Scientists of the Max Planck Institute for Chemical Ecology in Jena have investigated another navigational skill of desert ants. These ants are already well-known for their remarkable visual orientation: they use a sun compass along with a step counter and visible landmarks to locate their nest after foraging for food.
After the research team from Jena recently discovered that these ants also use olfactory cues to pinpoint their nests, they conducted new experiments: they revealed that the animals can not only locate an odour source, but also use the distribution of different odours in the vicinity of their nests in a map-like manner. The scientists found that the ants need both their antennae for this odour-guided navigation: they smell the scenery in stereo. (Animal Behaviour, online first, doi:10.1016/j.anbehav.2010.01.011)
The desert ant Cataglyphis fortis is an insect native to the inhospitable salt-pans of Tunisia. To pinpoint the nest - a tiny hole in the desert ground - after foraging for food, Cataglyphis combines several navigation systems: a sun compass, a path integrator (the ant literally counts its steps), and visual recognition of landmarks. Recently, Kathrin Steck, Bill Hansson and Markus Knaden, neuroethologists at the Max Planck Institute for Chemical Ecology in Jena, discovered that local odours also play an important role in the insect's orientation (Frontiers in Zoology, 2009, Vol. 6 No. 5): ants learn to associate a smell with their nest and distinguish this smell from others. But the researchers wanted to know if the insects are also able to recognize odour patterns that emerge, when several odour sources are located at different positions around the nest. And if so, they asked, do ants need both their antennae like stereo receivers just as we employ two eyes and two ears for spatial perception?
"We conducted two key experiments," says Kathrin Steck, PhD student at the institute. "First we marked four odour sources surrounding the nest entrance with the substances methyl salicylate, decanal, nonanal, and indole, and got the ants trained on them. If these four odour points were shifted away from the nest in the original arrangement, the ants repeatedly headed for the odours, even though the nest wasn't there anymore. If we rearranged the odour sources relative to each other, the ants were completely confused." Therefore the researchers assumed that ants do not "think" one-dimensionally - i.e. they do not associate the nest with only one smell - but multi-dimensionally, i.e., they relate an odour landscape to their nest. The odour landscape comprising the four substances was monitored with the help of a special measuring technique: the scientists used a specific photoionisation detector to determine the distribution of the odour substances in space and time.
Spatial perception can easily be acquired if two separate sensory organs are available, such as two eyes for visual orientation. In the case of the ants, this would be their two antennae. "With this assumption, the second key experiment seemed obvious: We tested ants that only had one antenna," Markus Knaden, the leader of the study, explains. In fact, ants with only one sensory device were unable to make use of the odour landscape for navigation.
Stereo smelling in animals is not new - rats and humans are thought to have this ability as well. This new study shows that ants smell in stereo, but not only that: "In our experiments we demonstrated that ants successfully use stereo smelling for navigation in the desert," says Bill Hansson, director at the institute. [JWK, AO]
Dipl. Biol. Kathrin Steck; MPI for Chemical Ecology, Tel.: 03641 / 57-1466, email@example.comPicture Material:
Dr. Jan-Wolfhard Kellmann | Max-Planck-Institut
Water forms 'spine of hydration' around DNA, group finds
26.05.2017 | Cornell University
How herpesviruses win the footrace against the immune system
26.05.2017 | Helmholtz-Zentrum für Infektionsforschung
Staphylococcus aureus is a feared pathogen (MRSA, multi-resistant S. aureus) due to frequent resistances against many antibiotics, especially in hospital infections. Researchers at the Paul-Ehrlich-Institut have identified immunological processes that prevent a successful immune response directed against the pathogenic agent. The delivery of bacterial proteins with RNA adjuvant or messenger RNA (mRNA) into immune cells allows the re-direction of the immune response towards an active defense against S. aureus. This could be of significant importance for the development of an effective vaccine. PLOS Pathogens has published these research results online on 25 May 2017.
Staphylococcus aureus (S. aureus) is a bacterium that colonizes by far more than half of the skin and the mucosa of adults, usually without causing infections....
Physicists from the University of Würzburg are capable of generating identical looking single light particles at the push of a button. Two new studies now demonstrate the potential this method holds.
The quantum computer has fuelled the imagination of scientists for decades: It is based on fundamentally different phenomena than a conventional computer....
An international team of physicists has monitored the scattering behaviour of electrons in a non-conducting material in real-time. Their insights could be beneficial for radiotherapy.
We can refer to electrons in non-conducting materials as ‘sluggish’. Typically, they remain fixed in a location, deep inside an atomic composite. It is hence...
Two-dimensional magnetic structures are regarded as a promising material for new types of data storage, since the magnetic properties of individual molecular building blocks can be investigated and modified. For the first time, researchers have now produced a wafer-thin ferrimagnet, in which molecules with different magnetic centers arrange themselves on a gold surface to form a checkerboard pattern. Scientists at the Swiss Nanoscience Institute at the University of Basel and the Paul Scherrer Institute published their findings in the journal Nature Communications.
Ferrimagnets are composed of two centers which are magnetized at different strengths and point in opposing directions. Two-dimensional, quasi-flat ferrimagnets...
An Australian-Chinese research team has created the world's thinnest hologram, paving the way towards the integration of 3D holography into everyday...
24.05.2017 | Event News
23.05.2017 | Event News
22.05.2017 | Event News
26.05.2017 | Life Sciences
26.05.2017 | Life Sciences
26.05.2017 | Physics and Astronomy