A “jungle nymph” is measured during the annual weight-in ZSL London Zoo on August 21, 2014 in London, England. The height and mass of every animal in the zoo, of which there are over 16,000, is recorded and submitted to the Zoological Information Management System. This is combined with animal measurement data collected from over 800 zoos and aquariums in almost 80 countries, from which zoologists can compare information on thousands of endangered species. (Photo by Oli Scarff/Getty Images)

In this picture taken Thursday, April 14, 2016, a Syrian man carries a carpet as walk through a devastated part of the town of Palmyra as families load their belongings onto a bus in the central Homs province, Syria. Thousands of residents of this ancient town who fled Islamic State rule are returning briefly to check on their homes and salvage what they can – some carpets, blankets, a fridge or a few family mementos. There is no water or electricity in the town, and it will be at least few months before anyone can return to stay. (Photo by Hassan Ammar/AP Photo)

A Pakistani owner tries to load camel on a truck at a cattle market set up for the upcoming Muslim festival Eid al-Adha in Karachi, Pakistan, Friday, August 17, 2018. Eid al-Adha, or Feast of Sacrifice, most important Islamic holiday marks the willingness of the Prophet Ibrahim (Abraham to Christians and Jews) to sacrifice his son. (Photo by Shakil Adil/AP Photo)

In this June 29, 2016 file photo, boats docked at Central Marine in Stuart, Fla., are surrounded by blue green algae. The 153-mile-long Indian River Lagoon has been plagued by harmful algae blooms. Water quality testing data analyzed by the AP showed the average phosphorous level – a byproduct of fertilizers and human waste that algae thrive on, rose nearly 75 percent between 2000 and 2016. (Photo by Greg Lovett/The Palm Beach Post via AP Photo)

This picture was taken in the 1890's and shows a group of loggers hauling a heavy load. It is hard to even picture how they got the logs stacked that high. It is also hard to imagine how they keep it from tipping over.

Miners pulling up lazy tourists to the rim of Kawah Ijen (Ijen Volcano), East Java, Indonesia on September 21, 2017. They will earn as much as they would bring down a load of sulfur. Nomadic Explorer, Cultural Lifestyle Photographer Claudio Sieber captured striking images of miners working at Ijen volcanic range in East Java, Indonesia. The sulphur miners risk their lives daily as they climb the active volcano carrying heavy loads, which they sell to sugar refineries. (Photo by Claudio Sieber/Barcroft Images)

People line up to pay inside a Makro supermarket in Caracas, January 9, 2015. Venezuela's socialist government decreed an “economic emergency” on Friday that will expand its powers and published the first data in a year that shows the depth of a recession fueled by low oil prices and a sputtering state-led model. (Photo by Jorge Silva/Reuters)

Indonesian air force personnel carry the flight data recorder of the ill-fated AirAsia Flight 8501 that crashed in the Java Sea, at airport in Pangkalan Bun, Indonesia, Monday, January 12, 2015. Divers retrieved one black box Monday and located the other from the AirAsia plane that crashed more than two weeks ago, a key development that should help investigators unravel what caused the aircraft to plummet into the Java Sea. (Photo by Achmad Ibrahim/AP Photo)