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Knowing the location of migratory birds throughout their annual cycle is fundamental for many questions in ornithology. Technological advances have provided several approaches, with increasing miniaturization allowing deployment on smaller and smaller birds. Here, we examine the strengths and limitations of barometric pressure geolocators (pressure tags), which have recently been shown to be extremely effective in tracking small birds (<25 g). The newly developed geolocation by pressure workflow (GeoPressureR) uses a global weather analysis dataset and hidden Markov movement model to reveal locations more accurately or continuously than can be achieved by other available light-weight devices (e.g. light-level geolocators, automated radio telemetry, and archival GPS tags). Additionally, pressure data can provide altitude information and document generally intractable flight behavior, as well as exact migratory phenologies. This new technology can be applied to important unresolved problems such as altitudinal migration, stopover site use, molt migration, vertical airspace use, and drivers of migratory flight initiation, duration, and direction. We provide an example of a pressure tag on a Swainson's Warbler (Limnothlypis swainsonii) deployed on its breeding territory in Virginia, USA, revealing the complete story of its migration to and from Cuba, including its refined wintering site, stopover sites, and migration routes, all with precise timing. Studies relying on pressure tags are still subject to biases related to recovery of the devices for data extraction, and application to birds that exhibit extensive aerial movements (e.g. swallows and swifts) remains challenging. Widespread deployment of pressure tags could show unprecedented details of bird migration and other aspects of aerial behavior, which could benefit conservation and greatly enrich our understanding of avian movement ecology. [ABSTRACT FROM AUTHOR]

The narrowest part of Central America (Costa Rica and Panama) concentrates the massive raptor migration traveling between North and South America. These sites have been traditionally considered a transit zone for these raptors, who move fast and almost without feeding in this stretch. This natural history note informs about the poorly known behavior of migrant Swainson's Hawks (Buteo swainsoni) in the Costa Rican Pacific lowlands. Hawks were observed between December and March, feeding in plowed sugar cane fields, and were attracted by agricultural fires to feed on insects driven away by the smoke. The observation dates and observed behaviors suggest that these hawks are overwintering in the area, instead of using it as a stopover. A potential overwintering site in Costa Rica poses the question of which selective forces and ecological conditions may be involved in shortening the migration. Las partes más angostas de Centroamérica (Costa Rica y Panamá) concentran la migración masiva de rapaces que viajan entre Norteamérica y Suramérica. Estos sitios se consideran tradicionalmente como áreas de paso para estos rapaces, que se mueven rápido y casi sin alimentarse sobre este estrecho. Esta nota de historia natural documenta el comportamiento poco conocido de los gavilanes Buteo swainsoni en las tierras bajas del Pacífico Norte de Costa Rica. Los gavilanes fueron vistos entre diciembre y febrero, alimentándose en campos recién cultivados y capturando presas que huían de las quemas de caña de azúcar. Las fechas y los comportamientos apoyan la hipótesis de que las tierras bajas del Pacífico costarricense son un sitio para pasar el invierno boreal, en lugar de ser una parada en el viaje de los gavilanes. Un sitio de estadía en Costa Rica deja la pregunta de cuáles fuerzas selectivas y condiciones ecológicas pueden estar involucradas en acortar el viaje de estos migrantes. Palabras clave: Centroamérica, Guanacaste, migración de rapaces, quemas. agrícolas, sitio de invernada, sitio de parada. [ABSTRACT FROM AUTHOR]

