A look at avian intelligence with Nathan Emery

EmeryWhat really goes on inside the mind of a bird? Are these creatures as simplistic as the expression “bird brain” would have us believe? In Bird Brain: An Exploration of Avian Intelligence, Nathan Emery shines new light on the minds of birds, offering insight into their sophisticated neurological functions and the diverse behaviors these functions give rise to. An extraordinary work of cognitive biology, Bird Brain uncovers an array of unexpected abilities including mental time travel, self-recognition, empathy, problem solving, imagination, and insight. Recently, Emery took the time to talk with us about avian intelligence, why it has long been misunderstood, and how he first became hooked on birds.

Can you tell us something about how you go into studying avian intelligence?

NE: I completed undergraduate degree in Neuroscience at the University of Central Lancashire in the northwest of England. Then I moved north of the border to do my PhD studying face responsive neurons and social signals in primates at the University of St Andrews. After that, I moved to UC Davis in California for 3 years to work on an animal model of autism, that didn’t exactly work out as expected, but it did result in me meeting my future wife, Nicky Clayton. We moved to Cambridge in 2000, me continuing my neuroscience research at the Sub-department of Animal Behaviour, where both Jane Goodall and Dian Fossey did their PhDs; Nicky as a lecturer in the Department of Psychology. It was at Cambridge that I started getting focusing on birds instead of monkeys.

How did you become interested in birds?

NE: My wife Nicky got me hooked on birds. I was never a birdwatcher, I didn’t keep a pet parrot, and it would be fair to say that I’d never really considered them, except as a tasty meal at Christmas. Nicky has worked with birds for her entire career, first studying bird song for her PhD, then concentrating on spatial memory and caching behaviour. I was writing a review paper on how different animals use eye gaze as a social signal. I didn’t know what to say about birds, as my knowledge up to that point had been entirely about primates. She made me see the light! She told me dozens of fascinating facts about birds. I was hooked and haven’t turned back. My review completed from a new perspective, Nicky and I collaborated on a project looking at whether scrub-jays appreciated that others were watching where they cached, and whether they protected their caches from these potential thieves. This lead to our first joint paper, which we were lucky enough to get into the highly prestigious journal Nature a few months after we got married. It was published on our joint birthday, probably the first, and possibly the last occasion this happened to a paper in Nature! In the 15 years since, I’ve not looked back on either front, and now my research is entirely on birds.

How did you get involved in writing Bird Brain?

NE: I’ve wanted to write a popular book on avian intelligence for about 10 years, but things always seemed to get in the way. Then I was approached by Ivy Press to write a chapter on avian brains for an edited book they were putting together. My wife was asked to edit it, but she didn’t want to do so, so suggested me. I was keen, but then thought ‘why don’t I just write the whole thing myself?’ Ivy agreed, so that’s what I did. I had already arranged a year long sabbatical from work, so switched focus from the experiments I’d planned, to writing the book.

The book is beautifully designed and illustrated. Did you have any input into how it looks?

NE: One of the reasons I was excited to be working with Ivy Press (the UK publisher of Bird Brain) was their reputation for producing beautiful books with a specific focus on design.

They were producing some very attractive nature and science books for a popular audience, and I really liked what they had planned for this project as it tallied with my own ideas. I’ve always been interested in illustration. At that crucial point in my life when I had to choose what I was going to study, I had to decide between science and science illustration. I chose science, but have always tried to incorporate illustration into my science work – whether the design of my lectures or talk slides, the illustrations in papers or even the design of problem-solving tasks. This project was a dream come true. I designed and drew all the illustrations in the book (except for three) using Photoshop, but they were then changed into a style more consistent with other Ivy books by three great illustrators. I do get credited for Illustration Concept, but would love to illustrate my own books in the future.

It’s quite unusual to see detailed brain wiring diagrams and experiments illustrated in a popular science book. Was this something you had in mind from the start?

