Dataset DOI: 10.5061/dryad.51c59zwm3

Description of the data and file structure

Migratory shorebirds are experiencing rapid population declines. Monitoring programs along shorebird flyways provide information on their population dynamics and habitat requirements at different life stages, which is important for conservation planning. Such surveys often occur at several high-tide roosts during daytime high tide, when birds are more concentrated and easier to count. However, it remains unclear whether these surveys can cover the entire shorebird community within a site and represent shorebirds' preferences during both day and night.

Here, we tested two community-level hypotheses: (1) surveys at high-tide roosts can adequately represent the community within a site; and (2) daytime surveys can adequately represent birds' preferences over the whole day. We combined GPS tracking data of four species — nine common redshanks (Tringa totanus), three grey plovers (Pluvialis squatarola), two greater sand plovers (Charadrius leschenaultii) and two red knots (Calidris canutus) — with community-level shorebird survey data from aquaculture ponds and nearby tidal flats on their overwintering grounds in southern China.

Our results showed that, in an area with extensive artificial roosting habitats, shorebirds using the same feeding area on the tidal flat may choose different roosts, even when alternative roosts are available nearby. Individuals within the three tracked species exhibited marked differences in roost selection between day and night, and the factors influencing roost selection varied both among species and between day and night. Therefore, daytime high-tide surveys alone are insufficient to assess habitat use and preferences at the species level. Management of shorebird roosting habitats should not assume uniform preferences across species.

Files and variables

File: Raw_data.zip

This dataset (stored in Raw_data.zip) contains:

1. GPS tracking data of four shorebird species — nine common redshanks (Tringa totanus), three grey plovers (Pluvialis squatarola), two greater sand plovers (Charadrius leschenaultii) and two red knots (Calidris canutus) — at one of their overwintering sites, Fucheng Township, Leizhou, Guangdong Province, during the winters of 2019–2020 and 2020–2021;
2. Count data from overwintering shorebird surveys on tidal flats and aquaculture ponds, from October 2018 to January 2021, in the same area;
3. A shorebird habitat map together with the boundaries of individual aquaculture ponds for the same region.

The tracking and field survey data are stored in CSV format. The habitat map is stored as a GeoTIFF, and the boundaries of individual aquaculture ponds are stored as an ESRI shapefile.

Contents of Raw_data.zip:

• /individual aquaculture pond boundaries/ — boundaries of individual aquaculture ponds used in the analysis (ESRI shapefile; CRS: WGS 84, EPSG:4326).
• /tracking data/ — a CSV file of all GPS tracking locations used in the analysis.
• SN to id.txt — a lookup table mapping each tag serial number (S/N) in the tracking data to its individual identifier (the identifier prefix encodes the species; see below).
• field survey data.csv — all field count data used in the analysis.
• Habitat map.tif — the habitat map used in the analysis (CRS: WGS 84, EPSG:4326); the classification scheme is recorded in Habitat mapping scheme.txt.

Missing values are coded as NA throughout the CSV files.

Variables — field survey data (field survey data.csv)

Variables — GPS tracking data

Tag serial number to individual (SN to id.txt)

Individual identifiers use a four-letter species prefix: CORE = common redshank (Tringa totanus), GRPL = grey plover (Pluvialis squatarola), GSPL = greater sand plover (Charadrius leschenaultii), REKN = red knot (Calidris canutus).

Access information

This dataset is associated with the following open-access publication:

The conservation of migratory shorebirds needs to account for the different
habitat selection patterns across species and between day and night.
Biological Conservation, 309 (2025): 111256.
https://doi.org/10.1016/j.biocon.2025.111256

Data were derived in part from the following source:

• Sentinel-2 satellite imagery. The habitat map (Habitat map.tif) was derived from a single Sentinel-2 scene (granule identifier 20201208T031121_N0209_R075_T49QDD). The scene itself is not redistributed in this deposit; it is freely available from the Copernicus Data Space Ecosystem and can be retrieved using the identifier above: https://dataspace.copernicus.eu/explore-data/data-collections/sentinel-data/sentinel-2 Sentinel data are provided by the EU Copernicus programme on a free, full and open basis (contains modified Copernicus Sentinel data 2020).

All files included in this deposit (GPS tracking data, field survey data, the derived habitat map, and the aquaculture-pond boundaries) are the authors' own work.

License: CC0 1.0 (Dryad default; data dedicated to the public domain).