Tuesday, January 17, 2017

Can you feel the love tonight?

Last week, I stumbled across something unforgettable:

A pair of lions alternates between resting, mating, and fighting!

This amazing wildlife sighting got me thinking: What makes one male more attractive than another? Why does the female invite the male over and then fight him off? What are the chances that she will have cubs?

What's in a mane?

Rather than a crown, the King of the Jungle sports a thick and beautiful mane -- perhaps his best claim to fame. However, not all manes are created equal. Lions' manes vary in length and coloration, conveying important information to competing kings as well as flirty females.

Male lions' manes grow longer and thicker as they approach adulthood. This young subadult is approximately one year old (lions in all photos were aged using the Mara Predator Project's guide to aging lions). Males at this age begin to develop a small, pale "mohawk mane."

These young brothers sport the very beginnings of what will one day be thick, charming manes.

This young adult has a medium-sized, blonde mane. He is in his prime and reigns over his own pride. His face already bears battle scars. As he ages, his mane will continue to grow longer and darker.

This male lives north of our camp and is known as "Scar." Scar is very old and relies on the females in his pride to take care of him. He is missing one eye, is extremely gaunt, and limps badly when he walks. His distinguished mane has grown thick and dark throughout his long lifetime.
Lions' manes have perplexed scientists for hundreds of years. One hypothesized function was communication, but what specifically could this communicate? To find out, researchers at the University of Minnesota's Lion Center asked the lions.

Anna Club Plush Toys of Holland donated two life-sized toy lions to the Lion Center: one with a dark mane and one with a light mane. (Photo obtained from the the Lion Center's Mane Research web page.)
Two toy lions were placed near lion prides: one toy lion had a long, dark mane and one had a short, blonde mane. Reactions of males and females elucidated the role of manes in communication among lions.

Male lions were quick to approach the toy lion with the short, blonde mane. This suggests that long, dark manes make male lions look formidable to competing males. Why would this be so?
      •Researchers at the Lion Center found that males with short manes are often those that have 
      recently suffered from injury or illness, thus potentially reducing their current fighting ability.
      •These researchers found that males with dark manes had higher testosterone levels than males 
      with pale manes, suggesting that they are more aggressive.
      •Males with dark manes were also found to recover from injuries more effectively than their pale-
      maned competitors, as well as sire a higher proportion of surviving cubs. Thus, dark manes likely 
      indicate higher potential reproductive success.

Dark manes don't only say, "back off" to male competitors; they also say, "come hither" to females. In this experiment, female lions paid no mind to mane length, but couldn't resist a dark mane!

Female lions are suckers for dark manes. Selecting a mate with a dark mane may mean that she will have more cubs survive. Besides, who wouldn't want a son with that handsome, dark mane? (Also known as the Sexy Son Hypothesis.)
So, long, dark manes are better than short, pale manes. Mystery solved. Right?

Wait... then why don't all males have these long, dark, and handsome manes?

Females aren't the only ones who find manes hot. They're hot for the males who sport them too! Manes make lions hot, and the dark manes are even hotter -- both literally and figuratively speaking. Dark manes may lead to over-heating in males, which leads to elevated proportions of defective sperm. Over-heating males also have to eat smaller meals, meaning that they have to eat many small meals. This necessitates more foraging time.

One of the stars of our story sports a particularly handsome mane!
One morning while searching for our hyena friends, a particularly handsome male caught my eye. I quickly realized that I wasn't the only one whose attention he had caught. A flirty female had decided that he was a worthy suitor... This is where the story gets good!

Sources: http://livingwithlions.org/mara/how-to/age-lions/

A Public Affair

After noticing this male meandering through the tall grass, I quickly noticed a female rolling on her back and reaching out to him playfully. I've seen enough nature documentaries to know what that means!

These female is in estrus and has selected this gentleman as her mate.
The pair spent hours together. They lied close together in the grass, with their paws touching. Each time she stood up -- or even lifted her head -- he jumped to his feet and pursued her. She assumed the lordosis position and he mounted her. As they mated, she emitted a continuous grumbling sound as he roared into the back of her neck. (Males often bite the female's neck during copulation, likely to elicit passive behavior from their females partners temporarily.)

The male roars as he copulates with this receptive female.
Male cats have barbed phalluses, which rake the female's vaginal walls. This is believed to induce ovulation, thus allowing her to become pregnant with his cubs. However, this can be painful! Each mating bout ended in a small spat. However, they both seemed to put it behind them within mere seconds.

Each mating bout ended in a small lovers' quarrel.

The pair mated many times over the course of an hour. Lions remain together for the female's entire estrus period (four days!), mating  multiple times per hour.

Sources: http://animaldiversity.org/accounts/Panthera_leo/#behavior

Just the beginning

If this pair was successful, she will give birth to 1-6 cubs in approximately 3.5 months. She will cooperate with the other females in her pride to raise them. Females even nurse each other's offspring!

A lion family makes themselves at home right outside of our camp!

Becoming pregnant and giving birth is only half of the battle. Cub survivorship is very low in lions. It has been estimated that for every 3,000 copulations, only one cub will survive to one year of age.
Moments after leaving the mating pair, I stumbled across a lioness leading her fat, healthy cubs across the savanna.

Lion populations have declined by more than 40% over the last two decades alone and they are now considered a Vulnerable species (IUCN Red List). If this female bears cubs, they will help to reinforce the lion population within the Mara Triangle. As a result of strict and thoughtful management, the Mara Triangle offers excellent habitat to lions and other carnivores. This female will have a beautiful place to raise her cubs!

To learn more about lions in the Masai Mara National Reserve, follow the Mara Lion Project and the Mara Predator Project!

Sources: http://animaldiversity.org/accounts/Panthera_leo/#behavior

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