Size changes from place to place, and the largest jaguars live in the Brazilian Pantanal, where males average 100 kg and females 76 kg. In Honduras, males average 57 kg and females 42 kg. Adult jaguars weigh between 80 and 348 pounds (36 to 158 kg), though the ends of that range are exceptional, and male jaguars are usually 10 to 20 percent larger than females. Measured from the nose to the tip of the tail, an adult jaguar is 5 to 8 feet (1.5 to 2.4 meters) long.

The jaguar lineage is believed to have evolved in Asia and reached North America across the Bering Land Bridge at least once during the Pleistocene. The oldest known American fossil assigned to the jaguar lineage is from Hamilton Cave in West Virginia and dates to about 850 to 820 thousand years ago.

In the late Pleistocene, jaguars in North America were larger than living jaguars, and their fossils are 15% to 20% larger than the average living jaguar. Ancient DNA from a large late-Pleistocene jaguar from Kingston Saltpeter Cave, Georgia, fell inside the variety of living jaguars. All the jaguar mitochondrial genomes in the study share an ancestor about 400 thousand years ago.

In 1986 a conservation area was set up in Belize specially for jaguars, and Panthera says the work of a researcher in the 1980s led to the world's first jaguar reserve in the Cockscomb Basin Wildlife Sanctuary.

CITES put jaguars on Appendix I in 1973, and as of November 2026 this bans all international trade in jaguars and their parts. In 1997 the U.S. Fish and Wildlife Service added the United States to the area where the jaguar is listed as Endangered, as of November 2026.

As of November 2026, the International Union for Conservation of Nature has changed the jaguar's category over time: Vulnerable in 1982 and 1990, Lower Risk/Near Threatened in 1996, and Near Threatened in a 2016 assessment.

A 2018 estimate by Jedrzejewski and colleagues put the world jaguar population at 173,000, with 163,000 in South America and 10,000 in North America, and the population trend was listed as declining, as of November 2026.

Scientists photograph jaguars with camera traps and tell each animal apart by its spot pattern. In 2004 a team described the first systematic camera-trap method for estimating jaguar numbers, and camera-trap researchers in Colombia placed cameras in pairs so that both flanks of each passing jaguar were photographed. A jaguar-identification project with Panthera and its partners in the Brazilian Pantanal has identified more than 300 jaguars, as of November 2026. Panthera has monitored jaguars in the Cockscomb Basin of Belize since the early 2000s, and it describes this as one of the longest-term jaguar databases in the world.

Since 1996, Arizona has had photos and tracks of four adult males and possibly a fifth. In Arizona, conservationists used dogs to sniff out jaguar scat and then set cameras at those spots. That is how they filmed the jaguar El Jefe. In the U.S. Southwest, El Jefe was photographed by trail cameras more than a hundred times over three years in Arizona's Santa Rita Mountains.

One study estimated that the jaguar's range shrank by 48 percent over the last century; using area of occupancy, the estimate was 55 percent. As of November 2026, jaguars have been found in 19 countries; long ago they lived in 21. Jaguars live in Central and South America, in places such as the Amazon, in tropical rainforests and also in swamps, grasslands and dry places. About 57 percent of the places where jaguars are known to occur are in the rainforest of the Amazon basin.

Words to know

• Pleistocene: long-ago age
• mitochondrial: inherited from mothers
• scat: animal droppings
• assessment: careful review
• Panthera: wild cat group
• lineage: family line