Bird's wings

Who wrote the book "How birds fly"

What part of the bird's body is strong enough to fight the air currents/force?

A bird's wings is covered with a layer of __________?

why do birds have hallow bones?

The feathers of a bird need to be ________ so that if it is lost it can be replaced.

Who wrote the book "A bird watcher's guide"

_____ and ____ of the wings helps you identify the type of bird it is

The peregrine falcon can reach speeds of nearly ___ kilometers per hour.

Which bird has the longest and narrowest wings?

short wings allows a bird to ______ and ____.