Characterization of the North American aerial migratory niche

Seasonal measures from 143 NEXRAD sites of fights height envelopes and timing of peak migration within 24-hour phases as measured as hour after sunset. Flight height envelopes include the envelope starting height (<i>mean_start_height_m</i>), width (<i>mean_envelope_width_m</i>), and ending height (<i>mean_end_height_m</i>), and timing of peak migration is measured in hours after sunset including the mean (<i>mean_peak_hr_after_sunset</i>), median timing (<i>median_peak_hr_after_sunset</i>), and standard deviation (<i>sd_peak_hr_after_sunset</i>).