Day-active bees, such as the honeybee, are well known for using visual landmarks to locate a favoured patch of flowers, and to find their way home again to their hive. Researchers have now found that nocturnal bees can do the same thing, despite experiencing light intensities that are more than 100 million times dimmer than daylight. The new findings, reported in the latest issue of Current Biology by a team led by Eric Warrant at Lund University, Sweden, advance our understanding of the visual powers of nocturnal animals.
The competitive and dangerous world of the tropical rainforest has driven many normally day-active animals to adopt a nocturnal lifestyle, with the cover of darkness allowing them to exploit food resources in relative peace. Several groups of bees and wasps – including the Central American halictid bee Megalopta genalis – have become nocturnal, and despite the darkness and their apparently insensitive compound eyes, they have retained remarkable visual abilities. In the new work, performed on Barro Colorado Island in Panama, the researchers used infrared night-imaging cameras to show that by performing special orientation flights, Megalopta visually learns landmarks around the nest entrance prior to foraging and uses these landmarks to locate the nest upon return. The researchers found that if landmarks were moved to a nearby site while the bee was away, upon her return she intently searched for her nest in the landmark-bearing, but wrong, location.
Despite this impressive behavioral sensitivity, optical and physiological measurements revealed that Megalopta’s eyes are only about 30 times more sensitive to light than those of day-active honeybees, woefully inadequate to account for Megalopta’s nocturnal homing abilities. A solution to this paradox may lie outside the eye. The researchers identified in the bee’s brain specialised visual cells with morphologies suited to summing light signals and intensifying the received image.
A Map of the Cell’s Power Station
18.08.2017 | Albert-Ludwigs-Universität Freiburg im Breisgau
On the way to developing a new active ingredient against chronic infections
18.08.2017 | Deutsches Zentrum für Infektionsforschung
Whether you call it effervescent, fizzy, or sparkling, carbonated water is making a comeback as a beverage. Aside from quenching thirst, researchers at the University of Illinois at Urbana-Champaign have discovered a new use for these "bubbly" concoctions that will have major impact on the manufacturer of the world's thinnest, flattest, and one most useful materials -- graphene.
As graphene's popularity grows as an advanced "wonder" material, the speed and quality at which it can be manufactured will be paramount. With that in mind,...
Physicists at the University of Bonn have managed to create optical hollows and more complex patterns into which the light of a Bose-Einstein condensate flows. The creation of such highly low-loss structures for light is a prerequisite for complex light circuits, such as for quantum information processing for a new generation of computers. The researchers are now presenting their results in the journal Nature Photonics.
Light particles (photons) occur as tiny, indivisible portions. Many thousands of these light portions can be merged to form a single super-photon if they are...
For the first time, scientists have shown that circular RNA is linked to brain function. When a RNA molecule called Cdr1as was deleted from the genome of mice, the animals had problems filtering out unnecessary information – like patients suffering from neuropsychiatric disorders.
While hundreds of circular RNAs (circRNAs) are abundant in mammalian brains, one big question has remained unanswered: What are they actually good for? In the...
An experimental small satellite has successfully collected and delivered data on a key measurement for predicting changes in Earth's climate.
The Radiometer Assessment using Vertically Aligned Nanotubes (RAVAN) CubeSat was launched into low-Earth orbit on Nov. 11, 2016, in order to test new...
A study led by scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg presents evidence of the coexistence of superconductivity and “charge-density-waves” in compounds of the poorly-studied family of bismuthates. This observation opens up new perspectives for a deeper understanding of the phenomenon of high-temperature superconductivity, a topic which is at the core of condensed matter research since more than 30 years. The paper by Nicoletti et al has been published in the PNAS.
Since the beginning of the 20th century, superconductivity had been observed in some metals at temperatures only a few degrees above the absolute zero (minus...
16.08.2017 | Event News
04.08.2017 | Event News
26.07.2017 | Event News
18.08.2017 | Life Sciences
18.08.2017 | Physics and Astronomy
18.08.2017 | Materials Sciences