Collective behavior scientist Alex Jordan of the Max Planck Institute for Ornithology holds his hand in a tank with fish of the species of African cichlid from the African Lake Tanganyika at a laboratory at the University of Konstanz in Konstanz, Germany February 14, 2019. Picture taken February 14, 2019. REUTERS/Arnd WIegmann 

Collective behavior scientist Alex Jordan of the Max Planck Institute for Ornithology holds his hand in a tank with fish of the species of African cichlid from the African Lake Tanganyika at a laboratory at the University of Konstanz in Konstanz, Germany February 14, 2019. Picture taken February 14, 2019. REUTERS/Arnd WIegmann 

Migrating cranes fly over the Hula Lake Ornithology and Nature Park in northern Israel, which is a stopping point for hundreds of species of birds along their migration route between the northern and southern hemispheres during the cold season December 7, 2016. REUTERS/Baz Ratner 

Migrating cranes rest on the Hula Lake Ornithology and Nature Park in northern Israel, which is a stopping point for hundreds of species of birds along their migration route between the northern and southern hemispheres during the cold season December 7, 2016. REUTERS/Baz Ratner 

Migrating cranes rest on the Hula Lake Ornithology and Nature Park in northern Israel, which is a stopping point for hundreds of species of birds along their migration route between the northern and southern hemispheres during the cold season December 7, 2016. REUTERS/Baz Ratner 

Migrating cranes rest on the Hula Lake Ornithology and Nature Park in northern Israel, which is a stopping point for hundreds of species of birds along their migration route between the northern and southern hemispheres during the cold season December 7, 2016. REUTERS/Baz Ratner 

Migrating cranes rest on the Hula Lake Ornithology and Nature Park in northern Israel, which is a stopping point for hundreds of species of birds along their migration route between the northern and southern hemispheres during the cold season December 7, 2016. REUTERS/Baz Ratner 

Migrating cranes fly over the Hula Lake Ornithology and Nature Park in northern Israel, which is a stopping point for hundreds of species of birds along their migration route between the northern and southern hemispheres during the cold season December 7, 2016. REUTERS/Baz Ratner 

A migrating crane flies over the Hula Lake Ornithology and Nature Park in northern Israel, which is a stopping point for hundreds of species of birds along their migration route between the northern and southern hemispheres during the cold season December 7, 2016. REUTERS/Baz Ratner 

Migrating cranes rest on the Hula Lake Ornithology and Nature Park in northern Israel, which is a stopping point for hundreds of species of birds along their migration route between the northern and southern hemispheres during the cold season December 7, 2016. REUTERS/Baz Ratner 

Migrating cranes fly over the Hula Lake Ornithology and Nature Park in northern Israel, which is a stopping point for hundreds of species of birds along their migration route between the northern and southern hemispheres during the cold season December 7, 2016. REUTERS/Baz Ratner 

Migrating cranes are seen at the Hula Lake Ornithology and Nature Park in northern Israel, which is a stopping point for hundreds of species of birds along their migration route between the northern and southern hemispheres during the cold season December 7, 2016. REUTERS/Baz Ratner 

Migrating cranes rest on the Hula Lake Ornithology and Nature Park in northern Israel, which is a stopping point for hundreds of species of birds along their migration route between the northern and southern hemispheres during the cold season December 7, 2016. REUTERS/Baz Ratner 

Employee of ornithological flight support service Nika Ryzhova-Alenicheva holds her hawk, which is used to control fauna to avoid bird strikes during takeoffs and landings, at Domodedovo airport outside Moscow, Russia September 2, 2016. Picture taken September 2, 2016. REUTERS/Maxim Zmeyev 

Employee of ornithological flight support service Nika Ryzhova-Alenicheva sits in a vehicle with her hawk, which is used to control fauna to avoid bird strikes during takeoffs and landings, at Domodedovo airport outside Moscow, Russia September 2, 2016. Picture taken September 2, 2016. REUTERS/Maxim Zmeyev 

