species_code: alphanumeric eBird species code.
region_type: country for countries or state for states, provinces,
or other sub-national regions.
region_code: alphanumeric code for the region.
region_name: English name of the region.
season: name of the season that the summary statistics were calculated
for.
abundance_mean: mean relative abundance in the region.
total_pop_percent: proportion of the seasonal modeled population
falling within the region.
range_percent_occupied: the proportion of the region occupied by the
species during the given season.
range_total_percent: the proportion of the species seasonal range
falling within the region.
range_days_occupation: number of days of the season that the region was
occupied by this species.