GENERAL INFORMATION

1. Content:
This dataset contains data used in the following publication: Piironen, A. & Laaksonen, T. 2023: A gradual migratory divide determines not only the direction of migration but also migration strategy of a social migrant bird. Proceedings of the Royal Society B: Biological Sciences. https://doi.org/10.1098/rspb.2023.1528

2. Author information for the data:
Name: Antti Piironen
Institution: University of Turku
Email: antti.p.piironen@utu.fi, antti.p.piironen@gmail.com

Name: Toni Laaksonen
Institution: University of Turku
Email: tokrla@utu.fi

Name: Tuomas Seimola
Institution: Natural Resources Institute Finland
Email: tuomas.seimola@luke.fi

3. Date of data collection: Years 2019-2022

4. Geographic location of data collection: Finland

1. Links to publications that cite or use the data:
Piironen, A. & Laaksonen, T. 2023: A gradual migratory divide determines not only the direction of migration but also
migration strategy of a social migrant bird. Proceedings of the Royal Society B: Biological Sciences. https://doi.org/10.1098/rspb.2023.1528

2. Links to other publicly accessible locations of the data: None

4. Links/relationships to ancillary data sets: None

5. Was data derived from another source: No

1. File List:
greylag-data-all-010819-310722-one-per-hour.csv
individual-data-clean.csv
neckband-observation-data-clean.csv
ringing-data-greylag-clean.csv

2. Relationship between files, if important: Variables with the same names on different mean the same thing (for example variable "NECK_BAND" in different files). In addition, individual identifier is "bird" in the first file, but "NECK_BAND" in the next ones.

3. Additional related data collected that was not included in the current data package: None

• UTC_datetime: date and time for each GPS fix (timezone UTC) in format "YYYY-MM-DD HH:MM:SS"
• lon: longitude (WGS84)
• lat: latitude (WGS84)
• hdop: horizontal dilution of precision for each GPS fix
• tag: serial number for each tag
• bird: individual identifier for each tracked bird
• date: date for each GPS fix (timezone UTC) in format "YYYY-MM-DD"
• date_chr: date without the year in format "MM-DD)
• burst: Burst (anniversary date in the turn of the year) for each GPS fix, format "bird-year" (for example F12-2019)
• hour.UTC_datetime: hour of the day (range 1-23) for each GPS fix (timezone UTC)
• as.Date.UTC_datetime: date for each GPS fix (timezone UTC) in format "YYYY-MM-DD" (this is a redundant variable as it occurs two times in the data)

4. Missing data codes: NA (not applicable) or the value is simply missing

DATA-SPECIFIC INFORMATION FOR: individual-data-clean.csv
The original version of this file is downloaded from geese.org, and hence, there are several variables with missing data (NA). These are not used in the analysis of the paper and hence,
do not prevent reproducing the analysis.
1. Number of variables: 10
2. Number of cases/rows: 244
3. Variable List:

• NECK_BAND: individual identifier for marked birds
• FLYWAY: flyway for each bird if known (W = western flyway, C = central flyway)
• NOTES: notes regarding flyway for some remarkable birds
• PAIRED_WITH_MARKED: whether the bird is known to be paired with another marked bird (TRUE/FALSE)
• AGE: age (A = adult, J = juvenile, 2CY = second calendar year)
• SEX: sex of the bird
• COUNTY: county of origin for each bird
• SUMMER_BURST: Burst (anniversary date 1 July) for each GPS-tracked bird, format "bird-season" (for example F12-19-20)
• BURST: Burst (anniversary date in the turn of the year) for GPS-tracked birds in years
• FLYWAY_BIN: Flyway in binary form for each bird if known (1 = western flyway, 0 = central flyway)

4. Missing data codes: NA (not applicable) or the value is simply missing

DATA-SPECIFIC INFORMATION FOR: neckband-observation-data-clean.csv
1. Number of variables: 33
2. Number of cases/rows: 2536
3. Variable List:

