Vampire bats are exceptional social groomers

Undergraduate Lauren Leffer and I just published a paper in PLOS One entitled Social Grooming in Bats: Are Vampire Bats Exceptional? The answer, I think, is yes. Here’s the story behind the paper.

Grooming monkeys

When you think of social grooming, you think of primates. Social grooming in primates has been viewed as a social glue that helps maintain social bonds, and as a social currency that can be exchanged for favors. In fact, I would wager that there are more data on social grooming in primates than almost any other mammalian cooperative behavior (outside humans). But many other animals groom each other too, including some bats. In 1986, Jerry Wilkinson published a great observational study on social grooming in vampire bats, and he showed that it correlated with both food sharing and differed between ages and sexes. My impression has always been that vampire bats are pretty unique among bats in their propensity for social grooming. But we know that at least some other group-living bats also groom each other, and some people have told me that, in captivity, other bat species groom each other maybe even just as much as the vampires. So how special are vampire bats? Are they really more like primates than other bats?
ARKive video - Common vampire bats allogrooming and territorial males fightingDoing a comparative study on social grooming across species is a bit tricky in the field, because other factors, like the number of ectoparasites, or the nature of the relationships between the individual bats, might predict grooming rates even more than the species differences. For example, vampire bats have lots of ectoparasites, and they also form long-term social bonds, and maybe that’s why they social groom each other more.

At the Bat Zone, run by the Organization for Bat Conservation (OBC), there are several species of group-living bats living in captivity. None of them have bat flies or other ectoparasites, and since all the bats are stuck in captivity, there are not species differences in proximity or association, like you would normally have in the wild. In other words, the environments are pretty similar for all the bats there. So, in my mind, it’s a great opportunity to compare social grooming rates.

Undergraduate student Lauren Leffer, with help from volunteers at OBC, sampled social grooming by watching a single random individual, and then going from cage to cage, species to species, and recording what the bats were doing. Social grooming was of course, pretty rare overall; but I was surprised to find that observers witnessed it in many of the captive bats, even in species, like Carollia perspicillata, where it has never, to my knowledge, been observed in the wild. But the rates were very low compared to the vampire bats. You can read the paper for more details on that.

To me, this all suggests that there’s a real species difference in social grooming, and it’s not just an artifact of some particular vampire bats being more familiar with each other than members of other species.

Here in Panama, graduate student Victoria Flores has been watching many videos of social interactions between roosting frog-eating bats (Trachops cirrhosus).  Like all bats, they spend some time grooming themselves. But Victoria has never seen Trachops grooming others either.

I also did a study where I put several completely unfamiliar vampire bats together for several weeks. At first, there was no social grooming, but gradually the bats began to groom each other. You could see bonds forming in real time; it was fascinating. I’m replicating that study in a couple of months here in Panama. We are in search of roosts and places to catch vampires. A couple of days ago, Thomas Sattler sent me these pictures of a (very) large roost of common vampire bats in a hollow tree in Panama.

IMG_2936 IMG_0100

That’s a lot of vampire bats!

Here at the Smithsonian Tropical Research Institute, I’m starting a project on the sensory ecology of vampires with Rachel Page and John Ratcliffe (starting in January 2016). I’m also applying for NSF fellowship money to work on social behavior, oxytocin, and oxytocin receptors with Alex Ophir. If successful, this work would start January 2017 at the latest, but the competition is quite stiff and seems unlikely. The sensory ecology work is guaranteed, and should be quite fun, because it will involve experiments with single subjects that one can watch in real time. In contrast, the social behavior experiments take much more time, the data require weeks to accumulate, and one has to analyze interactions between multiple subjects (social networks). We are currently planning and preparing for the arrival of our vampire bat colony, while waiting for our permits to be approved.

Finally, this short note paper also just came out, from my visit to Thailand.

