The lion (Panthera leo) is the only truly social feline and the second largest after the tiger. Belonging to the Felidae family, it mainly inhabits savannas, grasslands, and semi-arid areas of sub-Saharan Africa. Its muscular body, strong jaws, and retractable claws allow it to take down large prey. Males are noted for their mane, a unique trait among felines, the shape and coloration of which can vary depending on the region and genetics. This species displays clear sexual dimorphism: males exceed females in size, weight, and ornamentation. Evolutionarily, the lion is part of the Panthera genus, along with the tiger, the jaguar, and the leopard. Although historically it occupied much of Africa, Asia, and even southern Europe, today its distribution has been drastically reduced. The Asian subspecies (Panthera leo persica) survives exclusively in India, with an estimated population of less than 700 individuals.

The lion is the only felid that lives in stable groups called prides. These are made up of several related females, their cubs, and up to three or four adult males who compete with each other for the chance to reproduce. Lionesses cooperate in hunting, defending their territory, and raising their cubs. This cooperative behavior favors the group's survival. Males, for their part, defend their territory against other rival males, and their stay in a pride typically lasts between two and four years. Cubs are usually weaned at six months and begin hunting around one year of age. Lions are most active at night (nocturnal and crepuscular) and can sleep between 2 and 4 hours a day, conserving energy for hunting. Vocalizations are essential in intraspecific communication, especially roars, which serve to mark territory or maintain contact at a distance.

The situation of the lion in the wild is alarming. Classified as "Vulnerable" by the IUCN, it has lost more than 90% of its historical distribution. It is estimated that between 23.000 and 39.000 individuals remain, mostly in eastern and southern Africa. The most serious threats include habitat loss and fragmentation, poaching (either as a trophy or in retaliation for attacks on livestock), and the decline in natural prey. Furthermore, contact with human settlements brings diseases such as canine distemper. The Asiatic subspecies is most at risk, limited to a single park in India. Various conservation programs focus on habitat protection, coexistence with human communities, and captive breeding through programs such as the EEP. The species is listed on CITES (Appendix II) and, in the case of the Asiatic lion, on Appendix I. The future of the species will depend on collaboration between governments, local communities, and zoological centers.