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Gorillas: Strong, Sexy & Smart

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‘Tool use in wild western gorillas (Gorilla gorilla).’

The use of a tool to aid in the search for food can be seen in many different animals, from crows using twigs to dig for grubs, to elephants using tree branches to swat flies and scratch themselves (Holdrege, 2001). Western gorillas (Gorilla gorilla) are no exception to this phenomenon. Recently there have been some interesting observations of gorillas using tools as a way to obtain previously unaccessible foods. Wild gorillas have been seen using rocks in a hammer and anvil fashion in order to smash apart nuts and extract the inner contents (McNamara 2005). Eli, a female gorilla living in Nouabal-Ndoki National Park in the Republic of the Congo was caught on film using the trunck of a tree as a base of support to hang off as she leaned over a body of water to search for herbs to eat (Bruerer et al, 2005).

Lead using a walking stick to navigate water

Lead using a walking stick to check the depth of water (Bruerer et al, 2005).

Gorillas have also been observed using tools for more than just acquiring food. Gorillas are not notorious for their ability to swim, therefore falling into deep water would not be conducive to a happy and long life for a gorilla. Leah, a different female gorilla living in Nouabal-Ndoki National Park has been observed using a stick as a means to check the depth of the water as she passes through swampy areas (Breurer et al). Such behaviors should not be surprising from an animal that shares 98.4% of it’s genetic make up with humans. Darwin was probably right, we did evolve from monkeys.

References:

“A Tough Nut To Crack For Evolution,” by Melissa McNamara. CBS News. 18 October 2005. URL: http://www.cbsnews.com/stories/2005/10/18/tech/main951800.shtml (accessed on 3 April 2010).

Breuer T, Ndoundou-Hockemba M, Fishlock V, 2005. First Observation of Tool Use in Wild Gorillas. PLoS Biology, 3(11): 2041-2043.

Holdrege, C, 2001. Elephantine Intelligence. Spring 5:10-13.

BOOMZ, you know you know?

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DSCN8194_small

“ Camponotus saundersi“, by stormfront.org (Grand_Inquisitor). Suicide bomber ants. http://www.stormfront.org/forum/showthread.php?t=118290 (accessed 29 March 2010)

It has been documented throughout human history that war demands self sacrifice for “the greater good” and this is most personified by the Kamikaze actions of the Japanese pilots during the Second World War. However, this also occurs in the animal world in an equally explosive fashion. Most would/should know that bees die after stinging in an attempt to defend the hive from enemies, however, certain species of ant also display this self sacrificial behaviour albeit with more ‘drama’.

Camponotus saundersi is a fairly common species of carpenter ants that build nests in dead wood. Interestingly, this species of ant displays autothysis – a term first coined by Maschwitz and Maschwitz which means the destruction of the animal (or insect) by internal rupturing [1]. By exploding, a mixture of chemicals is released that acts as both glue and (possibly) toxins [2] which ultimately kills the enemies in the ‘line of fire’. The ‘initiation’ for this act of altruism requires a contraction of the abdomen which then releases the contents [3]. It is this act that also earns them their nickname as ‘Kamikaze Ants’ or ‘walking chemical bombs‘.

I hope that the next time you think of ants, not only will “as hard working as an ant” come to mind but also “as self sacrificing as an ant”.

References:

1 – Ulrich Maschwitz & Elenore Maschwitz (1973). Bursting Workers : A New Means of Detente
in Social Hymenoptera . Oecologia (Berl.) 14, 289–294 (1974)

2 – T.H Jones (2004). The Chemistry of Exploding Ants, Camponotus SPP. (cylindricus complex). Journal of Chemical Ecology Vol 30, No. 8, August 2004

3 – Emery, Carlo (1889). Viaggio di Leonardo Fea in Birmania e regioni vicine. XX. Formiche di Birmania e del Tenasserim raccolte da Leonardo Fea (1885-87). Annali del Museo Civico di Storia Naturale Giacomo Doria (Genova) 2 7(27): 485-520.

How do Squirrels Find their Nuts?

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Sciurus carolinensis, commonly known as the grey squirrels, have been labelled as “household pests” in the United States(1) because of their infamous accomplishments for finding food in people’s homes. They are known to find food accurately and quickly hide them then return for more and they never seem to forget their hiding places. A video from BBC Worldwide(2) shows an experiment on how grey squirrels manage to find their nuts so quickly and accurately.

How do Squirrels find food? – Clever Critters – BBC Pets & Animals

It is interesting to note that squirrels search for nuts using not only using their sense of smell, but also visual cues. In other words, they seem to have great memory power to remember the exact positions of their nuts. So, using both their sense of smell and their sense of sight, they are able to find their nuts very accurately and never ‘forget’ where they hide their nuts.

In addition, squirrels are able to find their food better in places where they are more familiar to. In a journal article(3) written by Jacobs and Liman, it is mentioned that “the squirrels retrieved significantly more nuts from their own sites than from sites used by other squirrels”. It seems like squirrels stick to the familiar sites and thus causes many problems in the neighborhood where they roam. However, it does not justify the killing of the grey squirrels. The people should also play their parts by keep their food in tight containers to stop tempting squirrels to visit their homes.

In conclusion, squirrels find their food easily in a place where they are familiar with, and they are also able to remember their hiding place for food accurately, these enable them to hunt fast and stock up food very quickly and sustain their survival.

References:

(1) “Grey Squirrel Fact File,” by Pete Carpenter. New Forest National Park: http://www.new-forest-national-park.com/grey-squirrel-fact-file.html (accessed on 27 Mar 2010).
(2) “How do Squirrels find food? – Clever Critters – BBC Pets & Animals,” by BBC Worldwide YouTube Channel, 24 November 2008. URL: http://www.youtube.com/watch?v=sMYuIK5YWVE&feature=fvsr (accessed on 27 Mar 2010).
(3) Lucia F. Jacobs & Emily R. Liman, 1991. Grey squirrels remember the locations of buried nuts. Animal Behaviour, 41(1): 103-110.