Posted in Uncategorized | Leave a comment

Names of farmers and ranchers in Panama

I need names and addresses of farmers and ranchers in Panama that have seen vampire bat bites on their animals! If you or anyone you know has information, please email me or call me at 68293025 (Panama).

Fresh vampire bat by Uwe Schmidt

Fresh vampire bat bite by Uwe Schmidt

The urgency is that I need a this list as soon as possible to meet a permit deadline. I need authorization from all landowners >50 days before I catch any bats!

Posted in Uncategorized | Leave a comment

A suggested reading list

I just gave a talk on vampire bat cooperation, and someone asked me for a reading list to introduce them to the topics I talked about (cooperation, reciprocity, social bonds, etc). So here it is (real quick, no time to put links). I chose review papers wherever possible and only picked empirical studies with results that make important points (marked with ***). Some of the empirical results are just a single paper that’s part of a larger story with more papers. In this case, I picked my favorite one. My suggested reading list of papers on cooperation (just my opinion, don’t get mad if your favorite is missing):

Evolution of cooperation

  • West, S. A., Griffin, A. S., & Gardner, A. (2007). Evolutionary explanations for cooperation. Current Biology—This paper is the best short introduction to the field.
  • ***Griffin, A.S., West, S.A. & Buckling, A. (2004) Cooperation and competition in pathogenic bacteria. Nature—An experimental evolution study that demonstrates empirically how the scale of competition interacts with genetic relatedness: cooperating with kin is less advantageous when you compete with those same kin for resources.

Human cooperation

  • West, S. A., El Mouden, C., & Gardner, A. (2011). Sixteen common misconceptions about the evolution of cooperation in humans. Evolution and Human Behavior. —Great review paper that helps clear up the huge amount of confusion in evolutionary studies of human cooperation.
  • ***Burton-Chellew, M.N. & West, S.A. (2013). Pro-social preferences do not explain human cooperation in public-goods games. Proceedings of the National Academy of Science. — Great paper. Explains the problem with an entire faulty approach to studying human cooperation.
  • DeScioli, P., & Kurzban, R. (2013). A solution to the mysteries of morality. Psychological Bulletin. — A very innovative solution to a very good puzzle.

Direct fitness benefits

  • Trivers, R. L. (1971). The evolution of reciprocal altruism. Quarterly Review of Biology. —People should read this paper again. There’s a lot of great ideas packed into it.
  • Carter, G. G. (2014). The reciprocity controversy. Animal Behavior and Cognition. —Please ignore the fact that you’ve never heard of this journal! I argue that most of the reciprocity controversy is semantic (much like the “kin selection” vs “group selection” confusion).
  • ***Wilkinson, G. S. (1984). Reciprocal food sharing in the vampire bat. Nature. —Argues that reciprocity can occur between relatives, but that point was, and still is, largely overlooked.
  • Bshary, R., Grutter, A. S., Willener, A. S., & Leimar, O. (2008). Pairs of cooperating cleaner fish provide better service quality than singletons. Nature, 455(7215), 964-966.
  • ***Zöttl, M., Heg, D., Chervet, N., & Taborsky, M. (2013). Kinship reduces alloparental care in cooperative cichlids where helpers pay-to-stay. Nature communications, 4, 1341. —This study shows an interesting interaction between kinship and enforcement.
  • Ratnieks, F. L., & Wenseleers, T. (2008). Altruism in insect societies and beyond: voluntary or enforced? TREE. —A good review of the same topic.

