This report attempts to review the abundance, status and distribution of natural wild goose populations in the northern hemisphere. The report comprises three parts that 1) summarise key findings from the study and the methodology and analysis applied; 2) contain the individual accounts for each of the 68 populations included in this report; and 3) provide the datasets compiled for this study which will be made accessible on the Arctic Biodiversity Data Service.

There are few true Arctic specialist birds that remain in the Arctic throughout their annual cycle. They include the willow and rock ptarmigan (Lagopus lagopus and L. muta), gyrfalcon (Falco rusticolus), snowy owl (Bubo scandiacus), Arctic redpoll (Carduelis hornemanni) and northern raven (Corvus corax)—a cosmopolitan species with resident populations in the Arctic. All other terrestrial Arctic-breeding bird species migrate to warmer regions during the northern winter, connecting the Arctic to all corners of the globe. Hence, their distributions are influenced by the routes they follow. These distinct migration routes are referred to as flyways and are defined by a combination of ecological and political boundaries and differ in spatial scale. The CBMP refers to the traditional four north–south flyways, in addition to a circumpolar flyway representing the few species that remain largely within the Arctic year-round (Figure 3-20). STATE OF THE ARCTIC TERRESTRIAL BIODIVERSITY REPORT - Chapter 3 - Page 48- Figure 3.20

There is a great variation and heterogeneity among terrestrial Arctic ecosystems. This is further described as biogeographical areas in the Annotated Checklist of the Pan-Arctic Flora (Elven et al. 2020), as vegetation zones (Walker et al. 2005, Raynolds et al 2019) or as ecoregions recognised by Terrestrial Ecoregions of the World (Olson et al. 2001). The START focuses on high and low Arctic regions consistent with the CAVM’s subzones A to E, as shown in Figure 1-2 and Figure 2-1 STATE OF THE ARCTIC TERRESTRIAL BIODIVERSITY REPORT - Chapter 2 - Page 19 - Figure 2.1

The CBMP–Terrestrial Plan identifies five FECs for monitoring terrestrial birds; herbivores, insectivores, carnivores, omnivores and piscivores. Due to their migratory nature, a wider range of drivers, from both within and outside the Arctic, affect birds and their associated FEC attributes compared to other terrestrial FECs. Figure 3-21 illustrates a conceptual model for Arctic terrestrial birds that includes examples of FECs and key drivers. STATE OF THE ARCTIC TERRESTRIAL BIODIVERSITY REPORT - Chapter 3 - Page 46 - Figure 3.21

Figure 1-1. CBMP’s adaptive, integrated ecosystem–based approach to inventory, monitoring and data management. This figure illustrates how management questions, conceptual ecosystem models based on science, Indigenous Knowledge, and Local Knowledge, and existing monitoring networks guide the four CBMP monitoring plans––marine, freshwater, terrestrial and coastal. Monitoring outputs (data) feed into the assessment and decision-making processes and guide refinement of the monitoring programmes themselves. Modified from CAFF 2017 STATE OF THE ARCTIC TERRESTRIAL BIODIVERSITY REPORT - Chapter 1 - Page 4 - Figure 1-1

Arctic foxes are currently monitored at 34 sites throughout the North, with most monitoring efforts concentrated in Fennoscandia (Figure 3-32). The duration of monitoring across all sites is variable at between 2 and 56 years and was ongoing at 27 of the 34 sites (79%) as of 2015. Monitoring projects cover almost equally the four climate zones of the species’ distribution—high Arctic, low Arctic, sub-Arctic, and montane/alpine. STATE OF THE ARCTIC TERRESTRIAL BIODIVERSITY REPORT - Chapter 3 - Page 82 - Figure 3.32

Trends and distribution of muskoxen populations based on Table 3-5. Modified from Cuyler et al. 2020. STATE OF THE ARCTIC TERRESTRIAL BIODIVERSITY REPORT - Chapter 3 - Page 79 - Figure 3.30

Study sites across the Arctic where phenological mismatches between timing of reproduction and peak abundance in food have been studied for terrestrial bird species. Grey symbols show study sites where this phenomenon has been studied for <10 years, light red symbols show sites with >10 years of data but no strong evidence of an increasing mismatch, and dark red symbols indicate sites with >10 years of data and strong evidence of an increasing mismatch. Circles indicate studies of shorebirds, squares for waterfowl and diamonds(triancle) for both shorebirds and passerines. Graphic: Thomas Lameris, adapted from Zhemchuzhnikov (submitted). STATE OF THE ARCTIC TERRESTRIAL BIODIVERSITY REPORT - Chapter 3 - Page 65 - Figure Box 3.3

Population estimates and trends for Rangifer populations of the migratory tundra, Arctic island, mountain, and forest ecotypes where their circumpolar distribution intersects the CAFF boundary. Population trends (Increasing, Stable, Decreasing, or Unknown) are indicated by shading. Data sources for each population are indicated as footnotes. STATE OF THE ARCTIC TERRESTRIAL BIODIVERSITY REPORT - Chapter 3 - Page 70 - Table 3.4

Vegetation monitoring occurs across the Arctic, but the duration of monitoring efforts is variable and is dependent upon both study design and access to resources. Although many field studies on vegetation have been conducted in the Arctic (Figure 3-5), not all can be considered monitoring since some recorded only select measurements over limited time frames. Studies reporting on abundance and composition of vegetation reflect a larger and more widespread geographical coverage than the typically more site-limited and time-consuming phenology studies (Figure 3-5). Geographical gaps in coverage of Siberia and large parts of the Canadian Arctic are evident. STATE OF THE ARCTIC TERRESTRIAL BIODIVERSITY REPORT - Chapter 3 - Page 34 - Figure 3.5