Panthera onca is a genus within the Felidae family that was named and first described by the German naturalist Lorenz Oken in 1816. The British taxonomist Pocock revised the classification of this genus in 1916 as comprising the species lion, tiger, jaguar, and leopard on the basis of cranial features. Results of genetic analysis indicate that the snow leopard also belongs to the Panthera, a classification that was accepted by IUCN Red List assessors in 2008.

The tiger, lion, leopard, and jaguar are the only felines with the anatomical structure that enables them to roar. The ability to roar is due to morphological features, especially of the larynx. In Panthera species, the dorsal profile of the skull is flattish or evenly convex. The frontal interorbital area is not noticeably elevated, and the area behind the elevation is less steeply sloped. The basicranial axis is nearly horizontal. The inner chamber of the bullae is large, the outer small. The partition between them is close to the external auditory meatus. The convexly rounded chin is sloping. All Panthera species have an incompletely ossified hyoid bone. Specially adapted larynx with proportionally larger vocal folds are covered in a large fibro-elastic pad. These characteristics enable all Panthera species except snow leopard to roar.

Image of Jaguar skull fossil

Genetic studies indicate that pantherine cats diverged from the subfamily Felinae between six and ten million years ago. Fossil records that appear to belong within the genus Panthera reach only 2.0 to 3.8 million years back.

Genome mapping research by an international team under Henrique V. Figueiró et al. (See Genome-wide signatures of complex introgression and adaptive evolution in the big cats, Science Advances (2017). DOI: 10.1126/sciadv.1700299 ) has concluded a surprising result. The researchers report that they found over 13,000 genes that were similar through all of the species included in the study. They also found that the cats all diverged from a single ancestor approximately 4.6 million years ago—one that was apparently most like the modern leopard. The team also found that all of the species populations have also declined over the past 300,000 years, which means lower genetic diversity.

All five extant species are represented as follows: lion (Panthera leo), leopard (Panthera pardus), jaguar (Panthera onca), snow leopard (Panthera uncia), and tiger (Panthera tigris).

Diagram of cats

One surprise they found was that the big cats have all engaged in cross-breeding multiple times over the course of their history, and because of that, have evolved new features that have proved useful in other areas. They suspect, for example, that the jaguar, which has the strongest bite of all the big cats, found itself with a larger head after breeding with lions—that may have led to a bite strength increase, which made it possible for them to hunt better protected animals in the New World.

The modern jaguar is thought to have descended from a pantherine ancestor in Asia that crossed the Beringian land bridge into North America during the Early Pleistocene. From North America, it spread to Central and South America. The ancestral jaguar in North America is referred to as Panthera onca augusta.

Unlike jaguars in South America, jaguars in Central or North America are fairly small. Those in the Chamela-Cuixmala Biosphere Reserve on the Mexican Pacific coast weigh just about 50 kg (110 lb), similar in weight as female cougars. 57.2 kg (126 lb) was the average for six males in Belize, making them similar to South American females in Venezuela.

Today the Jaguar is found in these locations:

Panthera Onca Arizonenis – Arizona and Mexico

Panthera Onca Centralis – Central America

Panthera Onca Goldmani – Mexico and Belize

Panthera Onca Hemandesii – Western Mexico

Panthera Onca Onca – Amazon Rainforest

Panthera Onca Palustris – Paraguay

Panthera Onca Peruvianas – Peru

Panthera Onca Veracrucis – Texas

In North America, the jaguar ranges from the southern part of the United States in the north, to the southern part of Central America in the south. Recently, jaguars of Mexican origin have been spotted in Arizona. Prior to that, the Arizona jaguar was treated as a cryptid cat.

In the early 1900s, the German scientist Alfred Wegener noticed that the coastlines of Africa and South America looked like they might fit together. He also discovered evidence that the same plant and animal fossils were found along the coasts of these continents, although they were now separated by vast oceans. In addition, he noticed that geologic formations, like mountain ranges, on the two continents also matched up. 

In 1915, Wegener published his book, The Origin of Continents and Oceans, suggesting that the earth’s continents were once joined together in one large mass. He called the original landmass (or supercontinent) “Pangaea,” the Greek word for “all the earth.” According to Wegener, over time “Pangaea” split apart and the different landmasses, or continents, drifted to their current locations on the globe.

We now know he was correct. It obviously took billions of years to create the various continents, but life likely sprang from the oceans. Many scientists think life got its start around 3.7 billion years ago in deep-sea hydrothermal vents. If so, life maybe formed first in the oceans, creating amphibian and then terrestrial life forms throughout the continents of the globe.

It is worth noting that wildlife existed in South America before the isthmus formed 2.8 million years ago. Fossils of the condor like bird, Argentavis magnificens (see earlier blog) found in Argentina are dated to over 5 million years old. Once the isthmus formed, species from North and South could intermingle and hybridize through direct species-to-species contact. We still don’t know for certain the origins of the Jaguar in the Americas. Perhaps there was an evolving cat already living in South America before the isthmus formed.

Jaguars are now an endangered species. They once roamed from Argentina in South America all the way up to the Grand Canyon in Arizona. Today, jaguars have been almost completely eliminated from the United States and are endangered throughout their range, which stretches down to Patagonia in South America. 

