The ant colonies showed sophisticated nest-site choice, selecting the superior site even though it was nine times further away than the alternative. The best nest was chosen, despite the fact that very few individual ants made direct comparisons between the nest-sites.
When a colony of rock ants needs to emigrate to a new nest, scouting ants first discover new nests and assess them then the scouts recruit nest-mates to the new nest using tandem-running, where an informed ant leads a second ant to her destination. When the number of ants in the new nest reaches a quorum, scouts begin rapid transport of the rest of the colony by carrying nest-mates and brood.
In the Bristol tests, very few ants appeared to make direct comparisons between the two nests by making multiple visits to each before choosing one or the other. However, approximately half (forty-one per cent) of the ants that first visited the near nest later switched to the far nest, whereas only a tiny minority (three per cent) of the ants that first visited the far nest switched to the near nest. This ultimately resulted in the entire colony ending up in the better nest.
Dr Robinson said: "Each ant appears to have its own 'threshold of acceptability' against which to judge a nest individually. Ants finding the poor nest were likely to switch and find the good nest, whereas ants finding the good nest were more likely to stay committed to that nest. When ants switched quickly between the two nests, colonies ended up in the good nest. Individual ants did not need to comparatively evaluate both nests in order for the entire colony to make the correct decision.
"On the other hand, animals – including humans – who use comparative evaluation frequently make 'irrational' decisions, due to the context in which options are compared or by inconsistently ranking pairs of options, (for example option A preferred to B, B preferred to C but C preferred to A).
"The ants' threshold rule makes an absolute assessment of nest quality that is not subject to these risks, and circumvents the necessity for memorization and comparison of every site visited. Thus, simple individual behaviour substitutes for direct comparison, facilitating effective choice between nest sites for the colony as a whole."
The research is published today in Proceedings of the Royal Society B.
Caroline Clancy | EurekAlert!
One step closer to reality
20.04.2018 | Max-Planck-Institut für Entwicklungsbiologie
The dark side of cichlid fish: from cannibal to caregiver
20.04.2018 | Veterinärmedizinische Universität Wien
University of Connecticut researchers have created a biodegradable composite made of silk fibers that can be used to repair broken load-bearing bones without the complications sometimes presented by other materials.
Repairing major load-bearing bones such as those in the leg can be a long and uncomfortable process.
Study published in the journal ACS Applied Materials & Interfaces is the outcome of an international effort that included teams from Dresden and Berlin in Germany, and the US.
Scientists at the Helmholtz-Zentrum Dresden-Rossendorf (HZDR) together with colleagues from the Helmholtz-Zentrum Berlin (HZB) and the University of Virginia...
Novel highly efficient and brilliant gamma-ray source: Based on model calculations, physicists of the Max PIanck Institute for Nuclear Physics in Heidelberg propose a novel method for an efficient high-brilliance gamma-ray source. A giant collimated gamma-ray pulse is generated from the interaction of a dense ultra-relativistic electron beam with a thin solid conductor. Energetic gamma-rays are copiously produced as the electron beam splits into filaments while propagating across the conductor. The resulting gamma-ray energy and flux enable novel experiments in nuclear and fundamental physics.
The typical wavelength of light interacting with an object of the microcosm scales with the size of this object. For atoms, this ranges from visible light to...
Stable joint cartilage can be produced from adult stem cells originating from bone marrow. This is made possible by inducing specific molecular processes occurring during embryonic cartilage formation, as researchers from the University and University Hospital of Basel report in the scientific journal PNAS.
Certain mesenchymal stem/stromal cells from the bone marrow of adults are considered extremely promising for skeletal tissue regeneration. These adult stem...
In the fight against cancer, scientists are developing new drugs to hit tumor cells at so far unused weak points. Such a “sore spot” is the protein complex...
13.04.2018 | Event News
12.04.2018 | Event News
09.04.2018 | Event News
20.04.2018 | Physics and Astronomy
20.04.2018 | Interdisciplinary Research
20.04.2018 | Physics and Astronomy