Employee of ornithological flight support service Nika Ryzhova-Alenicheva feeds her hawk, which is used to control fauna to avoid bird strikes during takeoffs and landings, at Domodedovo airport outside Moscow, Russia September 2, 2016. Picture taken September 2, 2016. REUTERS/Maxim Zmeyev 

Employee of ornithological flight support service Nika Ryzhova-Alenicheva releases her hawk, which is used to control fauna to avoid bird strikes during takeoffs and landings, at Domodedovo airport outside Moscow, Russia September 2, 2016. Picture taken September 2, 2016. REUTERS/Maxim Zmeyev 

Employee of ornithological flight support service Nika Ryzhova-Alenicheva holds her hawk, which is used to control fauna to avoid bird strikes during takeoffs and landings, at Domodedovo airport outside Moscow, Russia September 2, 2016. Picture taken September 2, 2016. REUTERS/Maxim Zmeyev 

Employee of ornithological flight support service Nika Ryzhova-Alenicheva holds her hawk, which is used to control fauna to avoid bird strikes during takeoffs and landings, at Domodedovo airport outside Moscow, Russia September 2, 2016. Picture taken September 2, 2016. REUTERS/Maxim Zmeyev 

Employee of ornithological flight support service Nika Ryzhova-Alenicheva holds her hawk, which is used to control fauna to avoid bird strikes during takeoffs and landings, at Domodedovo airport outside Moscow, Russia September 2, 2016. Picture taken September 2, 2016. REUTERS/Maxim Zmeyev TPX IMAGES OF THE DAY

Migrating cranes rest on the Hula Lake Ornithology and Nature Park in northern Israel February 14, 2016. The Hula Valley is a stopping point for hundreds of species of birds along their migration route between the northern and southern hemispheres and during the cold season it becomes one of the largest concentrations of cranes in the world, a spokeperson for the Jewish National Fund said. REUTERS/Baz Ratner 

Migrating cranes fly over the Hula Lake Ornithology and Nature Park in northern Israel February 14, 2016. The Hula Valley is a stopping point for hundreds of species of birds along their migration route between the northern and southern hemispheres and during the cold season it becomes one of the largest concentrations of cranes in the world, a spokeperson for the Jewish National Fund said. REUTERS/Baz Ratner 

Migrating cranes fly over the Hula Lake Ornithology and Nature Park in northern Israel February 14, 2016. The Hula Valley is a stopping point for hundreds of species of birds along their migration route between the northern and southern hemispheres and during the cold season it becomes one of the largest concentrations of cranes in the world, a spokeperson for the Jewish National Fund said. REUTERS/Baz Ratner 

Migrating cranes fly over the Hula Lake Ornithology and Nature Park in northern Israel February 14, 2016. The Hula Valley is a stopping point for hundreds of species of birds along their migration route between the northern and southern hemispheres and during the cold season it becomes one of the largest concentrations of cranes in the world, a spokeperson for the Jewish National Fund said. REUTERS/Baz Ratner 

Migrating cranes fly over the Hula Lake Ornithology and Nature Park in northern Israel February 14, 2016. The Hula Valley is a stopping point for hundreds of species of birds along their migration route between the northern and southern hemispheres and during the cold season it becomes one of the largest concentrations of cranes in the world, a spokeperson for the Jewish National Fund said. REUTERS/Baz Ratner 

Migrating cranes fly over the Hula Lake Ornithology and Nature Park in northern Israel February 14, 2016. The Hula Valley is a stopping point for hundreds of species of birds along their migration route between the northern and southern hemispheres and during the cold season it becomes one of the largest concentrations of cranes in the world, a spokeperson for the Jewish National Fund said. REUTERS/Baz Ratner 

A migrating crane fly over the Hula Lake Ornithology and Nature Park in northern Israel February 14, 2016. The Hula Valley is a stopping point for hundreds of species of birds along their migration route between the northern and southern hemispheres and during the cold season it becomes one of the largest concentrations of cranes in the world, a spokeperson for the Jewish National Fund said. REUTERS/Baz Ratner 

