Quick Overview: Riverland Migratory Bird Sanctuary, St. Charles, Mo. It's a partnership that's as unlikely as any: herds of bison on the move are kicking up chunks of earth. This, in turn, gives Cliff swallows gathering mud for their nests
Cliff Swallows Getting Mud - Detailed Overview & Context
Riverland Migratory Bird Sanctuary, St. Charles, Mo. It's a partnership that's as unlikely as any: herds of bison on the move are kicking up chunks of earth. This, in turn, gives Cliff swallows gathering mud for their nests
![Cliff Swallows Building Nests, Mating, and Facing Home Invaders [NARRATED]](https://i.ytimg.com/vi/A_EAHjWhvf0/mqdefault.jpg)
