Arctic Fauna Research Articles

Measuring the emissivity of mammal pelage

Infrared thermography is an increasingly used technology in veterinary science and in mammal physiology. However, its employment as a quantitative method to accurately determine mammal surface temperatures requires knowledge of the emissivity of that individual’s pelage. To-date, few researchers have measured emissivity of their study animal’s pelage, or determined the relationship between fur metrics and emissivity. Instead, studies have relied on historic values generated from a single study on arctic fauna. Therefore, this study aimed to determine pelage emissivity for a range of mammal species and to establish the putative correlation between emissivity and fur metrics. Emissivity was measured at different sites of the body for 22 species. In addition, hair length and hair diameter were measured from hairs collected at the same sites that emissivity was measured. The mean pelage emissivity of sampled specimens was 0.86 ± 0.01, which was lower than the range (0.95–1.00) reported previously. Emissivity was neither related to taxonomy nor to hair metrics but may be related to other factors not measured in this study. Contrary to common practice, a single (0.98) or a narrow range (0.95–1.00) of emissivity values is unlikely to be appropriate for obtaining accurate surface temperature readings in quantitative IRT studies on mammals.

Qualitative risk assessment of impact of Toxoplasma gondii on health of beluga whales, Delphinapterus leucas from the Eastern Beaufort Sea, Northwest Territories

In recent years, the protozoan parasite Toxoplasma gondii has increasingly been recognized in Arctic fauna, including beluga whales (Delphinapterus leucas) in the Eastern Beaufort Sea (EBS), Northw...

Spatiotemporal snowmelt patterns within a high Arctic landscape, with implications for flora and fauna

ABSTRACT Snow conditions are important drivers of the distribution and phenology of Arctic flora and fauna, but the extent and effects of local variation in snowmelt are still inadequately studied. We analyze snowmelt patterns within the Zackenberg valley in northeast Greenland. Drawing on landscape-level snowmelt dates and meteorological data from a central climate station, we model snowmelt trends during 1998–2014. We then use time-lapse photographs to examine consistency in spatiotemporal snowmelt patterns during 2006–2014. Finally, we use monitoring data on arthropods and plants for 1998–2014 to investigate how snowmelt date affects the phenology of Arctic organisms. Despite large interannual variation in snowmelt timing, we find consistency in the relative order of snowmelt among sites within the landscape. With a slight overall advancement in snowmelt during the study period, early melting locations have advanced more than late-melting ones. Individual organism groups differ greatly in how their phenology shifts with snowmelt, with much variance attributable to variation in life history and diet. Overall, we note that local variation in snowmelt patterns may drive important ecological processes, and that more attention should be paid to variability within landscapes. Areas optimal for a given taxon vary between years, thereby creating spatial structure in a seemingly uniform landscape.

Extreme spring conditions in the Arctic delay spring phenology of long-distance migratory songbirds

Arctic regions are warming rapidly, with extreme weather events increasing in frequency, duration, and intensity just as in other regions. Many studies have focused on how shifting seasonality in environmental conditions affects vegetation phenology, while far fewer have examined how the breeding phenology of arctic fauna responds. We studied two species of long-distance migratory songbirds, Lapland longspurs, Calcarius lapponicus, and white-crowned sparrows, Zonotrichia leucophrys gambelii, across five consecutive breeding seasons in northern Alaskan tundra. We aimed to understand how spring environmental conditions affected breeding cycle phenology, including the timing of arrival on breeding grounds, territory establishment, and clutch initiation. Spring temperatures, precipitation, and snow-free dates differed significantly among years, with 2013 characterized by unusually late snow cover. In response, we found a significant delay in breeding-cycle phenology for both study species in 2013 relative to other study years: the first bird observed was delayed by 6-10days, with mean arrival by 3-6days, territory establishment by 6-13days, and clutch initiation by 4-10days. Further, snow cover, temperature, and precipitation during the territory establishment period were important predictors of clutch initiation dates for both species. These findings suggest that Arctic-breeding passerine communities may have the flexibility required to adjust breeding phenology in response to the increasingly extreme and unpredictable environmental conditions-although future generations may encounter conditions that exceed their current range of phenological flexibility.

