Ty, a 15-year-old boy, poses for a picture while collecting usable items at a landfill dumpsite outside Siem Reap March 19, 2015. Ty, who finished six-grade primary school, said he makes 5 USD per month working at the dumpsite. (Photo by Athit Perawongmetha/Reuters)

An Egyptian Coptic Christian girl carries palm decoration during Palm Sunday inside a church in Old Cairo, Egypt, April 5, 2015. For Christians worldwide, Palm Sunday marks Jesus Christ's entrance into Jerusalem, when his followers laid palm branches in his path, prior to his crucifixion. Western Christian churches and most Orthodox Christian churches follow different calendars and observe Easter on different dates. (Photo by Asmaa Waguih/Reuters)

A 5.5 metre massive crocodile makes mince meat out of a bull shark in Kakadu's Adelaide River on August 5, 2014 in Kakadu, Australia. The crocodile forced the bull shark into the mangroves and devoured the bull shark. A 43 year old Sydney father took these exclusive photos in the Northern Territory. (Photo by Andrew Paice/Getty Images)

An employee feeds a one-week-old coati cub with a bottle of milk at the Royev Ruchey zoo in the suburbs of Krasnoyarsk, Siberia, October 10, 2014. The mother of three cubs refused to nurse them, according to zoo employees. (Photo by Ilya Naymushin/Reuters)

14 week-old twin polar bear cubs play during their first presentation to the media in Hellabrunn zoo on March 19, 2014 in Munich, Germany. The male and female twins were born on December 9, 2013 in the zoo. (Photo by Alexandra Beier/Getty Images)

A three month old white Bengal female tiger cub looks around her enclosure at the Buenos Aires Zoo, Argentina, Wednesday, April 16, 2014. Cleo, a captive Bengal white tiger at the zoo, gave birth to two females and one male white tiger cubs on January 16, 2014. (Photo by Natacha Pisarenko/AP Photo)

In this Tuesday, June 18, 2013 photo, Zita, a liger – half-lioness, half-tiger – carries her one month-old liliger cub in the Novosibirsk Zoo. The cub's father is a lion, Sam. (Photo by Ilnar Salakhiev/AP Photo)