So what do i think?  I am an avid animal watcher and former zoo keeper and i visit Chimpanzees and Orangutans regularly at zoos and which do i think act more human?

It is hard to say.  I have been amazed at how smart the Orangutans are, same for the chimps.  I have seen both animals make and use tools.  I have seen obvious communication when a group of chimpanzees discovered a snake in the exhibit.

The Great Ape Sex Debate – Looking at the difference in sex

Chimpanzees Mating

Chimpanzees have sex in one main position, the male sitting down and the female backs up into the male and sits down on the male for a few seconds. As you can see in the image i have photographed, this seems like a very basic, animal-like way of sex.  Also, sex usually happens in the chimpanzee world when the female is ready, when her sexual organs swell to a very noticeable size, giving male chimpanzees the sign that they are ready to mate.

This leaves the males to have sex with the female mainly when she is ready, only a few days out of a month, which jokingly sounds like married women who only want to have sex to become pregnant.

The Chimpanzees look very similar to humans except for a few key features, mainly the very flat nose and protruding brow, the short thumb and longer fingers and the hand-like foot.

Orangutans Mating

The Orangutans definitely mate more similar to humans than the chimpanzees.  The orangutans are very special and will mate in many different, as you can see on the image i took on the right at the National Zoo in Washington DC.  As you can see, the male is lying on it’s back and the female is on top.  This did not last for seconds, but minutes, as i was shocked to see!

These two Orangutans are so sexually active that the keepers have to keep these guys separated as much as possible because they would probably have sex most of the day, which would be hard for mothers to explain to their children, especially when the sexual acts look so human like.

Which species Looks and acts more human?

A Bonobo Chimpanzee appearing very human-like.

To me, the appearance of the Chimpanzee is very similar to the humans in appearance.   If you add in the Bonobo Chimpanzee (or Pygmy Chimpanzee), which are more slender and a little more human like in appearance, it is very easy to imagine millions of years ago a human that looked almost identical to the bonobos, as you can see from the image i photographed to the right.

When viewing the Bonobos, it almost seems obvious that we evolved from them.  But what if scientists are wrong?  What if we are more closely related to the Orangutans?

Orangutan with long hair and it's hairline.

The Orangutans can look very human like at times too.  It is said that the Orangutans are the only animal to be able to smile with closed lips.  Another interesting study is the fact that Orangutans and humans can grow out their hair to amazing lengths, not seen in the Chimpanzees or Bonobos.   The Orangs also have a hairline on their head, something they share with humans.

The Orangutans have an amazing ability to show emotions with facial expressions, especially with their babies.  The Orangutan babies will whimper and cry, smile and frown.  The Orangutans also spend the second longest time raising their baby, guess who is first?  Humans of course!

A male chimpanzee teaches the younger chimps how to use a tool.

As i mentioned earlier, both the Orangutans and Chimpanzees are great tool users.  While watching the Chimpanzees at the Maryland Zoo in Baltimore, i have seen older chimpanzees pick up a twig and fashion it for it’s liking to use for various tasks, mainly the “honey feeder” which the chimps have to find their own tools to stick inside a black box with many holes to get to the delicious treats.  What is fascinating about watching this task is viewing the young Chimpanzees curiously watching the adults figure out how to get the contents out of the box, as you can see in the image to the right that i took.  This is amazingly human like to me, seeing a young adult male chimpanzee showing the younger chimpanzees how to use a tool to complete a task.  With all three of the young chimpanzees watching, they pretty much got the hang of it and were seen doing it themselves within days.

The Orangutans are amazing tool users also, and what i witnessed in the National Zoo in Washington DC left me dumb-founded.  I witnessed an Orangutan creating her own cleaning cloth to wash the glass in her own exhibit!

Orangutan using tools to clean a window - click for more photos

I witnessed the young female Orangutan imitating the zoo keepers who would spray the window with a cleaning solution, wipe down the window with a cloth and then squeegee the window clean. This amazing girl ripped apart a piece of cloth with her teeth and hands and wrapped pieces of hay into the strip of cloth and rolled it up like a sushi roll, creating a sponge.  Next, she would collect as much saliva in her mouth and spit it out onto the window.  This was her cleaning liquid!  Now with the liquid on the window she took her cleaning cloth and wiped the windows clean!  What next, you may ask?  Using her forearms, the brilliant Orangutan squeegeed the windows dry using her long arm hairs!

If you want to see more photos from this, please visit my animal photos on flickr.

So what do you think?  Who are we closer related to?

Now i would like to hear from you!  What do you think about this debate?  Could we be closer related to the Orangutans, or do you believe in the original theory?  What about Gorillas?  Is there any way we could be related to them?  Your comments are needed!