The strategies that migratory raptors adopt during migration reveal their long-term adaptations to different environments along their migration routes and of their stopover sites. We recorded the daily departure time of Chinese Sparrowhawks (Accipiter soloensis) and Gray-faced Buzzards (Butastur indicus) during their southward migration in autumn 2019 at Kenting National Park, southern Taiwan, and 2020 in Yushan National Park, central Taiwan. At both watchsites, Gray-faced Buzzards started their migration journey about 1 hr earlier than Chinese Sparrowhawks. After adjusting for the local sunrise time, the first daily appearance time of Gray-faced Buzzards (–2.5 ± 9.3 min) was significantly earlier than that of Chinese Sparrowhawks (47.0 ± 29.3 min) by about 50 min at Kenting National Park. Though they initiated migration later in morning at montane stopover sites in Yushan National Park, the same trend was observed and with even greater difference, about 70 min. These results indicate that these two species migrate in different daily periods and suggest that Chinese Sparrowhawks might choose to exploit stronger thermal uplifts in September before leaving the island, as they started migration later in the morning. In contrast, Gray-faced Buzzards, a species more dependent on soaring-gliding flight, set off earlier in the day, probably to take advantage of stronger northeastern tailwinds that begin in October. We conclude that the prevailing monthly wind conditions, particularly influenced by the northeast monsoons, shape the different diurnal migration times of these two raptors migrating along the East-Asian Oceanic Flyway. Las estrategias que adoptan las rapaces migratorias durante la migración revelan sus adaptaciones a largo plazo a diferentes ambientes a lo largo de sus rutas migratorias y de sus sitios de parada. Registramos la hora de partida diaria de Accipiter soloensis y Butastur indicus durante su migración hacia el sur en el otoño de 2019 en el Parque Nacional Kenting, en el sur de Taiwán, y en 2020 en el Parque Nacional Yushan, en el centro de Taiwán. En ambos sitios de observación, B. indicus comenzó su migración aproximadamente 1 hora antes que A. soloensis. Después de ajustar por la hora local del amanecer, el primer horario diario de aparición de B. indicus (–2,5 ± 9,3 min) fue significativamente más temprano que el de A. soloensis (47,0 ± 29,3 min) por unos 50 min en Kenting. Aunque iniciaron la migración más tarde en la mañana en los sitios montanos de parada en Yushan, se observó la misma tendencia y con una diferencia aún mayor, alrededor de 70 min. Estos resultados indican que estas dos especies migran en diferentes períodos diarios y sugieren que A. soloensis podría optar por explotar corrientes térmicas ascendentes más fuertes en septiembre antes de abandonar la isla, ya que comenzó a migrar más tarde en la mañana. Por el contrario, B. indicus, una especie que depende más del vuelo planeado, partió más temprano en el día, probablemente para aprovechar los fuertes vientos de cola del noreste que comienzan en octubre. Concluimos que las condiciones mensuales predominantes de viento, particularmente influenciadas por los monzones del noreste, moldean los diferentes horarios migratorios diurnos de estas dos rapaces que migran a lo largo de la ruta migratoria oceánica del este de Asia. [Traducción del equipo editorial] [ABSTRACT FROM AUTHOR]

Simple Summary: Studies on the migration patterns, habitat use, and conservation of the Eastern common crane Grus grus lilfordi in East Asia are insufficient. Most of the summering, breeding, wintering, and stopover sites are located outside the current protected areas boundary, so it is necessary to pay attention to these areas for the future protection of this subspecies. Studies on the subspecies Eastern common crane Grus grus lilfordi are still scarce, especially in Southeastern Siberia, the far east of Russia, Eastern Mongolia, and Northeastern China. This study explores the migration pattern, habitat use, and conservation status of the Eastern common crane. Using GPS/GSM tracking data, 36 complete migrations of 11 individuals were obtained from 2017 to 2021. The cranes migrated an average of 1581.5 km (±476.5 SD) in autumn and 1446.5 (±742.8 SD) in spring between their breeding site in Eastern Mongolia and the following wintering sites: the Xar Moron River, Chifeng; the Bohai Bay; the Yellow River Delta; Tangshan, Hebei; and Tianjin. During the autumn and spring migrations, the cranes used three critical stopover sites. The subspecies spent 60.3% of their time in rangeland, 18.1% in cropland, and 14.2% in water. The tracking data determined that, of the areas used by cranes, 97–98% of the summering sites were in Russia, 96% of the breeding sites were in Mongolia, and over 70% of the stopover sites and 90% of the wintering sites in China lay outside the current protected area boundaries. Consequently, establishing and expanding protected areas in summering, breeding, stopover, and wintering sites should be a central component of future conservation strategies. [ABSTRACT FROM AUTHOR]