Migrating cranes can be seen at the Hula Lake Ornithology and Nature Park in northern Israel February 14, 2016. The Hula Valley is a stopping point for hundreds of species of birds along their migration route between the northern and southern hemispheres and during the cold season it becomes one of the largest concentrations of cranes in the world, a spokeperson for the Jewish National Fund said. REUTERS/Baz Ratner 

Migrating cranes stand as another flies over the Hula Lake Ornithology and Nature Park in northern Israel February 14, 2016. The Hula Valley is a stopping point for hundreds of species of birds along their migration route between the northern and southern hemispheres and during the cold season it becomes one of the largest concentrations of cranes in the world, a spokeperson for the Jewish National Fund said. REUTERS/Baz Ratner 

Migrating cranes stand as others fly over the Hula Lake Ornithology and Nature Park in northern Israel February 14, 2016. The Hula Valley is a stopping point for hundreds of species of birds along their migration route between the northern and southern hemispheres and during the cold season it becomes one of the largest concentrations of cranes in the world, a spokeperson for the Jewish National Fund said. REUTERS/Baz Ratner 

Migrating cranes fly over the Hula Lake Ornithology and Nature Park in northern Israel February 14, 2016. The Hula Valley is a stopping point for hundreds of species of birds along their migration route between the northern and southern hemispheres and during the cold season it becomes one of the largest concentrations of cranes in the world, a spokeperson for the Jewish National Fund said. REUTERS/Baz Ratner 

Migrating cranes can be seen at the Hula Lake Ornithology and Nature Park in northern Israel February 14, 2016. The Hula Valley is a stopping point for hundreds of species of birds along their migration route between the northern and southern hemispheres and during the cold season it becomes one of the largest concentrations of cranes in the world, a spokeperson for the Jewish National Fund said. REUTERS/Baz Ratner 

Migrating cranes stand as another comes to land at the Hula Lake Ornithology and Nature Park in northern Israel February 14, 2016. The Hula Valley is a stopping point for hundreds of species of birds along their migration route between the northern and southern hemispheres and during the cold season it becomes one of the largest concentrations of cranes in the world, a spokeperson for the Jewish National Fund said. REUTERS/Baz Ratner 

Migrating cranes stand as others fly over the Hula Lake Ornithology and Nature Park in northern Israel February 14, 2016. The Hula Valley is a stopping point for hundreds of species of birds along their migration route between the northern and southern hemispheres and during the cold season it becomes one of the largest concentrations of cranes in the world, a spokeperson for the Jewish National Fund said. REUTERS/Baz Ratner TPX IMAGES OF THE DAY

A black-winged kite hovers as it hunts at the Hula Lake Ornithology and Nature Park in northern Israel January 5, 2016. The Hula Valley is a stopping point for hundreds of species of birds along their migration route between the northern and southern hemispheres. REUTERS/Baz Ratner TPX IMAGES OF THE DAY

Migrating cranes fly over the Hula Lake Ornithology and Nature Park in northern Israel January 5, 2016. The Hula Valley is a stopping point for hundreds of species of birds along their migration route between the northern and southern hemispheres. REUTERS/Baz Ratner

Migrating cranes fly over the Hula Lake Ornithology and Nature Park in northern Israel January 5, 2016. The Hula Valley is a stopping point for hundreds of species of birds along their migration route between the northern and southern hemispheres. REUTERS/Baz Ratner

Sky, young male Asian peregrine falcon, also known as Sapsan in Russia, looks on during a training session conducted by employee of the ornithological department of the Royev Ruchey Zoo in Taiga area outside the Siberian city of Krasnoyarsk, Russia, October 21, 2015. Sky and its sister peregrine Sapa are involved in the zoo project to tame wild animals for research and their interaction with visitors, according to zoo employees. REUTERS/Ilya Naymushin 

