Friday, August 5, 2016

The Chimp Olympics!

Are you excited for the Olympics?  How about for the Chimp&See Chimp Olympics?!  Chimpanzees can be agile, strong, and fast, and over the next few weeks, we'll be showcasing videos of them at their very best.  Check back each day for a new "event", but today we have the Parade of Athletes to start us off!

Some bonus information about today's videos: chimpanzees live in communities of about 20 to about 200 individuals, but you won't ever see 200 chimps gathered at the same time!  They break off into temporary parties that may be as small as a single lone individual or as large as a few dozen (and in rare cases even more), that form and reform over hours to days.  Today's videos show some of the larger parties we've seen on C&S.

Check back tomorrow for the first event!

Day 2:
Today's event is jumping!  Since chimpanzee anatomy isn't specialized for standing upright, they often look a bit awkward when jumping and landing.  It's possible for them to land both quadrupedally, putting down their hands and then their feet, or bipedally, putting down their feet first.  Leaping is an uncommon behavior for chimpanzees of all ages: in one study chimpanzees spent less than 1% of their locomotion time leaping.

Original videos at ACP0002itc ACP000cf37 ACP000bw65 ACP00064ot

Doran, Diane M. "Sex differences in adult chimpanzee positional behavior: the influence of body size on locomotion and posture." American Journal of Physical Anthropology 91.1 (1993): 99-115.

Day 3:
Today's event is stonethrowing!  Chimpanzees may throw stones during play or during displays.  In some cases, they throw stones habitually against the same trees during displays -- see PanAf's first published paper for more information.  Watch the video below for some of our best stone throws!

Original videos at ACP0005652 ACP0005a6j ACP0005a91 ACP0005a9y

Day 4:
Today's event is climbing!  When chimps climb trees or vines smaller than a few inches in diameter, they grip them like a baseball bat, with the thumb opposite the fingers.  They also grip with their feet, using their opposable toes for extra control and traction.  For medium to large size trees, they "hug" the trunk and then basically walk up, placing each foot flat against the trunk and pushing to gain height.  When returning to the ground, they usually use the same motions in reverse, but they can also "hug" the trunk and slide as seen in this video from our collaborators at the Goualougo Triangle Ape Project!

Original videos at ACP0007g9e ACP000bepc ACP00071qe ACP00071qf ACP00064or ACP0007gbi ACP000ceus ACP000b03e

Day 5:
Today's event is galloping!  The normal walking pattern for chimpanzees is to move each arm in time with the opposite leg, and to place them down before moving the other arm/leg.  However, when they want to move faster, they can gallop instead, pushing off with both feet at once, then picking up both hands, becoming airborne for a moment!

Day 6:
Today's event is nut-cracking!  Chimpanzees in some communities crack hard-shelled nuts to eat, which can provide them with over 3000 calories in a single day.  Nut-cracking is cognitively complex, requiring knowledge of the location of nut trees, anvils, and hammers, plus the correct method for cracking.  It also requires precise manipulation to correctly line up the anvil, nut, and hammer, and the physical strength to strike the nut hard enough to break it open.
Boesch, Christophe, and Hedwige Boesch-Achermann. The chimpanzees of the Taï Forest: Behavioural ecology and evolution. Oxford University Press, USA, 2000.

Day 7:
Today's event is branchshaking!  Chimpanzees shake branches as a social signal.  They may do it to impress a potential mate, or to intimidate a rival, or they may even direct it at another species (e.g. humans or baboons).  Branchshaking displays are most often performed by adult males, but females and even juveniles perform them too.

Original videos at ACP0002l0t ACP000b8ft ACP000cmch ACP00058bq ACP00081ir ACP0002j59


van Lawick-Goodall, Jane. "The behaviour of free-living chimpanzees in the Gombe Stream Reserve." Animal behaviour monographs 1 (1968): 161IN1-311IN12.

Day 8:
Today's event is infant carrying!  Chimpanzee newborns have a strong clinging reflex and hold tightly to the hair on mom's belly.  She'll carry the infant like this on her front usually for around six to twelve months, at which point the infant starts to ride on her back instead.  Infants don't all develop at the same rate, and it may be quite a number of years before mom completely stops carrying them.  In fact, it may be long enough that there is a younger sibling and mom carries both at once!  See if you can spot the video with a mom carrying two kids -- it's a quick one.

Original videos at ACP000gnpq ACP0007aq2 ACP0007s48 ACP0007tpu ACP00055ty ACP00077tx ACP000781n ACP0004832 ACP000cid1 ACP000cid2 ACP0004zva ACP000asly ACP000asm2

van Lawick-Goodall, Jane. "The behaviour of free-living chimpanzees in the Gombe Stream Reserve." Animal behaviour monographs 1 (1968): 161IN1-311IN12.

Day 9:
Today's event is crutch walking!  Crutch walking is a locomotion pattern usually used on steep terrain where both hands are planted, and the body and feet are swung through the arms.  It's similar to a gallop, but slower.  New moms also sometimes walk this way, keeping their infant cradled in their lap.

Original videos at ACP000bwj4 ACP000bwj6 ACP00051fe ACP000bw74 ACP0005dhx ACP0005dhy ACP000bwhk ACP00055si

Nishida, Toshisada, et al. "Ethogram and ethnography of Mahale chimpanzees." Anthropological Science 107.2 (1999): 141-188.

To see the rest of the Chimp Olympic events, continue to Week 2!