NE: Yes. Jacqui Sayers, the book’s original editor was very keen on doing something visually different with the book, to try and make some of the arcane aspects of science more accessible to the public. I tried to illustrate the various steps in an experiment in a way that could be easily understood. We also tried not to dumb down how the information is presented, which is why there are quite a few complex diagrams detailing the avian brain’s wiring patterns. Also, it is called Bird Brain! However, the brain is said to be the most complicated object in the known universe, so it would be a travesty to present it too simply. We think we’ve achieved the right balance.

Why do you think birds have been maligned for so long?

NE: The term ‘birdbrain’ is part of our language. Our ancestors knew more about the capabilities of our feathered cousins than we did, until very recently. They feature as the clever protagonists of many fables and legends, including origin stories concerning the beginning of the world. Although somewhat fanciful, there is a lot of truth – at least in terms of their behaviour and intelligence – about these birds. A bigger issue is that most people have little experience of birds, outside of pigeons, chickens, ducks and sparrows, and they wouldn’t know what constitutes intelligence. You see an animal using a tool, such using a stick to move food into reach, and it is easy to use your own experience to understand that this requires some intelligence. This is possibly why a video of a New Caledonian crow solving a problem requiring 8 different steps has received over 10 million hits on YouTube. It just looks clever. Compare that to a study of long-term memory, such as remembering where something was hidden 6 months ago. This doesn’t translate very well to a single video. All the relevant information about what maybe going on in the bird’s mind when it’s recovering a memory of a past caching event, such as ‘where or when did I hide that worm?’ is hidden in the details of the experiment rather than a video clip. Our perception of all animals is guided by what we see in front of us, and its relationship to our past experiences. Unfortunately, our day-to-day view of the natural world is not enhanced by a Sir David Attenborough voice over. This clouds our view of an animal’s intelligence more than any particular aspect of their behaviour.

What would you say were your most important findings about clever birds?

NE: There are three pieces of research of which I’m the proudest. The first is the study that I mentioned earlier, that scrub-jays are protective of their caches by implementing different strategies to reduce the chance of them being pilfered. The most intriguing fact about this, is that not all scrub-jays do this. It’s not an innate response to being watched. Only birds that have previous experience of being thieves protect their caches – it takes a thief to know a thief! Birds without such experience, do not protect their caches. They are too naïve to know that the world is a bad place until they experience otherwise. This finding has been proposed as evidence that jays have a theory of mind – thinking about another’s thoughts. However, I’m not sure that this is akin to human theory of mind or a process that is special to creatures who cannot speak.

The second finding is a series of studies on tool-related cognition in rooks; namely whether they are capable of creating novel tools to solve unique problems, such as bending a wire to reach and pull up a bucket containing a treat, or placing stones into a water-filled tube to raise the water level to reach a treat floating on the surface. There is no evidence that rooks use tools in the wild, so it is striking that in captivity they can do things that great apes have yet to demonstrate. One of my greatest loves is designing experiments, especially new cognitive tasks. I have notebooks filled with my experimental designs, and we’re currently testing the problem-solving abilities of the famous ravens at the Tower of London using some of these new designs. It’s extremely rewarding when others adopt your tasks, especially when they add their own improvements and test them on their own species. One case is the Water Displacement Task, my ex-PhD student Chris Bird and I adapted from Aesop’s Fable ‘The Crow and the Pitcher’, that has now been used to test rooks, New Caledonian crows, Eurasian jays, western scrub-jays, grackles and young children. It’s one of the challenges of comparative psychology to develop tasks that assess cognitive differences across species that aren’t based on simpler factors, such as visual acuity or manual dexterity. Certainly for birds, the Aesop’s Fable Task appears to be achieving this aim.

The final contribution for which I’m proudest is not the result of an experiment, but an idea. Nicky and I wrote a review paper in the journal Science in 2004 in which we proposed that crow and ape intelligence is an example of convergent evolution – namely that complex cognition evolved in these distantly related animals due to facing similar selection pressures, such as living in complex social groups or having to find and process a range of foods, some that are difficult to acquire or with external defences. This idea lead to me coining the term ‘feathered apes’ for corvids. It is gratifying to see this has become part of the scientific furniture where the general public just accepts that crows are smart, and just as smart as apes, dolphins and elephants.

