Why do Male Lions have Manes?
At first this seems like a simple question!
Whilst growing up I was always told that the mane of a lion acted as a shield against injury. The long wiry hair acted as a cushion protecting the neck regions during the big blows of battle. I agreed, thinking that it would be very difficult to sink canines into the jugular when the mane was so long and thick. It was preached that the males with the longer, thicker, darker manes were the males who were better with regards to fighting. It appears that I was not alone in this thinking…
Craig Packer and Peyton M. from the University of Minnesota’s lion research department set out to prove, or disprove, once and for all if this shield hypothesis was true. Other ideas thrown around was that the mane may act as a signal of the male’s ability to fight and protect his cubs, or even as a signal of the male’s nutritional status.
The team analysed all records from witnessed lion fights, together with an extensive database of injuries. These records showed that the wounds to the mane area were no more frequent or lethal than wounds to other parts of the body—even for females and sub-adults, which lack manes. They started focusing on trying to work out where the ‘killer blows’ were on a lions body. They found that more often than not a lion was killed by a strong bite to the back (just above the tail region). This bite would break the back of the lion leaving it without movements of its legs. In this state the lion would often be left for dead. There is no mane on the spine of the lion, so it appears that the ‘shield hypothesis’ may not hold water! It seems that a lion’s teeth provide more than enough incentive to avoid tangling with the front end.
Next they looked closely at what happens to a mane as an individual ages. They found that manes of injured males were often reduced and could fall out altogether.
“This fact is significant because it suggests that mane length might signal a male’s current fighting ability—injured males should be less able or less aggressive fighters. Mane color proved more interesting still: In addition to the age effect, we found that males with darker manes had higher levels of testosterone, suggesting greater aggression, and were on average better fed throughout the year, suggesting either general dominance or superior hunting ability. These results implied that both length and color provided interesting information for other lions, and that both males and females would benefit from using it”
A couple of years ago I wrote a blog post called the “Demise of a King” in which I posted photographs of a male lion, known by many as “The Golf Course Male”. Every time I saw this male I snapped a picture. It was quite incredible to see what happens to his mane as his condition deteriorated. It is well worth having a look at the pictures of his mane here.
It was becoming clear to the research team that the mane was being used as a method to signal fitness, strength and health.
Through a series of wonderful experiments this ingenious research team managed to prize out data and information pertaining to the question of the mane. They used life-size and very realistic toy ‘manikin’ lions. On these manikins they could easily alter the mane colour and mane length. These ‘toys’ were then set up in clearings throughout wilderness areas in east Africa. Tape recordings of hyenas fighting, laughing and feeding were then played loudly to attract and lure lions into the area.
They did this to numerous lion prides (females) as well as to coalitions (males). All observations were filmed and all behaviour noted down. They found that the coalitions always ran at the lightest manned ‘toy’ and the females always ran towards the darkest manned ‘toy’. When they began to analyse this behaviour they concluded that the females were seeing the darkest manned male as the strongest most dominant individual and so were attracted to him as he would be the one to ultimately offer support and protection. The approaching male lion members saw the lightest manned ‘toy lion’ as the weakest individual and so knew that if they were to get into a fight they would need to do so against the weaker one first and only take on the stronger ‘darker’ manned individual at a later stage (if at all).
Lastly, they tried to find a relationship between mane darkness and age. They plotted a graph that showed that the mane of a male lion usually starts to darken before his first birthday and continues to do so for the next four to five years. Over the same time period, mane length and testosterone show similar increases. There appeared to be a strong link between the increasing testosterone levels, increasing body size, age and mane growth.
In conclusion, the mane is thus thought be used as a signal, to females and males, of the current health and status of a male. Its like a giant advertising board attached to your body telling others how good you are, as a fighter, a partner, a lover and a hunter. Currently, within the Sabi Sands the adult lion population is about 35 % male! Needless to say, there is a lot of ‘mane action’ currently taking place in this part of the world. Lion Warfare relentlessly continues at Londolozi Game Reserve.
Written by Adam Bannister
Inspired by West, P. M., and C. Packer. 2002. Sexual selection, temperature and the lion’s mane. Science 297:1339–1343.
All pictures, graphs and illustrations are to be credited to these gentlemen from their work