PeriodicalId":142406,"journal":{"name":"Northwestern Naturalist","volume":"14 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115785242","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}
Alexandria M. Fulton, Jonathan P. Rose, B. Halstead
Abstract The Northwestern Pond Turtle (Actinemys marmorata; WPT) was once widespread throughout the Sacramento Valley and the Sacramento-San Joaquin River Delta. Much of its historical range has been converted into agricultural land, reducing and altering aquatic habitat and surrounding uplands. Red-eared Sliders (Trachemys scripta elegans; RES) have been introduced throughout much of the existing WPT range, particularly near urban centers, potentially competing with WPT for resources. Previous surveys for turtles in central California have primarily focused on rivers, lakes, and protected wetlands. Little is known about where WPT and RES occur in the vast expanses of agricultural land across the Sacramento Valley and Sacramento-San Joaquin River Delta. Using aquatic hoop nets, we surveyed 142 locations (102 irrigation canal sites, 39 wetlands, 1 tidally influenced slough) across 8 counties during the summers of 2018 and 2019. Both species were detected in agricultural habitats. Using occupancy modeling, we estimated that WPT occur at 44 (95% CRI = 38–53) of our trapping sites and RES occur at 51 (41–66) sampled sites. Co-occurrence of these 2 species was rare; the species were found together at only 6 sites. RES were primarily found in restored wetlands near major roads and the Sacramento metropolitan area, whereas WPT were more commonly found farther from urban areas in wider canals. Our work provides a picture of how WPT and RES occupy this modified agroecosystem that can inform future conservation efforts.
{"title":"RURAL TURTLES: ESTIMATING THE OCCUPANCY OF NORTHWESTERN POND TURTLES AND NON-NATIVE RED-EARED SLIDERS IN AGRICULTURAL HABITATS IN CALIFORNIA'S SACRAMENTO VALLEY AND SACRAMENTO-SAN JOAQUIN RIVER DELTA","authors":"Alexandria M. Fulton, Jonathan P. Rose, B. Halstead","doi":"10.1898/NWN20-22","DOIUrl":"https://doi.org/10.1898/NWN20-22","url":null,"abstract":"Abstract The Northwestern Pond Turtle (Actinemys marmorata; WPT) was once widespread throughout the Sacramento Valley and the Sacramento-San Joaquin River Delta. Much of its historical range has been converted into agricultural land, reducing and altering aquatic habitat and surrounding uplands. Red-eared Sliders (Trachemys scripta elegans; RES) have been introduced throughout much of the existing WPT range, particularly near urban centers, potentially competing with WPT for resources. Previous surveys for turtles in central California have primarily focused on rivers, lakes, and protected wetlands. Little is known about where WPT and RES occur in the vast expanses of agricultural land across the Sacramento Valley and Sacramento-San Joaquin River Delta. Using aquatic hoop nets, we surveyed 142 locations (102 irrigation canal sites, 39 wetlands, 1 tidally influenced slough) across 8 counties during the summers of 2018 and 2019. Both species were detected in agricultural habitats. Using occupancy modeling, we estimated that WPT occur at 44 (95% CRI = 38–53) of our trapping sites and RES occur at 51 (41–66) sampled sites. Co-occurrence of these 2 species was rare; the species were found together at only 6 sites. RES were primarily found in restored wetlands near major roads and the Sacramento metropolitan area, whereas WPT were more commonly found farther from urban areas in wider canals. Our work provides a picture of how WPT and RES occupy this modified agroecosystem that can inform future conservation efforts.","PeriodicalId":142406,"journal":{"name":"Northwestern Naturalist","volume":"87 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122218143","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}
B. Slough, C. Lausen, B. Paterson, I. J. Hansen, Julie P. Thomas, Piia M. Kukka, T. Jung, Jason Rae, Debbie van de Wetering