Nathan Emery is Senior Lecturer in Cognitive Biology at Queen Mary University of London, UK has studied the intelligence of corvids, and parrots, as well as apes and monkeys for the last 20 years. Emery is the co-editor Social Intelligence: From Brain to Culture and The Cognitive Neuroscience of Social Behaviour, and is on the editorial board of the journals. He is the author of Bird Brain: An Exploration of Avian Intelligence, a visually stunning guide to the brain, behaviour and cognition of our feathered friends. Emery’s work has been extensively covered by international newspapers and magazines, in books, and on TV. He is currently working with the ravens at the Tower of London.

The making of a field guide in Ecuador: an interview with Nick Athanas and Paul Greenfield

birds of western ecuador athanas jacketIn Birds of Western Ecuador: A Photographic Guide, Nick Athanas and Paul Greenfield provide a practical field guide for birders wanting to explore the region. Filled with bright and beautiful photographs, their extensively researched and photographed volume is a striking guide for the area’s birds, with nearly every species in Western Ecuador included. Recently, both authors agreed to answer some questions about their personal passions for the project.

Why did you want to write Birds of Western Ecuador?

NA: I had been photographing birds in South America for about ten years, and had built up a sizable collection of nice images. I wanted to do something useful with them. Since I am also a birder and a birding tour guide based in Ecuador, a field guide to the region was an obvious project to think about. Iain Campbell, longtime friend and business partner, was working on a photographic guide for Australia, and encouraged us to do it; he put us in contact with Robert Kirk at Princeton University Press.

PG: Ecuador is a huge country in terms of bird species diversity, and with the advent of digital photography, actually capturing nice images of much of its avifauna made doing such a project a viable possibility. When the project was first presented to me by Nick and Iain, I hesitated a bit, only because I had already spent over 20 years working on the painted illustrations of the Birds of Ecuador, but after looking over some of the proposed shots, the idea of presenting a photographic testimonial to the Ecuador’s rich birdlife instantly became very attractive.

What is your target audience?

NA & PG: Our book targets English-speaking birders visiting western Ecuador, either on their own or on an organized tour. We assumed no previous birding experience in the Neotropics. However, the guide will be useful and inspiring for anyone with an interest in the birds of the region, even those with a lot of experience birding the Neotropicals. We excluded photos of some species that are very rare visitors to the region in order make the book smaller and more user-friendly, but it will have everything most visiting birders will see on a typical trip to western Ecuador. The excluded species are also usually mentioned in the text so that readers are aware of them. While not specifically designed for it, the guide also covers the vast majority of birds occurring in southwestern Colombia and northwestern Peru.

So this is a real field guide, and not just a collection of pretty bird photos?

NA & PG: Absolutely, this is a field guide. It was designed to help identify birds. The photos were chosen to show the relevant field marks, the text is extensive and helps to distinguish between similar species, and the range maps are completely new and based on up to date sighting information. Text, species accounts, and maps are all laid out side-by-side and everything is indexed.

Do you believe photographs can be as effective as paintings in a field guide?

NA: With good photos and clear text, I really do believe that. It would have been impossible even just five years ago. With the amazing recent technological advances in digital cameras, it is now possible to get great shots of shy rainforest species in natural light that were impossible before. The better gear also has led to an explosion in interest in wildlife photography, so there are a lot more people out there shooting bird photos. There are now good images available of the vast majority of the world’s bird species. A clear, sharp photo can show a bird’s important field marks at least as well as a good painting, and can even reveal features that other field guides might overlook.

PG: Having experience with both bird photography and painting, I believe that each presents effective, but slightly different strengths for illustrating field guides. Bird painting, with its respective pros and cons, can be quite effective—through hardly noticeable distortions—in presenting field marks from above and below a bird at the same time, as well as creating a sense of wondrous anticipation in the viewer. Bird photography presents the ‘real’ image of the actual species—it brings in the element of reality with ‘real-time’ accuracy when it comes to field-marks, ‘attitude’ and expression.

