Search

Correct material identification is considered essential when documenting museum objects. This study examines the morphology of mammal hair and records the geographical use of common species in Inuit fur clothing collected by the National Museum of Denmark (NMD) from c. 1830–1940 in the Bering Strait region, Alaska, Arctic Canada, and Greenland. Through hair microscopy, the purpose is to test whether original identifications are correct to assess the origin of unique Inuit garments. By means of transmitted light microscopy (TLM) of stained, 1 µm thick cross-sectioned hairs and undyed, longitudinally mounted hairs, the research reveals that specific morphological structures are characteristic of the common native reindeer/caribou, musk ox, members of the seal family, domestic dog, wolf, Arctic fox, polar bear, and wolverine. Rarer animals (hare, lynx, otter, etc.) are not part of this study because of limitations in the collection. Hairs from seal species are difficult to distinguish from one another. Hairs from dog and wolf are distinguishable but have relatively similar morphology. Therefore, to confirm identification, supplementary analyses are required. The hair microscopy technique was used on 49 garments in NMD's collections, and the results were compared to the original macroscopic species identification. The study revealed that the latter method is often erroneous when it comes to dog/wolf and wolverine fur. [ABSTRACT FROM AUTHOR]

Egg predation is the primary cause of nest failure for tundra nesting birds. Taverner's Cackling Geese (Branta hutchinsii taverneri) breeding on the North Slope of Alaska have increased approximately 5-fold over the last 25 years and are now one of the most encountered waterbird species breeding at our study site on the coastal plain of Arctic National Wildlife Refuge. This rapid population growth may offer a new food resource for egg predators, impacting predator populations, which in turn could have cascading effects for other tundra nesting bird species, many of which are declining. To determine how the population growth of geese may affect the nest-predator community, and to establish a baseline of predators as the area is impacted by climate change and development, we used digital time-lapse cameras to record predation events at Cackling Goose nests. We determined fate for 52 nests in 2017, 2019, and 2021, of which 20 were depredated. The most frequent predator differed each year. Red foxes (Vulpes vulpes) were responsible for 89% of depredations in 2017 and wolverines (Gulo gulo) for 67% in 2019, and those species only depredated nests in those single years. In contrast, Arctic foxes (Vulpes lagopus) were responsible for nest failure in all years, but did not exceed 40% of total depredations in any year. Golden Eagles (Aquila chrysaetos) were an unexpected egg predator, depredating 2 nests. Our results were notably different than work on other Arctic goose species, where Arctic foxes were the primary predator. The inter-annual variability of egg predators at this Arctic Refuge study site provides insights into complex predator–prey interactions on the Arctic Coastal Plain. La depredación de huevos es la causa primaria del fracaso de nido para aves que anidan en la tundra. El ganso Branta hutchinsii taverneri, que se reproduce en la pendiente Norte de Alaska ha quintuplicado su presencia en los últimos 25 años y ahora es una de las especies acuáticas en reproducción más observadas en nuestro sitio de estudio en la planicie costera del Arctic National Wildlife Refuge. Este crecimiento poblacional acelerado puede ofrecer una nueva fuente de alimentación para depredadores de huevos, impactando las poblaciones de depredadores, que podría tener efectos en cascada en otras especies de aves que anidan en la tundra, muchas en declive. Para determinar cómo el crecimiento poblacional de gansos puede afectar la comunidad de depredadores de nidos y establecer una línea base de depredadores en un área que es impactada por el cambio climático y el desarrollo, usamos cámaras digitales con temporizador automático para registrar eventos de depredación en nidos de ganso Branta hutchinsii. Determinamos el destino de 52 nidos en 2017, 2019 y 2021, de los cuales 20 fueron depredados. El depredador más frecuente varió cada año. Los zorros rojos (Vulpes vulpes) fueron responsables del 89% de las depredaciones en el 2017, mientras que los glotones (Gulo gulo) lo fueron del 67% en el 2019, y esas especies solo depredaron nidos en esos años. En contraste, el zorro artico (Vulpes lagopus) fue responsable de fracaso de anidación durante todos los años, pero su cuota de depredación no excedió el 40% en ninguno de los años. El águila real (Aquila chrysaetos) fue un depredador inesperado, depredando 2 nidos. Nuestros resultados fueron notablemente diferentes que otros estudios con otras especies de gansos silvestres del Artico, donde los zorros articos fueron los depredadores primarios. La variación interanual de depredadores de huevos en este sitio de estudio en el Refugio Artico proporciona información en interacciones complejas depredador-presa en la Planicie Costera Artica. Palabras clave: cámaras para vida silvestre, depredador de huevos, ganso Branta hutchinsii taverneri, gansos de anidación artica, Planicie Costera Artica. [ABSTRACT FROM AUTHOR]

