Actually, Bats See Just Fine, Neil.

By Christie Wilcox | March 25, 2016 5:26 pm
*FACEPALM* (Photo by Maksimilian)

*FACEPALM* (Photo by Maksimilian)

Many know Neil deGrasse Tyson for his pithy, humorous science tweets, which are a part of his greater science communication strategy. As of late, though, scientists have become quite vexed with NDT’s 140-character stylings, as he’s been foraying outside his planetary expertise and into biological phenomena, getting the facts wrong every time. First, there was his mistaken evaluation of evolutionary drivers and how sex works, excellently torn apart by Emily Willingham (a Ph.D. scientist whom Tyson then condescendingly called “a woman who has a blog”, prompting some to suggest he be referred to as just a “man with a twitter”). Then came his misunderstanding of genetics and deleterious alleles, which was ripped apart by Jeremy Yoder (another Ph.D. scientist). Now, he’s stepped in guano again with this tweet related to this weekend’s powerhouse movie release:

Alas, the phrase “blind as a bat” is simply wrong. Let me explain why:

The Eyes Have It

Many bats are active at night and use a sonar-like sense (echolocation) to find their prey, which is probably where the myth that they are blind came from. But all 1,100 bat species can see just fine, and in many cases, their vision is quite good.

Some of the fruit-loving megabats, referred to as flying foxes, don’t fit the usual bat stereotype. For one, they don’t do as much insect hunting, preferring nectar, pollen and fruit. They’re also crepuscular, which means they are active at dawn and dusk, rather than being night-loving nocturnal species. And unlike their smaller cousins, they have large, well-developed eyes, which they use nearly exclusively, as most in this lineage have lost their ability to use sound to hunt.

Those eyes don’t just see, they see well. According to Australian expert Martin Cohen, the vision of some large flying foxes is 20 times better than ours*; they can see objects up to 1 kilometer (over 1/2 a mile) away at night. 

"I'm keeping my eyes on you, Neil." (Photo by Andrew Burgess)

“I’m keeping my eyes on you, Neil.” (Photo by Andrew Burgess)

And it’s not just the megabats that use their sight—their littler relatives, the microbats, can see, too. A 2009 study in Proceedings of the National Academy of Sciences sequenced the genes encoding opsins, light-sensitive proteins used in vision, in 33 species of bats, concluding that color vision “plays a considerably more important role in nocturnal mammalian sensory ecology than previously appreciated.” Similar studies “suggest a functional role of vision…despite being nocturnal and using echolocation,” stating that night-flying bats “may be able to use visual cues to orientate, navigate and forage at night, to discriminate color under moonlight and starlight conditions, or to avoid predation by diurnal raptors.” And another 2009 study, published in PLoS ONE, looked carefully at the eyes of two nocturnal, echolocating bat species, and found that they “have the prerequisites for daylight vision, dichromatic color vision, and UV vision.”

Rather than rely entirely on their hearing, a fascinating study published in Frontiers in Physiology in 2013 showed that even nocturnal microbats likely use a combination of vision and echolocation to “see.” The scientists from Tel Aviv University studied two bat species which, like many bats, awaken and begin to hunt just after the sun goes down. By glueing special recorders to bats, they were able to determine that the bats use echolocation regardless of light levels, dismissing the notion that they switch to sound as darkness sets in. Instead, they use it all the time, because it’s better at detecting small, moving objects. “Imagine driving down the highway: Everything is clear in the distance, but objects are a blur when you pass them,” lead author Arjan Boonman told Popular Science. “Echolocation gives bats the unique ability to home in on small objects–mostly insects–while flying at high speeds.” Their eyes, on the other hand, are key for general orientation. “We find that echolocation is better than vision for detecting small insects even in intermediate light levels,” write the authors, “while vision is advantageous for monitoring far-away landscape elements in both species.”

As a 2003 doctoral thesis from Göteborg University explained, sonar is best for short-range targeting, like hunting insects, while true vision is better for detecting landmarks and avoiding objects when traveling over large distances. And when bats are performing large movements like migrating, “there seems to be precedence of vision over sonar,” Johan Eklöf writes. Even at smaller scales, bats may use visual cues as well as sonar and spatial memory to orient themselves. “Although echolocation is the key innovation that have made it possible for bats to fly at night, vision is retained as an important complement; and indeed bats use an array of different sensory inputs to solve the different tasks of life.”

