Desert ants smell the way back to the nest

When lost in the desert, people often hang around in a deadlock circle. This prompted scientists to ask how the desert living organisms could find their way without a marker. Now a new study has demonstrated that desert ants have to use both odor and visual cues for their navigation system to find their way back to the nest.

Until now researchers were still like desert ants Cataglyphis fortis nesting in harsh salt lakes in Tunisia is a visual-only insect. But Kathrin Steck, Bill Hansson and Markus Knaden of the Max Planck Institute of Chemical Ecology in Jena, Germany used gas chromatography to clarify that micro-habitats in the desert have characteristic odor signs that guide the way. give ants to the nest.

After identifying some of the signs, the researchers trained the ants in the experiments to recognize the odors only to the secret way to the nest. The ants learned the connection of sugar to the nest with a characteristic odor, and distinguished the smells used for training and other odors. They even select the smell from the four-odor mixture. They are less focused when faced with the odor mixture instead of just a single odor.

Cataglyphis fortis is looking for food.Its brain is equipped with a navigation system that uses both visual and olfactory markers to find their way back to the nest.(Photo: Copyright Max Planck Institute for Chemical Ecology, Markus Knaden)

The use of environmental olfactory signs exists in pigeons, while most ants rely on their homemade pheromon sugar. However, Cataglyphis ants have a food search area of ​​up to 100m in an environment where high temperatures as well as changing food positions can make pheromone sugar ineffective. This may be one reason why these ants look for other stable odor signs that they have learned on the way to the nest.

Knaden wants to learn about the interaction between visual and olfactory information in later studies, he said: 'We were surprised to find that while moderate tracking of sugar analysis, learning Visual cues, these ants can also collect olfactory information. '

Refer:
Kathrin Steck, Bill S Hansson and Markus Knaden.Smells like home: Desert ants, Cataglyphis fortis, use olfactory landmarks to pinpoint the nest.Frontiers print Zoology, (in press)