Were you able to get all the photos you needed?

NA & PG: All but a few. There were two species that we could not find any photos which were of high enough quality to publish: Berlepsh’s Tinamou and Colombian Crake. There were a few species where we could not find photos of one of the sexes. There are also a few of marginal quality, but in general we are extremely happy with the selection of photos. About half the photos are Nick’s, but we also invested a huge amount of time looking for other photos and contacting dozens of talented photographers. In the end, over 70 photographers contributed shots to Birds of Western Ecuador. It includes images of nearly 950 species. To put that in perspective, that’s more bird species than are found in all of the continental US.

This guide only covers half of Ecuador. Why?

NA & PG: We did not think we had the photos to do the entire country, nor did I we think we would be able to get them in the few years we had to write this book. Eastern Ecuador has significantly more species, and many of them are rainforest birds that are extremely hard to find and see, never mind photograph. Western Ecuador was a manageable starting place, and even still it was a far larger project than we anticipated.

Will you write a companion volume?

NA & PG: If this book is well-received, and if PUP is interested, we’d like to write another volume. It could be for eastern Ecuador, or possibly for the whole country. Most of Ecuador’s birds are in the East, so including everything won’t make the book proportionally that much larger. I think that in the years that have passed since we started Birds of Western Ecuador, many more species have been photographed, so that we should be able to obtain nice shots of almost all of Ecuador’s birds by the time a companion volume is finished.

Some people may see all these photos of amazingly colorful birds and be inspired to visit. When is the best time of year?

NA & PG: Come any time! We go out birding any month of the year and always find great birds. June-September are usually the driest months, and January to May are usually the wettest months. A lot of people like to visit the Northwest in the intermediate months of October-November since some rain is good for activity but it usually isn’t too much. January in the Southwest is usually great because the rains are just starting, the birds are singing, but the trees still haven’t leafed out much so the birds are easier to spot and enjoy. But really, if you can only come at a certain time, by all means do so.

Do you have a favorite bird?

NA: I have many! Hard to pick favorites when there are so many amazing choices. One of them, however, is definitely the Velvet-purple Coronet that went on the cover. It’s such a uniquely-colored hummer and its shimmering hues change depending on the angle and the lighting conditions.

PG: I have always said that my favorite bird is the one I am looking at ‘right now’, and I believe that’s really true. I especially get a kick out of remembering the circumstances when I first saw a species, each time I see it again; but how can you not go nuts with tanagers, hummingbirds, trogons, cotingas, antbirds, toucans… well all of them!

Nick Athanas is cofounder of the tour company Tropical Birding. He leads bird tours throughout the Neotropics and has photographed more than 2,500 bird species. Paul J. Greenfield is a longtime resident of Ecuador, where he leads bird tours and is active in bird conservation. He is the coauthor and illustrator of The Birds of Ecuador. Together they have written Birds of Western Ecuador: A Photographic Guide.

From “rolling stone” to World’s Best Dad: Richard Bribiescas on fathers

How Men Age jacketWhy is paternal investment so rare in the animal world? Why do some human fathers choose the caring route, while others don’t? Biological anthropologist Richard Bribiescas, author of How Men Age: What Evolution Reveals About Male Health and Mortality, reveals how many of the physical and behavioral changes that we negatively associate with male aging may have actually facilitated the emergence of positive traits. These traits, including how we parent, have been crucial to our success as a species. We caught up with Richard for a special Father’s Day Q&A.

Many in the animal kingdom aren’t noted for being the best fathers. What’s the evolutionary significance?

Chimps aren’t very good fathers. They just aren’t. They don’t care for their offspring, provide food, or offer any assistance to moms. Don’t get me wrong, chimpanzees are noble creatures who merit our stewardship as well as the common courtesy of not destroying their forests. They’re just not the fatherly type. In fairness to our great ape cousins, most males in the natural world won’t be earning waffles in bed. With a few exceptions such as certain South American monkeys 1, most mammalian males are unlikely to earn a “World’s Best Dad” coffee mug on Father’s Day. Men however can be terrific dads with paternal care being one of the hallmarks of our species. Human males often invest significant amounts of time and resources in their offspring. This is true in modern industrialized societies as well as hunter/gatherer groups. Pass the butter and maple syrup.

