DOI: 10.5443/11402
title: Arctic Wildlife Observatories Linking Vulnerable EcoSystems (ArcticWOLVES)

description: Extensive monitoring of the abundance, timing and success of reproduction, habitat use and diet of key wildlife species (primarily geese, small mammals, shorebirds, avian predators and mammalian predators like foxes and weasels), as well as annual plant production and arthropod diversity and abundance, was conducted at most sites from 2007 to 2009. Our results provide increasing evidence that predation plays a dominant role in the functioning of Arctic terrestrial ecosystems. At one site, less than 10% of the annual primary production was consumed by herbivores but up to 50% of the herbivore production was consumed by predators. The latter proportion also increased over the past two decades, suggesting a strengthening of top-down effects in this food web. Winter habitat quality appears to be a key factor in the population dynamics of lemmings, the primary prey of most tundra predators. Deep snow provides insulation from the cold air temperature, protection from predators and allows winter reproduction, upon which depend the periodic population irruptions of small mammals. However, deep snow is spatially uncommon in the Arctic, thus the distribution and spatial extent of good quality winter habitat may be limiting population irruptions in some regions or years. Radio-tracking of tundra predators such as snowy owls and arctic foxes revealed that they travel over very large areas and they can extensively use the marine ecosystem during winter, when terrestrial food resources are scarce. Snowy owls in particular display a remarkable nomadism when searching for suitable nesting sites in spring and an outstanding ability to find locally abundant lemming populations, which may contribute to the regional synchrony of lemming population dynamics. We found evidence that the strength of predation decreases with latitude. Using artificial birds¿ nests, we showed that risk of predation decreases by as much as 66% between 53 and 82 N latitude (a 3,400 km distance). We also found that soil-plant-herbivore interactions are quite sensitive to climate warming. On the one hand, earlier thaw or increasing freeze-thaw cycles will likely result in a loss of soil nutrients in some wetland ecosystems, leading to a decrease in plant production and food resource for herbivores. On the other hand, earlier and warmer springs could have a negative impact on the synchrony between the reproductive phenology of herbivores and plant growth, leading to reduced annual production.
description: Purpose: Climate change is strongly affecting Arctic ecosystems, as the distribution, abundance, and interactions of species are altered. Hence, there is an urgent need to develop programs for conserving biodiversity in response to likely losses of a significant proportion of Arctic species assemblages. These changes will also impact Inuit and other indigenous people that depend on wildlife species. In response to those needs, we developed the project ArcticWOLVES, which is a circumpolar study of tundra ecosystems aimed at understanding food webs and ecosystem processes affecting them, measuring current impact of climate change on wildlife, and predicting future impacts through modelling. Our program has two complementary goals. A first goal is to determine the relative importance of various processes in structuring Arctic food webs and to quantify the magnitude of these interactions. The second goal is to document direct and indirect impacts of climate change on terrestrial animal biodiversity (insects, birds, mammals) and forecast future impacts on animal populations and the Arctic ecosystem. A key feature of our project is to simultaneously document changes occurring in a large number of wildlife species at a number of sites over a large geographical range using standard protocols. This approach will provide the much-needed spatial replicates that are essential to make strong inferences, whereas variability among sites will give insights at different spatial scales and allow a comparative approach. Wildlife species of primary interest for ArcticWOLVES include herbivorous, insectivorous and predatory birds, small mammals and their predators and the insect and food plants of these species. Our project integrates scientific methodology and traditional knowledge of northern inhabitants to obtain data that will allow us to expand our temporal and spatial understanding of wildlife populations. ArcticWOLVES is a circumpolar initiative linked to sister projects in other countries. Arctic Predators is a Norwegian/Russian joint project funded by both countries, and is an integral part of ArcticWOLVES. In the Netherlands, the project BirdHealth has links with our project. In Canada, our project has established close ties with CiCAT, another project funded by the International Polar Year (IPY) program studying the tundra vegetation.
description: Summary: Changes are occurring in the distribution, abundance and behavior of wildlife species that live on the Arctic tundra. How and why these changes are occurring remains unclear. By monitoring the abundance, reproductive success, interactions, habitat use, and diet of mammals and birds across the Canadian North, this project is evaluating how Arctic biodiversity is changing in response to various pressures like climate change. Species of interest include plants, insects, herbivorous, insectivorous and predatory birds (ex. sandpiper, snow geese, snowy owl, rough-legged hawk) and small mammals (ex. voles, lemmings) and their predators (ex. fox, weasel). Data will be used to predict future climate impacts on wildlife populations through modeling.