At the Gir National Park in India in December 2018, researchers discovered a lioness which was seen with a baby leopard treating it as one of its own. The male cub was about two months old was seen nursing from the mother lioness and eating meat from the animals that she killed. It was also seen playing with the two lion cubs that were almost the same age as the leopard. This kind of interspecies adoption is very rare to be seen in nature and left the researchers in shock. An article was published in the Ecosphere journal which describes the behavior of the lioness as ‘bizarre’.
From the perspective of evolution, taking care of the offspring of another animal is not very logical. Taking care of the young, gathering food, nursing them, and making sure they’re safe takes a huge amount of time and energy. This is usually done by a mother for her own flesh and blood. Doing all of these things for a baby that’s not her biological offspring but from the same species is not unusual. However, a study author wrote that “such acts directly help in boosting the [caregiver’s] lifetime reproductive success.” For example, a female cheetah is known to take care of orphaned male cubs. After the cub reaches adulthood, they form large unions with the mother’s offspring.
Before the lioness and the baby leopard were spotted, there were only two other documented situations of interspecies adoption. One was in 2006 where the scientists saw a marmoset being adopted by capuchin monkeys. Recently, a melon-headed whale calf was seen been taken by a bottlenose dolphin mother for more than three years. However, researchers have stated that “none of the foster parents and adoptees … belonged to mutually competing species,” whereas lions and leopards compete for the same resources and usually fight with one another.
Lions have been seen to kill both adults and baby leopards all of the time. Leopards are also seen attacking lion cubs that are unguarded.
With that said, the mother lion alongside her lion cubs was spotted with the leopard cub all playing along just the same. Researchers were skeptical that this relationship will last a while. A similar situation was seen in 2017 where an African lioness in Tanzania was seen nursing a leopard cub. She took care of the cub for only one day, which was not considered an adoption. However, this lioness was observed for 45 days and the researchers saw the baby leopard with the family of lions on 29 days.
However, the relationship came to an end after the baby leopard was found dead in February 2019. The body of the baby was found near a watering hole. No injuries were spotted on the body which would suggest that the baby was attacked. After a necropsy was done on the body, it was proven that the baby was suffering from a congenital femoral hernia. This means that it was born with a bulging blood vessel in its groin which eventually ruptured.
It is not exactly clear how the lioness came onto the baby leopard and adopted it. A day after the leopard baby was seen with the mother lioness, the experts saw a female leopard in a location nearby. It is possible that she was the mother of the cub, however, the researchers aren’t completely certain that the leopard was lactating.
Researchers suggest that the lioness was encouraged by her inexperience. She was a very young mother at the age of five or six. The two firstborn cubs died very young, thus why her recent litter marked the first venture into parenting. Additionally, researchers wrote that “given that she was a lactating mother with cubs of her own, her maternal and hormonal instincts could have overridden her recognition or the lack thereof for an unusually spotted cub.”
This confusing adoption might have been possible with the different behavior that Asiatic lions have. Indifference to the African lions, male Asiatic lions do not live with the females. The only times a male Asiatic lion was seen with the female is if they’re mating or sharing a big kill. Females are also living on their own for a few months after giving birth. This probably allowed the baby leopard and the lioness to exist. It’s amazing to think what could’ve been off the leopard baby if it interacted with more adult lions. However, the answer can never be found since the baby leopard died.