Benthic Crustacea and Mollusca distribution in Arctic fjord – case study of patterns in Hornsund, Svalbard

Summary We present the results of species distribution modeling conducted on macrobenthic occurrence data collected between 2002 and 2014 in Arctic fjord – Hornsund. We focus on species from Mollusca and Crustacea taxa. This study investigates the importance of individual environmental factors for benthic species distribution, with a special emphasis on bottom water temperature. It aims to verify the hypothesis that the distribution of species is controlled by low water temperatures in the fjord and that the inner basins of the fjord serve as potential refugia for Arctic species threatened by the climate change-related intensification of warmer water inflows. Our results confirm the importance of bottom water temperature in regulating the presence of benthic fauna in the Hornsund fjord. The distribution of studied species is clearly related to specific water mass – colder ( 1°C); and the preferred temperature regimes seem to be species specific and unrelated to analyzed groups. This study supports the notion that inner basins of the Hornsund fjord are potential refugia for cold water Arctic fauna, while the outer and central basins provide suitable habitats for fauna that prefer warmer waters.

Genetic profiling links changing sea-ice to shifting beluga whale migration patterns

There is increasing concern over how Arctic fauna will adapt to climate related changes in sea-ice. We used long-term sighting and genetic data on beluga whales (Delphinapterus leucas) in conjunction with multi-decadal patterns of sea-ice in the Pacific Arctic to investigate the influence of sea-ice on spring migration and summer residency patterns. Substantial variations in sea-ice conditions were detected across seasons, years and sub-regions, revealing ice–ocean dynamics more complex than Arctic-wide trends suggest. This variation contrasted with a highly consistent pattern of migration and residency by several populations, indicating that belugas can accommodate widely varying sea-ice conditions to perpetuate philopatry to coastal migration destinations. However, a number of anomalous migration and residency events were detected and coincided with anomalous ice years, and in one case with an increase in killer whale (Orcinus orca) sightings and reported predation on beluga whales. The behavioural shifts were likely driven by changing sea-ice and associated changes in resource dispersion and predation risk. Continued reductions in sea-ice may result in increased predation at key aggregation areas and shifts in beluga whale behaviour with implications for population viability, ecosystem structure and the subsistence cultures that rely on them.

Multi-scale taxonomic diversity of marine harpacticoids: Does it differ at high and low latitudes?

We used a comprehensive database comprising a worldwide distribution of 3074 species of marine benthic harpacticoid copepods to explore Arctic (north to 60°N) and tropical (32°S–32°N) faunas. In addition to species and genus richness, we compared the number of observed genera with that expected from a neutral model (random samples from a corresponding species pool). This analysis was performed at three scales: global (Arctic vs. tropics), regional (three Arctic and four tropical regions) and local (78 assemblages). Overall, more than three times as many species and twice as many genera were found in the tropics compared with the Arctic. The number of taxa restricted to a given zone (“climatic endemics”) was much higher in the tropics. All zonal and regional faunas had significantly fewer genera than expected (phylogenetic clumping), but this depletion was more substantial in the Arctic. Phylogenetically, younger families included fewer widely distributed genera and were more species rich at low latitudes, in conformity with the “Out of tropics” hypothesis. At the local level, there was no latitudinal difference in the average species richness. However, the Arctic assemblages comprised considerably fewer genera than expected, whereas phylogenetic diversity in the tropics only slightly deviated from the expected level. Thus, compared with the tropics, the Arctic harpacticoid fauna shows lower global but similar local species diversity and a lower level of endemicity. The Arctic fauna also shows stronger phylogenetic clumping at all scales, indicating multiple underlying processes of species filtering (evolutionary and ecological).

The palaeobiology of high latitude birds from the early Eocene greenhouse of Ellesmere Island, Arctic Canada.

Fossils attributable to the extinct waterfowl clade Presbyornithidae and the large flightless Gastornithidae from the early Eocene (~52–53 Ma) of Ellesmere Island, in northernmost Canada are the oldest Cenozoic avian fossils from the Arctic. Except for its slightly larger size, the Arctic presbyornithid humerus is not distinguishable from fossils of Presbyornis pervetus from the western United States, and the Gastornis phalanx is within the known size range of mid-latitude individuals. The occurrence of Presbyornis above the Arctic Circle in the Eocene could be the result of annual migration like that of its living duck and geese relatives, or it may have been a year-round resident similar to some Eocene mammals on Ellesmere and some extant species of sea ducks. Gastornis, along with some of the mammalian and reptilian members of the Eocene Arctic fauna, likely over-wintered in the Arctic. Despite the milder (above freezing) Eocene climate on Ellesmere Island, prolonged periods of darkness occurred during the winter. Presence of these extinct birds at both mid and high latitudes on the northern continents provides evidence that future increases in climatic warming (closer to Eocene levels) could lead to the establishment of new migratory or resident populations within the Arctic Circle.

