Two men using an electric power saw to fell a tree circa 1940's. (Photo by Keystone View/FPG/Getty Images)

A Santa Claus puppet holding a Christmas tree is pictured against the sun in Berlin November 23, 2014. (Photo by Hannibal Hanschke/Reuters)

German pensioner Volker Kraft decorates an apple tree with Easter eggs in the garden of his summerhouse, in the eastern German town of Saalfeld, March 19, 2014. Each year since 1965 Volker and his wife Christa spend up to two weeks decorating the tree with their collection of 10,000 colourful hand-painted Easter eggs in time for Easter celebrations. (Photo by Fabrizio Bensch/Reuters)

A firefighter holds a red panda (Ailurus fulgens) from its tail while removing it from a tree at a residential area in Kunming, Yunnan province, July 3, 2014. The animal was spotted in the residential area and was brought down from the tree after residents reported its sighting to the police, local media reported. (Photo by Reuters/Stringer)

Sap runs out of a frankincense tree near Mader Moge, Somaliland, a breakaway region of Somalia on August 4, 2016In a tradition dating to Biblical times, men rise at dawn in the rugged Cal Madow mountains of Somaliland in the Horn of Africa to scale rocky outcrops in search of the prized sap of wild frankincense trees. (Photo by Jason Patinkin/AP Photo)

Tatyana Abramova, 33, plays with her home fox Plombir at her countryside house outside Siberian city of Novosibirsk on September 12, 2020. The official start of the Soviet experiment to better understand the domestication of animals by humans began in 1959, and was initiated by geneticists Dmitri Beliaiev and Lioudmila Trout on a farm in Akademgorodok, the scientific center of excellence in Siberia. Their primary objective was to domesticate foxes, to understand how the ancestor of wolves, another canine, evolved into a loyal and loving dog. And understand what this domestication tells us about the genetic evolution of species. (Photo by Alexander Nemenov/AFP Photo)

A chimpanzee bottle-feeds a lamb at Southam Zoo Farm in Warwickshire. The owners of the zoo, Mr and Mrs Clews, bring up many of the animals as their pets; the animals, are, as a result, of a friendly disposition. (Photo by Fox Photos/Getty Images). 23rd August 1968

Three workers demonstrating the different types of gas masks used in mine rescue work. (Photo by Fox Photos/Getty Images). December 1925