Partner choice and biological markets

  • Noë, R., & Hammerstein, P. (1994). Biological markets: supply and demand determine the effect of partner choice in cooperation, mutualism and mating. Behavioral Ecology and Sociobiology. — The best new ideas for understanding more complex cooperation since Trivers (1971).
  • Noë, R. (2006). Cooperation experiments: coordination through communication versus acting apart together. Animal Behaviour. — The best review of cooperation/reciprocity experiments and what’s wrong with so many of them.
  • ***Fruteau, C., Voelkl, B., Van Damme, E., & Noë, R. (2009). Supply and demand determine the market value of food providers in wild vervet monkeys. Proceedings of the National Academy of Sciences. — This is maybe my favorite study of cooperation. It demonstrates so many things: not only partner choice and market effects like supple and demand, but also that food is easily exchanged for other services like grooming.
  • ***Kiers, E. T., Duhamel, M., Beesetty, Y., Mensah, J. A., Franken, O., Verbruggen, E., … & Bücking, H. (2011). Reciprocal rewards stabilize cooperation in the mycorrhizal symbiosis. Science. I love it!! Very clean result. Amazing experiment.

Cooperative social bonds

  • Seyfarth, R. M., & Cheney, D. L. (2012). The evolutionary origins of friendship. Annual Review of Psychology. The best review on this growing literature.
  • Dunbar, R. I., & Shultz, S. (2007). Evolution in the social brain. Science, 317(5843), 1344-1347.—a good argument for why social bonds are not simple emergent byproducts (like psuedoreciprocity).

Oxytocin and cooperation

  • ***Madden, J. R., & Clutton-Brock, T. H. (2011). Experimental peripheral administration of oxytocin elevates a suite of cooperative behaviours in a wild social mammal. Proceedings B. — Shows the power of peripheral OT for manipulating behavior, and that one mechanism underlies several cooperative behaviors.
  • Crockford, C., Deschner, T., Ziegler, T. E., & Wittig, R. M. (2014). Endogenous peripheral oxytocin measures can give insight into the dynamics of social relationships: a review. Frontiers in Behavioral Neuroscience.— A great review of an exploding field.

Others, maybe unrelated, but personal favorites of mine

  • Karban, R., Shiojiri, K., Ishizaki, S., Wetzel, W. C., & Evans, R. Y. (2013). Kin recognition affects plant communication and defence. Proceedings B. —Incredible.
  • Page, R. A., & Ryan, M. J. (2006). Social transmission of novel foraging behavior in bats: frog calls and their referents. Current Biology. — One of the best behavioral studies on bats and paved the way for many other great studies.
  • Gould, E. (1988). Wing-clapping sounds of Eonycteris spelaea (Pteropodidae) in Malaysia. Journal of Mammalogy. A hidden gem. Ed Gould was right: they do echolocate with their wings: See the confirmation experiments by Yossi Yovel.
  • von Helversen, D., & von Helversen, O. (1999). Acoustic guide in bat-pollinated flower. Nature. — What a great discovery.
  • Killingsworth, M. A., & Gilbert, D. T. (2010). A wandering mind is an unhappy mind. Science. — Fun quick read.
  • Dudley, S. A., & File, A. L. (2007). Kin recognition in an annual plant. Biology Letters. — What a joy!
  • Ratcliffe, J. M., Fenton, M. B., & Galef, B. G. (2003). An exception to the rule: common vampire bats do not learn taste aversions. Animal Behaviour. — This is a nice example of a great prediction leading to a great experiment and a great result. A great little story.
  • Gould, E., Woolf, N. K., & Turner, D. C. (1973). Double-note communication calls in bats: occurrence in three families. Journal of Mammalogy, 998-1001. — I like this study because it introduced the idea of really studying bats for communication rather than just echolocation. Also, it kick-started and inspired my masters work when I notice these same call types made by adult vampires.
  • Boughman, J. W., & Wilkinson, G. S. (1998). Greater spear-nosed bats discriminate group mates by vocalizations. Animal Behaviour, 55(6), 1717-1732. — Such a great story and fits together so well with other work.

I’m sorry if your own paper does not show up in this list. There are a lot of great papers and I can’t think of them all off the top of my head. These are the ones that came to me just now.

Posted in About cooperation | 2 Comments

How bats respond to distress calls: mobbing? Or predator inspection?