The Arctic Coastal Plain is one of the most important avian breeding grounds in the world; however, many species are in decline. Arctic‐breeding birds contend with short breeding seasons, harsh climatic conditions, and now, rapidly changing, variable, and unpredictable environmental conditions caused by climate change. Additionally, those breeding in industrial areas may be impacted by human activities. It is difficult to separate the impacts of industrial development and climate change; however, long‐term datasets can help show patterns over time. We evaluated factors influencing reproductive parameters of breeding birds at Prudhoe Bay, Alaska, 2003–2019, by monitoring 1265 shorebird nests, 378 passerine nests, and 231 waterfowl nests. We found that nest survival decreased significantly nearer high‐use infrastructure for all guilds. Temporally, passerine nest survival declined across the 17 years of the study, while there was no significant evidence of change in their nest density. Shorebird nest survival did not vary significantly across years, nor did nest density. Waterfowl nest density increased over the course of the study, but we could not estimate nest survival in all years. Egg predator populations varied across time; numbers of gulls and ravens increased in the oilfields 2003–2019, while Arctic fox decreased, and jaeger numbers did not vary significantly. Long‐term datasets are rare in the Arctic, but they are crucial for understanding impacts to breeding birds from both climate change and increasing anthropogenic activities. We show that nest survival was lower for birds nesting closer to high‐use infrastructure in Arctic Alaska, which was not detected in earlier, shorter‐term studies. Additionally, we show that Lapland longspur nest survival decreased across time, in concert with continent‐wide declines in many passerine species. The urgency to understand these relationships cannot be expressed strongly enough, given change is continuing to happen and the potential impacts are large. [ABSTRACT FROM AUTHOR]

Museum skull specimens from 224 Arctic foxes (Vulpes lagopus) were examined macroscopically using an established protocol for examination of mammalian skull specimens. Foxes were collected from coastal and island regions of Alaska, USA, except for two individuals. Collection years ranged from 1931 to 2016 with most specimens collected during the 1950s and 1960s. The study population comprised more females (n = 134, 59.8%) than males (n = 83, 37.0%) and individuals of unknown sex (n = 7, 3.1%). There were 108 (48.2%) young adults, 115 (51.3%) adults, and one (0.4%) individual of unknown age. A total of 8,891 teeth (94.5%) were available for examination. The most common types of pathology observed were periodontitis (n = 222, 99.1%), dental fractures (n = 175, 78.1%) and attrition/abrasion (n = 198, 88.4%). Periapical lesions (n = 12, 5.3%), temporomandibular joint (TMJ) osteoarthritis (n = 3, 1.3%) and root number variation (n = 5, 2.2%) were less common. Enamel hypoplasia was noted in eight foxes (3.6%), all of which were discovered on St. Matthew Island, Alaska, in 1963. As in other canid species, periodontitis, attrition/abrasion and tooth fractures are common in the Arctic fox, while TMJ pathology is rare. Loss of tooth crown substance probably reflects the influence of diet, interspecific and conspecific aggression and oral trauma due to trapping and hunting methods. The high prevalence of periodontitis is probably also due to the combined effects of diet, genetics and host immune reaction to oral bacteria. [ABSTRACT FROM AUTHOR]