Anthropogenic activities in the wetland and surrounding land are threatening the waterbirds. Population dynamics and waterbirds' arrival and departure dates are also influenced by wetland characteristics, food availability, and weather conditions. However, this information is rarely available for Taudaha Lake, a small stopover site in the Kathmandu Valley, Nepal, for many north-south migratory waterbirds. We observed the waterbird species, counted their number, and recorded their exact arrival date (October 2019) and departure date from January 2019 to April 2020. In addition, we recorded the air temperature and humidity of the lake during the monitoring time to identify the potential effects of these weathers on the arrival departure of migratory waterbirds. We developed a linear model to understand the factors influencing the arrival and departure of migratory waterbirds. Altogether we recorded ten migratory waterbird species, including one globally threatened species that used Taudaha as a stopover site during their migration. Arrival and departure times vary among the species. With increasing temperature, the migratory bird population decreases at the lake. Despite smaller area, Taudaha Lake at Kathmandu Valley acts as an important stopover site to facilitate the northsouth migration of waterbirds. Therefore, we recommend local government to avoid concrete constructions on the lake. [ABSTRACT FROM AUTHOR]

The Oriental Stork (Ciconia boyciana) is listed as ‘Endangered’ on the International Union for the Conservation of Nature (IUCN) Red List of Threatened Species and is classified as a first category nationally protected bird species in China. Understanding this species' seasonal movements and migration will facilitate effective conservation to promote its population. We tagged 27 Oriental Stork nestlings at Xingkai Lake on the Sanjiang Plain in Heilongjiang Province, China, used GPS tracking to follow them over the periods of 2014–2017 and 2019–2022, and confirmed their detailed migratory routes using the spatial analysis function of ArcGIS 10.7. We discovered four migration routes during autumn migration: one common long-distance migration route in which the storks migrated along the coastline of Bohai Bay to the middle and lower reaches of the Yangtze River for wintering, one short-distance migration route in which the storks wintered in Bohai Bay and two other migration routes in which the storks crossed the Bohai Strait around the Yellow River and wintered in South Korea. There were no significant differences in the number of migration days, residence days, migration distances, number of stopovers and average number of days spent at stopover sites between the autumn and spring migrations (P > 0.05). However, the storks migrated significantly faster in spring than in autumn (P ​= ​0.03). The same individuals did not exhibit a high degree of repetition in their migration timing and route selection in either autumn or spring migration. Even storks from the same nest exhibited considerable between-individual variation in their migration routes. Some important stopover sites were identified, especially in the Bohai Rim Region and on the Songnen Plain, and we further explored the current conservation status at these two important sites. Overall, our results contribute to the understanding of the annual migration, dispersal and protection status of the endangered Oriental Stork and provide a scientific basis for conservation decisions and the development of action plans for this species.

Almost no systematic monitoring of bird population trends occurs in West Africa, despite rapid human population increase, habitat change, and climate change, making conservation planning problematic. We monitored bird population trends using constant-effort mist netting, in a newly protected area (Amurum Forest Reserve) on the outskirts of Jos, central Nigeria, from 2002 to 2019. We modelled the 18-year changes in trends of 10 Palearctic migrant and 41 common resident bird species and related this to any changes in annual environmental site quality using NDVI and rainfall data. The populations of most bird species were stable; 30% of migrants and 7% of residents increased, while 10% of migrants and 29% of residents declined moderately. Primary productivity, measured by NDVI, increased, and rainfall pattern was stable, suggesting that environmental conditions at the site improved slightly during the period. However, only a few species showed significant correlations of population trends with NDVI and rainfall. Overall, our results suggest that population changes were locally similar for both the Afro-Palearctic and resident bird species, being reasonably stable or increasing — although perhaps this reflected the fact that the monitoring was done within a newly protected area, which at present represents the best habitat in the wider locality. Those species that declined were mostly associated with open, grassland areas, which will have decreased as anthropogenic influences were reduced at the study site. Though we only monitored one site, the results are encouraging in that simple protection of a small habitat fragment (∼300 ha) in Nigeria yielded generally positive population benefits for both resident and Palearctic migrant species. [ABSTRACT FROM AUTHOR]

The phenology and routes of long-distance migrations of European Nightjars are well described for Western European individuals migrating within the East Atlantic and Mediterranean flyways, while little is known about populations from other parts of the Eurasian breeding range. We describe the route choice and timing of European Nightjars breeding in eastern Mongolia, migrating within the Asia–East Africa flyway to reach wintering destinations in South-East Africa. After covering about 15,000 km during autumn migration, Mongolian nightjars arrived 1 month later in their wintering grounds compared to nightjars breeding in Western Europe. A similar difference was also observed in the timing of their arrival back at their respective breeding grounds illustrating the differences in timing of migration events between the two populations. We identify the steppes of Central Asia and the savannah of the Horn of Africa and Eastern Africa as key stopover zones for nightjars associated with the crossing of an ecological barrier formed by the deserts and mountains of the Iranian Plateau and the Arabian Peninsula. [ABSTRACT FROM AUTHOR]

