Geese and other large birds definitely fly at night. About twenty years ago my S76 was hit by a bird with a wingspan of around a metre. We knew that because of the marks from its wings, which wrapped around the upper cowling. It briefly blocked out my view of the cultural lighting behind it. It was after midnight during a casevac flight. Thankfully it hit just above the windscreen and did no real damage but the blood and guts took a lot of cleaning off. If it had hit the windscreen or the pitch control rods I might not be here writing this.