New paper came out on responses of a tropical free-tailed bat to distress calls. The title is Distress Calls of a Fast-Flying Bat (Molossus molossus) Provoke Inspection Flights but Not Cooperative Mobbing. Here’s the story behind the paper.

A year ago, I took a great field course on animal communication sponsored by a collaboration between German and US labs. The goal of this course was to create teams with both German and US graduate students. Each team focused on studying acoustic communication in a different taxa (bird, frogs, bats, and bats). There were two bat teams because all of the instructors and about half of the students studied bats. Each team was expected to do conduct a small research project that would lead to a peer-reviewed publication. I thought that was pretty ambitious.

I was interested in studying responses of bats to distress calls. At the international bat conference the previous year, I met a M.Sc. student who did a fascinating playback study where he played distress calls of bats (a Rhinolophus) outside of caves, where the calls were recorded at the same or different caves. After talking a bit, he asked me for help with the statistical analysis. So I re-did all the statistics and sent it back. In the original drafts, he claimed that the bats were mobbing and attacking the speaker, but it seemed possible (and more likely to me)  that the bats were simply making more passes to inspect the source of the distress calls, especially given the effect sizes. He also did not take video footage, so there was no direct evidence of what the bats were actually doing. I thought the conclusion of mobbing was therefore unwarranted. I suggested he tone down his interpretations and send the paper to PLOS One. Instead he stuck to the more exciting story and sent the paper to Biology Letters and Behavioral Ecology and Sociobiology… with my name on it, even though I did not approve or even see the manuscript. Thankfully, it was rejected from both journals. I have not heard back about the manuscript since then. I don’t blame the author that much. I think it was largely 1) a communication error, because he could not speak English very well, and 2) and example of how distorted the academic incentive structures have become.

But I still wanted to know about cooperative mobbing in bats. Is it real? If so, how common is it? This is something that is relatively common in birds. Where I used to live I would see crows and other birds mobbing raptors all the time:

There have been a number of papers suggesting that bats, like birds, will also mob if they hear distress calls. I’ve heard many people talk about this behavior, so it is something that at least some people believe bats do. But I have never seen it myself. There have been two studies that have actually observed bats mobbing predators, so we know some bats do mob. But we don’t know common it is, and I was a skeptical of reports in the literature based on playbacks of distress calls, including the recent one above that was not published.

In a playback experiment, it’s hard to know what is mobbing and what might be “predator inspection behavior”.  Imagine you hear the an animal growling and a person screaming. Would you just run away immediately and blindly? Maybe. Or maybe you would try to see what exactly was going on. This would involve actually going towards the sounds. And you might even do it in pairs or small groups (like many prey animals do). That’s predator inspection. And that’s what I thought the bats might be doing when they fly over a speaker playing distress calls.

Getting back to the field course, Profs. Annette Denzinger and Hans Ulrich Schnitzler had been recording free-tailed bats (Molossus molossus) on Barro Colorado Island. They live under the eaves of the field station buildings. They fly out in fast direct flights, forage for 30-45 minutes and then come back to the roost. There is also evidence for group foraging in Molossus molossus. They also make many social calls. Dina Dechmann and others are doing great long-term studies on this bat’s social behavior, which I am excited to see published.

Annette served as the leader and advisor of our group, and she helped us develop the project throughout. We also got recordings of distress calls, advice, and feedback from Mirjam Knoernschild who has been studying the sac-winged bats there for years. The two German students in the group Diana and Marie-Kristin also recorded many echolocation calls and social calls of these bats in flight and in the roosts.

My interest was whether I could replicate the past studies that attracted bats with distress calls and see with my own eyes if these bats would do anything like mobbing. The experiment was very simple. I played distress calls from the bats as they exited the roosts. I played silence and noise as controls. I recorded responses using video and audio. What I observed and recorded was that the free-tailed bat and the sac-winged bat that also lived on the same buildings were both attracted to the distress calls, but they did not do anything that looked like mobbing. Usually one bat would fly nearby or circle nearby. Nothing like the mobbing Mirjam had observed in Phyllostomus hastatus.