Migratory animals likely play an important role in the geographic spread of parasites. In fact, a common assumption is that parasites are potentially transmitted by migratory animals at temporary stopover sites along migratory routes, yet very few studies have assessed whether transmission at stopover sites can or does occur. We investigated the potential for a group of vector-transmitted parasites, the avian haemosporidians, to be transmitted during migratory stopover periods at Rushton Woods Preserve in Pennsylvania, USA. Using an analysis of 1454 sampled avian hosts, we found that while a core group of abundant haemosporidians was shared between local breeding birds and passing migrants, the parasite community of migratory birds at Rushton was distinct from that of local breeding birds and showed similarity to a previously sampled boreal forest haemosporidian community. Haemosporidians that were unique to passing migratory birds were associated with sampling sites in North America with cooler summer temperatures than haemosporidians that are transmitted at Rushton, suggesting that the transmission of these parasites may be restricted to high-latitude regions outside of our temperate stopover site. We also found that the abundance of mosquitoes in our study region is offset from that of migratory bird abundance during avian migratory periods, with the peak period of bird migration occurring during periods of low mosquito activity. Collectively, these findings suggest that although abundant haemosporidians are possibly transmitted between local and passing migratory birds, a combination of biotic and abiotic factors may constrain haemosporidian transmission during avian stopover at our study site.

Determining the migration routes and connections of migratory birds at the population level helps clarify intraspecific differences in migration. Five subspecies have been recognized in the Whimbrel (Numenius phaeopus) in Eurasia. Ssp. rogachevae is the most recently described subspecies. It breeds in Central Siberia, while its non-breeding region and migration routes are still unclear. We tracked the migration of Eurasian Whimbrels captured at three non-breeding sites (Moreton Bay in east coast of Australia, Roebuck Bay in Northwest Australia and Sungei Buloh Wetland in Singapore) and two migration stopover sites (Chongming Dongtan and Mai Po Wetland in China). We determined the breeding sites and inferred the subspecies of the tagged birds in the East Asian – Australasian Flyway (EAAF) based on the known breeding distribution of each subspecies. Of the 30 tagged birds, 6 and 21 birds bred in the breeding range of ssp. rogachevae and variegatus, respectively; one bred in the presumed transition area between the breeding range of ssp. phaeopus and rogachevae, and two bred in the region between the breeding range of ssp. rogachevae and variegatus. The birds that bred in the ssp. rogachevae breeding range spent their non-breeding season in the northern Sumatra, Singapore, East Java and Northwest Australia and mainly stopped over along China's coasts during migration. None of our birds bred in the exclusive breeding range of the phaeopus subspecies. Previous studies have predicted that rogachevae whimbrels migrate along the Central Asian Flyway and spend the non-breeding season in West India and East Africa. We found that at least some rogachevae whimbrels migrate along the EAAF and spend the non-breeding season in Southeast Asia and Australia. The ssp. phaeopus is at best sparsely distributed in the EAAF in the west region, or possibly does not occur at all.

Phenological mismatch is often cited as a putative driver of population declines in long‐distance migratory birds. The mechanisms and cues utilized to advance breeding ground arrival will impact the adaptability of species to further warming. Furthermore, timing of post‐breeding migration potentially faces diverging selective pressures, with earlier onset of tropical dry seasons favouring migration advancement, while longer growing seasons in temperate areas could facilitate delayed departures. Despite this, few studies exist of migration phenology on the non‐breeding grounds or on post‐breeding passage. Here, we use first arrival and last departure dates of 20 species of trans‐Saharan migratory birds from tropical non‐breeding grounds (The Gambia), between 1964 and 2019. Additionally, we use first arrival and last departure dates, as well as median arrival and departure dates, at an entry/departure site to/from Europe (Gibraltar), between 1991 and 2018. We assess phenological trends in pre‐ and post‐breeding migration, as well as individual species' durations of stay in breeding and non‐breeding areas. Furthermore, we assess the extent to which inter‐annual variation in these timings may be explained by meteorological and ecological variables. We find significant advances in pre‐breeding migration at both locations, while post‐breeding migration is delayed. At Gibraltar, these trends do not differ between first/last and median dates of migration. The combination of these trends suggests substantial changes in the temporal usage of the two continents by migratory birds. Duration of stay (of species, not individuals) within Europe increased by 16 days, on average, over the 27‐year monitoring period. By contrast, duration of species' stays on the non‐breeding range declined by 63 days, on average, over the 56‐year monitoring period. Taken together these changes suggest substantial, previously unreported alterations to annual routines in Afro‐Palaearctic migrants. [ABSTRACT FROM AUTHOR]

