How to tell the age of a lion
Working out the age of a lion is an important part of our research, as this information can help us identify individuals and understand the structure of a population. However, unless you have been following a lion since it was born, it can be very difficult to know the exact age of a lion just by looking at it. This is why we estimate how old a lion is using a combination of different traits, and group them into broad age categories of cubs (0-2 years old), sub-adults (2-3 years old), and adults (3+ years old).
Cubs (0-2 years old)
Very young cubs are only visible from the age of around 2 months, when their mother brings them to join the pride. The easiest way to estimate the age of a cub is to compare how big it is relative to its mother:
At 2 months they will fit below the bottom of their mother’s belly
At 4 months they will reach her elbow
At 6 months they will reach halfway up her body. Young males may start to show the first signs of a mane from this age.
At 12 months they will reach about halfway up her shoulder.
Sub-adults (2-3 years old)
Lions between 2 and 3 years old are classified as sub-adults. Although they have started to look like adult lions, sub-adults still have a cub-like appearance. When they are 2 years old, females will still be smaller than their mother. Males of the same age will be bigger than their sisters and often taller than their mothers.
Both males and females reach their full adult size by the age of 3, at which point males will leave their natal pride.
The male lions in this picture are sub-adults, feeding at the carcass of a giraffe kill. Their mother is resting close by after having eaten first.
Ageing Adults: Nose, teeth and facial markings
Once lions are adults, we have to age them by looking at features like their nose, teeth, and facial markings.
Cubs and sub-adult lions have pink or light grey noses, but from the age of 3 small, dark freckles will start to appear on their nose. As a lion gets older, more and more of these freckles will appear, until the nose is completely black by around 8 years old.
Lions’ teeth will also change in appearance as they grow older: by the time they reach adulthood, a lion’s teeth will have changed from white to yellow, and will continue to darken, wear down, and even break or fall out as they age.
Scars and facial markings can also be a useful indicator of a lion’s age. The smooth, glossy fur you can see on the face of young lions will become increasingly dull as they age. Adult lions also bear the marks of their fights, hunts, and general tough life in the wild: the more scars and ear tears you see on a lion, the older it is likely to be. This is especially true for males, who frequently get into scraps with other males when attempting to take over a pride or defending their own.
Adult female lions. You can see the one on the right is quite old, her nose is completely black and her teeth are in very poor condition. The younger lion on the left still has her smooth glossy fur and few facial markings.
Adult male lions. The male on the right is clearly the older one: lots of scars, a torn ear, a dark nose and a missing tooth.
Ageing a lion by it's mane size
A male lion’s mane will begin to rapidly develop on the chest and neck when they are one year old, and will continue to grow as he gets older. However, mane size and development can vary a lot between different lion populations, and males in hotter climates often have smaller manes than those in cooler climates. Males can also temporarily lose their manes when they are injured. This is why we can’t reliably tell the age of a male lion from his mane alone!
Mane size can vary dramatically between populations, even within a single country. In Tanzania, the lions of the Serengeti are famous for their thick, lustrous manes (left), while many males in the Selous-Nyerere ecosystem have quite small and scraggly manes (right).
Keeping animals wild should be prioritised over keeping them safe
The Pride Lion Conservation Alliance was founded in 2015 by six women working in lion conservation – including our Joint CEOs – with the goal of creating a new, collaborative approach to lion conservation. The Pride Alliance recently published an essay on Mongabay arguing that conservation efforts should prioritise keeping populations and areas wild, rather than keeping individual animals safe.
The urge to intervene and treat injured lions, and perhaps even scoop up their cubs to keep them safe at rescue centres, is of course deeply human. But when we take these actions, these animals' lives are often degraded and endangered. While in some cases intervention is unavoidable and warranted – such as treating animals injured through human impacts, such as snares or poison – intervening to treat injuries obtained through natural causes goes against the essence of wilderness embodied in these animals.
Instead of bowing to uninformed social pressure, we should strive for more considered discussions of these issues which embrace their complexity and nuance. Only then will we be able to find solutions that balance the need to protect these inspiring wild animals with the rights, views, and needs of local people.