Dietmar Nill / Tengmalm's Owl (Aegolius funerus) pouncing on mouse, Germany

Nick Saunders/ BIA / Boreal Owl (Aegolius funereus) chicks, Saskatchewan, Canada

Markus Varesvuo / Tengmalm's Owl (Aegolius funereus) close-up of eye. Kuusamo Finland, May. Winner of the Birds Category in the Finnish Nature Photo of the Year Competition 2013

Wild Wonders of Europe / Lesniewski / Tengmalm's Owl (Aegolius funereus) nesting in an old beech tree. Bieszczady, Carpathian Mountains, Poland, May.

Gerrit Vyn / Two Northern Saw-whet Owls (Aegolius acadicus) fledgling chicks, that have recently left the safety of their nest cavity. Alberta, Canada. June.

Wild Wonders of Europe / Cairns / Tengmalm's owl (Aegolius funereus) peering out of nestbox, Bergslagen, Sweden, June 2009

Konrad Wothe / Boreal Owl (Aegolius funereus) in nest cavity, Sweden

Konrad Wothe / Boreal Owl (Aegolius funereus) in nest cavity, Sweden

Tim Fitzharris / Northern Saw-whet Owl (Aegolius acadicus) perching in a wild rose bush, British Columbia, Canada

Karine Aigner / Tourist with Tengmalm's Owl (Aegolius funereus) at Akiba Fukurou Owl Cafe, Tokyo, Japan.

Markus Varesvuo / Tengmalm's owl (Aegolius funereus) Helsinki, Finland, December.

Christof Wermter/ BIA / Boreal Owl (Aegolius funereus), Bavaria, Germany