Subchapter 9.7 – PIREPs and Flight Condition Reports

Bird and Wildlife Activity Reports

In addition to weather PIREPs, you should report:

Bird activity: If you observe flocks of birds near the aerodrome or along your route, report it. "Zurich Approach, HB-CDA, large flock of birds observed at 500 feet altitude, 5 kilometers north of the aerodrome."
Wildlife on runway: If you observe deer, sheep, or other large animals on a runway before landing, report it. "Zurich Tower, HB-CDA, wildlife on Runway 28, unable to land."

ATC will then issue NOTAMs to alert other aircraft.