The paper would have made a bit more sense if I could refer to the other study and data from Rhinolophus, but since that one was never published, I could not refer to it. This is an example of the importance of publishing negative results. If people do playbacks and find evidence for mobbing, that’s a neat paper. But if they do not, that’s seen as less publishable. So the literature on this topic is skewed.

One simple point from this study was that an increase in activity is not good evidence for cooperative mobbing. If not familiar with bats, many people in a room with a bat, or even in a place where bats are foraging, will often report that bats are attacking or “dive bombing” them. Likewise, the fact that bats approach a speaker playing distress calls does not indicate that they are cooperatively attacking or harrassing the speaker.

It would be interesting to studies like this with more bat species and with a predator model. Perhaps if the bats detected a predator instead of a metal box, they would have started mobbing. I just bought a life-like owl model for this purpose. It would make a neat undergraduate project.

Posted in About cooperation, Other topics | Leave a comment

Fixes to problems in science: 3 happening now, 3 unlikely to happen soon

I recently wrote about how both the incentive structures for academics and publishers can create problems for science. I posted it to twitter. I did not truly understand twitter until that day.  Visits to the post grew exponentially up to >8,000 visitors (and yes I fit the curve: R-squared= 0.97). Yikes. That’s not a big deal for most websites, but this is a blog about vampire bat food-sharing. Perhaps more people have read that particular blogpost than all of my actual research combined.

I was both surprised and inspired by the supportive response it sparked. I’ve since talked to many people about this topic in person and online, and it’s opened my eyes to the extraordinary number of dedicated people working to improve scientific practices and publishing. Things are improving much faster than I realized.

Concerns over scientific integrity are still on the rise, as lampooned by xkcd. A recent attempt to replicate a sample of 98 high-impact psychology studies could only replicate 36-47% of them (depending on how loosely you define “replicate”)*.

[*By the way: The wrong takeaway message from that finding is that the problem is specific to psychology or the social sciences (vs other fields). Another bad interpretation is that science is less reliable (vs other sources of information). You should not trust that really cool scientific “facts” are true, but all other “facts” are even less likely to be true. So just don’t trust “facts” in general. But it doesn’t really matter that most facts are wrong. Contrary to its popular conception, science has very little to do with facts.]

But casting those problems aside, the replication crisis has many people wondering how to move towards scientific greater integrity, reliability, and transparency. The problems are numerous and intertwined. While some changes in the culture of science are going to be easy (and it’s just a question of how long it will take), other problems are deeper, and we might just be banging our heads against the wall trying to change them. Which ones should we target first?

There are three emerging scientific norms will immediately benefit everyone in science. There’s nothing holding us back except for old traditions. We need to make these happen as quickly as possible.

Step 1. All science should be open access.

How it works now: We have somehow managed to make all the worst information easy to find on the internet, and we have put much of the best and most reliable information behind paywalls (even though the authors want to give it away for free). It’s hard to think of a more frustrating lose-lose situation.

I just arrived at the Smithsonian Tropical Research Institute in Panama, where I will have full unbridled access to some of the greatest nature and science, but no access to Nature or Science, as I’m not yet affiliated with a university. So if I need a research article, I will be asking friends on Facebook and Twitter to send me the PDF via email. But apparently this is illegal. It gets better.

Science magazine has an article entitled “PROMOTING AN OPEN RESEARCH CULTURE” but when I tried to read it, I saw this:

Screen Shot 2015-09-09 at 7.23.35 PM

They let me read the first 4 sentences. And I can purchase access to the rest of this one-page article for $20/day.

Thankfully, PMC makes the article available here.

One thing that bothers me is when journals say that, for a hefty fee (>$1500), they can “make” your published article “open access”. We’ve all gotten used to this language. But scientific articles don’t become open access; that’s their natural born state!