An Astronomer’s Blindspots

In a very un-batlike manner, it seems that Neil deGrasse Tyson is the one who is blind. He simply doesn’t seem to be able to see when he’s making a mistake.

Bats are fascinating animals. They are amazingly successful, comprising a staggering one-fifth (20%) of all mammal species on Earth. They have bizarre, kinky sex lives. And in the U.S., many species are threatened by White-Nose Syndrome, an emerging infectious disease which has contributed to population declines of nearly 80% in the past decade. Don’t trivialize them by restating myths about their biology, Neil. Living organisms deserve the same respect you afford to astronomical bodies.

Perhaps the blindness of bats might seem like a small falsehood to perpetuate, but it undermines NDT’s overall credibility, including his commentary on far more important issues. And because NDT is one of the few scientists with such a massive following, it undermines the credibility of scientists everywhere and science as a whole.

When someone with the prominence and authority of Neil deGrasse Tyson tweets an inaccurate statement about bat biology, he doesn’t just do the animals a disservice; he misleads his sizable audience, many of whom don’t know that what he’s saying is wrong. As a human, he’s of course allowed to have shortcomings—no one, not even scientists with over five million twitter followers, can know everything. But we expect scientists to recognize when they don’t know something, and to critically evaluate popular conceptions to determine whether or not they are true. And when, inevitably, a scientist gets something wrong, they should be willing and able to reevaluate and correct the misinformation. Yet, in response to the previous critiques about his biologyFAILs, Neil has failed to admit he’s been wrong, preferring to double-down and move goal posts to make it seem as if he’s all-knowing. That’s not how a good scientist should react to critique, and as one of, if not the most prominent face of science, Neil needs to do better.


And for those of you who are comic aficionados: Yes, he’s also wrong about Batman wanting to be a bat. We biologists hear you. 

*Rob Mies, executive director of the Michigan-based Organization for Bat Conservation, says bat vision is three times better than ours (it’s unclear how either arrived at those numbers). Point is, the big flying foxes see better than we do, and are anything but blind.

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  • Hollister David

    Tyson’s tweet on bat vision’s not showing on my browser.

    Neil’s been saying wrong stuff for years. See

    • Christie Wilcox

      Weird… Here’s a screen grab:

    • Maia

      NDT is just another victim of oversimplication…or reductionism spilling out everywhere. It’s not that this works in astrophysics and not elsewhere, it doesn’t work ANYWHERE.

  • Oliver Hamilton

    It was probably a sponsored post by Marvel to promote the new series.

  • OWilson

    Neil is just a symptom of the problem with today’s culture. He’s a likable popular guy, like Bill Nye, “The Science Guy”, or Carl Sagan who brought us “science with a message” to the world, or David Suzuki.

    Like art, entertainment, literature and music, science has been re-defined by academia, education, and popular culture to fit a political narrative, which presently has a political obsession with what they refer to as climate change, but really mean Man Made Global Warming.

    You can watch or read 95% of their factual and interesting stuff and come away more knowledgeable, but the end message is usually a warning and an unvarnished appeal to “save the planet”. We, of course, know who they want us to save the planet from, right? (If you don’t, just go to their web sites :)

    If you ask schoolkids to name more than one scientist, you will be surprised to find, aside from Einstein, the discoverers of the most important theories which govern our modern world missing.

    The great ones who gave the world The Periodic Table, The Inflationary Cosmological Model, The Standard Quantum Particle Model, the DNA Model, won’t be there, but the aforementioned names will pop up with regularity.

    Today Bill Nye is really the “Science Guy”.

    He has 50 times more hits on Google, than Watson and Crick.

    Who are they, you say?

    Precisely! :)

    • Hollister David

      In some forums I see people asking if Einstein and Newton would be in the same league as Nye and deGrasse Tyson. The sad thing is I can’t tell if they’re trolling or serious.

