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

Many population counts of gregarious migrant species, such as waders and geese, take place along the flyways and at wintering grounds outside the Arctic which stresses the importance of continued development of movement ecology studies. Monitoring of FEC attributes related to breeding success and links to environmental drivers within the Arctic takes place in a wide network of research sites across the Arctic, although with low coverage of the high Arctic zone (Figure 3-25) STATE OF THE ARCTIC TERRESTRIAL BIODIVERSITY REPORT - Chapter 3 - Page 58 - Figure 3.25

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

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

The Peregrine Falcon (Falco peregrinus tundrius) population in South Greenland has been monitored annually 1981-2018 (except 1993 and 2004). At visits to known breeding sites we recorded presence/absence of territorial falcons as well as their breeding outputs (number of eggs and/or young). The file named S_Greenland_Peregrine_monitoring_data.csv contains the raw data from 725 site checks (sometimes several per site per year). The file named S_Greenland_Summary_occupancy_and_productivity.csv contains a summary of the raw data, providing annual estimates of occupancy, productivity and average brood size. The respective ReadMe files specify the contents.

The Peregrine Falcon (Falco peregrinus tundrius) population in South Greenland has been monitored annually 1981-2021 (except 1993, 2004 and 2020). At visits to known breeding sites we recorded presence/absence of territorial falcons as well as their breeding outputs (number of eggs and/or young). The file named S_Greenland_Peregrine_monitoring_data-1981-2021.csv contains the raw data from 835 site checks (sometimes several per site per year). The file named S_Greenland_Summary_occupancy_and_productivity-1981-2021.csv contains a summary of the raw data, providing annual estimates of occupancy, productivity and average brood size (young/ successful nest). The respective ReadMe files specify the contents.