How it should work: You type a quote or keyword from a scientific paper, and it shows up in Google or Google Scholar. From there, you can read the whole paper, look directly at the data, supplements, and the peer reviews. For a great example of how this would look, check out elife or PeerJ. You don’t have to download anything, because it’s always just available online, just like wikipedia. You don’t have to be at a university. You don’t have to ask people for PDFs. You just google it. You can read primary research on your phone, your tablet, whatever and wherever. Just like everything else on the internet. Even better, maybe you can read not only finished science, but even hypotheses and works in progress.

How are we doing: Pretty good actually. First, off there are some great new futuristic OA journals like the ones linked above. These are doing quite well. If only we would not discriminate against them for being new, these journals would quickly dominate the traditional journals, given the superior quality of their actual service. Second, the price of OA publishing for authors is dropping fast. Largely, this is because institutions are agreeing to pay for author fees. Only a couple of years ago, very few universities paid for research to be published open access. Now, many do. Finally, it’s also getting easier and easier to get free articles as authors post them to repositories. Open access is quickly becoming the norm.

Step 2. Every paper should have post-publication peer review.

How it works now: Some papers are bad (even those in the high-impact journals) and it’s not immediately obvious to people without the necessary technical knowledge. We can’t read and understand every paper, so instead we often use the journal name to judge the quality of the paper. It’s not until you read the literature more deeply that you realize that this is a huge mistake. But you have no choice, because journals have quality scores but individual papers do not.

How it should work: Every article has an individual impact factor. Reviewers and editors can give a score to the paper’s quality at the time it gets published. Over time, more reviews will accumulate. If someone has found a flaw in a paper’s logic or argument, you can see that posted alongside the paper. If there’s an error or a clarification required, the author can fix it, and the new version will be available on top of the old version (just like how we share code).

How are we doing: Ok, but not great. There are a few journals that encourage article level metrics and post-publication peer review, but not many. There’s PubPeer and similar websites popping up. Read more here.

Step 3. Institutions should encourage, rather than discourage, replication.

How it works now: Students and researchers are discouraged from replicating past work. Most journals won’t even publish replications. When people do finally try and replicate studies: Surprise! Many of them can’t be replicated.

How it should work: Imagine if graduate students were encouraged to replicate past studies as part of their training. This would also help us know what studies were accurate and which ones were flukes.

How are we doing: The project I discussed above was a huge first step. Many people are talking about replication now.

Now here are 3 problems that I believe are not going away anytime soon.

Not going away soon: “Luxury” journals, academic competition, self-interest

Why: Everywhere and throughout all of human history, people have wanted to be better than other people. In some cultures, competition is rewarded. In other cultures where competitiveness is looked down upon, many people just end up competing over being seen as the least competitive. Self-interest is deeply human too. We are not bees or ants. Rather than trying to radically change culture or human nature to make people more selfless, if you want people to vote, give blood, or donate to charity, its easier to just give the reward of social prestige. That’s what works: bring individual incentives in line with the public good.

Not going away soon: p-values, p-hacking, post hoc hypotheses, etc.

Why: The basic problem with statistics (and other maths and hard sciences more generally) is that they carry an authority that comes from many people not understanding them. If you know a little bit of statistics it’s easy to fool readers who know less than you. It’s also easy to fool yourself.

That problem is not going away soon. Let’s consider p-values as an example. Everyone who knows enough to agree, will agree, that p-values can be misleading and can encourage all kinds of problems and misunderstandings. But what is going to replace them? There is not something obviously better. In this thoughtful article entitled “The alternative to p-values”, the author gives a detailed example of how to make inferences without p-values or Bayesian posteriors. But then looking over the procedure he just outlined, the author perfectly expresses exactly what every reader is thinking:

Gee, that’s a lot of work. “I have to decide about a, b, c and all the rest as well as theta 1 and theta 2, and I have to figure how far apart p1 and p2 are to be ‘far’ apart?” [p1 and p2 are probabilities of y given various values of X].

