Archive for January, 2006

Ants, unlike bees, do not use maps, but adhere to learnt routes in tussock rich desert habitats of Central Australia. A team of Swiss researchers highlight these findings in the Australian endemic ant Melophorus bagoti. Melophorus are solitary foragers, and each ant establishes idiosyncratic paths in their cluttered environment and adheres to them. What’s interesting is that, the foodbound and nestbound routes are different and are not mere 180 degree reversals of each other. When an ant heading home is displaced, she searches till she finds the familiar homebound route and then ‘channels in’ to reach the nest. However in this period if the ant crosses the foodward path, they continue to search as if lost, thus providing evidence of ‘one-way route navigation’.

From: Wehner et al, 2006. Current Biology 16: 75-79.
highlighted: Nature 2006 439: 246.

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Tandem running

A recent paper in Nature, talks about the well established recruiting behaviour in ants called tandem running in a different perspective: teaching and learning. Tandem running involves the leader ant waiting for a confirmation of the presence of the follower ant before taking a few steps. The follower ant confirms its presence by tapping the leader ant’s legs, with its antennae, which triggers the leader ant to take a few more steps. The article talks about the same, but highlights that this behaviour in Temnothorax albipennis has an added cost as it slows down the leader ant. Ants use different forms of recruitment, tandem running being one of them and hence whether this is actually teaching and learning is highly debatable. If a leader ant moves slowly than usual, it would make it more vulnerable to predators. Even ants that produce alarm or recruitment pheromones for their nestmates end up attracting predators, but the recuritment remains in the best interest of the nest, rather than the individual. Though the article was interesting, I must confess, I did not find anything spectacularly new, compared to findings from earlier papers where tandem running or tandem calling was established. For earlier articles on tandem running see:
  1. Moglich M, U Maschwitz and Holldobler B (1974). Tandem calling: a new kind of signal in ant communication. Science 186, 1046-1047.
  2. Holldobler B and Wilson E O (1990). The Ants.
  3. Holldobler B, Moglich M and U Maschwitz (1974). Communication by tandem running in the ant Camponotus sericeus. J Comp Physio A 90: 105-127.

Franks NR and Richardson T. 2006. Teaching in tandem running ants. Nature 439: 153

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