What does this bird's low-altitude flight portend?

Many birds fly low at night, which indicates cloudy or rainy.

Because when the weather is cloudy, the water content in the air increases, and the feathers on the wings of birds will absorb the water, thus increasing the negative weight of the wings, so they will fly very low. The air humidity is high, insects fly low, and birds fly low for food.

Swallows always fly low to catch insects before it rains, so they are called "weathermen".