Biomedical subjects

Juergen Tautz

Publications and source records attributed to Juergen Tautz.

3 recordsLinked to original sources

PubMed2006

Honeybee memory: A honeybee knows what to do and when.

Honeybees have the ability to flexibly change their preference for a visual pattern according to the context in which a discrimination task is carried out. This study investigated the effect of time of day, task, as well as both parameters simultaneously, as contextual cue(s) in modulating bees' preference for a visual pattern. We carried out three series of experiments to investigate these interactions. The first series of experiments indicated that trained bees can reverse their pattern preference following midday breaks, as well as an overnight break, at the feeder and at the hive. The second series of experiments showed that trained bees are able to reverse their pattern preference in just a few minutes, depending on whether they are going out to forage or returning to the hive. The third series of experiments demonstrated that trained bees can significantly reverse their pattern preference at the feeder and at the hive entrance following midday breaks, as well as after an overnight break; the bees could also learn to choose different patterns at the feeder and at the hive entrance within each testing period. The training thus imposed a learnt pattern preference on the bees' daily circadian rhythm. This study demonstrates that the bee with a tiny brain possesses a sophisticated memory, and is able to remember tasks within a temporal context. Honey bees can thus ;plan' their activities in time and space, and use context to determine which action to perform and when.

Animals↗

PubMed2005

Visual working memory in decision making by honey bees.

The robustness and plasticity of working memory were investigated in honey bees by using a delayed matching-to-sample (DMTS) paradigm. The findings are summarized as follows: first, performance in the DMTS task decreases as the duration between the presentation of the sample stimulus and the presentation of the comparison stimuli is increased. This decrease is well approximated by an exponential decay function. Performance is significantly better than random-choice level even at delays as long as 5 sec and is reduced to random-choice levels at an average delay time of 8.68 +/- 0.06 sec. Second, when the DMTS task involves two samples (one relevant, the other irrelevant), bees can be trained to learn to use the relevant sample to perform the task if (i) the relevant sample is always at a fixed position, or (ii) the relevant sample always has the same place in the sequence of presentation (always first or always second). Bees that have learned to use the relevant sample and to ignore the irrelevant sample can generalize this learning, and apply it to novel sets of sample and comparison stimuli that they have never previously encountered. The findings point to a remarkably robust, and yet plastic, working memory in the honey bee.

Animals↗

PubMed2004

Honeybee odometry: performance in varying natural terrain.

Recent studies have shown that honeybees flying through short, narrow tunnels with visually textured walls perform waggle dances that indicate a much greater flight distance than that actually flown. These studies suggest that the bee's "odometer" is driven by the optic flow (image motion) that is experienced during flight. One might therefore expect that, when bees fly to a food source through a varying outdoor landscape, their waggle dances would depend upon the nature of the terrain experienced en route. We trained honeybees to visit feeders positioned along two routes, each 580 m long. One route was exclusively over land. The other was initially over land, then over water and, finally, again over land. Flight over water resulted in a significantly flatter slope of the waggle-duration versus distance regression, compared to flight over land. The mean visual contrast of the scenes was significantly greater over land than over water. The results reveal that, in outdoor flight, the honeybee's odometer does not run at a constant rate; rather, the rate depends upon the properties of the terrain. The bee's perception of distance flown is therefore not absolute, but scene-dependent. These findings raise important and interesting questions about how these animals navigate reliably.

Animal Communication↗