Arctic foxes are significant predators of pups in lairs in much of the geographic range of ringed seals (Smith, [25]; Smith et al., [29]). Arctic fox predation of ringed seals occurs on pups at lairs in spring (Smith, [25], [26]; Smith & Lydersen, [30]; Stirling, [32]; Stirling & Archibald, [33]). During unusual warm temperatures and rain events on southeast Baffin Island in April 1972, lairs collapsed prematurely and pups exposed in their subnivean lairs experienced elevated rates of bear and fox predation (Stirling & Smith, [35]). During spring, polar bear predation of ringed seals in the fast ice is focused on pups in lairs (Smith, [25], [26]; Smith & Lydersen, [30]; Stirling, [32]; Stirling & Archibald, [33]). [Extracted from the article]

Colonial nesting is associated with numerous costs and benefits that may either increase or decrease fitness of individuals in colonies. Fitness can vary as a function of the location within colonies and individuals may attempt to improve their fitness by changing their nesting location between years. We used a 24 year data set on nest locations within the Tutakoke River Black Brant (Branta bernicla nigricans) colony on the Yukon-Kuskokwim Delta in western Alaska and multi-state capture-mark-recapture models to study the movement of individuals between 2 spatial strata in the colony separated by the Tutakoke River. We found that individuals nesting in a stratum that experienced higher levels of predation by arctic foxes (Vulpes lagopus) were 3 times more likely to move to the other stratum than vice versa, despite slightly higher risk of tidal flooding in the second stratum. These results suggest that Black Brant changed nest locations in an attempt to maximize reproductive fitness and they are consistent with a long-term shift in nest density over the course of the study. La anidación en colonias está asociada con numerosos costos y beneficios que pueden aumentar o reducir la sobrevivencia de individuos en colonias. La sobrevivencia puede variar en función de la localización del nido al interior de la colonia y los individuos pueden intentar mejoras en su sobrevivencia mediante el cambio de sitio de anidación en diferentes años. Usamos un juego de datos de localización de nidos de 24 años en la colonia de gansos Branta bernicla nigricans del río Tutakoke en el delta del Yukon-Kuskokwin en el occidente de Alaska y modelos multiestado de capura-marcado-recaptura para estudiar el movimiento de individuos entre 2 estratos espaciales en la colonia separados por el río Tutakoke. Encontramos que los individuos anidando en un estrato que experimentó mayores niveles de depredación por zorros del Ártico (Vulpes lagopus) tenían una probabilidad 3 veces mayor de moverse al otro estrato que viceversa, aún pese a un ligeramente mayor riesgo de inundación por mareas en el segundo estrato. Estos resultados sugieren que estos gansos cambiaron la ubicación de sus nidos para intentar maximizar su sobrevivencia reproductiva y son consistentes con un cambio a largo plazo en la densidad de nidos a largo plazo a lo largo del periodo de este estudio. Palabras clave: ártico, colonialidad, dispersión, ganso, información privada, información pública, multi-estado. [ABSTRACT FROM AUTHOR]

We evaluated skeletal remains of five blue arctic foxes from St. Paul Island, Pribilof Islands, Alaska. All five had been found dead. Cleared skeletal remains were examined visually and by magnification or backlighting where necessary. Pathological features were described and photographed. Results suggested that more than one disorder may have occurred in these foxes, with primary observations being demineralizing and/or proliferation. Most prominently affected were the skull, maxillae, mandibles, pelvis, long bones, and major diarthrodial joints. It was critically important to recognize certain other pathological features that can be observed on many or most fox skeletal remains but are unlikely to relate to conditions that demineralize bone or cause overt bone loss, multifocal loss of joint architecture, or severe multifocal periarticular boney proliferation. The differential diagnosis of canid skeletal demineralizing includes primary and secondary (nutritional or renal) hyperparathyroidism. Boney proliferation has a wider differential spectrum that can include hypervitaminosis A, osteomyelitis, abnormalities related to inbreeding, and environmental toxicosis. In our view, given the lack of soft tissue for histological evaluation and biochemical analysis, a well‐considered differential diagnosis is an appropriate scientific point of conclusion. In the many similar circumstances that would require additional studies for valid definitive diagnosis during life, investigators should review relevant literature and consider the value of well‐structured differential diagnosis, as contrasted with more speculative definitive diagnoses. [ABSTRACT FROM AUTHOR]

