The lion ( Panthera leo ), one of the best-known big cats in popular culture and misnamed “king of the jungle” is a species that is also endangered by human activity.
Characterized by their territoriality, lions are excellent animals for the study of ethology – the study of animal behavior -, specifically to better understand the social behavior between these animals inside and outside their prides .
A new study carried out with a group of 23 African lions has made it possible to find a way to promote social relationships between members of the same species in an unnatural environment . An investigation that opens the doors to an improvement in the conditions of these animals in captivity and in private reserves.
Competition as a way of life
Lion prides, also known as harems, are made up of several males that form coalitions along with a larger number of females with whom they mate. The males have a key role in the harem: defending the territory and ensuring the survival of the offspring.
Lion harems are not static over time, but rather change. When a male gets older, a younger male can come to fight with him and “take over his territory”. This means that territoriality is part of the daily life of lions . But… what happens to lions in captivity?
A hormone to “tame” them all
Due to the loss of habitat due to the growth and expansion of African cities, the transfer and refuge of lions in private fenced reserves and their breeding in captivity is increasingly necessary. This has the consequence that lions from different prides can mix in a small environment.
Despite the advantage that it can give them in nature, territorial behavior and aggressiveness with other individuals of their species (intraspecific competition) can make coexistence between lions in reserves and in captivity a real challenge, because this circumstance is on the rise.
The group of scientific researchers led by animal biologist Craig Packer and neuroscientist Sarah Heilbronner, from the University of Minnesota, tested a new method to study how it could change the behavior of these animals in a wildlife reserve: The Kevin Richardson Wildlife Sanctuary (Dinokeng, South Africa).
The experiment consisted of administering intranasally (using the nose as a door to their brain) a hormone called oxytocin , which is characteristic for its role in childbirth, lactation, sexual arousal and orgasm. In addition, due to its involvement in social behavior in mammals, oxytocin is a neurotransmitter that can also play a relevant role as a modulator, influencing social behavior in some species when administered nasally.
In order to deliver oxytocin to lions, the researchers used meat by luring them into a fence . At that moment, taking advantage of the opportunity, they sprayed their noses with the hormone using a diffuser bottle .
After this treatment, they identified that those lions that were administered oxytocin became more “sociable” with other lions in their same territory and had a less vigilant behavior against possible intruders. This change was also seen in their physical features, which, according to the researchers, indicated that they “relaxed completely.”
One of the most outstanding behaviors in which this behavioral change could be verified was the game. Captive lions may have some objects that they consider “their belonging”, such as a toy, for which they fight and show aggressive behavior as a result of their territoriality. Thus marking the distance with other individuals. However , after the administration of oxytocin, the lions allowed other individuals to get closer to them than those who had not received the hormone.
Despite the change in the socialization of these big cats in play behavior, this same effect was not observed in eating behavior , where they showed a more possessive attitude (something common in nature). By the time food was involved, the lions showed no increased tolerance for one another despite being given oxytocin.
Despite its limitations due to the conditions in which it was carried out, this study, published in the journal iScience, has allowed us to better understand the potential influence of oxytocin on the prosocial behavior of these animals, as well as finding a possible way to facilitate coexistence between lions that have been rescued from circuses or war zones that are in safe spaces such as sanctuaries (where they are isolated individually). An even more important question is the relevance of these management results for the introduction of lions, both in the wild and in captivity. One of the great efforts in conservation.
Burkhart et al. 2022. Oxytocin promotes social proximity and decreases vigilance in groups of African lions, iScience, https://doi.org/10.1016/j.isci.2022.104049