Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Desert ants have an amazing odor memory

25.09.2018

Scientists at the Max Planck Institute for Chemical Ecology used behavioral experiments to show that desert ants are able to quickly learn many different food odors and remember them for the rest of their lives. However, their memory for nest odors seems to differ from their food odor memory: Whereas food odors are learned and kept after a single contact, ants need several trials to memorize nest odors. Moreover, ants forget a nest-associated odor very quickly after it has been removed from the nest. Hence, ants process food and nest odors differently in their brains. (Proceedings of the National Academy of Sciences of the United States of America, DOI: 10.1073/pnas.1809433115, September 2018).

The desert ant Cataglyphis fortis has amazing abilities to trace food and to return to its nest in the North African desert. Its sense of smell has a central function for orientation. The ant is not only a master navigator, it is also a memory artist. Behavioral scientists Markus Knaden from the Max Planck Institute for Chemical Ecology has been studying the navigational skills of this ant species for years.


The desert ant Cataglyphis fortis has an extraordinary memory for different food odors.

Markus Knaden, Max Planck Institute for Chemical Ecology


Desert ants have evolved impressing abilities to survive in the salt pans of the Tunisian Sahara, which are pretty barren habitats.

Markus Knaden, Max Planck Institute for Chemical Ecology

Until now, he was particularly interested in how the small insects find their way back to their nest after an extensive search for food in the vast salt pans of the Tunisian Sahara. After all, the nest entrance is only a small inconspicuous hole in the desert surface. He and his team found that – apart from other factors - the specific nest odor plays a crucial role.

However, during their experiments, the researchers had noticed that ants learned food odors much faster than nest odors. “Our central question was whether different types of memory exist for food and nest search. The idea to compare both learning processes popped up when we observed that the ants were able to learn food odors so incredibly fast in comparison to nest odors which need to be trained much longer,” first author Roman Huber explains.

The scientists developed a simple experiment to test the response of ants to more than 30 different food odors. They held the end of a stick which had been scented with an odor about two meters away from a foraging ant on the ground so that the wind blew the odor to the ant. At first, most odors were ignored by the ants and did not evoke any response.

“After we had offered a food crumb to the ants which had been scented with one of these odors, however, the ants were almost always attracted by this odor afterwards,” Markus Knaden says. “We were amazed how quickly the ants learned food-associated odors and how long they could remember them. Even ants, that had learned an odor more than 25 days ago, were able to remember it.”

In nature, most ants have a short life and are usually killed by a predator within six days. Therefore it is particularly astonishing that ants that have reached more than four times the average age could still remember what they had learned.

On the other hand, ants were not able to learn nest-associated odors as quickly as food odors. When the researchers attached a scent to the nest entrance, the ants needed five to ten trials to learn the odor as a nest cue. Only after several trainings did they concentrate their nest search on this odor.

When the odor was removed from the nest and after the ants had returned to the nest a few times, they completely stopped responding to the former nest cue. In ants, odors are obviously processed differently in the brain depending on whether they are food or nest cues.

Markus Knaden provides an explanation: “The two different odor memories make sense. During its entire life, an ant encounters many different pieces of food while foraging. Since the insect finds its food mainly through olfactory cues, it is important for an ant to learn the odor of good food in order to specifically search for it later. The nest, in contrast, should always smell the same during an ant’s short life. Therefore no extraordinary memory is needed to locate the nest entrance by following olfactory cues. It is sufficient if an ant knows how the nest smelled when it left to search for food, to find it on its way home. It is unlikely that the nest odor changes while an ant is away foraging.”

The scientists now want to design lab studies to underpin the results of the behavioral experiments in the natural habitat of the desert ants. Their goal is to employ imaging techniques, like calcium imaging, to locate and visualize the different memories in the ant brain and to compare brain activities during food and nest search. “We already use similar techniques for the visualization of brain activity in flies and moths. It would be great to establish these techniques for ants as well, because ants exhibit a particularly complex behavior,” Markus Knaden says.