Why is paternal investment so rare in the animal world? There are several evolutionary reasons but one especially salient explanation is that caring for offspring requires knowing who your offspring are. This is known as paternal uncertainty and is evident in all species that have internal fertilization. In humans, estimates of paternal misidentification when asking individuals to identify their fathers and then testing that assumption genetically ranges from one to around ten percent, depending on the study and population 2. Conservatively that means for every hundred readers, at least one of you was fathered by a man who is not the recipient of your Father’s Day card. But don’t freak out. This simply means that women are just as likely as men to evolve a range of reproductive strategies. Plus the odds are still in your favor of being correct so there’s no need to forward the mail.

A recent finding that illustrates the evolutionary significance of paternal investment is the capacity for men to display different reproductive states. This has long been observed in women since non-pregnant, pregnant, and lactating states are readily visible with numerous associated hormone changes. In men, different reproductive states are less obvious but evident when you look at reproductive hormones such as testosterone. Anthropologists Peter Gray and Lee Gettler have demonstrated this in numerous cross-cultural studies that show testosterone declines in response to fatherhood 3,4. This is more evident when men are in paired relationships with women.

Then what about male/male relationships and gay fathers?

Good question. We’ll get to that in a bit. So what is the significance of lower testosterone in association with fatherhood? It is still unclear but declines in testosterone may have behavioral, immunological, or metabolic effects that promote paternal investment. Stay tuned.

But fathering children is not the same as being fatherly. Again, hormones provide a spiffy way of getting at this subtle but important point. Anthropologist Martin Muller and colleagues looked at testosterone levels in association with fatherhood in two African societies, the Datoga who are cattle herding people in which the men do not commonly engage in childcare and the Hadza, an adjacent population of hunter/gatherers in which the men regularly hold and care for their children. Testosterone levels were not significantly different between the two populations even when looking at paternal status. But when Muller and colleagues looked at within group testosterone levels in association with having their children close by, interesting differences emerged. When their children were around, Hadza men were much more engaged with them compared to Datoga men who do not pay much attention to their children. Among the Hadza testosterone levels were significantly lower when children were in their household compared to when they were not around. The presence or absence of children among the Datoga had no influence on testosterone levels 5. This suggests that paternal engagement is important to any changes in testosterone. Caring and engagement makes a difference.

What does it mean to be a good father?

While human males are unique in their potential to be doting fathers, they also exhibit a much broader spectrum of paternal behaviors compared to other primates and mammals. Men can be extremely caring to simply providing food to being infanticidal. As a boy growing up in the Watts area of south central Los Angeles in the ‘60’s and 70’s, my friends and I listened to a lot of The Temptations. Among their hits was “Papa Was a Rolling Stone”, a song that tells the story of children asking their mother about their estranged, wandering father. “Papa was never much on thinkin’, spent much of his time chasing women and drinkin’…” Why some men choose the caring route while others do not is unclear. Evolutionary theory suggests that in environments with lots of hazards and a low probability of living a long life, caring for offspring may take a backseat to more risky reproductive strategies such as seeking out additional mates in lieu of investing in family. This is true of both men and women 6. Since humans have evolved the ability to thrive in a broad range of ecological and social settings, it makes sense that behavioral biology of fatherhood would be broad and malleable7,8.

Let’s go back to the question of gay dads. There is no reason to assume that caring for children should be limited to straight men but adding the variable of sexual orientation is an interesting question given the range of variability in reproductive behavior in humans. Researchers examined brain scans of gay men in association with interactions with their children. They found that areas of the brain that are commonly activated in mothers and heterosexual fathers in response to children were also evident in gay fathers suggesting that the neurobiological mechanisms associated with childcare transcend gender or sexual orientation 9. Compared to other mammals and certainly other great apes, humans seem to be biologically predisposed to care for children. Do gay fathers exhibit the same hormonal changes as heterosexual dads? We don’t know yet although Yale anthropology Ph.D. candidate Erin Burke, Dr. Pasquale Patrizio of Yale Medical School and I are hot on the trail of this question 10. There are many ways to be a dad and we’re only beginning to understand that fatherhood is as varied as the colors and patterns on a homemade necktie.

