Jaguars are the third-largest cat species on Earth, smaller only than lions and tigers, and the largest one left in the Americas. They're incredibly sneaky despite their size, though, and excel at fading into the background. They may have been an uncommon sight even in their heyday, when they roamed from Argentina to as far north as the Grand Canyon and Colorado.

Still, they're especially ghostlike today, and not just because of their natural stealth. Jaguars now exist only in fragments of their former range, having been wiped out in many places by generations of habitat loss and hunting. And while camera traps have given us glimpses of these elusive cats in recent years — including a few high-quality shots, like these from photographers Steve Winter, Nick Hawkins and Sebastian Kennerknecht — it's relatively rare to record wild jaguars in the vivid detail they deserve.

In hopes of capturing new high-resolution images of jaguars in their element, WWF France commissioned photographer and videographer Emmanuel Rondeau for an expedition to French Guiana. This quest, documented in the WWF's new web series "Mission Jaguar: Guiana," took Rondeau to Nouragues Natural Reserve, which protects 105,800 hectares (408 square miles) of tropical forest in northeastern South America. Below are some of the images he caught there, courtesy of WWF France.

Welcome to the jungle

Nouragues Natural Reserve borders the Guiana Shield, a geological formation and biodiversity hotspot on the northeastern coast of South America. (Photo: © Emmanuel Rondeau/WWF France)

Nouragues Natural Reserve lies at the edge of the Guiana Shield, a roughly 2 billion-year-old geological formation where up to 80% of the native biodiversity may be unknown to science. It's also near the Amazon, the world's largest protected tropical rainforest and still one of its most mysterious. Scientists continue to find previously unknown wildlife there, such as the 381 species discovered during surveys in 2014 and 2015, including 216 plants, 93 fish, 32 amphibians, 20 mammals, 19 reptiles and one bird.

The reserve lies at the heads of two watersheds, formed by the Approuague and Comté rivers, and hosts a wide variety of riparian habitats. (Photo: © Emmanuel Rondeau/WWF France)

Founded in 1995, Nouragues stretches across a swath of French Guiana between the Approuague River and the Haute-Comté region. About 99% of the park's vegetation is dense tropical rainforest, but it also supports other ecosystems like riparian forests, liana forests and "cambrouses," or thick formations of bamboo-like grasses.

Spotted cat spotted

Rondeau's high-resolution camera trap captured several striking images as the jaguar cautiously crept through the forest. (Photo: © Emmanuel Rondeau/WWF France)

Jaguars are the top predator in the Amazon Basin, where they play an important ecological role by controlling populations of many other species across their habitat. They prey on large land mammals like deer, peccaries and tapirs, but also defy the feline stereotype of avoiding water. Jaguars are good swimmers, and prowl rivers for fish, turtles and caimans.

Jaguars are the top predator in the Amazon and the largest big cat species in the Americas. They're the third-largest feline on Earth, trailing only lions and tigers. (Photo: © Emmanuel Rondeau/WWF France)

The jaguar's range has shrunk by half in the last 100 years, according to the WWF, which cites deforestation and agriculture as the primary reasons. Jaguar populations have shrunk, too, disappearing entirely from some countries. This decline continues today, driven by ongoing habitat loss as well as depletion of prey species, conflict with humans and rising demand for jaguar parts in Asia.

An estimated 64,000 jaguars exist in the wild today, divided into 34 subpopulations — 25 of which are threatened, and eight of which are in danger of extinction. (Photo: © Emmanuel Rondeau/WWF France)

Due to the demand for jaguar teeth, claws and other body parts in some Asian countries, poaching now poses a growing threat to the already embattled cats. There are signs of an emerging trade network for jaguar parts between Central America and Asia, a 2018 report found, and the WWF warns this surge in demand can even spur poaching in jaguar strongholds like the Amazon.

Jaguars have lost about half of their range in the last 100 years, according to the WWF, resulting in reduced and even extinct populations in some countries. (Photo: © Emmanuel Rondeau/WWF France)

Jaguars are listed as Near Threatened by the International Union for Conservation of Nature (IUCN), which also classifies the species' population as decreasing. Yet despite their dire situation overall, these resilient cats have seized on some recent opportunities to claw back. In Mexico, for example, a 2018 study found that wild jaguar populations had grown by 20% in the last eight years. The increase is credited largely to a conservation program launched in 2005.