Contact and Media Requests:
Angela Overmeyer M.A., Max Planck Institute for Chemical Ecology, Hans-Knöll-Str. 8, 07745 Jena, +49 3641 57-2110, E-Mail overmeyer@ice.mpg.de

Download of high resolution images via http://www.ice.mpg.de/ext/downloads2018.html

Wissenschaftliche Ansprechpartner:

Dr. Markus Knaden, Tel. +49 3641 57 1421, E-Mail: mknaden@ice.mpg.de, Max Planck Institute for Chemical Ecology, Jena, Germany

Originalpublikation:

Huber, R., Knaden, M. (2018). Desert ants possess distinct memories for food and nest odors. Proceedings of the National Academy of Sciences of the United States of America, DOI: 10.1073/pnas.1809433115
https://doi.org/10.1073/pnas.1809433115

Weitere Informationen:

http://www.ice.mpg.de/ext/downloads2018.html

Angela Overmeyer | Max-Planck-Institut für chemische Ökologie

More articles from Life Sciences:

nachricht Molecular motors run in unison in a metal-organic framework
20.03.2019 | University of Groningen

nachricht Active substance from plant slows down aggressive eye cancer
20.03.2019 | Rheinische Friedrich-Wilhelms-Universität Bonn

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Self-healing coating made of corn starch makes small scratches disappear through heat

Due to the special arrangement of its molecules, a new coating made of corn starch is able to repair small scratches by itself through heat: The cross-linking via ring-shaped molecules makes the material mobile, so that it compensates for the scratches and these disappear again.

Superficial micro-scratches on the car body or on other high-gloss surfaces are harmless, but annoying. Especially in the luxury segment such surfaces are...

Im Focus: Stellar cartography

The Potsdam Echelle Polarimetric and Spectroscopic Instrument (PEPSI) at the Large Binocular Telescope (LBT) in Arizona released its first image of the surface magnetic field of another star. In a paper in the European journal Astronomy & Astrophysics, the PEPSI team presents a Zeeman- Doppler-Image of the surface of the magnetically active star II Pegasi.

A special technique allows astronomers to resolve the surfaces of faraway stars. Those are otherwise only seen as point sources, even in the largest telescopes...

Im Focus: Heading towards a tsunami of light

Researchers at Chalmers University of Technology and the University of Gothenburg, Sweden, have proposed a way to create a completely new source of radiation. Ultra-intense light pulses consist of the motion of a single wave and can be described as a tsunami of light. The strong wave can be used to study interactions between matter and light in a unique way. Their research is now published in the scientific journal Physical Review Letters.

"This source of radiation lets us look at reality through a new angle - it is like twisting a mirror and discovering something completely different," says...

Im Focus: Revealing the secret of the vacuum for the first time

New research group at the University of Jena combines theory and experiment to demonstrate for the first time certain physical processes in a quantum vacuum

For most people, a vacuum is an empty space. Quantum physics, on the other hand, assumes that even in this lowest-energy state, particles and antiparticles...

Im Focus: Sussex scientists one step closer to a clock that could replace GPS and Galileo

Physicists in the EPic Lab at University of Sussex make crucial development in global race to develop a portable atomic clock

Scientists in the Emergent Photonics Lab (EPic Lab) at the University of Sussex have made a breakthrough to a crucial element of an atomic clock - devices...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

International Modelica Conference with 330 visitors from 21 countries at OTH Regensburg

11.03.2019 | Event News

Selection Completed: 580 Young Scientists from 88 Countries at the Lindau Nobel Laureate Meeting

01.03.2019 | Event News

LightMAT 2019 – 3rd International Conference on Light Materials – Science and Technology

28.02.2019 | Event News

 
Latest News

Molecular motors run in unison in a metal-organic framework

20.03.2019 | Life Sciences

Active substance from plant slows down aggressive eye cancer

20.03.2019 | Life Sciences

Novel sensor system improves reliability of high-temperature humidity measurements

20.03.2019 | Trade Fair News

VideoLinks
Science & Research
Overview of more VideoLinks >>>