Arctic biodiversity: from science to policy

In 2013, the Conservation of Arctic Flora and Fauna (CAFF) and the biodiversity working group of the Arctic Council released the Arctic Biodiversity Assessment (ABA), a report containing the best available science informed by traditional ecological knowledge on the status and trends of Arctic biodiversity and accompanying policy recommendations (ABA 2013a) for biodiversity conservation. This text provides a summary of the ABA recommendations and a discussion on their path from key scientific findings to policy and subsequent actions.

The effects of changing climate on faunal depth distributions determine winners and losers.

Changing climate is predicted to impact all depths of the global oceans, yet projections of range shifts in marine faunal distributions in response to changing climate seldom evaluate potential shifts in depth distribution. Marine ectotherms' thermal tolerance is limited by their ability to maintain aerobic metabolism (oxygen- and capacity-limited tolerance), and is functionally associated with their hypoxia tolerance. Shallow-water (<200 m depth) marine invertebrates and fishes demonstrate limited tolerance of increasing hydrostatic pressure (pressure exerted by the overlying mass of water), and hyperbaric (increased pressure) tolerance is proposed to depend on the ability to maintain aerobic metabolism, too. Here, we report significant correlation between the hypoxia thresholds and the hyperbaric thresholds of taxonomic groups of shallow-water fauna, suggesting that pressure tolerance is indeed oxygen limited. Consequently, it appears that the combined effects of temperature, pressure and oxygen concentration constrain the fundamental ecological niches (FENs) of marine invertebrates and fishes. Including depth in a conceptual model of oxygen- and capacity-limited FENs' responses to ocean warming and deoxygenation confirms previous predictions made based solely on consideration of the latitudinal effects of ocean warming (e.g. Cheung et al., 2009), that polar taxa are most vulnerable to the effects of climate change, with Arctic fauna experiencing the greatest FEN contraction. In contrast, the inclusion of depth in the conceptual model reveals for the first time that temperate fauna as well as tropical fauna may experience substantial FEN expansion with ocean warming and deoxygenation, rather than FEN maintenance or contraction suggested by solely considering latitudinal range shifts.

The letters between James Lamont and Charles Darwin on Arctic fauna

ABSTRACTIn the summers of 1858 and 1859, the Scot Sir James Lamont of Knockdow embarked on two cruises to Svalbard (referred to by Lamont as Spitzbergen [sic]) to hunt, make geographical surveys, and collect geological and biological specimens. Lamont's return from these voyages coincided with the publication of the joint Charles Darwin-Alfred Russel Wallace paper, ‘On the tendency of species to form varieties; on the perpetuation of varieties and species by natural means of selection’ by the Linnean Society in August 1858 and, a year later, the publication of Darwin's On the origin of species (Darwin 1958). Profoundly influenced by Darwin's ideas, Lamont initiated a correspondence with the naturalist, relating examples of what he considered to be natural selection, observed during his hunting expeditions. In his Svalbard travelogue, Seasons with the sea-horses (1861), Lamont expounded specifically upon walrus and polar bear evolution, ideas inspired by sporadic yet encouraging letters from the renowned naturalist.

Phylogeography of northern Dolly VardenSalvelinus malma malmabased on analysis of mitochondrial DNA

The northern Dolly Varden, Salvelinus malma malma, is a typical representative of arctic fauna distributed in northeastern Asia and northwestern North America. Because its spawning habitats were affected by Pleistocene glacial advances over most of its natural range, S. m. malma is among the most interesting objects of phylogeographic and microevolutionary studies. We reconstructed the genealogy of mtDNA haplotypes from 27 Alaskan and Asian populations to study the influence of glacial and geological vicariance events on the contemporary population genetic structure, phylogeographic subdivision and distribution of the northern Dolly Varden. Analysis of restriction site states in three PCR-amplified mtDNA regions (ND1/ND2, ND5/ND6, Cytb/D-loop; 47% of the mitochondrial genome) resolved 75 haplotypes in 436 fish. Similar patterns of subspecific variation apparent from hierarchical diversity and nested clade analyses of mtDNA haplotypes identify weak spatial differentiation and low levels of divergence. Our results suggest that (1) demographic history has been influenced by historical range expansions and recent isolation by distance, (2) present populations from Asia and North America were colonized from one main Beringian Refugium, and (3) that this taxon's ancestral population probably experienced a bottleneck in the Beringian Refugium during the late Pleistocene (Wisconsin) glacial period.