Populations are exposed to different types and strains of pathogens across heterogeneous landscapes, where local interactions between host and pathogen may present reciprocal selective forces leading to correlated patterns of spatial genetic structure. Understanding these coevolutionary patterns provides insight into mechanisms of disease spread and maintenance. Arctic rabies (AR) is a lethal disease with viral variants that occupy distinct geographic distributions across North America and Europe. Red fox (Vulpes vulpes) are a highly susceptible AR host, whose range overlaps both geographically distinct AR strains and regions where AR is absent. It is unclear if genetic structure exists among red fox populations relative to the presence/absence of AR or the spatial distribution of AR variants. Acquiring these data may enhance our understanding of the role of red fox in AR maintenance/spread and inform disease control strategies. Using a genotyping-by-sequencing assay targeting 116 genomic regions of immunogenetic relevance, we screened for sequence variation among red fox populations from Alaska and an outgroup from Ontario, including areas with different AR variants, and regions where the disease was absent. Presumed neutral SNP data from the assay found negligible levels of neutral genetic structure among Alaskan populations. The immunogenetically-associated data identified 30 outlier SNPs supporting weak to moderate genetic structure between regions with and without AR in Alaska. The outliers included SNPs with the potential to cause missense mutations within several toll-like receptor genes that have been associated with AR outcome. In contrast, there was a lack of genetic structure between regions with different AR variants. Combined, we interpret these data to suggest red fox populations respond differently to the presence of AR, but not AR variants. This research increases our understanding of AR dynamics in the Arctic, where host/disease patterns are undergoing flux in a rapidly changing Arctic landscape, including the continued northward expansion of red fox into regions previously predominated by the arctic fox (Vulpes lagopus). [ABSTRACT FROM AUTHOR]

Rabies spreads in both Arctic (Vulpes lagopus) and red foxes (Vulpes vulpes) throughout the Canadian Arctic but limited wildlife disease surveillance, due to the extensive landmass of the Canadian north and its small widely scattered human population, undermines our knowledge of disease transmission patterns. This study has explored genetic population structure in both the rabies virus and its fox hosts to better understand factors that impact rabies spread. Phylogenetic analysis of 278 samples of the Arctic lineage of rabies virus recovered over 40 years identified four sub-lineages, A1 to A4. The A1 lineage has been restricted to southern regions of the Canadian province of Ontario. The A2 lineage, which predominates in Siberia, has also spread to northern Alaska while the A4 lineage was recovered from southern Alaska only. The A3 sub-lineage, which was also found in northern Alaska, has been responsible for virtually all cases across northern Canada and Greenland, where it further differentiated into 18 groups which have systematically evolved from a common predecessor since 1975. In areas of Arctic and red fox sympatry, viral groups appear to circulate in both hosts, but both mitochondrial DNA control region sequences and 9-locus microsatellite genotypes revealed contrasting phylogeographic patterns for the two fox species. Among 157 Arctic foxes, 33 mitochondrial control region haplotypes were identified but little genetic structure differentiating localities was detected. Among 162 red foxes, 18 control region haplotypes delineated three groups which discriminated among the Churchill region of Manitoba, northern Quebec and Labrador populations, and the coastal Labrador locality of Cartwright. Microsatellite analyses demonstrated some genetic heterogeneity among sampling localities of Arctic foxes but no obvious pattern, while two or three clusters of red foxes suggested some admixture between the Churchill and Quebec-Labrador regions but uniqueness of the Cartwright group. The limited population structure of Arctic foxes is consistent with the rapid spread of rabies virus subtypes throughout the north, while red fox population substructure suggests that disease spread in this host moves most readily down certain independent corridors such as the northeastern coast of Canada and the central interior. Interestingly the evidence suggests that these red fox populations have limited capacity to maintain the virus over the long term, but they may contribute to viral persistence in areas of red and Arctic fox sympatry. [ABSTRACT FROM AUTHOR]

