Two young russet-backed thrushes in nest among ferns.

Two young russet-backed thrushes, one sitting on nest among ferns.

Young Sierra hermit thrush chicks in their nest near Paradise River in Mount Rainier National Park.

A Sierra hermit thrush and three young chicks in their nest in Mount Rainier National Park.

A Sierra hermit thrush and three young chicks in their nest in Mount Rainier National Park.

A Sierra hermit thrush and three young chicks in their nest in Mount Rainier National Park.

Two young russet backed thrushes in their nest. Image taken by Dr. Kellogg. Image note: negative broken and top half of plate missing.

A russet backed thrush at its nest with young inside. Image note: plate showing motion.

A russet backed thrush at its nest with young inside. Image note: plate showing motion.

A russet backed thrush in its nest.