New combination for Malacoceros jirkovi and a key for Spio (Polychaeta: Annelida) from Norwegian waters and adjacent Arctic areas

The species Malacoceros jirkovi Sikorski, 1992 is transferred to Spio Fabricius, 1785 in the light of new data (listed below).The de scription of this species is given for the first time in English. About 30 years of the study of polychaetous material from the economic zone of Norway has eventually shown there to be nine species belonging to Spio inhabiting this area: S. filicornis (Müller, 1776) [including S. malmgreni Sikorski, 2001 as a junior synonym], S. mecznikovianus Claparede, 1868, S. decoratus Bobretzky, 1871, S. arctica Söderström, 1920, S. armata Thulin, 1957, S. goniocephala Thulin, 1957, S. jirkovi (Sikorski, 1992), newly described S. symphyta Meißner, Bick et Bastrop, 2011 and S. arndti Meißner, Bick et Bastrop, 2011. The species S. theeli Söderström, 1920 and S. tzetlini Sikorski, 2001 which might be obtained in the adjacent areas (the Barents and White Seas) are also mentioned to fulfill the list of Arctic fauna.

Phylogeography of northern Dolly Varden Salvelinus malma (Salmoniformes: Salmonidae) from Asia and North America: An analysis based on the mitochondrial DNA genealogy

Spawning in habitats affected by Pleistocene glacial advances over most of its natural range, northern Dolly Varden Salvelinus malma malma typifies Arctic fauna distributed in northeastern Asia and northwestern North America. We reconstructed a genealogy of mtDNA haplotypes from 27 Alaskan and Asian populations to study the influence of historical events on the phylogeography and contemporary population genetic structure. Analysis of molecular variance partitioned most of the mtDNA variability to the intrapopulation component (72.5%) with much reduced differences between populations (21.1%) and regions (6.4%). Similar patterns of variation apparent from hierarchical diversity and nested clade phylogeographical analysis (NCPA) of mtDNA haplotypes identify weak spatial differentiation and low levels of divergence. These findings suggest (1) that demographic history has been influenced by historical range expansions and recent isolation by distance, (2) that present populations from Asia and North America were colonized from one main Beringian Refugium, and (3) that this taxon’s ancestral population probably experienced a bottleneck in the Beringian Refugium during the late Pleistocene (Wisconsin) glacial period. The genealogical and NCPA analyses, and mismatch distribution of S. m. malma mtDNA haplotypes do not confirm the assumptions about presence of the two refugia on the territories of the Beringian Land, in which allopatric S. m. malma ancestral populations evolved, and independent origin of the Sea of Okhotsk populations.

The ratio of species of Atlantic and Pacific origin in modern Arctic fauna of bivalve molluscs

The ratio of species of Atlantic and Pacific origin in modern Arctic fauna of bivalve molluscs

CircumArctic Rangifer monitoring and assessment (CARMA) network – origins, goals, accomplishments and future

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Microsatellite and mtDNA analysis of lake trout, Salvelinus namaycush, from Great Bear Lake, Northwest Territories: impacts of historical and contemporary evolutionary forces on Arctic ecosystems.

Resolving the genetic population structure of species inhabiting pristine, high latitude ecosystems can provide novel insights into the post-glacial, evolutionary processes shaping the distribution of contemporary genetic variation. In this study, we assayed genetic variation in lake trout (Salvelinus namaycush) from Great Bear Lake (GBL), NT and one population outside of this lake (Sandy Lake, NT) at 11 microsatellite loci and the mtDNA control region (d-loop). Overall, population subdivision was low, but significant (global FST θ = 0.025), and pairwise comparisons indicated that significance was heavily influenced by comparisons between GBL localities and Sandy Lake. Our data indicate that there is no obvious genetic structure among the various basins within GBL (global FST = 0.002) despite the large geographic distances between sampling areas. We found evidence of low levels of contemporary gene flow among arms within GBL, but not between Sandy Lake and GBL. Coalescent analyses suggested that some historical gene flow occurred among arms within GBL and between GBL and Sandy Lake. It appears, therefore, that contemporary (ongoing dispersal and gene flow) and historical (historical gene flow and large founding and present-day effective population sizes) factors contribute to the lack of neutral genetic structure in GBL. Overall, our results illustrate the importance of history (e.g., post-glacial colonization) and contemporary dispersal ecology in shaping genetic population structure of Arctic faunas and provide a better understanding of the evolutionary ecology of long-lived salmonids in pristine, interconnected habitats.

