A rose is seen in a public garden in Vienna, Austria, June 13, 2018. REUTERS/Heinz-Peter Bader 

A rose is seen in a public garden in Vienna, Austria, June 13, 2018. REUTERS/Heinz-Peter Bader 

A feather is pictured in a burnt area where Palestinians have been causing blazes by flying kites and balloons loaded with flammable materials, across the border between Israel and Gaza Strip, near Sderot, Israel June 4, 2018. REUTERS/Amir Cohen TPX IMAGES OF THE DAY 

A feather is pictured in a burnt area where Palestinians have been causing blazes by flying kites and balloons loaded with flammable materials, across the border between Israel and Gaza Strip, near Sderot, Israel June 4, 2018. REUTERS/Amir Cohen 

Lotus flowers are seen outside of the house of Wang-Chen Bi-Jin, 91 years old, a member of the "Six Carat" elderly Hip Hop dance group, in Taichung, Taiwan April 24, 2018. Picture taken April 24, 2018. REUTERS/Tyrone Siu 

A spider is seen in front of the hydro power plant next to the HydroMiner cryptocurrency farming operation near Waidhofen an der Ybbs, Austria April 25, 2018. REUTERS/Leonhard Foeger 

Butterflies sit on cocoons during an event to launch the Sensational Butterflies exhibition at the Natural History Museum in London, Britain, March 28, 2018. REUTERS/Hannah McKay 

Blooming cherry blossoms are seen in Tokyo, Japan March 23, 2018. REUTERS/Toru Hanai 

A great tit picks up to fly on a winter day in Warsaw, Poland March 3, 2018. REUTERS/Kacper Pempel 

A jay rests on a tree as the air temperature drops to about minus 12 degrees Celsius (10.4 degrees Fahrenheit), near the Ozerny village, Belarus March 3, 2018. REUTERS/Vasily Fedosenko 

A fieldfare feeds on a tree as the air temperature drops to about minus 12 degrees Celsius (10.4 degrees Fahrenheit), near the Ozerny village, Belarus March 3, 2018. REUTERS/Vasily Fedosenko 

A blackbird rests on a tree as the air temperature drops to about minus 12 degrees Celsius (10.4 degrees Fahrenheit), near the Ozerny village, Belarus March 3, 2018. REUTERS/Vasily Fedosenko 

Flowers are seen in Santana on Madeira's North coast, Portugal, March 30, 2017. REUTERS/Rafael Marchante 

A pair of boots is planted with flowers on a floating barge, which is planted with fruit trees, with the Manhattan skyline in the background, as part of the Swale project called a collaborative floating forest, in the East River in the Brooklyn borough of New York, U.S., May 2, 2017. REUTERS/Carlo Allegri 

A potato flower is pictured on a field of potatoes produced from local seeds by global food and beverage giant PepsiCo International at green fields near the coastal city of Alexandria, Egypt April 20, 2017. Picture taken April 20, 2017. REUTERS/ Sherif Fahmy 

The inside of a Tulip blossom is lit by the sun on a sunny spring day on a field in Seeheim, south of Frankfurt, Germany, April 9, 2017. REUTERS/Kai Pfaffenbach 

Daisies are seen on a field on a sunny spring day in Seeheim, south of Frankfurt, Germany, April 9, 2017. REUTERS/Kai Pfaffenbach 

A Monarch butterfly rests on a visitor's hand during the official Inauguration of the month of the Monarch butterfly at Chapultepec Zoo in Mexico City, Mexico, April 6, 2017. REUTERS/Edgard Garrido 

A Monarch butterfly clings to a plant during the official Inauguration of the month of the Monarch butterfly at Chapultepec Zoo in Mexico City, Mexico, April 6, 2017. REUTERS/Edgard Garrido 

A Monarch butterfly rests on the floor during the official Inauguration of the month of the Monarch butterfly at Chapultepec Zoo in Mexico City, Mexico, April 6, 2017. REUTERS/Edgard Garrido 

A Monarch butterfly rests on a visitor's hand during the official Inauguration of the month of the Monarch butterfly at Chapultepec Zoo in Mexico City, Mexico, April 6, 2017. REUTERS/Edgard Garrido 

A banded orange heliconian butterfly sits on a flower during the official Inauguration of the month of the Monarch butterfly at Chapultepec Zoo in Mexico City, Mexico, April 6, 2017. REUTERS/Edgard Garrido 

The Television Tower is seen behind blooming cherry blossom trees in Berlin, Germany March 28, 2017. REUTERS/Fabrizio Bensch 

A daffodil is seen in a garden on a sunny spring day in Sint-Pieters-Leeuw, Belgium March 27, 2017. REUTERS/Yves Herman 

Daffodils are seen in a garden on a sunny spring day in Sint-Pieters-Leeuw, Belgium March 27, 2017. REUTERS/Yves Herman 

Daffodils are seen in a garden on a sunny spring day in Sint-Pieters-Leeuw, Belgium March 27, 2017. REUTERS/Yves Herman 

Daffodils are seen in a garden on a sunny spring day in Sint-Pieters-Leeuw, Belgium March 27, 2017. REUTERS/Yves Herman 

Women with umbrellas walk under the cherry blossoms near the Tidal Basin on a misty morning in Washington, U.S., March 27, 2017. REUTERS/Kevin Lamarque 