Abstract The bat fauna of northwestern Canada remains poorly known, principally owing to a lack of dedicated surveys across this vast region. To better assess the diversity of bats in the region, we compiled records from several acoustic survey projects and capture sessions whose purpose was to inventory bats in Yukon and northwestern British Columbia (BC) from 2013 to 2018. During our surveys we obtained the 1st apparent acoustic records for Yuma Myotis (Myotis yumanensis), Californian Myotis (M. californicus), Long-eared Myotis (M. evotis), Silver-haired Bat (Lasionycteris noctivagans) and Eastern Red Bat (Lasiurus borealis) from this region. We also captured 2 Long-eared Myotis in northwestern BC. Additionally, our surveys provided range extensions of Northern Myotis (M. septentrionalis), Long-legged Myotis (M. volans), and Hoary Bat (Lasiurus cinereus). Finally, by deploying bat detectors in late autumn, and in some cases throughout the winter, we provide data about seasonal patterns for bat activity in some locations, revealing that bats in northwestern BC may be active as late as 29 October and emerge as early as 30 March, a pattern similar to that observed in southern BC. By combining data from several disparate surveys, conducted for different reasons by different researchers, we were able to provide a fuller picture of the bat fauna of this vast region. Our data provides further evidence that the bat fauna of northwestern Canada is richer than previously documented.
{"title":"NEW RECORDS ABOUT THE DIVERSITY, DISTRIBUTION, AND SEASONAL ACTIVITY PATTERNS BY BATS IN YUKON AND NORTHWESTERN BRITISH COLUMBIA","authors":"B. Slough, C. Lausen, B. Paterson, I. J. Hansen, Julie P. Thomas, Piia M. Kukka, T. Jung, Jason Rae, Debbie van de Wetering","doi":"10.1898/NWN21-10","DOIUrl":"https://doi.org/10.1898/NWN21-10","url":null,"abstract":"Abstract The bat fauna of northwestern Canada remains poorly known, principally owing to a lack of dedicated surveys across this vast region. To better assess the diversity of bats in the region, we compiled records from several acoustic survey projects and capture sessions whose purpose was to inventory bats in Yukon and northwestern British Columbia (BC) from 2013 to 2018. During our surveys we obtained the 1st apparent acoustic records for Yuma Myotis (Myotis yumanensis), Californian Myotis (M. californicus), Long-eared Myotis (M. evotis), Silver-haired Bat (Lasionycteris noctivagans) and Eastern Red Bat (Lasiurus borealis) from this region. We also captured 2 Long-eared Myotis in northwestern BC. Additionally, our surveys provided range extensions of Northern Myotis (M. septentrionalis), Long-legged Myotis (M. volans), and Hoary Bat (Lasiurus cinereus). Finally, by deploying bat detectors in late autumn, and in some cases throughout the winter, we provide data about seasonal patterns for bat activity in some locations, revealing that bats in northwestern BC may be active as late as 29 October and emerge as early as 30 March, a pattern similar to that observed in southern BC. By combining data from several disparate surveys, conducted for different reasons by different researchers, we were able to provide a fuller picture of the bat fauna of this vast region. Our data provides further evidence that the bat fauna of northwestern Canada is richer than previously documented.","PeriodicalId":142406,"journal":{"name":"Northwestern Naturalist","volume":"19 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131633986","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: 10.1898/1051-1733-103.1.1
N. D. Reynolds, E. Holman, S. Bergh, Nicholle R Stephens, Erik R White, Stuart J Freitas, James M. Wainwright
Abstract The powerful volcanic eruption of Mount St. Helens in 1980 is commonly reported to have killed large numbers of wildlife species, including near-extirpation of the local Mountain Goat (Oreamnos americanus) population. In the decade after 2000 we increasingly received reports of goat sightings around Mount St. Helens, including nannies with kids in 2007. By 2011, we estimated 15 to 25 goats were present on the landscape. In 2014, we initiated 2 lines of research. The first was a review of historic records to document pre-eruption goat populations. The second was the establishment of an annual minimum population-size survey using simple ground-count methods. In 2015, we revised our methods, and our results between 2015 and 2020 show a general growth trend of minimum population size from 152 goats in 2015 to 200 in 2020, with a peak of 240 goats observed in 2019. In 2017 and 2020, we paired ground counts with aerial surveys (with sighting correction) to better estimate population size, and observed 246 goats (245.9, 90% CI = 232.3–260.4) in 2017 and 252 (251.7, 90% CI = 233.2–270.1) in 2020. Our 2020 aerial estimate of ∼252 goats is a population 5 times (and possibly 10 times) the size of the 20–50 Mountain Goats we speculate were present in the same landscape prior to the 1980 eruption landscape, and reveals a substantial local recovery of the species.