Many species of seabirds and waterfowl are predominantly colonial breeders, suggesting that colonial breeding is beneficial in some way. For Arctic nesting geese, colonial breeding may be an adaptive approach to minimize the risk of nest failure through predator swamping. Yet evidence for predator swamping is inconclusive. Species in low-lying coastal zones may have to manage tradeoffs between historical (e.g., predation) and increased frequency of other threats (e.g., coastal flooding associated with storm events). As the climate continues to change, coastal obligates will be subject to rising sea levels and an increase in extreme weather events, which could exacerbate the tradeoff between flooding and predation risk. We studied the effect of nest density on nest success in the colonial nesting Black Brant (Branta bernicla nigricans) on the Tutakoke River Colony in western Alaska and explored how density effects change during years of heavy Arctic fox (Alopex lagopus) predation and coastal flooding associated with storm events. We classified the colony as containing 2 strata that differed in elevation and vegetation, and were separated by the Tutakoke River. The stratum north of the Tutakoke River was 0.25 m lower in elevation and subject to periodic tidal flooding, while the southern stratum never flooded. Nest density positively affected brant nest success in years with high levels of fox predation. Nest success was greatest at the highest density during Normal years (low levels of fox predation and no flooding; northern stratum nest success 0.81 ± 0.01, southern stratum nest success 0.81 ± 0.01) and lowest in areas of low density during Fox years (northern stratum nest success 0.38 ± 0.01, southern stratum nest success 0.31 ± 0.01). Nest success was routinely higher during Normal years at all densities compared to Flood and Fox years. Our results support the hypothesis that colonial nesting, at least in tundra habitats, may have developed as a defense mechanism to swamp mammalian predators. [ABSTRACT FROM AUTHOR]

We compiled present-day observations and survey data of the avian and mammal fauna in the Islands of Four Mountains, Alaska, which primarily consist of marine-adapted species, to provide insight into the prehistoric fauna found in the archaeological record. We documented 63 bird species, mainly seabirds (67%). The majority (71%) of the estimated number of breeding birds are ledge nesters, predominately murres, and most (68%) spend the majority of their lives in the offshore environment. We lack good estimates for burrow and crevice nesters, which were impacted by and are still recovering from a period of arctic fox farming in the twentieth century. Marine mammals, predominately Steller sea lion, harbor seal, and sea otter, primarily use accessible land as haul-outs and are found in low numbers compared with the rest of the Aleutians. Red fox, the only land mammal, presently only reside on Chuginadak Island. While the present-day fauna is similar to the fauna recorded in the archaeological record, we found no indication of nesting by ancient murrelets and northern fulmars in the Island of Four Mountains, whereas both species were present in midden sites on Carlisle and Chuginadak Islands, with the possibility of prehistoric breeding colonies on Carlisle Island. [ABSTRACT FROM AUTHOR]