      • OWilson

        Is Lady Ga Ga in the same league as Mozart?
        Picasso up to Michelangelo?
        J.K. Rowling up to Shakespeare?
        Rambo 6 up to Casablanca?
        Obama up to Anybody?

        “I did not have sex with that woman—-” up to “Four Score and Seven years Ago….”

        • OWilson

          Happy Easter :)

          “An Easter egg hunt descended into chaos on Saturday after parents in Orange, Connecticut, stormed the field.

          Children as young as four were trampled by adults in a rampage to steal buckets and grab as many of the 9,000 hidden eggs as possible from the third annual free event at the PEZ headquarters.

          One four-year-old son was left ‘bloody’ on the sports field and a two-year-old girl was shoved into the mud, witnesses claimed.

          A horrified parent described the scene as ‘an angry mob of chaos’ with ‘not one toddler hunting for eggs’ among the crowds of adults.

          Read more:

        • Maia

          Cheap shot re: Obama. Until then, I was leaning toward taking your commentary on this article seriously. Seems YOUR political “slip” (into bais) is showing

          • OWilson

            Fair enough, it’s just an opinion.

            I’m not in the U.S.A., but I pulled so hard for this guy’s election.

            I thought he would be able to unite the country and cool the racism.

            Needless to say I am disappointed!

          • Maia

            I empathize with what you are saying. It was really an impossible job we handed him. I think he has been blocked at every turn and had abuse heaped on him from day one. In impossible circumstances, he tried hard and responded graciously, but of course he has disappointed those of us who supported his presidency because we wanted so much, in fact, I think, more than any presidency could ever deliver.

          • OWilson

            As a community organizer, he gave what he had.

            The job of Most powerful Man on the Planet, Leader of the Free world, was far, far bigger than the man.

            But, as a supporter, he insulted me with these quotes, I will always remember:

            “We Won!” “They (the Republicans, and the other half of the country that voted for him) can come along for the ride, but they gonna have to sit in back of the bus”

            And (to a minority ethnic group) “Punish your enemies, reward your friends”.

            Perhaps we shouldn’t have laughed off this solemn precursor,during his first campaign,“If they bring a knife to the fight, we bring a gun”. Obama said at a Philadelphia fundraiser, “because from what I understand folks in Philly like a good brawl. I’ve seen Eagles fans.”

            Trump has been crucified for far less.

          • Maia

            I am not going to impugn you , but I do doubt those are actual quotes. Doesn’t even sound like him, I’ve listened to him a lot (I live in the US) and he’s never come close to such inflammatory remarks, except in humor. (Which means he did not mean them literally) Do you happen to have links to those words?

          • OWilson

            Well, that why we on the right so detest the Liberal Main Stream Media.

            Stuff like the is only news if it comes from the right.

            But, it is easily verified. Thank goodness for the Internet.

  • John C

    “On this day long ago, a child was born who, by age 30, would transform the world. Happy Birthday Isaac Newton b. Dec 25, 1642,” the StarTalk host tweeted.


    His famous Christmas Eve troll tweet. How brave! How cutting edge! Gratuitously insulting Christians on one of their most sacred days of the year. Another planet sized ego with the maturity of a snotty 14 year old boy.

    • OWilson

      There’s more than a few of those around, unfortunately.

    • zb

      screw their “sacred day”, Isaac Newton is more important then any ancient fake holy books combined !

  • Shalryn

    Somebody needs to remind the guy with the twitter of the first rule of writing: write about what you know. Stick to astrophysics and don’t try to teach us what you don’t know.

  • BT.IC

    I never realised that bats have functional eyes until now which is terrible because I feel like I should’ve learned this at some point in my science degree. I know a lot of people in my course that follow Neil and I think most of them (including me) would’ve believed his tweet had I not seen this post.

  • Patty Bousquet Parsons Caswell

    conquering not concurring


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About Christie Wilcox

Dr. Christie Wilcox is a science writer based in the greater Seattle area. Her bylines include National Geographic, Popular Science, and Quanta. Her debut book, Venomous, released August 2016 (Scientific American/FSG Books). To learn more about her life and work, check out her webpage or follow her on Twitter, Google+, or Facebook.


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@NerdyChristie on Twitter

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