• NECK_BAND: individual identifier for marked birds (neckband code)
• EURING: Euring code for species
• SUB_EURING: redundant (all NA)
• SITE_CODE: redundant (all NA)
• LATITUDE: latitude for each observation (WGS84)
• LONGITUDE: longitude for each observation (WGS84)
• OBS_DATE: observation date
• OBS_TIME: observation time
• RING_TYPE: type of neckband (NB = blue neckband, NW = white neckband)
• OAS_ID: observation id in geese.org
• LEG_RING: redundant (all NA)
• METAL: redundant (all NA)
• ALIVE_DEAD: whether the bird was observed alive or dead (geese.org coding)
• DATE_ACC: date accuracy (geese.org coding)
• HABITAT_C: redundant
• ROW_ID: row id in geese.org (redundant here)
• BIRD_ID: individual identifier for marked birds in geese.org
• SEXE: sex
• INSERTED: date for observation submission
• CNTRY_NAME: name of the country
• PROV_NAME: name of the province
• PROV_CODE: code for the province
• API: redundant (all NA)
• DOWNLOADER: downloader of the data (redundant here)
• DUMMY: redundant
• FLYWAY: flyway for each bird if known (W = western flyway, C = central flyway)
• NOTES: notes regarding flyway for some remarkable birds
• PAIRED_WITH_MARKED: whether the bird is known to be paired with another marked bird (TRUE/FALSE)
• AGE: age (A = adult, J = juvenile, 2CY = second calendar year)
• SEX: sex (redundant as the variable is duplicated in the file)
• COUNTY: county of origin for each bird
• SUMMER_BURST : Burst (anniversary date 1 July) for each GPS-tracked bird, format "bird-season" (for example F12-19-20)
• BURST: Burst (anniversary date in the turn of the year) for GPS-tracked birds in year

4. Missing data codes: NA (not applicable) or the value is simply missing

DATA-SPECIFIC INFORMATION FOR: ringing-data-greylag-clean.csv
The original version of this file is downloaded from geese.org, and hence, there are several variables with missing data (NA). These are not used in the analysis of the paper and hence,
do not prevent reproducing the analysis.
1. Number of variables: 33
2. Number of cases/rows: 2536
3. Variable List:

• EURING: Euring code for species
• SUB_EURING: redundant (all same as species)
• LOCATION: ringing site name
• SITE_CODE: redundant (all NA)
• LATITUDE: latitude for marking sites (WGS84)
• LONGITUDE: longitude for marking sites (WGS84)
• HABITAT_C: redundant (all NA)
• OBS_DATE: redundant (all 00:00)
• OBS_TIME: redundant (all 00:00)
• OBSERVER: redundant (all same here)
• RING_TYPE: type of neckband (NB = blue neckband, NW = white neckband)
• NECK_BAND: individual identifier (neckband code)
• LEG_RING: redundant (all NA)
• METAL: individual identifier (legring code)
• SCHEME: ringing centre code
• CATCH_TYPE: redundant (all "FALSE")
• SEX_RNG: sex
• SEX_DEF: redundant (all same as SEX_RNG)
• YEAR_BIRTH: year of birth, if known
• DEATH_DATE: death date, if known
• WEIGHT: redundant (all NA)
• WING_LEN: redundant (all NA)
• HEAD_LEN: redundant (all NA)
• CULMEN: redundant (all NA)
• BEAK_TYPE: redundant (all NA)
• TARSUS: redundant (all NA)
• TAIL_FTHRS: redundant (all NA)
• AGE: age (A = adult, J = juvenile, 2CY = second calendar year)
• NAIL_SIZE: redundant (all NA)
• NAIL_SHAPE: redundant (all NA)
• TEETH: redundant (all NA)
• OLD_SCHEME: redundant (all NA)
• OLD_TYPE: redundant (all NA)
• OLD_NECK: redundant (all NA)
• OLD_METAL: redundant (all NA)
• OLD_LEG: redundant (all NA)
• OAS_ID: observer id in geese.org
• BIRD_ID: bird id in geese.org
• ROW_ID: row id in geese.org
• DOWNLOADER: downloader of the data (redundant here)

4. Missing data codes: NA (not applicable) or the value is simply missing