The direct and interactive effects of climate change on host species and infectious disease dynamics are likely to initially manifest\ at latitudinal extremes. As such, Alaska represents a region in the United States for introspection on climate change and disease. Rabies is enzootic among arctic foxes ( Vulpes lagopus) throughout the northern polar region. In Alaska, arctic and red foxes (Vulpes vulpes) are reservoirs for rabies, with most domestic animal and wildlife cases reported from northern and western coastal Alaska. Based on passive surveillance, a pronounced seasonal trend in rabid foxes occurs in Alaska, with a peak in winter and spring. This study describes climatic factors that may be associated with reported cyclic rabies occurrence. Based upon probabilistic modelling, a stronger seasonal effect in reported fox rabies cases appears at higher latitudes in Alaska, and rabies in arctic foxes appear disproportionately affected by climatic factors in comparison with red foxes. As temperatures continue a warming trend, a decrease in reported rabid arctic foxes may be expected. The overall epidemiology of rabies in Alaska is likely to shift to increased viral transmission among red foxes as the primary reservoir in the region. Information on fox and lemming demographics, in addition to enhanced rabies surveillance among foxes at finer geographic scales, will be critical to develop more comprehensive models for rabies virus transmission in the region. [ABSTRACT FROM AUTHOR]

We used data from aerial surveys (1992-2010) of >100,000 km2 and ground surveys (1998-2004) of >150 km2 to estimate the density and abundance of birds on the North Slope of Alaska (U.S.A.). In the ground surveys, we used double sampling to estimate detection ratios. We used the aerial survey data to compare densities of birds and Arctic fox (Vulpes lagopus), the major nest predator of birds, on the North Slope, in Prudhoe Bay, and in nearby areas. We partitioned the Prudhoe Bay oil field into 2 × 2 km plots and determined the relation between density of aquatic birds and density of roads, buildings, and other infrastructure in these plots. Abundance and density (birds per square kilometer) of 3 groups of aquatic birds-waterfowl, loons, and grebes; shorebirds; and gulls, terns, and jaegers-were highest in the National Petroleum Reserve-Alaska (NPRA) and lowest in the Arctic National Wildlife Refuge. Six other major wetlands occur in the Arctic regions of Canada and Russia, but the largest population of aquatic birds was in the NPRA. Aquatic birds were concentrated in the northern part of the NPRA. For example, an area that covered 18% of the NPRA included 53% of its aquatic birds. The aerial surveys showed that bird density was not lower and fox density was not higher in Prudhoe Bay than in surrounding areas. Density of infrastructure did not significantly affect bird density for any group of species. Our results establish that the NPRA is one of the most important areas for aquatic birds in the Arctic. Our results and those of others also indicate that oil production, as practiced in Prudhoe Bay, does not necessarily lead to substantial declines in bird density or productivity in or near the developed areas. Prioridades para la Conservación de Aves en el Norte de Alaska [ABSTRACT FROM AUTHOR]

The article presents a study to investigate Toxascaris leonina in the northern vole (Microtus oeconomus), following definition of the cycle of Echinococcus multilocularis, the cause of alveolar echinococcosis on St. Lawrence Island, Alaska. Findings suggest that the larvae tended to migrate anteriad in voles and repeated exposure intensified the immune response, preventing completing migration to the musculature. Vole-to-vole transmission of third-stage larvae was confirmed in 11 of 29 trials.

The extensive use of sea-ice by three arctic foxes ( Alopex lagopus) in northern Alaska was documented using satellite telemetry during the winter of 2005–2006. Here we present the first detailed data on movements of individual foxes while on the sea-ice. Two juvenile males and one juvenile female traveled long distances (904, 1,096, and 2,757 km) and remained on the sea-ice for extended periods of time (76, 120, and 156 days). Average distances traveled per day ranged from 7.5 to 17.6 km and foxes achieved maximum rates of travel of up to 61 km/day. These findings verify the use of sea-ice by arctic foxes and raise concerns that the diminishing arctic ice cover may negatively impact populations by limiting access to marine food sources. [ABSTRACT FROM AUTHOR]

Deals with a study which determined the diet, age, sex, and body condition of arctic foxes (Alopex lagopus) carcasses found in western Alaska from 1986-1991. Relation of their predation activities during winter and spring to their stomach contents; Results; Discussion.