His answer:

Well, yes. Hey, it was you who put all those other Xs into consideration. If they’re in the model, you have to think about them. All that stuff interacts, or rather affects, your knowledge of y. Tough luck. Easy answers are rare. The problem was that people, using p-values, thought answers were easy.

He then admits that any metric to replace the p-value… 

can attain mythic status, like the magic number for p-values. If you’re presenting a model’s results for others, you can’t anticipate what decisions they’ll make based on it, so it’s better to present results in as “raw” a fashion as possible…

So there’s simply no “easy” way forward. People fail to grasp a simple concept in statistics, and the solution is, ironically, even more nuanced and difficult statistical concepts. In my opinion, it’s much better that students just learn how to interpret a p-value properly, rather than trying to ban them from use. The move away from p-values and towards Bayesian or other approaches is going to require more time. To get rid of p-values, an entire generation is going to have to learn how to do statistics differently.

Practices like p-hacking and post hoc hypothesizing are even harder to control because they can literally happen inside the mind of the person. Who knows for sure whether I made a hypothesis and then tested it with a correlation, or whether I saw a correlation and then made sense out of it after? Who knows how many tests I ran? How many p-values I calculated? Only me.

There are other statistical changes coming sooner, such as a move away from parametric assumptions. In the much sooner future, hypothesis-testing will be based almost entirely on permutation and simulation. That’s a good thing. But even that will take awhile, because not everyone in science is good at writing code.

Not going away soon: “Science/academia is too much work”

Why:  Of course scientists work hard and are paid little; it’s a simple supply and demand issue. In biology, there are 16,000 students who start a PhD each year in the USA. So imagine 16 aspiring biologists. About 10 of them will finish their PhD and take an average of 7 years doing so. Of those PhDs, 7 of 10 will get a postdoc position. But only about 1 of those 7 postdocs will get a tenure-track job within the next 6 years. Given these odds, why do so many people enter research as a profession? I’m pretty sure most students have no idea about these chances. That’s one reason. But there’s another…

The stereotypical detective thriller Hollywood movie trope is that our protagonist gets caught up in a conspiracy and becomes obsessed with figuring out some mystery, turning themselves into an amateur detective and casting aside their other obligations and responsibilities. They end up wearing dirty clothes, sleep-deprived, in a poorly lit room, surrounded by piles of papers and coffee mugs, staring at a wall with a complex network of all kinds of facts, graphs, pictures, and newspaper clippings pinned to the wall, waiting in desperation for that eureka moment. If only they could figure out this puzzle. Then another character comes in, “When was the last time you slept?”

The best and most compelling research is like that sometimes. The best research is a labor of love and/or obsession. Without more science funding overall, we can’t all be paid the same amount as tenure track professors and have large research grants. We can only make this job less demanding at time B by moving the competitive filter point to time A. We can either make it really difficult to get into graduate school, or difficult to graduate from graduate school, or difficult to start a postdoc, or difficult to get tenure. No matter what, it’s going to be really hard at some point. Basically, there are too many people like me. I’m willing to work at whatever pay level just so I can keep working on the scientific problems I’m interested in. The rewards of doing research are creative pleasure, the respect of your peers, and the joy of finding out cool stuff. The fact you get paid enough to survive is a bonus. But that said, yes it would be nice if there were more funding for science.

How much does the public support science?