Daria Zhirnova, an employee of the ornithological department of the Royev Ruchey Zoo, feeds Sapa, young female Asian peregrine falcon, also known as Sapsan in Russia during a training session outside the Siberian city of Krasnoyarsk, Russia, October 21, 2015. Sapa and its brother peregrine Sky are involved in the zoo project to tame wild animals for research and their interaction with visitors, according to zoo employees. REUTERS/Ilya Naymushin 

Irina Vorontsova, an employee of the ornithological department of the Royev Ruchey Zoo trains Sapa, young female Asian peregrine falcon, also known as Sapsan in Russia during a training session outside the Siberian city of Krasnoyarsk, Russia, October 21, 2015. Sapa and its brother peregrine Sky are involved in the zoo project to tame wild animals for research and their interaction with visitors, according to zoo employees. REUTERS/Ilya Naymushin 

Daria Zhirnova, an employee of the ornithological department of the Royev Ruchey Zoo, releases Sapa, young female Asian peregrine falcon, also known as Sapsan in Russia during a training session outside the Siberian city of Krasnoyarsk, Russia, October 21, 2015. Sapa and its brother peregrine Sky are involved in the zoo project to tame wild animals for research and their interaction with visitors, according to zoo employees. REUTERS/Ilya Naymushin 

Ivan Bogdanovich, a Belarussian ornithologist, holds a mute swan to ring, weigh and make measurements of it, at a lake on the outskirts of Minsk December 18, 2014. REUTERS/Vasily Fedosenko (BELARUS - Tags: ANIMALS SOCIETY) 

Ornithologist Simon Evans of Britain inspects a goldcrest (Regulus regulus) during a bird migration study in Kabli September 20, 2014. REUTERS/Ints Kalnins (ESTONIA - Tags: ENVIRONMENT ANIMALS EDUCATION TPX IMAGES OF THE DAY) 

Ornithologist Steve Piotrowski of Britain releases a coal tit (Periparus ater) after inspecting it during a bird migration study in Kabli September 17, 2014. REUTERS/Ints Kalnins (ESTONIA - Tags: ENVIRONMENT ANIMALS EDUCATION) 

A tractor disperses food for cranes at the Hula Lake Ornithology and Nature Park in northern Israel January 22, 2014. REUTERS/Ammar Awad (ISRAEL - Tags: ENVIRONMENT ANIMALS) 

Canada's Prime Minister Stephen Harper (front row 3rd R) sits next to his wife Laureen (2nd R) as they watch cranes during a tour of the Hula Lake Ornithology and Nature Park in northern Israel January 22, 2014. Harper attended a dedication ceremony on Wednesday for a visitor's center at the nature park, which is also named after him, and was funded by donations raised in Toronto, a spokesperson for the park said. Israel's Minister of Strategic and Intelligence Affairs Yuval Steinitz is seated in the front row (2nd L). REUTERS/Ammar Awad (ISRAEL - Tags: POLITICS ENVIRONMENT ANIMALS) 

Canada's Prime Minister Stephen Harper (2nd R) stands with his wife Laureen (R) as they tour Hula Lake Ornithology and Nature Park in northern Israel January 22, 2014. Harper attended a dedication ceremony on Wednesday for a visitor's center, which is also named after him, and was funded by donations raised in Toronto, a spokesperson for the Hula Lake Ornithology and Nature Park said. REUTERS/Ammar Awad (ISRAEL - Tags: POLITICS ENVIRONMENT) 

A flock of migrating cranes is seen at the Hula Lake Ornithology and Nature Park in northern Israel December 20, 2013. The Hula Valley is a stopping point for hundreds of species of birds along their migration route between the northern and southern hemispheres. REUTERS/Nir Elias (ISRAEL) BEST QUALITY AVAILABLE 

A flock of migrating cranes are seen at the Hula Lake Ornithology and Nature Park in northern Israel December 20, 2013. The Hula valley is a stopping point for hundreds of species of birds along their migration route between the northern and southern hemispheres. REUTERS/Nir Elias (ISRAEL - Tags: ANIMALS ENVIRONMENT) 