Cherry blossoms bloom along the Tidal Basin in Washington, U.S., March 26, 2017. REUTERS/Joshua Roberts 

Puppies are seen holding for photo with the cherry blossom flowers blooming near the Washington Monument in Washington, U.S., March 25, 2017. REUTERS/Yuri Gripas TPX IMAGES OF THE DAY 

The Washington Monument is seen through the cherry blossoms as they start blooming in Washington, U.S., March 25, 2017.REUTERS/Yuri Gripas 

Cherry blossoms are seen as they start blooming near the Washington Monument in Washington, U.S., March 25, 2017.REUTERS/Yuri Gripas 

A sick Turkana tribesman sits in the bush in a village near Loiyangalani, Kenya, March 20, 2017. Picture taken on March 20, 2017. REUTERS/Goran Tomasevic 

A dancer takes part in a ceremony to welcome the spring equinox in front the Pyramid of the Sun in the pre-hispanic city of Teotihuacan, on the outskirts of Mexico City, Mexico, March 20, 2017. REUTERS/Henry Romero 

One the first day of Spring a field blooming Giant Tecolote Ranunculus flowers is pictured at the Flower Fields in Carlsbad, California, U.S., March 20, 2017. REUTERS/Mike Blake 

Flowers in bloom are seen at a farmers market in Union Square on the first day of spring, in New York City, New York, U.S., March 20, 2017. REUTERS/Mike Segar 

Yellow primroses are blossoming in a garden, on the first day of spring, in Weidling, Austria March 20, 2017. REUTERS/Heinz-Peter Bader 

A combination photo shows yellow primroses, snowdrops, pink primroses and hepatica (clockwise) blossoming in a garden, on the first day of spring, in Weidling, Austria March 20, 2017. REUTERS/Heinz-Peter Bader 

Pink primroses are blossoming in a garden, on the first day of spring, in Weidling, Austria March 20, 2017. REUTERS/Heinz-Peter Bader 

Hepatica primroses are blossoming in a garden, on the first day of spring, in Weidling, Austria March 20, 2017. REUTERS/Heinz-Peter Bader 

Snowdrops are blossoming in a garden, on the first day of spring, in Weidling, Austria, March 20, 2017. REUTERS/Heinz-Peter Bader 

Snowdrop flowers bloom in a garden on the first day of spring in Weidling, Austria March 20, 2017. REUTERS/Heinz-Peter Bader 

Snowdrop flowers bloom in a garden on the first day of spring in Weidling, Austria March 20, 2017. REUTERS/Heinz-Peter Bader 

Snowdrop flowers bloom in a garden on the first day of spring in Weidling, Austria March 20, 2017. REUTERS/Heinz-Peter Bader 

Snowdrop flowers bloom in a garden on the first day of spring in Weidling, Austria March 20, 2017. REUTERS/Heinz-Peter Bader 

A bee searches for pollen among cherry blossoms on a sunny spring day in Lausanne, Switzerland March 20, 2017. REUTERS/Denis Balibouse 

A bee searches for pollen among cherry blossoms on a sunny spring day in Lausanne, Switzerland March 20, 2017. REUTERS/Denis Balibouse 

A bee searches for pollen among cherry blossoms on a sunny spring day in Lausanne, Switzerland March 20, 2017. REUTERS/Denis Balibouse 

A bee searches for pollen among cherry blossoms on a sunny spring day in Lausanne, Switzerland March 20, 2017. REUTERS/Denis Balibouse 

A bee searches for pollen among cherry blossoms on a sunny spring day in Lausanne, Switzerland March 20, 2017. REUTERS/Denis Balibouse 

A massive spring wildflower bloom caused by a wet winter is seen in Anza-Borrego Desert State Park, California, U.S., March 11, 2017. Picture taken March 11, 2017. REUTERS/Sue Horton 

A massive spring wildflower bloom caused by a wet winter is seen in Anza-Borrego Desert State Park, California, U.S., March 13, 2017. Picture taken March 13, 2017. REUTERS/Steve Gorman 

A massive spring wildflower bloom caused by a wet winter is seen in Anza-Borrego Desert State Park, California, U.S., March 13, 2017. Picture taken March 13, 2017. REUTERS/Steve Gorman 

A massive spring wildflower bloom caused by a wet winter is seen in Anza-Borrego Desert State Park, California, U.S., March 13, 2017. Picture taken March 13, 2017. REUTERS/Steve Gorman 

A massive spring wildflower bloom caused by a wet winter is seen in Anza-Borrego Desert State Park, California, U.S., March 13, 2017. Picture taken March 13, 2017. REUTERS/Steve Gorman 

A dog stands in a massive spring wildflower bloom caused by a wet winter in Lake Elsinore, California, U.S., March 14, 2017. REUTERS/Lucy Nicholson 

A massive spring wildflower bloom caused by a wet winter is seen in Lake Elsinore, California, U.S., March 14, 2017. REUTERS/Lucy Nicholson 

A massive spring wildflower bloom caused by a wet winter is seen in Lake Elsinore, California, U.S., March 14, 2017. REUTERS/Lucy Nicholson 

A massive spring wildflower bloom caused by a wet winter is seen in Lake Elsinore, California, U.S., March 14, 2017. REUTERS/Lucy Nicholson 

A massive spring wildflower bloom caused by a wet winter is seen in Lake Elsinore, California, U.S., March 14, 2017. REUTERS/Lucy Nicholson