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For five consecutive years (2001–2005), during a one-month period in August–September, we studied the turnover of juvenile Ruddy Turnstones Arenaria interpres at a tidal area along the Dutch coast, by colour-marking cohorts of migrants. Taking turnover into account revealed that 1.8–2.4 times as many juvenile birds used the area during their southward migration, compared to the numbers based on maximum counts. This larger estimate amounts to 35% of the number at which the 1% criterion of the Ramsar Convention is met, whereupon a wetland is designated as internationally important, with significant implications for conservation commitments. Presuming adult birds had the same turnover factor, adult birds contributed almost 70% to the 1% criterion during the same period. Autumn migration of juvenile Ruddy Turnstones was rapid, with more than 50% of individuals leaving within 4 days (95%-CI: 3.4–4.6). The mean mass at departure, as derived from median staging duration and mean body mass gain from recaptured birds (1.1 g/d), was 104.3 g (±10.3 SD). The mean potential flight range as calculated using the aerodynamic approach by Pennycuick was 1981 km (±717 SD), which suggests that juvenile birds that leave the area can cover short to medium distances at most. The fuel loads are sufficient to reach one of the four key wintering sites along the coast of France, but not the Banc d'Arguin in Mauretania, which is the first key wintering site in West Africa. By early October, 80% of the birds had left the study area. Our study shows the importance of a small tidal area during autumn migration and raises the question of whether a considerable number of comparable small stopover sites along the coast of Western Europe and West Africa are needed. More attention to the designation and the protection of such sites and the achievement of a network would have the potential to greatly support juvenile birds on their first journey south. [ABSTRACT FROM AUTHOR]

From July to November 2018, 10 Black-necked Crane (Grus nigricollis) juveniles were tracked using GPS-GSM satellite transmitters to study their migration routes and stopover sites in Yanchiwan Nature Reserve, Gansu Province, China. By the end of the autumn migration in November 2018, more than 25,000 GPS locations had been obtained during tracking. Migration routes, migration distances and stopover sites were determined, and the stopover home range was estimated for each individual. Individuals moved away from Yanchiwan during 2-25 October 2018 and migrated through Da Qaidam, Golmud City, Qumarleb County, Zadoi County, Zhidoi County, and Nagqu City. In mid-November 2018, the birds arrived in Linzhou County, Tibet, China to winter. The migration routes of all individuals were the same, and the average migration distance was 1,500 ± 120 km. Da Qaidam Salt Lake was an important stopover site, with an average stopover duration of 27.11 ± 8.43 d, and the average stopover range of the Black-necked Cranes at Da Qaidam was 27.4 ± 6.92 km2. Through field monitoring and satellite maps, the main habitats were determined to be grasslands and wetlands. [ABSTRACT FROM AUTHOR]

We tracked 39 western flyway white-naped cranes (Antigone vipio) throughout multiple annual cycles from June 2017 to July 2020, using GSM-GPS loggers providing positions every 10-min to describe migration routes and key staging areas used between their Mongolian breeding and wintering areas in China’s Yangtze River Basin. The results demonstrated that white-naped cranes migrated an average of 2556 km (±187.9 SD) in autumn and 2673 km (±342.3) in spring. We identified 86 critical stopover sites that supported individuals for more than 14 days, within a 100–800 km wide migratory corridor. This study also confirmed that Luan River catchment is the most important staging region, where white-naped cranes spent 18% of the annual cycle (in both spring and autumn) each year. Throughout the annual cycle, 69% of the tracking locations were from outside of the currently protected areas, while none of the critical staging areas enjoyed any form of site protection. We see further future potential to combine avian tracking data and remote-sensing information throughout the annual range of the white-naped crane to restore it and other such species to a more favourable conservation status.