A flock of migrating cranes is seen at the Hula Lake Ornithology and Nature Park in northern Israel December 20, 2013. The Hula Valley is a stopping point for hundreds of species of birds along their migration route between the northern and southern hemispheres. REUTERS/Nir Elias (ISRAEL - Tags: ANIMALS SOCIETY ENVIRONMENT) 

A flock of migrating cranes is seen at the Hula Lake Ornithology and Nature Park in northern Israel December 20, 2013. The Hula Valley is a stopping point for hundreds of species of birds along their migration route between the northern and southern hemispheres. REUTERS/Nir Elias (ISRAEL - Tags: ANIMALS ENVIRONMENT SOCIETY) 

Migrating cranes are seen at the Hula Lake Ornithology and Nature Park in northern Israel December 20, 2013. The Hula Valley is a stopping point for hundreds of species of birds along their migration route between the northern and southern hemispheres. REUTERS/Nir Elias (ISRAEL - Tags: ANIMALS ENVIRONMENT SOCIETY) 

A flock of migrating cranes is seen at the Hula Lake Ornithology and Nature Park in northern Israel December 20, 2013. The Hula valley is a stopping point for hundreds of species of birds along their migration route between the northern and southern hemispheres. REUTERS/Nir Elias (ISRAEL - Tags: ANIMALS ENVIRONMENT SOCIETY) 

A flock of migrating cranes is seen at the Hula Lake Ornithology and Nature Park in northern Israel December 20, 2013. The Hula Valley is a stopping point for hundreds of species of birds along their migration route between the northern and southern hemispheres. REUTERS/Nir Elias (ISRAEL - Tags: ANIMALS ENVIRONMENT SOCIETY) 

A flock of migrating cranes is seen at the Hula Lake Ornithology and Nature Park in northern Israel December 20, 2013. The Hula Valley is a stopping point for hundreds of species of birds along their migration route between the northern and southern hemispheres. REUTERS/Nir Elias (ISRAEL - Tags: SOCIETY ANIMALS ENVIRONMENT) 

A flock of migrating cranes is seen at the Hula Lake Ornithology and Nature Park in northern Israel December 20, 2013. The Hula Valley is a stopping point for hundreds of species of birds along their migration route between the northern and southern hemispheres. REUTERS/Nir Elias (ISRAEL - Tags: ANIMALS ENVIRONMENT SOCIETY) 

A flock of migrating cranes is seen at the Hula Lake Ornithology and Nature Park in northern Israel December 20, 2013. The Hula Valley is a stopping point for hundreds of species of birds along their migration route between the northern and southern hemispheres. REUTERS/Nir Elias (ISRAEL - Tags: ANIMALS ENVIRONMENT SOCIETY) 

A flock of migrating cranes is seen at the Hula Lake Ornithology and Nature Park in northern Israel December 20, 2013. The Hula Valley is a stopping point for hundreds of species of birds along their migration route between the northern and southern hemispheres. REUTERS/ Nir Elias (ISRAEL - Tags: ANIMALS ENVIRONMENT SOCIETY) 

A flock of migrating cranes flies over the Hula Lake Ornithology and Nature Park in northern Israel December 20, 2013. The Hula Valley is a stopping point for hundreds of species of birds along their migration route between the northern and southern hemispheres. REUTERS/Nir Elias (ISRAEL - Tags: ANIMALS ENVIRONMENT SOCIETY) 

A flock of migrating cranes is seen at the Hula Lake Ornithology and Nature Park in northern Israel December 20, 2013. The Hula Valley is a stopping point for hundreds of species of birds along their migration route between the northern and southern hemispheres. REUTERS/Nir Elias (ISRAEL - Tags: ANIMALS ENVIRONMENT SOCIETY TPX IMAGES OF THE DAY) FOR BEST QUALITY SEE GF2EA180KOS01