Richard G. Bribiescas is professor of anthropology and ecology and evolutionary biology at Yale University, where he also serves as deputy provost for faculty development and diversity. He is the author of Men: Evolutionary and Life History. He lives in Hamden, Connecticut.

References and Endnotes


1          Fernandez-Duque, E., Valeggia, C. R. & Mendoza, S. P. The biology of paternal care in human and nonhuman primates. Annual Review of Anthropology 38, 115–130, doi:10.1146/annurev-anthro-091908-164334 (2009).

2          Anderson, K. G. How well does paternity confidence match actual paternity? Evidence from worldwide nonpaternity rates. Curr Anthropol 47, 513-520, doi:Doi 10.1086/504167 (2006).

3          Gray, P. B. & Anderson, K. G. Fatherhood : evolution and human paternal behavior. (Harvard University Press, 2010).

4          Gettler, L. T., McDade, T. W., Feranil, A. B. & Kuzawa, C. W. Longitudinal evidence that fatherhood decreases testosterone in human males. Proc Natl Acad Sci U S A 108, 16194-16199, doi:10.1073/pnas.1105403108 (2011).

5          Muller, M. N., Marlow, F. W., Bugumba, R. & Ellison, P. T. Testosterone and paternal care in East African foragers and pastoralists. Proceedings of the Royal Society, Biological Sciences 276, 347-354 (2009).

6          Quinlan, R. J. Human parental effort and environmental risk. Proc Biol Sci 274, 121-125, doi:10.1098/rspb.2006.3690 (2007).

7          Bribiescas, R. G. Men: Evolutionary and Life History. (Harvard University Press, 2006).

8          Bribiescas, R. G. How Men Age: What Evolution Reveals about Male Health and Mortality. (Princeton University Press, 2016).

9          Abraham, E. et al. Father’s brain is sensitive to childcare experiences. Proc Natl Acad Sci U S A 111, 9792-9797, doi:10.1073/pnas.1402569111 (2014).

10        Burke, E. E. & Bribiescas, R. G. Hormones and behavior in same-sex male parents: implications for the evolution of paternal care in humans. Am J Phys Anthropol 159, 105 (2016).


Bird Fact Friday – Why do birds hybridize?

From page 26-27 of Waterfowl of North America, Europe & Asia:

Birds mate with other birds of different species in the wild for several reasons. Usually there is genetic closeness, since if the parent genomes’ are too distant offspring will be sterile or unviable. Birds with different courtship rituals, breeding times, or habitats usually won’t mate, unless geographic restrictions are lifted (such as in captivity) when it becomes more common. Sometimes hybridization occurs because of interspecific parasitism, which leads some species of ducks to lay a portion of their eggs in the nests of other species. This can produce an imprinting phenomenon in the female of the host species, affecting the choice of sexual partners later in life. Other causes of hybridization are described in Waterfowl of North America, Europe & Asia.

Waterfowl of North America, Europe, and Asia
An Identification Guide
Sébastien Reeber

ReeberThis is the ultimate guide for anyone who wants to identify the ducks, geese, and swans of North America, Europe, and Asia. With 72 stunning color plates (that include more than 920 drawings), over 650 superb photos, and in-depth descriptions, this book brings together the most current information on 84 species of Eurasian and North American waterfowl, and on more than 100 hybrids. The guide delves into taxonomy, identification features, determination of age and sex, geographic variations, measurements, voice, molt, and hybridization. In addition, the status of each species is treated with up-to-date details on distribution, population size, habitats, and life cycle. Color plates and photos are accompanied by informative captions and 85 distribution maps are also provided. Taken together, this is an unrivaled, must-have reference for any birder with an interest in the world’s waterfowl.