In the last 15 years, the west population of white-naped crane (Antigone vipio) decreased dramatically despite the enhanced conservation actions in both breeding and wintering areas. Recent studies highlighted the importance of protecting the integrity of movement connectivity for migratory birds. Widespread and rapid landcover changes may exceed the adaptive capacity of migrants, leading to the collapse of migratory networks. In this study, using satellite tracking data, we modeled and characterized the migration routes of the white-naped crane at three spatial levels (core area, migratory corridor, and migratory path) based on the utilization distribution for two eras (1990s and 2010s) spanning 20 years. Our analysis demonstrated that the white-naped crane shifted its migratory route, which is supported by other lines of evidences. The widespread loss of wetlands, especially within the stopover sites, might have caused this behavioral adaptation. Moreover, our analysis indicated that the long-term sustainability of the new route is untested and likely to be questionable. Therefore, directing conservation effects to the new route might be insufficient for the long-term wellbeing of this threatened crane and large-scale wetland restorations in Bohai Bay, a critical stopover site in the East Asian-Australasian flyway, are of the utmost importance to the conservation of this species.

Satellite‐based technologies that track individual animal movements enable the mapping of their spatial and temporal patterns of occurrence. This is particularly useful in poorly studied or remote regions where there is a need for the rapid gathering of relevant ecological knowledge to inform management actions. One such region is East Asia, where many intertidal habitats are being degraded at unprecedented rates and shorebird populations relying on these habitats show rapid declines.We examine the utility of satellite tracking to accelerate the identification of coastal sites of conservation importance in the East Asian–Australasian Flyway. In 2015–2017, we used solar‐powered satellite transmitters to track the migration of 32 great knots (Calidris tenuirostris), an "Endangered" shorebird species widely distributed in the Flyway and fully dependent on intertidal habitats for foraging during the non‐breeding season.From the great knot tracks, a total of 92 stopping sites along the Flyway were identified. Surprisingly, 63% of these sites were not known as important shorebird sites before our study; in fact, every one of the tracked individuals used sites that were previously unrecognized.Site knowledge from on‐ground studies in the Flyway is most complete for the Yellow Sea and generally lacking for Southeast Asia, Southern China and Eastern Russia.Synthesis and applications. Satellite tracking highlighted coastal habitats that are potentially important for shorebirds but lack ecological information and conservation recognition, such as those in Southern China and Southeast Asia. At the same time, the distributional data of tracked individuals can direct on‐ground surveys at the lesser known sites to collect information on bird numbers and habitat characteristics. To recognize and subsequently protect valuable coastal habitats, filling knowledge gaps by integrating bird tracking with ground‐based methods should be prioritized. [ABSTRACT FROM AUTHOR]

Because migration is highly time‐constrained and migration timing varies among individuals, the responses of migrants to food shortage at a refuelling site could differ between individuals that arrive early and late at the site. To test this hypothesis, we compared the stopover decision, in terms of occurrence and length of stay (LOS), of radiotagged Great Knots Calidris tenuirostris before (2012) and after (2015) a dramatic decline in food supply at a critical spring final pre‐breeding refuelling site in the northern Yellow Sea. The probability of occurrence at the refuelling site was consistent between the two years, whereas the average LOS significantly shortened in the year of food shortage in late‐arriving individuals. This suggests migration timing intensifies the influence of food shortage in late‐arriving individuals, which might be more sensitive and vulnerable to food shortage at refuelling sites compared with early‐arriving individuals. [ABSTRACT FROM AUTHOR]

Large numbers of Semipalmated Sandpipers (Calidris pusilla) use the Bay of Fundy, Canada, as a stopover site during their southbound migration from breeding to wintering grounds. The species exhibits a geographic cline in bill length on the breeding grounds (larger in east). Based on a previous analysis of morphometric traits that detected a small temporal decline in bill length, it has been suggested that observed declines in the Semipalmated Sandpiper population staging in the Bay of Fundy were driven by a disproportionate loss from the eastern breeding population. New data collected in the Bay of Fundy has made it possible to reassess this suggestion. We compared new bill length data from the Bay of Fundy (2009–2014) to historical data (1981–1989, 1997–2007) to examine temporal changes in bill length at this stopover site. We also examined count data at a major roost site from 1981 to 2014 to assess temporal changes in migratory passage. Variation in median passage date is explained best by a combination of year and Arctic climate data. Birds are now migrating through the region later in the season; median passage date has advanced approximately 5 d from 1980s values. Our analyses suggest that while there was a small decline in bill length between the 1980s and early 2000s, it has since reversed and bills are now comparable to historical values. Given this reversal in mean bill length, coupled with population estimates that are still low relative to historical values, there is now little evidence to support the hypothesis that the decline between the 1980s and today in birds passing through the Bay of Fundy is linked to disproportionate losses of eastern breeders. We therefore suggest that population declines may be distributed more broadly across the breeding range of birds that use the Bay of Fundy as a stopover site. [ABSTRACT FROM AUTHOR]