Life history of tundra-dwelling wolf spiders (Araneae: Lycosidae) from the Yukon Territory, Canada

We studied populations of three tundra-dwelling wolf spider (Lycosidae) species to determine reproductive trait relationships and developmental timing in the Arctic. We collected 451 Pardosa lapponica (Thorell, 1872), 176 Pardosa sodalis Holm, 1970, and 117 Pardosa moesta Banks, 1892 during summer 2008. We used log-likelihood ratio tests and multiple linear regressions to determine the best predictors of fecundity and relative reproductive effort. Female body size best explained the variation in fecundity and body condition was the best predictor for relative reproductive effort. We tested for a trade-off between the allocation of resources to individual eggs and the number of eggs produced (fecundity) within each species using linear regression. There was variation in detectable egg size and number trade-offs among sites and these may be related to local variation in resource allocation linked to density-related biotic or abiotic factors. These findings contribute to knowledge about the fitness of arctic wolf spiders in the region of study and are particularly relevant in light of the effects that climate changes are predicted to have on the arctic fauna.

Centennial scale benthic foraminiferal record of late Holocene oceanographic variability in Disko Bugt, West Greenland

A new centennial scale benthic foraminiferal record of late Holocene climate variability and oceanographic changes off West Greenland (Disko Bugt) highlights substantial subsurface water mass changes (e.g. temperature and salinity) of the West Greenland Current (WGC) over the past 3.6 ka BP. Benthic foraminifera reveal a long-term late Holocene cooling trend, which may be attributed to increased advection of cold, low-salinity water masses derived from the East Greenland Current (EGC). Cooling becomes most pronounced from c. 1.7 ka BP onwards. At this point the calcareous Atlantic benthic foraminiferal fauna decrease significantly and is replaced by an agglutinated Arctic fauna. Superimposed on this cooling trend, centennial scale variability in the WGC reveals a marked cold phase at c. 2.5 ka BP, which may correspond to the 2.7 ka BP cooling-event recorded in marine and terrestrial archives elsewhere in the North Atlantic region. A warm phase recognized at c. 1.8 ka BP is likely to correspond to the ‘Roman Warm Period’ and represents the warmest bottom water conditions. During the time period of the ‘Medieval Climate Anomaly’ we observe only a slight warming of the WGC. A progressively more dominant cold water contribution from the EGC on the WGC is documented by the prominent rise in abundance of agglutinated Arctic water species from 0.9 ka BP onwards. This cooling event culminates at c. 0.3 ka BP and represents the coldest episode of the ‘Little Ice Age’. Gradually increased influence of cold, low-salinity water masses derived from the EGC may be linked to enhanced advection of Polar and Arctic water by the EGC. These changes are possibly associated with a reported shift in the large-scale North Atlantic Oscillation atmospheric circulation pattern towards a more frequent negative North Atlantic Oscillation mode during the late Holocene.

Sub-fossil beetle assemblages associated with the “mammoth fauna” in the Late Pleistocene localities of the Ural Mountains and West Siberia

The distribution of beetles at the end of the Middle Pleninglacial (=terminal Quaternary) was examined based on sub-fossil material from the Ural Mountains and Western Siberia, Russia. All relevant localities of fossil insects have similar radiocarbon dates, ranging between 33,000 and 22,000 C14 years ago. Being situated across the vast territory from the southern Ural Mountains in the South to the middle Yamal Peninsula in the North, they allow latitudinal changes in beetle assemblages of that time to be traced. These beetles lived simultaneously with mammals of the so-called “mammoth fauna” with mammoth, bison, and wooly rhinoceros, the often co-occurring mega-mammalian bones at some of the sites being evidence of this. The beetle assemblages found between 59° and 57°N appear to be the most interesting. Their bulk is referred to as a “mixed” type, one which includes a characteristic combination of arcto-boreal, boreal, steppe and polyzonal species showing no analogues among recent insect complexes. These peculiar faunas seem to have represented a particular zonal type, which disappeared since the end of the Last Glaciation to arrive here with the extinction of the mammoth biota. In contrast, on the sites lying north of 60°N, the beetle communities were similar to modern sub-arctic and arctic faunas, yet with the participation of some sub-boreal steppe components, such as Poecilus ravus Lutshnik and Carabus sibiricus Fischer-Waldheim. This information, when compared with our knowledge of synchronous insect faunas from other regions of northern Eurasia, suggests that the former distribution of beetles in this region could be accounted for both by palaeo-environmental conditions and the impact of grazing by large ruminant mammals across the so-called “mammoth savannas”.