LRGV Nocturnal Bird Migration Study
Grasshopper Sparrow nocturnal flight call (nfc) activity at Alamo Inn B&B automatically detected by Nighthawk software. Call monitoring in 2023 occurred from 9pm-5am. In 2025 it occurred from half an hour after sunset to 90 minutes before sunrise. So, 2023 data involve a consistent 8-hour sample of the night and 2025 involves a consistent time frame relative to sunset and sunrise. For example on September 24, 9 hours and 56 minutes of the night was sampled and on October 15 the nightly sample was 10 hours and 28 minutes. 2026 monitoring is like 2025 except the recording window extend to half and hour befor sunrise, so an hour longer recording time each night. W. Evans checked whether automatic detections were correctly identified and removed false positives. Nfc activity is the sum of all incidences of a GRSP detection that occurred at least one minute from another GRSP detection. In other words, calls occurring within one minute were tallied as one.