North American populations of Gull-billed Terns (Gelochelidon nilotica) are thought to winter in low numbers throughout Central America, with highest single-site concentrations of up to 200 individuals known from the Panama Canal zone. This paper presents information on a previously unknown stopover and wintering site in southern Honduras, where up to 1,640 individuals, approximately 20% of the entire North American metapopulation, are present during the non-breeding season. This site may be of key importance to full cycle conservation of declining North American populations. Information on habitat use in the eastern Gulf of Fonseca is also included. [ABSTRACT FROM AUTHOR]

Mallard is a dominant waterfowl species wintered in Korea. We researched the mallard spring migration route, stopover sites, and breeding sites. We used cannon nets in Central Korea to catch and attach 10 wild trackers (WT-200). The mallards’ spring departure dates were from the end of March to early April. The spring migration route varied by individual mallards, with most moving through the North Korean east coast. Breeding sites were distributed among the interior of Northeastern China. The average distance to the breeding areas was 1,265 km [standard deviation (SD)=491 km] and the average days spent from wintering site to breeding site was 25.3 days (SD=19.2 days). The mallards used several stopover sites when on the spring migration route (average 3.3±2.1, range 2–9). The time spent at the stopover sites was a minimum of 1 day to a maximum of 16 days. Wintering mallards in Korea showed various individual trends regarding spring migration timing, migration route, stopover sites, and usage days.

A Fairy Pitta Pitta nympha was observed on Oshima Island in the Danjo Islands, located in the northeastern East China Sea on May 30, 2019. This is the first record of this species from the Danjo Islands. [ABSTRACT FROM AUTHOR]

Abstract: East Asian migratory waterfowl have greatly declined since the 1950s, especially the populations that winter in China. Conservation is severely hampered by the lack of primary information about migration patterns and stopover sites. This study utilizes satellite tracking techniques and advanced spatial analyses to investigate spring migration of the greater white‐fronted goose (Anser albifrons) and tundra bean goose (Anser serrirostris) wintering along the Yangtze River Floodplain. Based on 24 tracks obtained from 21 individuals during the spring of 2015 and 2016, we found that the Northeast China Plain is far‐out the most intensively used stopover site during migration, with geese staying for over 1 month. This region has also been intensely developed for agriculture, suggesting a causal link to the decline in East Asian waterfowl wintering in China. The protection of waterbodies used as roosting area, especially those surrounded by intensive foraging land, is critical for waterfowl survival. Over 90% of the core area used during spring migration is not protected. We suggest that future ground surveys should target these areas to confirm their relevance for migratory waterfowl at the population level, and core roosting area at critical spring‐staging sites should be integrated in the network of protected areas along the flyway. Moreover, the potential bird–human conflict in core stopover area needs to be further studied. Our study illustrates how satellite tracking combined with spatial analyses can provide crucial insights necessary to improve the conservation of declining Migratory species. [ABSTRACT FROM AUTHOR]

To determine the timing of the Kamchatka Leaf Warbler Phylloscopus examinandus migration, I conducted bird observations at a park in Asahikawa, Hokkaido, about five times a week during the spring migration period from 2017 to 2020. I found that the timing of the Kamchatka Leaf Warbler migration varied from year to year, but that warblers were most frequently recorded in late May and early June, and rarely in late June. Furthermore, the Japan Bird Research Association's database were reviewed, and included records of 73 Kamchatka Leaf Warblers observed in Hokkaido from late May to mid-June. Because of the late migration by Kamchatka Leaf Warblers, it was difficult to judge whether the birds were observed while still on migration, or if they may have been in Hokkaido for breeding. Our result suggests that observation of Kamchatka Leaf Warblers after late June suggests a strong possibility of breeding, if observations are recorded in suitable breeding habitat. In such cases, an intensive investigation may confirm the presence of breeding. [ABSTRACT FROM AUTHOR]