A horse is paraded during the Arabian Horse Festival at the Bait al-Arab in Kuwait City on February 5, 2022. (Photo by Yasser Al-Zayyat/AFP Photo)

Visitors attend the balloon festival on the Eid al-Fitr holiday at Ronggolawe Stadion on April 23, 2023, in Wonosobo, Central Java, Indonesia. Javanese people fly giant hot air balloons during Eid, which has long been a tradition of the Wonosobo regency. (Photo by Garry Lotulung/Anadolu Agency via Getty Images)

A killdeer (Charadrius vociferus) chick on sand dunes in Pacific Grove, California, US on June 21, 2023. The killdeer gets its name from its shrill, loud call. (Photo by Rory Merry/ZUMA Press Wire/Rex Features/Shutterstock)

A young Catholic waits for the start of mass at the church of Saint John the Baptist during the mud festival at Bibiclat, Nueva Ecija province, northern Philippines, Monday, June 24, 2024. (Photo by Aaron Favila/AP Photo)

“Sniff out the Appenzell Cheese”. Alexander Hunter, 30, of Greenwich, Conn., took this photo in Appenzell, Switzerland, in September 2014. (Photo by Alexander Hunter)

Global wildlife populations will decline by 67% by 2020 unless urgent action is taken to reduce human impact on species and ecosystems, warns the biennial Living Planet Index report from WWF (World Wide Fund for Nature) and ZSL (Zoological Society of London). From elephants to eels, here are some of the wildlife populations most affected by human activity. Here: The maned wolf is among the large mammals in the Brazilian Cerrado that are threatened by the increasing conversion of grasslands into farmland for grazing and growing crops. (Photo by Ben Cranke/Nature Picture Library/Alamy Stock Photo)

The fourth annual BigPicture Natural World Photography Competition aims to celebrate the diversity of life on Earth, and encourages people to protect and conserve it. Here: “The Salmon Catchers”. Terrestrial Wildlife. To capture this view of a mother grizzly bear and her cub, photographer Peter Mather set up a camera trap on a log that he knew the bears tended to traverse while fishing for salmon, in the Yukon River watershed in Canada. (Photo by Peter Mather/BigPicture Natural World Photography Competition 2017)