ABSTRACT. Bats in temperate regions are relatively well studied, yet little research has focused on the northern limit of their distribution. We document the northwestern extent of bats in North America using museum holdings, literature records, and field research in Alaska. Six bat species are confirmed from Alaska: Myotis lucifugus, M. keenii, M. californicus, M. volans, Lasionycteris noctivagans, and Eptesicus fuscus. M. lucifugus occurs throughout much of Alaska south of the Arctic Circle, whereas four other species occur only in Southeast Alaska. Climate, roost availability, extent of forested habitat, geographic barriers, length of night, and prey abundance appear to influence the distribution of bats in Alaska, although the relative contribution of these factors is unknown.Key words: Alaska, latitude, bats, distribution, limiting factors, Myotis, Lasionycteris, Eptesicus RÉSUMÉ. Si, dans les régions tempérées, les chauves-souris ont fait l'objet d'études relativement approfondies, on a par contre mené peu de recherches sur la limite septentrionale de leur répartition. Cet article décrit l'extension nord-ouest de l'aire des chauves-souris en Amérique du Nord en faisant appel à des pièces muséologiques, des documents comportant des relevés, et des recherches sur le terrain en Alaska. On confirme que six espèces de chauves-souris se retrouvent en Alaska: Myotis lucifugus, M. keenii, M. californicus, M. volans, Lasionycteris noctivagans et Eptesicus fuscus. M. lucifugus est répandue presque partout en Alaska au sud du cercle polaire, tandis que quatre autres espèces ne se retrouvent que dans le sud-est de l'Alaska. Il semble que le climat, la disponibilité des sites de reproduction, l'étendue de l'habitat forestier, les barrières géographiques, la longueur de la nuit et l'abondance des proies influencent la distribution des chauves-souris en Alaska, bien qu'on ne connaisse pas la contribution relative de ces facteurs.
JSTOR is a not-for-profit service that helps scholars, researchers, and students discover, use, and build upon a wide range of content in a trusted digital archive. We use information technology and tools to increase productivity and facilitate new forms of scholarship. For more information about JSTOR, please contact support@jstor.org.. American Society of Mammalogists is collaborating with JSTOR to digitize, preserve and extend access to Journal of Mammalogy.Foods of Myotis lucifugus at Salcha, near Fairbanks, Alaska, at a time of 24-h daylight were: small moths (71.1% by volume), spiders (16.8%), and mosquitos (1.8%).
No abstract
St. Matthew Island (60Њ 24Ј N, 172Њ 42Ј W) and its small nearby satellites, Hall Island and Pinnacle Rock, are isolated in the northcentral Bering Sea. This infrequently visited location occupies a geographic position with a deep Bering Land Bridge history and is in an area of interdigitation of the Old World, New World, and Beringian avifaunas. It is known for its three Beringian endemics, a bird (McKay's Bunting, Plectrophenax hyperboreus), a small mammal, and a plant. This level of endemism is striking for a high-latitude island. The only previous summary of the avifauna of St. Matthew island (Hanna 1917) included 37 species. Our report considers more than 125 species and synthesizes data on presence and absence, abundance, and phenology. Because visits have been infrequent and concentrated during summer, our understanding of migration in this region remains poor, but the area is clearly affected by both the Old and New world migration systems. There is sufficient evidence to show that some profound changes among the island's breeding birds have occurred during the past century. In particular, the breeding range of Glaucous-winged Gulls (Larus glaucescens) has been extended north to include St. Matthew, a change that is correlated with a northward shift in the extent of sea ice (Maslanik et al. 1996). King and Common eiders (Somateria spectabilis and S. mollissima) also have shown substantial changes in summer abundance. Other changes in the summer avifauna (e.g., among shorebirds) may reflect the dynamics of edge-of-range phenomena. Because of its central position in a region undergoing profound climate change and its demonstrated track record in showing avifaunal shifts, St. Matthew Island may represent an important bellwether for monitoring the biological effects of further climate change in the northern Bering Sea.
As industrial development increases in the range of barren-ground caribou (Rangifer tarandus granti) across the warming Arctic, the need to understand the responses of caribou to development and to assess the effectiveness of mitigation measures increase accordingly. The Central Arctic Herd (CAH) of caribou ranges across northern Alaska, USA, and the herd's summer range includes the Prudhoe Bay and Kuparuk oilfields, where the herd has been exposed to oil development for >4 decades. We used location data from global positioning system (GPS) radio-collars deployed on female CAH caribou for 106 collaryears, recording locations every 2 hours during 2008-2019, to examine caribou distribution and movements during 7 different seasons of the year in relation to infrastructure in the Kuparuk oilfield, which is characterized by more design improvements and mitigation measures than the older Prudhoe Bay oilfield. We examined movement metrics in terms of distance to gravel infrastructure (roads and pads) and time before and after movements across infrastructure (crossings). We also employed integrated step-selection analysis to compare caribou movements with random movements. Caribou distribution was influenced by insect activity, distance to coast, landcover, and terrain ruggedness, and we found large seasonal differences in caribou responses to infrastructure. Consistent with previous research findings, avoidance of areas near roads and pads was strongest during the calving season and some caribou used roads and pads as insectrelief habitat when oestrid flies (warble fly [Hypoderma tarandi] and nose bot fly [Cephenemyia trompe]) were active. Caribou moved through the Kuparuk oilfield repeatedly during summer, averaging >2 road or pad crossings a day when harassment by mosquitoes (Aedes [Ochlerotatus] spp.) and oestrid flies were the predominant factors influencing caribou movements. Caribou moved faster while crossing roads and pads but showed little pattern in speed or turn angle with distance to roads and pads. These results demonstrate that the effects of petroleum development on a caribou herd with long-term exposure to industrial activity vary widely by season. Maternal caribou avoid active roads and pads during calving, but the incorporation of appropriate mitigation measures in oilfield design allows caribou to move through the Kuparuk oilfield during other snow-free seasons.
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