据报道，1980年圣海伦斯火山的强烈火山喷发导致大量野生动物死亡，包括当地山羊(Oreamnos americanus)种群几乎灭绝。在2000年之后的十年里，我们越来越多地收到在圣海伦山附近看到山羊的报告，包括2007年带孩子的保姆。到2011年，我们估计这片土地上有15到25只山羊。2014年，我们启动了两条研究线。首先是对历史记录的回顾，以记录火山爆发前的山羊数量。第二是使用简单的地面计数方法建立年度最小人口规模调查。2015年，我们对方法进行了修正，结果显示2015 - 2020年的最小种群规模总体呈增长趋势，从2015年的152只增加到2020年的200只，2019年达到240只的峰值。在2017年和2020年，为了更好地估计种群规模，我们将地面计数与空中调查(有目视校正)配对，2017年观察到246只山羊(245.9只，90% CI = 232.3-260.4)， 2020年观察到252只山羊(251.7只，90% CI = 233.2-270.1)。我们在2020年对~ 252只山羊的空中估计是我们推测在1980年火山喷发之前在同一景观中存在的20-50只山山羊的5倍(可能是10倍)，并揭示了该物种在当地的大量恢复。
{"title":"MOUNTAIN GOAT (OREAMNOS AMERICANUS) POPULATION RECOVERY AT POST-ERUPTION MOUNT ST. HELENS (LAWETLAT'ɬ A), WASHINGTON","authors":"N. D. Reynolds, E. Holman, S. Bergh, Nicholle R Stephens, Erik R White, Stuart J Freitas, James M. Wainwright","doi":"10.1898/1051-1733-103.1.1","DOIUrl":"https://doi.org/10.1898/1051-1733-103.1.1","url":null,"abstract":"Abstract The powerful volcanic eruption of Mount St. Helens in 1980 is commonly reported to have killed large numbers of wildlife species, including near-extirpation of the local Mountain Goat (Oreamnos americanus) population. In the decade after 2000 we increasingly received reports of goat sightings around Mount St. Helens, including nannies with kids in 2007. By 2011, we estimated 15 to 25 goats were present on the landscape. In 2014, we initiated 2 lines of research. The first was a review of historic records to document pre-eruption goat populations. The second was the establishment of an annual minimum population-size survey using simple ground-count methods. In 2015, we revised our methods, and our results between 2015 and 2020 show a general growth trend of minimum population size from 152 goats in 2015 to 200 in 2020, with a peak of 240 goats observed in 2019. In 2017 and 2020, we paired ground counts with aerial surveys (with sighting correction) to better estimate population size, and observed 246 goats (245.9, 90% CI = 232.3–260.4) in 2017 and 252 (251.7, 90% CI = 233.2–270.1) in 2020. Our 2020 aerial estimate of ∼252 goats is a population 5 times (and possibly 10 times) the size of the 20–50 Mountain Goats we speculate were present in the same landscape prior to the 1980 eruption landscape, and reveals a substantial local recovery of the species.","PeriodicalId":142406,"journal":{"name":"Northwestern Naturalist","volume":"34 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":"116664735","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}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：