Friday, 23 July 2010

The Private Life of... PIGS

AIRED: Thursday, 22 July, 20:00 on BBC Two

The Private Life of... turns its attention this week towards the mental lives of pigs.  Presented by Jimmy Doherty the series sets out to reveal the hidden lives of farmyard animals using a variety of simple psychometric testing measures.  Set on a farm in Dartmoor, Jimmy embarks on a quest to uncover the answers to questions such as, how sensitive is a pigs nose? Why can they find truffles underground? How do piglets find the right teat to feed from? (and by far the most interesting question of the episode), Can pigs recognise themselves in a mirror?

Traditionally the mirror test is a measure of self-awareness developed by Gordon Gallup Jr. (1970).  Inspired by the written accounts of Charles Darwin (1809-1882) and his reports on holding a mirror up to an orangutan and recording the corresponding facial and bodily actions.  Darwin suggested that these expressions were ambiguous and either signified that the primate was making expressions at what it perceived to the another animal, or it could be playing a sort of game with a new toy -  the animal might not be recognising itself but instead be attributing that image to another or, alternatively it might be recognising that the object that it holds represents an image of itself and so demonstrate an understanding of self-awareness.

It was through these observations that Gallup devised a test that attempted to gauge self-awareness by trying to discover whether an animal could recognise its own reflection in a mirror mark test.  Also referred to as the rouge test, the experiment is conducted covertly placing a mark of the participants body.  Ideally the spot should be placed in an area that is clearly visible to the animal in the mirror and can be physically reached with an appendage (reaching in this manner might suggest the identification of the foreign agent).  The control measure would therefore be a mark to an accessible part of the body but still remains out-of-sight.  Researchers then observe behaviours that might show the recognition of the placed mark.

To date animals that have passed the mirror test include all of the great apes, bottle-nosed dolphins, orcas, elephants and European magpies, with human children failing this test until they reach 18 months old.  Not surprisingly, pigs have previously been found to pass a variation of the mirror mark test, using the mirrors image to obtain information about a food source (Broom, Sena and Moynihan, 2009).  Under the watchful eye of Broom, it was precisely this measure of mirror self recognition that the programme used during the procedure.

Whilst the total amount of piglets used during testing was relatively low (expectantly due to the time constraints of the programme), the piglets did show a marked preference towards the location of the food when the mirror was present, suggesting that each piglet used the information from the mirror and its surroundings, deduced the relationship between the two and acted accordingly in finding the food source.  This therefore might suggest a form of assessment awareness in pigs.  Whilst the results were by no means conclusive, with a friend commenting on the suitability of the mirror mark test on an animal that has no flexible appendages and whether or not the piglet recognised itself in relation to the food (or just simple recognised the food), it does highlight the need for further research into the areas of animal cognition and self recognition.  I therefore suggest that what is needed are better designed measures of self-awareness and the acknowledgement of these mental lives in order to help in the welfare of all animal species.

Link: The Private Life of...Pigs

Thursday, 22 July 2010

Gorillas - Playful Minds

Published in the journal Animal Cognition, Dr. Joanne Tanner and Prof Richard Byrne at the University of St Andrews, have produced intriguing evidence that Gorillas, like human infants and bonobos, will actively engage in social play and another object - Whilst playing together, gorillas will share their toys.

The article entitled, Triadic and collaborative play by gorillas in social games with objects, discusses the current trend in the field of comparative psychology to assume that non-human primates lack (with the exception of bonobos - who are more cooperative in nature, and therefore more akin to humans than to chimpanzees in this respect) the key characteristics of children's collaborative play.  However, the study appears to show that gorillas do indeed play games that are both triadic and collaborative in nature.


The triadic and collaborative games were videotaped at the San Francisco Zoo in five different years and involved five different pairings of gorillas. The context was in most cases playfully competitive, involving objects such as balls, bags and leather pieces as foci of joint attention; the ostensible goal in most games was to gain or keep possession of a particular object.  In some episodes, roles as possessor or pursuer of an object were exchanged many times; in others, one gorilla retained possession of an object but encouraged pursuit from a partner.


Through gaze and gesture, gorillas invited others to: share interest in and attention to objects; share patterns of play; and re-engage after breaks in play. Sometimes, gorillas would assist others in their efforts to engage in collaborative play: older gorillas encouraged younger partners by ‘self-handicapping' their own actions.


Collaborative games may occur later in the ontogeny of gorillas than in humans, and depend on the challenges and artefacts available in a particular group's habitat.  It is hoped that the current findings will further help to trace the evolutionary origins of how humans take the perceptions and goals of others into account, back to around 6 million years ago.

The research is published by the journal Animal Cognition (January 2010)   

Wednesday, 21 July 2010

A Discovery Could Help Date Monkey-Ape Split


There are a few important differences between Old World monkeys and apes. Old World monkeys, like baboons and macaques, have tails and a great deal of agility, enabling them to jump and swing from tree branches.

Apes, which include gorillas and chimpanzees, are tail-less and tend to have a more upright posture. Scientists agree that Old World monkeys and apes share a common ancestry, but at some point two lineages diverged, one giving rise to the Old World monkeys and another to both apes and humans. Exactly when the split happened is a matter of debate.

A primate skull unearthed outside of Mecca in Saudi Arabia is the closest common ancestor to apes and Old World monkeys, researchers say, and helps date the split. Sediment records indicate that the fossil is 25 million to 29 million years old, making 24 million to 29 million years ago the window in which the monkey-ape split may have occurred. The ape and human lineages split later.

The research appears in the journal Nature.  

“It is neither a monkey, nor an ape,” said Iyad Zalmout a palaeontologist at the University of Michigan and the study’s lead author. “You have an intermediate primate that tells you a story about Old World monkeys and apes.”

Based on the skull, the primate was medium-sized and weighed about 30 pounds to 40 pounds. It had broad upper molars and a long, baboon like snout.  

A previous estimate, made with DNA samples of living primates found that the split occurred earlier, 34.5 million to 29.2 million years ago. There is however, no fossil evidence to support this.