A visitor stands behind an illustration of a Polar owl, part of an exhibition at the Summer Garden, in St. Petersburg May 23, 2013. The annual street photo-exhibition, which consists of 60 photos displaying animals and birds listed in the Red Book of Russia, was organized to match the International Day for Biological Diversity introduced by the United Nations General Assembly and marked on May 22, according to representatives. REUTERS/Alexander Demianchuk (RUSSIA - Tags: SOCIETY ENVIRONMENT ANNIVERSARY ANIMALS TPX IMAGES OF THE DAY) 

Visitors look at an illustration of a Polar owl, part of an exhibition at the Summer Garden, in St. Petersburg May 23, 2013. The annual street photo-exhibition, which consists of 60 photos displaying animals and birds listed in the Red Book of Russia, was organized to match the International Day for Biological Diversity introduced by the United Nations General Assembly and marked on May 22, according to representatives. REUTERS/Alexander Demianchuk (RUSSIA - Tags: SOCIETY ENVIRONMENT ANNIVERSARY ANIMALS) 

Two polar owls sit in an open-air cage at the Royev Ruchey zoo in the Siberian city of Krasnoyarsk, April 19, 2010. REUTERS/Ilya Naymushin (RUSSIA - Tags: ANIMALS ENVIRONMENT) 

A Polar Owl sits in an open-air cage at the "Royev Ruchey" zoo in the Siberian city of Krasnoyarsk November 6, 2007. REUTERS/Ilya Naymushin (RUSSIA) 

A Polar Owl sits in an open-air cage at the "Royev Ruchey" zoo in the Siberian city of Krasnoyarsk November 6, 2007. REUTERS/Ilya Naymushin (RUSSIA) 

A Polar Owl sits in an open-air cage at the "Royev Ruchey" zoo in the Siberian city of Krasnoyarsk November 6, 2007. REUTERS/Ilya Naymushin (RUSSIA) 

A polar owl sits looks out from its cage in Moscow's Zoo November 23, 2005. 

A polar owl looks out from its cage in Moscow's Zoo November 23, 2005. REUTERS/Alexander Natruskin 

A polar owl sits looks out from its cage in Moscow's Zoo November 23, 2005. REUTERS/Alexander Natruskin 

A polar owl looks out of its cage at St.Petersburg's Zoo, February 18, 2004. St.Petersburg Zoo, one of the oldest in Europe, will celebrate it's 140th anniversary next year. REUTERS/Alexander Demianchuk PP04020142 WAWAA 

A polar owl looks out of its cage at St.Petersburg's Zoo, February 18, 2004. St.Petersburg Zoo, one of the oldest in Europe, will celebrate it's 140th anniversary next year. 

Polar owls look out of their cage in St. Petersburg's Zoo, January 10, 2003. The Owls and [polar bears] were the rare animals which remained in their regular places while all others were taken to warmer shelters. [In European Russia and East Siberia, where temperatures approached minus 50 degrees Celsius, hot water pipeline systems collapsed in 13 regions, forcing about 23,000 people to live without heat, Russia's Emergecies Ministry said.] 

Polar owls look out of their cage in St. Petersburg's Zoo, January 10, 2003.
The Owls and polar bears were the rare animals which remained in their
regular places while all others were taken to warmer shelters. In European
Russia and East Siberia, where temperatures approached minus 50 degrees
Celsius, hot water pipeline systems collapsed in 13 regions, forcing about
23,000 people to live without heat, Russia's Emergecies Ministry said.
REUTERS/Alexander Demianchuk

AS/CRB 

A polar owl looks out of its cage at the St.Petersburg's Zoo, November 21,
2002. A snowstorm hit the Russian second biggest city, which will host the
summit of the U.S. President George Bush and Russian President Vladimir
Putin this Friday. REUTERS/Alexander Demianchuk PP03110011

AS/AA