Primatology.net

BBC’s Meeting the world’s smallest primate (click link for the site and video), is being criticized for its inaccurate information.  Made as an educational piece to show that the animal’s popularity with tourists is affecting the animals’ welfare, poor research and possibly bad editing culminated in some errors. While these errors are minute, they affect the overall educational purpose of this video.

The show’s host referred to Philippines tarsiers (Tarsius syrichta) as marsupials. T. syrichta (and all tarsiers for that matter) do not have marsupium, the hallmark of marsupials. Tarsiers are primates, grouped in the suborder of Haplorrhini. Tarsier offspring are born precocial, while marsupial offspring (joey) are born altricial.

Precocial offspring are relatively mature and mobile after birth. There is a distinct slowing down in brain growth relative to body growth at around time of birth. Altricial offspring on the other hand are born helpless. Their brain growth declines during the developmental stage instead of around the time of birth. Human babies are unique within primates because they are born “secondarily altricial” (Martin, 2007). While human offspring are born helpless, their brain growth relative to body growth continues for about a year before slowing down. Calling tarsiers marsupials is just rude (don’t we all want to be primates?).

The claim that Philippines tarsiers is the smallest primate is also false. The title for the smallest primate actually goes to Berthe’s mouse lemur (Microcebus berthae) (Dammhahn & Kappeler, 2005).

Male Philippines tarsiers weigh 119-153 g (4.2-5.4 oz) and females weigh 110-132 g (3.9-4.7 oz) (Gron, 2008). Philippines tarsiers exhibit sexual dimorphism, where males are slightly heavier than females. Berthe’s mouse lemur weigh 30.6 g (1.1 oz) for both males and females (Gron, 2009). Clearly, Philippines tarsiers weigh more than Berthe’s mouse lemur.


Philippines tarsiers have a  head and body length of 11.7-12.7 cm (4.6-5.0 in) for both males and females (Gron, 2008). Berthe’s mouse lemur have a head and body length of 9.2 cm (3.6 in) for both males and females (Gron, 2009). Clearly, Philippines tarsiers is longer in size than Berthe’s mouse lemur.


Also read Bonn Aure’s BBC’s Faulty Tarsier Video on Time Travelling for his take on this video.

References:

Dammhahn, M. Kappeler, PM. 2005. Social System of Microcebus berthae , the World’s Smallest Primate. International Journal of Primatology 407-435. Retrieved May 08, 2010 http://www.springerlink.com/content/u6u4372474318166/

Gron, K. 2008. Primate Factsheets: Tarsier (Tarsius). Primate Info Net Retrieved May 08, 2010 http://pin.primate.wisc.edu/factsheets/entry/tarsier

Gron, K. 2009. Primate Factsheets: Mouse lemur (Microcebus). Primate Info Net Retrieved May 08, 2010 http://pin.primate.wisc.edu/factsheets/entry/mouse_lemur

Martin, RD. 2007. The evolution of human reproduction: a primatological perspective. American Journal of Physical Anthropology 45:59-84. Retrieved May 08, 2010 http://www.ncbi.nlm.nih.gov/sites/entrez?cmd=PureSearch&db=pubmed&term=18046752[UID]

Originally posted on The Prancing Papio.

The concept of “family” and relatedness are prevalent in the animal kingdom. Individuals seem to be able to tell if they are related to one another, probably in effort to avoid incest breeding (to increase fitness). While “phenotype matching” is proposed to be one of the kin recognition mechanism between animals to assess their relatedness, “phenotype matching” using olfactory cues (body odor) have been poorly investigated and tested in anthropoids.

Célérier et al. (2010) uses mice to assess the relatedness of chacma baboons (Papio ursinus) through olfactory cues. But, why mice you asked?

Human noses are often quite weak compared with the rest of the animal kingdom, making it hard for us to find out if baboons can be told apart by smell. Researchers therefore decided to draft much better noses — those of mice. The researchers swabbed the armpits and groins of wild chacma baboons (Papio ursinus) from two different troops of the primates in Namibia. They next tested 24 adult male Swiss mice to scents from 14 adult female baboons. They chose female baboons partly because “some male mice were peeing on male baboon odors as if they were in competition,” said researcher Aurélie Célérier, a behavioral biologist at the CNRS and the University of Montpellier II, France.

Their research shows that mice can detect odor differences between individuals of the same sex and age class in another mammal species, and that the mice can perceive a higher similarity between baboons that are related than baboons that are unrelated. These results show that olfactory cues may play a role assessing the degree of relatedness in among individual baboons. Detective mice assess relatedness in baboons using olfactory cues by Célérier et al. (2010) was published on The Journal of Experimental Biology. Also read Detective Mice Help Scientists Study Baboons by Charles Q. Choi on LiveScience.

Anyone has access to this article, by any chance?

Originally posted on The Prancing Papio.