Revealing migration of an unknown EAAF waterbird: The Wood Snipe

EAAFP Small Grant Fund Project by Xiaotong Ren, Peking University Shen Zhang, Shanshui Conservation Center On the remote alpine meadows of Pingwu County, Mianyang, Sichuan, China, there is a mysterious bird species that even locals rarely have a chance to see. Some of the villagers who often go to the alpine meadow said: “The call and flight of 'mud driller' (the name for Wood Snipe by local people, because it usually feeds on the ground) could be heard nearby when we stayed in huts at night. Sometimes, the sound of its flight is very strange, like there are little bells on its body, and it ‘po-po-po’ falls to the ground.” This is the Wood Snipe (Gallinago nemoricola, Figure 1). Snipes (Gallinago spp.) are a very special group of shorebirds: unlike most "typical" shorebirds that prefer to live on muddy or sandy riverbanks and beaches, snipes tend to live in concealed wetland vegetation. The Wood Snipe is an even more distinctive species among snipes. According to historical specimen collections and birdwatching records, they appear in tropical forests near South Asia and Southeast Asia in winter but breeds in alpine meadows of the Himalayas and Hengduan Mountains in summer. Figure 1. Wood Snipe at Pingwu County ©Tong Mu The mystery of Wood Snipes is largely due to the difficulty in reaching alpine meadows, combined with their secretive behavior. Basic information about the species, such as population size, complete distribution range, habitat preferences, diet, and behavior, is extremely scarce. Prior to our project, the only modern research conducted on this species was a population survey project in Nepal. Current knowledge of the species is mostly based on piecing together various historical records and sporadic birdwatching records. While we know almost nothing about basic aspects of Wood Snipes, they have already been listed as Vulnerable in the IUCN Red List, with a declining population estimated at only 2,500-9,999 individuals globally. As the Chinese proverb goes, "the beginning is always the hardest," our fieldwork started in the midst of great unknowns. Based on historical records, interviews with local residents, and valuable information from Mr. Wang of the Mianyang Birdwatching Society, we speculated that the Wood Snipes would appear in early May at their breeding ground in Pingwu County. Our advance team gathered to conduct a final recce in late April 2021 before the formal field work started. However, to everyone's surprise, the Wood Snipes had arrived before us, even though it was still snowing heavily on the mountain (Figure 2). Just as the locals had said, we didn't spot any of them until nightfall when we heard their flying and singing near our shelters. The first batch of team members quickly assembled and departed on April 30th, only several days after the recce, rushing into the formal field work stage. Figure 2: Heavy snow suddenly falls when we were searching for Wood Snipes. The snowy weather at our study area could last until the beginning of June From May 1st, we started our 2-month fieldwork on alpine meadow living at a simple and crude camp (3400m in elevation, Figure 3) without electricity and stable mobile phone signal but surrounded by Wood Snipe display every sunrise and sunset. Our objective was to investigate the population size and distribution of Wood Snipes and characterize the habitats and threats to Wood Snipes at our study area and to identify the migratory route and wintering grounds of the Wood Snipe population that breeds in the Hengduan Mountains. We conducted population size and distribution survey, preliminary observation and description of breeding biology, call survey, individual capture and banding, survey for habitat characteristics and food resource. Figure 3: Camp site in the field We recorded a total of 123 Wood Snipe occurrence sites during the field survey in 2021. We estimated there were 9 home ranges in the entire study area, each representing 1 - 2 adult individuals. We also found that across the entire alpine meadow which seemed identical to us ranging from about 3400 - 3750 m, Wood Snipes preferred lower elevation (<3600m) and median level of soil moisture. They also had a higher probability of occurrence at sites with more potential food resources (soil macroinvertebrates). We also captured and banded 7 individual Wood Snipes and successfully fitted tracking devices to them while ensuring that the weight of each tracking device was less than 5% of the corresponding individual's body weight (Figure 4). Since the tracking devices were unstable, we only had the southward migration routes for two individuals and northward migration route for one individual (Figure 5). This was the first time that the migration of this cryptic species had been revealed. Figure 4: Wood Snipe individual fitted with satellite transmitter Figure 5: Map of Wood Snipe tracking in non-breeding season. Individuals marked by colors: orange indicates south-ward migration of one individual, dark blue and light blue indicate south-ward and north-ward migration of another individual respectively Our work for Wood Snipe in 2021 is just the beginning for the study and conservation of this species and much remains to be done in the future. You could find more details in our report and future publications. Please contact us if you are interested in our project or have any questions about it. The project was funded through the 2021 EAAFP WG/TF Small Grant Fund. View the report, Click here.  

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