Snowy Plover (snpl) data sets

1. Population survey data
1a. Population survey data of the Texas population (snpl_population survey_Texas.csv)
	year: the year in which the survey was conducted
	lake: the lake where the survey was conducted
	date: Julian date when the survey was conducted
	count: count data
1b. Population survey data of the New Mexico population (snpl_population survey_New Mexico.csv)
	year: the year in which the survey was conducted
	date: Julian date when the survey was conducted
	count: count data
1c. Population survey data of the Oklahoma population (snpl_population survey_Oklahoma.csv)
	year: the year in which the survey was conducted
	grid: the grid cell in which the survey was conducted
	count: count data
1d. Distance sampling data of the Oklahoma population (snpl_distance sampling_Oklahoma.csv)
	year: the year in which the survey was conducted
	grid: the grid cell in which the survey was conducted
	count: count data
	distance: the distance between the observer and the counted birds

2. Encounter history data (snpl_encounter history.csv)
	id: individual identity
	cohort: age-sex class at the first capture
		af: adult female
		am: adult male
		jf: juvenile female
		jm: juvenile male
		ju: juvenile without sex information
	region: region of the survey, Texas, New Mexico, or Oklahoma
	f: year of the first encounter
	year_1998 ~ year_2018: encounter history from 1998 through 2018
		0: not seen
		1: resighted but not recaptured
		2: recaptured but not resighted
		3: resighted and recaptured

3. Nest survey data (snpl_nest survey.csv)
	year: the year in which the survey was conducted
	region: region of the survey, Texas, New Mexico, or Oklahoma
	clutch: clutch size, 1, 2, or 3
	fate: clutch fate
		0: fail
		1: succeed

4. Covariates data
4a. Covariates data for Texas (snpl_covariates_Texas.csv)
4b. Covariates data for New Mexico (snpl_covariates_New Mexico.csv)
4c. Covariates data for Oklahoma (snpl_covariates_Oklahoma.csv)
	year: year
	palmer: Palmer drought severity index
	aet: actual evapotranspiration
	prcp: precipitation
	tmax: maximum temperature
	tmin: minimum temperature
	wind: wind speed