The jaguar makes its home in a wide-variety of habitats including deciduous forests, rainforests, swamps, pampas grasslands and mountain scrub areas. These habitats are continuously being cut back for industrialised purposes and cattle farming. Since Jaguars sometimes prey on calves, they are often killed by farmers on sight.

“Jaguars had been eliminated in the United States. A female was shot by a hunter in Arizona’s White Mountains in 1963. Arizona outlawed jaguar hunting in 1969, but by then no females remained and over the next 25 years only two male jaguars were found (and killed) in Arizona. Then in 1996, Warner Glenn, a rancher and hunting guide from Douglas, Arizona, came across a jaguar in the Peloncillo Mountains and became a researcher on jaguars, placing webcams which recorded four more Arizona jaguars. No jaguars sighted in Arizona in the last 15 years had been seen since 2006. Then, in 2009, a male jaguar named Macho B died shortly after being radio-collared by Arizona Game and Fish Department (AGFD) officials in 2009. In the Macho B incident, a former ADGF subcontractor pleaded guilty to violating the endangered species act for trapping the cat and a Game and Fish employee was fired for lying to federal investigators. In 2011, a male jaguar weighing 200 lb (91 kg) was photographed near Cochise in southern Arizona by a hunter after being treed by his dogs (the animal left the scene unharmed). A second 2011 sighting of an Arizona jaguar was reported by a Homeland Security border pilot in June 2011, and conservation researchers sighted two jaguars within 30 mi (48 km) of the border between Mexico and the United States in 2010.

In September 2012, a jaguar was photographed in the Santa Rita Mountains of Arizona, the second such sighting in this region in two years. This jaguar has been photographed numerous times over the past nine months through June 2013. On 3 February 2016, the Center for Biological Diversity released a video of this jaguar – now named El Jefe (Spanish for “The Boss”) – roaming the Santa Rita Mountains, about 25 mi (40 km) south of downtown Tucson. El Jefe is the fourth jaguar sighted in the Madrean Sky Islands in southern Arizona and New Mexico, over the last 20 years.

On 16 November 2016, a jaguar was spotted in the Dos Cabezas Mountains of Arizona, 60 mi (97 km) from the Mexican border, the farthest north one of these animals has been spotted in many decades. It is the seventh jaguar to be confirmed in the Southwest since 1996. On 1 December 2016, another male jaguar was photographed on Fort Huachuca also in Arizona. In February 2017, authorities revealed that a third jaguar had been photographed in November 2016, by the Bureau of Land Management in the Dos Cabezas Mountains, also in Arizona, some 100.0 km (62.1 miles) north of the border with Mexico. The only picture obtained allowed experts to determine this is a different individual, but it does not reveal its gender.

Conservation

Legal action by the Center for Biological Diversity led to federal listing of the cat on the endangered species list in 1997. However, on January 7, 2008, George W. Bush appointee H. Dale Hall, Director of the United States Fish and Wildlife Service (USFWS), signed a recommendation to abandon jaguar recovery as a federal goal under the Endangered Species Act. Critics, including the Center of Biological Diversity and New Mexico Department of Game and Fish, were concerned the jaguar was being sacrificed for the government’s new border fence, which is to be built along many of the cat’s typical crossings between the United States and Mexico.

In 2010, however, the Obama Administration reversed the policy of the Bush Administration, and pledged to protect “critical habitat” and draft a recovery plan for the species. The USFWS was ultimately ordered by the court to develop a jaguar recovery plan and designate critical habitat for the cats. On 20 August 2012, the USFWS proposed setting aside 838,232 acres in Arizona and New Mexico — an area larger than Rhode Island — as critical jaguar habitat. On 4 March 2014 Federal wildlife officials set aside nearly 1,200 square miles along the U.S.-Mexico border as habitat essential for the conservation of the jaguar. The reservation includes parts of Pima, Santa Cruz and Cochise counties in Arizona and Hidalgo County in New Mexico. In September 2015, El Jefe was photographed via camera trap and analysis of his spots confirms that he has been in southeastern Arizona (30 mi (48 km) south of Tucson) since 2011. Jaguars have been present in this region every year since 1997. El Jefe and other males may have originated from a breeding population in Sonora, Mexico, 125 mi (201 km) to the south of Tucson.

Northern Jaguar Project

The Northern Jaguar Project is a conservation effort on behalf of the jaguar that is headed by an Arizona-based organization of the same name, in conjunction with Mexico’s Naturalia. It is focused on protecting the jaguars living near the border between the United States and Mexico. The core of the project is the Northern Jaguar Reserve. The project began in 2003 with the purchase of the 10,000 acre Los Pavos Ranch in northern Mexico, just 125 mi (201 km) south of the border. In 2008 it was expanded to more than double its size when Rancho Zetasora was acquired. Both ranches are remote, difficult to access, and relatively untouched, making them perfect habitat, not just for jaguars, but for many other species as well. The Northern Jaguar Project is the “northernmost location where jaguars, mountain lions, bobcats, and ocelots are all found in the same vicinity”, and the park also features a variety of floral habitats as well.

The project is also focused on efforts to create a stable jaguar population in Northwestern Mexico. However, its long term aspirations include a return of the jaguar to the Southwestern United States. The potential for such a re-introduction is deemed high, since as much as 30% of Arizona alone is considered to be a suitable habitat for the jaguar.”

Extract from https://en.m.wikipedia.org/wiki/North_American_jaguar
Image of El Jefe