Spring migratory routes and stopover duration of satellite‐tracked Eurasian Teals Anas crecca wintering in Italy

Abstract

Identifying an organism's migratory strategies and routes has important implications for conservation. For most species of European ducks, information on the general course of migration, revealed by ringing recoveries, is available, whereas tracking data on migratory movements are limited to the largest species. In the present paper, we report the results of a tracking study on 29 Eurasian Teals, the smallest European duck, captured during the wintering period at three Italian sites. The departure date of spring migration was determined for 21 individuals, and for 15 the entire spring migratory route was reconstructed. Most ducks departed from wintering grounds between mid-February and March following straight and direct routes along the Black Sea-Mediterranean flyway. The breeding sites, usually reached by May, were spread from central to north-Eastern Europe to east of the Urals. The migratory speed was slow (approximately 36 km/day on average) because most birds stopped for several weeks at stopover sites, mainly in southeastern Europe, especially at the very beginning of migration. The active flight migration segments were covered at much higher speeds, up to 872 km/day. Stopover duration tended to be shorter when birds were closer to their breeding site. These results, based on the largest satellite tracking effort for this species, revealed for the first time the main features of the migratory strategies of individual Teals wintering in Europe, such as the migration timing and speed and stopover localization and duration.

Seasonal and population differences in migration of Whimbrels in the East Asian–Australasian Flyway

“…During migration, sites where birds remained within 0.5 degree of latitude for more than 48 h and where two successive fixes were less than 50 km apart were considered to be stopover sites. The geographical location of the nonbreeding site, stopover site, and breeding site for each individual was the arithmetic mean of all of the geographical coordinates at each site (Giunchi et al 2019). Migration distance was calculated as the accumulation of the great circle distance between the nonbreeding, successive stopover, and breeding sites.…”

“…If the time interval between two consecutive fixes before and after arrival at the site did not exceed 24 h, the first record at the site was used as the arrival time. If the time interval between two consecutive fixes of departure from or arrival at the site exceeded 24 h, the departure time was calculated as the average time between the last fix at the site and the next fix after departure from the site, and the arrival time was calculated as the average time between the first fix at the site and the previous fix before arrival at the site (Giunchi et al 2019).…”

Active Surveillance for Highly Pathogenic Avian Influenza Viruses in Wintering Waterbirds in Northeast Italy, 2020–2021

“…Most of the overseas recapturing of ringed Eurasian teals in Italy falls within a large geographical area located in northeastern and central European, Baltic, and Scandinavian areas [5,30]. Recaptures of Eurasian teals wintering in Italy were also recorded in eastern Russia up to western Siberia [30].…”

Spatial and temporal variation in the migration of Ruddy-headed Goose in southern South America using satellite tagging

“…Regardless of the use of stop-over areas closer to the final destination, tracked birds were not always faithful to their stop-over sites during subsequent migrations, meaning that these birds might not choose the same stop-overs. It could be that herbivores like the Ruddy-headed Goose rely heavily on the energy and nutrients built up concurrently while breeding and/or wintering, which allows them to reach different areas closer to their destination (Giunchi et al 2019). Another explanation could be that because suitable stop-over habitats for the birds are under variable intensive cropland management, the selection of stop-over habitat by geese closer to their final destination is directly influenced by such management (Giunchi et al 2019).…”

“…It could be that herbivores like the Ruddy-headed Goose rely heavily on the energy and nutrients built up concurrently while breeding and/or wintering, which allows them to reach different areas closer to their destination (Giunchi et al 2019). Another explanation could be that because suitable stop-over habitats for the birds are under variable intensive cropland management, the selection of stop-over habitat by geese closer to their final destination is directly influenced by such management (Giunchi et al 2019). Actually, some wildfowl migrating overland are known to follow a stepping-stone strategy, taking advantage of the food they find en route (Viana et al 2013).…”