I don’t know the answer to this. Here is an interesting table on public’s trust in different institutions. Government and popular support for science has traditionally been high. Based on what I’ve seen in my own little social bubble, I thought appreciation of science was increasing dramatically, but apparently not so. In 2009, when US adults were asked whether science made their life easier or more difficult, 10% replied that science had made their life more difficultIn 2014, that number was up to 15%. [One can only hope that the responders were actually thinking that answering endless poll questions was making their life more difficult.] As Pew reports, “public appreciation of scientists’ contribution dropped 5 points from 70% in 2009 to 65% in 2013 with a corresponding uptick to 8% in those saying scientists contribute “not very much” or “nothing at all” compared with 5% in 2009.”  But these trends are driven by only particular demographics. Survey data also show that “while trust in science declined between 1974 and 2010 among those who frequently attended church”, there was no detectable group-specific change in trust in science over that period among any of other sociodemographic factors examined, including gender, race/ethnicity, and socioeconomic status.

Most people enjoy the ways technology has benefited their lives, but I’ve come across many people who have this strange idea that the underlying foundational science and technology comes from the private sector: that Apple invented the technology for the iPhone, that a company like Google created the internet, that new medicines are discovered and developed by pharmaceutical companies. The sad thing is that basic science produces pretty much every societal benefit of long-term value that is informed by knowledge, yet it produces almost nothing of immediate value. It becomes nearly impossible to see the line from the iPhone to this guy or to the underpaid, sleep-deprived graduate student at MIT with immigrant parents, or to grants from the government based on promise of military application.

It’s hard to explain the value of knowledge for its own sake. So when asked of the value of their research, scientists must choose between conjuring up stories of its future potential value [like the last line of a grant proposal] or giving a response that often sounds condescending, irritated, or self-important. Faraday, one the of greatest scientists of 1800s, was often asked something like “Ok, that’s all very interesting, but of what use is electricity?”

There are two famous replies he gave (both are snobby and perfect at the same time). The first: “Of what use is a newborn baby.” And his reply to the Prime Minister of Great Britain: “Sir, there is every possibility that you will soon be able to tax it.”

Posted in About science as an activity | 1 Comment

Foraging vampire bats can expect big meals or none at all

About 7% of 340 adult vampire bats and 33% of 258 younger bats (<2 years of age) failed to feed on a given night. But when they do feed, wild vampire bats fill up like water balloons.


Jon Flanders took this picture of a male vampire bat. He had originally caught this bat around the time of emergence and then caught it again about 3-4 hours later. As you can see, it had just fed and it’s so full it looks pregnant. He described the recapture this way:

Urinating the whole time I was getting it out of the net (I could see where its urine was on the floor underneath it as well). When we weighed it, it was still 6g heavier than when we first caught it.

This is a great illustration of how foraging in vampire bats is a ‘boom-or-bust’ phenomenon, where a successful bat gets either a large meal or none at all.

If only they could store it for later. But alas– to make matters worse, vampire bats don’t put on fat like other mammals.

So the best way to save food for later might be in the form of social capital that leads to future sharing.

Before describing the food-sharing systems of the Ache people of Paraguay and the !Kung San of the Kalahari Dessert, Steven Pinker lucidly explains the basic logic of reciprocal food sharing in How the Mind Works:

…species are driven to share when the variance of success in gathering food is high. Say in some weeks I am lucky and have more food than I can eat, but in other weeks I am unlucky and in danger of starving. How can I store extra food in the fat weeks and draw on it in the lean weeks? … I can store it in the bodies and minds of other people, in the form of a memory of my generosity they feel obliged to repay when fortunes reverse. When the prospects are risky, it pays to pool the risk.

Compared with females, adult male vampire bats do not participate much in reciprocal food sharing. So one would predict that they starve to death more often, and that males may even have slightly different physiological strategies for dealing with fasting. But I’m not sure if there’s any evidence to support this conjecture.

Posted in About cooperation, About vampire bats | 3 Comments

Talk today (Aug 31) at Cambridge

Talk: Cooperative food-sharing in the vampire bat

Today! Monday August 31st @ 3 PM
Location: Zoology Part II Lecture Theatre, Cambridge University, Downing Street, Cambridge, UK CB2 3EJ


Thanks to Neeltje for organizing this talk.

Posted in News | Leave a comment