While collating contributions and comments from 36 researchers, the coordinating authors accidentally omitted Dr. Suzanne Carrière from the list of contributing co-authors. Dr. Carrière's data are described in Tables 1 and 3, Figure 2 and several places in the narrative.The new author list is thus updated in this article.
The Circumpolar North has been changing rapidly within the last decades, and the socioeconomic systems of the Eurasian Arctic and Siberia in particular have displayed the most dramatic changes. Here, anthropogenic drivers of environmental change such as migration and industrialization are added to climate-induced changes in the natural environment such as permafrost thawing and increased frequency of extreme events. Understanding and adapting to both types of changes are important to local and indigenous peoples in the Arctic and for the wider global community due to transboundary connectivity. As local and indigenous peoples, decision-makers and scientists perceive changes and impacts differently and often fail to communicate efficiently to respond to changes adequately, we convened a meeting of the three groups in Salekhard in 2017. The outcomes of the meeting include perceptions of how the three groups each perceive the main issues affecting health and well-being and recommendations for working together better.
Seasonal geophysical cycles strongly influence the activity of life on Earth because they affect environmental conditions like temperature, precipitation and day length. An increase in daylight availability during summer is especially enhanced when animals migrate along a latitudinal gradient. Yet, the question of how day length (i.e. daylight availability) influences the activity patterns of long-distance, latitudinal migrants is still unclear. Here, we ask whether migration provides benefits to long-distance migrants by enabling them to increase their diurnal movement activities due to an increase in daylight availability. To answer this question, we tested whether four vastly different species of long-distance migratory birds-two arctic migrants and two mid-latitude migrants-can capitalise on day length changes by adjusting their daily activity. We quantified the relationship between daily activity (measured using accelerometer data) and day length, and estimated each species' daily activity patterns. In addition, we evaluated the role of day length as an ultimate driver of bird migration. All four species exhibited longer activity periods during days with more daylight hours, showing a strong positive relationship between total daily activity and day length. The slope of this relationship varied between the different species, with activity increasing 1.5-fold on average when migrating from wintering to breeding grounds. Underlying mechanisms of these relationships reveal two distinct patterns of daily activity. Flying foragers showed increasing activity patterns, that is, their daytime activities rose uniformly up to solar noon and decreased until dusk, thereby exhibiting a season-specific activity slope. In contrast, ground foragers showed a constant activity pattern, whereby they immediately increased their activity to a certain level and maintained this level throughout the day. Our study reveals that long days allow birds to prolong their activity and increase their total daily activity. These findings highlight that daylight availability could be an additional ultimate cause of bird migration and act as a selective agent for the evolution of migration.
Los ciclos geofísicos estacionales influyen fuertemente la actividad de la vida en la Tierra ya que afectan diversas condiciones ambientales como la temperatura, la precipitación y la duración del día. El aumento de la disponibilidad de luz solar durante el verano favorece especialmente a las especies que migran a lo largo de un gradiente latitudinal. Sin embargo, el efecto de la duración del día (es decir, la disponibilidad de luz solar) en los patrones de actividad de las especies que migran latitudinalmente largas distancias, aún no es claro. Aquí nos preguntamos si un aumento de la disponibilidad de luz solar representa un beneficio para los animales que migran largas distancias, al prolongar el periodo de actividad diurna. Para responder a esta pregunta, investigamos si cuatro especies diferentes de aves migratorias de larga distancia, dos migrantes árticos y dos migrantes de latitudes medias, pueden ajustar su actividad diaria y aprovechar los cambios en la duración del día. Cuantificamos la relación entre la actividad diaria (medida con datos de acelerómetro) y la duración del día, y estimamos los patrones de actividad de cada especie. Además, evaluamos el papel de la duración del día como mecanismo último subyacente a la migración de las aves. Las cuatro especies mostraron períodos de actividad más largos durante los días con más horas de luz, mostrando una fuerte relación positiva entre la actividad diaria total y la duración del día. Esta relación varió entre las especies evaluadas. La actividad aumentó en promedio 1.5 veces durante la migración desde las áreas de invernada a las áreas de reproducción. Los mecanismos subyacentes a estas relaciones revelan dos patrones de actividad diaria. Las especies que forrajean en vuelo mostraron un aumento en su patrón de actividad. En este caso, la actividad diurna aumentó uniformemente hasta el mediodía y disminuyó hasta el atardecer, mostrando una pendiente de actividad específica para la estación. De otro lado, las especies que forrajean en tierra mostraron un patrón de actividad constante. Según este patrón, la actividad diurna aumenta hasta un determinado nivel, a partir del cual se mantiene durante el resto del día. Nuestro estudio revela que el aumento en la longitud del día le permite a las aves prolongar su actividad e incrementar su actividad diaria total. Estos resultados señalan que la disponibilidad de luz diurna podría ser otro mecanismo último subyacente a la migración de las aves y puede actuar como un factor de selección en la evolución de la migración.
Small rodents with multi-annual population cycles strongly influence the dynamics of food webs, and in particular predator-prey interactions, across most of the tundra biome. Rodents are however absent from some arctic islands, and studies on performance of arctic predators under such circumstances may be very instructive since rodent cycles have been predicted to collapse in a warming Arctic. Here we document for the first time how three normally rodent-dependent predator species-rough-legged buzzard, arctic fox and red fox - perform in a low-arctic ecosystem with no rodents. During six years (in 2006-2008 and 2011-2013) we studied diet and breeding performance of these predators in the rodent-free Kolguev Island in Arctic Russia. The rough-legged buzzards, previously known to be a small rodent specialist, have only during the last two decades become established on Kolguev Island. The buzzards successfully breed on the island at stable low density, but with high productivity based on goslings and willow ptarmigan as their main prey - altogether representing a novel ecological situation for this species. Breeding density of arctic fox varied from year to year, but with stable productivity based on mainly geese as prey. The density dynamic of the arctic fox appeared to be correlated with the date of spring arrival of the geese. Red foxes breed regularly on the island but in very low numbers that appear to have been unchanged over a long period - a situation that resemble what has been recently documented from Arctic America. Our study suggests that the three predators found breeding on Kolguev Island possess capacities for shifting to changing circumstances in low-arctic ecosystem as long as other small - medium sized terrestrial herbivores are present in good numbers.
Notes
Cites: Br Med J (Clin Res Ed). 1986 Mar 15;292(6522):746-503082422
The peregrine falcon (Falco peregrinus) and the gyrfalcon (Falco rusticolus) are top avian predators of Arctic ecosystems. Although existing monitoring efforts are well established for both species, collaboration of activities among Arctic scientists actively involved in research of large falcons in the Nearctic and Palearctic has been poorly coordinated. Here we provide the first overview of Arctic falcon monitoring sites, present trends for long-term occupancy and productivity, and summarize information describing abundance, distribution, phenology, and health of the two species. We summarize data for 24 falcon monitoring sites across the Arctic, and identify gaps in coverage for eastern Russia, the Arctic Archipelago of Canada, and East Greenland. Our results indicate that peregrine falcon and gyrfalcon populations are generally stable, and assuming that these patterns hold beyond the temporal and spatial extents of the monitoring sites, it is reasonable to suggest that breeding populations at broader scales are similarly stable. We have highlighted several challenges that preclude direct comparisons of Focal Ecosystem Components (FEC) attributes among monitoring sites, and we acknowledge that methodological problems cannot be corrected retrospectively, but could be accounted for in future monitoring. Despite these drawbacks, ample opportunity exists to establish a coordinated monitoring program for Arctic-nesting raptor species that supports CBMP goals.
