Honey Bees Have Sharper Eyesight Than We Thought

[BeeMaster2]

Research conducted at the University of Adelaide has discovered that bees have much better vision than was previously known, offering new insights into the lives of honey bees, and new opportunities for translating this knowledge into fields such as robot vision.

The findings come from "eye tests" given to western honey bees (also known as European honey bees, Apis mellifera) by postdoctoral researcher Dr Elisa Rigosi (Department of Biology, Lund University, Sweden) in the Adelaide Medical School, under the supervision of Dr Steven Wiederman (Adelaide Medical School, University of Adelaide) and Professor David O'Carroll (Department of Biology, Lund University, Sweden).

The results of their work were published April 6, 2017 in the Nature journal Scientific Reports.

Bee vision has been studied ever since the pioneering research of Dr Karl von Frisch in 1914, which reported bees' ability to see colors through a clever set of training experiments.

"Today, honey bees are still a fascinating model among scientists, in particular neuroscientists," Dr Rigosi says.

"Among other things, honey bees help to answer questions such as: how can a tiny brain of less than a million neurons achieve complex processes, and what are its utmost limits? In the last few decades it has been shown that bees can see and categorize objects and learn concepts through vision, such as the concept of 'symmetric' and 'above and below'.

"But one basic question that has only been partially addressed is: what actually is the visual acuity of the honey bee eye? Just how good is a bee's eyesight?"

Dr Wiederman says: "Previous researchers have measured the visual acuity of bees, but most of these experiments have been conducted in the dark. Bright daylight and dark laboratories are two completely different environments, resulting in anatomical and physiological changes in the resolution of the eye.

"Photoreceptors in the visual system detect variations in light intensity. There are eight photoreceptors beyond each hexagonal facet of a bee's compound eye, and their eyes are made out of thousands of facets! Naturally, we expected some differences in the quality of bees' eyesight from being tested in brightly lit conditions compared with dim light," he says.

Dr Rigosi, Dr Wiederman and Professor O'Carroll set out to answer two specific questions: first, what is the smallest well-defined object that a bee can see? (ie, its object resolution); and second, how far away can a bee see an object, even if it can't see that object clearly? (ie, maximum detectability limit).

To do so, the researchers took electrophysiological recordings of the neural responses occurring in single photoreceptors in a bee's eyes. The photoreceptors are detectors of light in the retina, and each time an object passes into the field of vision, it registers a neural response.

Dr Rigosi says: "We found that in the frontal part of the eye, where the resolution is maximized, honey bees can clearly see objects that are as small as 1.9? - that's approximately the width of your thumb when you stretch your arm out in front of you.

"This is 30% better eyesight than has been previously recorded," she says.

"In terms of the smallest object a bee can detect, but not clearly, this works out to be about 0.6? - that's one third of your thumb width at arm's length. This is about one third of what bees can clearly see and five times smaller than what has so far been detected in behavioral experiments.

"These new results suggest that bees have the chance to see a potential predator, and thus escape, far earlier than what we thought previously, or perceive landmarks in the environment better than we expected, which is useful for navigation and thus for survival," Dr Rigosi says.

Dr Wiederman says this research offers new and useful information about insect vision more broadly as well as for honey bees.

"We've shown that the honey bee has higher visual acuity than previously reported. They can resolve finer details than we originally thought, which has important implications in interpreting their responses to a range of cognitive experiments scientists have been conducting with bees for years.

"Importantly, these findings could also be useful in our work on designing bio-inspired robotics and robot vision, and for basic research on bee biology," he says.

[herbhome]

I read this article with interest also. It's clear to me that they do recognize individual animals and persons. Perhaps and most likely this could also be smell but it still amazes me that they can remember from one day to the next!

[DeepCreek]

Good read.  There's also new research in the last 10 or so years that show that honey bee's not only see color, but can in fact turn off their color vision while returning from foraging.  In other words they only see in black-n-white.

[Rurification]

I love it when you post these articles.  So interesting.

[bwallace23350]

Thanks for sharing. Keep it up.

[BeeMaster2]

Thanks for sharing. Keep it up.

OK. 

[FloridaGardener]

So here's a question: There's a lot written about how fast a honey bee can see, and how far.  But I can't find anything on how tiny a honey bee can see.

Can a bee see a grain of salt?  Bee brains are the size of a typical grain of salt: .3 mm.  If it were me, yes, I could see something the size of my brain...and I think for sure I could see it if I had 2 compound eyes and 3 ocelli.

When I was pressure-washing my mossy walkway today, the bees were all over, getting in the sludge.  What do they pick up? Mossiness has lots of water bears (tardigrades) that are about half the size of a grain of salt. Do bees take water bears back to the hive? Purposely, or inadvertently? Sometimes they can eat viruses.  Has anyone researched tardigrades in propolis?

https://www.wikihow.com/Find-and-Care-for-a-Pet-Tardigrade-(Water-Bear)

[Ben Framed]

Evolution?  0
Creation? ✔️

[Fishing-Nut]

Good stuff for sure!

[BeeMaster2]

FB,
I have never seen anyone ever mention tardigrades before. What value do you think they would have?
I suspect the bees were just collecting water to cool down the hive.
Jim Altmiller

[FloridaGardener]

Well, generally because...

Diversity fosters ecological health (rain forest, intestinal biomes).

Monoculture inhibits ecological health (Irish potato famine, 1930's dust bowl).

We know ants cultivate yeast.  Damselfish farm algae.  Ambrosia beetles farm fungus - and sadly, destroyed my beautiful old redbay tree in a matter of weeks with their new fungus farm.

Do bees instinctively cultivate some beneficial organisms too?  After all, water bears eat some bacteria, viruses, and nematodes.  What if bees brought microorganisms in, to act like tiny robotic vacuum cleaners in the hive?

      It occurred because during the pressure washing, the bees didn't seem too interested in the shallow clean runoff, but were willing to risk drowning in deep sludgy morass to pick something up.  They would hover an inch off the water and scan it first.
       Bees like algae, too, which would be full of water bears.   
       
Just putting out feelers here for that, along the eyesight theme that perhaps bees see tiny organisms we don't, and seek them out.

If anybody knows of any research on bees' close up vision, or farming as beetles and ants do, I'd love to know of it.

[CoolBees]

Some great (and not so simple  ) questions raised Florida.

Bees are amazing. At my house we have many 5-gallon buckets standing around with water in them. One of the buckets was once used for concrete mortar and has thick layers of dried mortar remaining on its walls. "Stuff" likes to grow in the mortar. The bees target this bucket above all others. Why? ... they don't seem to be strictly after the water. They could walk down the mortar walls and drink clean water, but they don't - they sit well above the water line sucking on the mortar itself. Why? Minerals or salts? Not likely. This bucket has been in use for water for more than 10 yrs - most "leaching" products (salts, etc) would long be gone. ... I dunno ... [shrug] ...

There's so much that we (science) don't know. Good questions.