mandrills

A mandrill invented a gesture for “leave me alone” and it spread through the community and is still in use more than 15 years later.

This demonstrates the creation of a cultural meme.

This also gives interesting insight into the evolution of language.

Also, given how the gesture works (preventing eye-contact, which is the initiation of most social interactions in primates), it will work in most monkeys and apes, including humans. Try it!

Read the full story here.

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Social Structure of a Semi-Free Ranging Group of Mandrills (Mandrillus sphinx): A Social Network Analysis

  • by Céline Bret, Cédric Sueur, Barthélémy Ngoubangoye, Delphine Verrier, Jean-Louis Deneubourg and Odile Petit 

“The difficulty involved in following mandrills in the wild means that very little is known about social structure in this species. Most studies initially considered mandrill groups to be an aggregation of one-male/multifemale units, with males occupying central positions in a structure similar to those observed in the majority of baboon species. However, a recent study hypothesized that mandrills form stable groups with only two or three permanent males, and that females occupy more central positions than males within these groups. We used social network analysis methods to examine how a semi-free ranging group of 19 mandrills is structured. We recorded all dyads of individuals that were in contact as a measure of association. The betweenness and the eigenvector centrality for each individual were calculated and correlated to kinship, age and dominance. Finally, we performed a resilience analysis by simulating the removal of individuals displaying the highest betweenness and eigenvector centrality values. We found that related dyads were more frequently associated than unrelated dyads. Moreover, our results showed that the cumulative distribution of individual betweenness and eigenvector centrality followed a power function, which is characteristic of scale-free networks. This property showed that some group members, mostly females, occupied a highly central position. Finally, the resilience analysis showed that the removal of the two most central females split the network into small subgroups and increased the network diameter. Critically, this study confirms that females appear to occupy more central positions than males in mandrill groups. Consequently, these females appear to be crucial for group cohesion and probably play a pivotal role in this species” (read more/open access).

(Open access sourcePLoS ONE 8(12): e83015, 2013; top image: Deccan Chronicle

 
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We got mandrills at the Zoo and they were finally out long enough for me to see them today!

Three males ages 10, 8, and 6 I believe. They were on testosterone suppressants at the last zoo they came from to discourage fighting and aggression but have been taken off it so we’re hoping they still get larger and their colouration more intense. Such a crazy looking primate!

The Hunger Games Catching Fire gets it (mostly) right

SPOILER ALERT: If you have not read or seen the Hunger Games Catching Fire, stop reading now. This post contains plot details that could be considered spoilers.

This Black Friday, while most people were out shopping, I decided to go and check out the latest installment of the Hunger Games film series, Catching Fire. 

I loved the film (and who wouldn’t?) with all the fast-paced action and intrigue surrounding President Snow, Katniss, and the uprisings in all the districts, but I was pleasantly surprised to see how they portrayed the monkey “mutts” (genetically altered animals specifically created for the Hunger Games arena) in the film.

In the book, Katniss (who has never seen a monkey before) describes them as having orange-ish fur, being half the size of a grown human, having long fangs, and switchblade-like claws. To begin, there are a few issues with this description. Primates have hair, not fur as well as fingernails, not claws (and certainly none that shoot out like switchblades). And generally we just refer to those “fangs” in mammals as canine teeth. But we’ll forgive Katniss and Suzanne Collins for not being primatologists, and not knowing this.

Luckily in the film, the filmmakers avoided doing something I absolutely hate in film/television, where they call something that is clearly an ape, a monkey or vice versa, and used CGI versions of these guys:

That’s a Mandrill, a type of Old World monkey, a member of the Cercopithecidae family that lives in the southern and western part of continental Africa. Their social groups, or hordes, are found in rain forests (like the one portrayed in Catching Fire) as well as forest-savannah mosaic landscapes. Only the males display the bright coloration used in the film, and as the heaviest monkey in the world they can weigh up to 54kg (119lbs). Males typically are solitary rangers, only entering hordes when females are receptive. So it is pretty rare to see that many adult male mandrills together in the wild, as portrayed in the film, nor are they generally all that aggressive towards humans, but we could probably chalk it up to the fact that they are mutts produced by the Capital for the game. 

High five though to the filmmakers for getting the monkey/ape thing right! 

Go see Catching Fire, in theaters now!

- Anne