My arrival at Resolute on Cornwallis Island in Canada’s Nunavut, one of the most remote settlements in the world, coincides with the spring thaw. On my first day I notice a pair of brent geese by a frozen pool: black silhouettes against an icy background, waiting for the snow to melt and the opportunity to breed. The next day I drive past the frozen pool again but am saddened to see that one of the geese has been shot. Beside its lifeless form stands the bird’s partner. A week later I pass the pond again, and the two birds, one alive and one dead, are still there. I left Resolute that day, so I don’t know how long the surviving bird stood vigil.
Is the bond that kept those geese together an emotional one, or simply an automatic response that programs birds like geese to remain close to their partners?
Charles Darwin was in no doubt that birds and mammals had feelings. In his book The Expression of the Emotions in Man and Animals (1872), he recognizes six universal emotions: fear, anger, disgust, surprise, sadness, and happiness, to which others later added jealousy, sympathy, guilt, and pride. Effectively, Darwin envisioned a continuum of emotions from pleasure to displeasure. Most of his book is about humans, and in particular his own children, whose facial expressions he studied in detail, but he also gained tremendous insights from his pet dog—which, as every owner of one knows, makes its feelings very obvious.
Like some of his predecessors, Darwin considered the vocalizations of birds an expression of their emotions. The sounds birds make under different circumstances have a quality that we identify with—harsh when aggressive, soft when directed to a partner, plaintive when grabbed by a predator. At one level this is utterly anthropomorphic. On the other hand, because we share both some ancestry and many sensory modalities with birds, it is possible that we share a common emotionality.
Ever since the study of animal behavior began in the early 1900s, researchers have been desperate to avoid the trap of anthropomorphism. Niko Tinbergen, one of ethology’s main architects, laid out the ground rules in his Study of Instinct (1951): “Knowing that humans often experience intense emotions during certain phases of behavior, and noticing that the behavior of many animals often resembles our ‘emotional’ behavior, they conclude that animals experience emotions similar to our own. ... This is not the method we shall follow in our study of animal behavior.” This view persisted well into the 1980s.
Some scholars, however, like the eminent biologist Donald Griffin, were confident enough to challenge this view. His book The Question of Animal Awareness, published in 1976, was the first to seriously address the issue of animal consciousness and understand the “mind” behind the behavior. Griffin’s book was greeted with widespread derision.
Emotions, feelings, awareness, sentience, and consciousness are all difficult concepts. They are tricky to define in ourselves, so is it any wonder they are difficult in birds and other nonhuman animals? Consciousness is one of the big remaining questions in science, making it both an exciting and a highly contentious area of research.
Those difficulties have not stopped researchers from trying to understand the emotional life of birds and other animals, but the lack of a clear conceptual framework has resulted in something of a free-for-all. Certain researchers, for example, believe that birds and mammals experience the same range of emotions as we do. Others are more conservative, arguing that only humans experience consciousness, so humans alone are capable of experiencing emotions.
Biologists, psychologists, and philosophers have argued over these issues for years, so I cannot hope to resolve them. Instead, I have adopted Darwin’s approach—thinking about what might be going on in a bird’s head and imagining a continuum, with displeasure and pain at one end and pleasure and rewards at the other.
Studying wild zebra finches in Australia, I spent many hours sitting quietly in a hide watching the birds. Inevitably, I saw lots of other wildlife, including one spectacular predation event. Galahs—pink-and-gray parrots—were common in the study area, and on one occasion I saw a brown falcon pluck a parrot from the sky. The parrot shrieked abominably, and even after the two birds disappeared into the trees I could hear the parrot’s plaintive cries for a further 15 minutes, leaving me in no doubt that the parrot was both terrified and in pain.
On Skomer Island, Wales, I watched a puffin step out of its burrow at exactly the moment that a female peregrine was gliding along the cliff-top. The falcon simply landed on top of the puffin and grasped it in its yellow talons. I know from capturing puffins myself that they are feisty and possess a powerful beak and sharp claws, so for a moment I thought the puffin might be able to escape. It didn’t. Instead, it lay still, looking up at its captor, which avoided its gaze, and stared resolutely out to sea.
Puffins are tough and peregrines are powerful: It was a stalemate. Five minutes passed with no obvious resolution. The puffin wriggled slightly, its eyes were bright, and it still looked full of life. As I watched through my telescope, it was like a traffic accident, simultaneously appalling and compelling. Eventually, after 15 minutes, the falcon started to pluck the breast feathers from the puffin, and five minutes after that began to eat it. Only after the peregrine had eaten its fill, a full 30 minutes after capture, did the puffin eventually expire. Did it feel any pain? It was impossible to tell, for at no point during this grisly spectacle did the puffin show any sign of distress. However, careful physiological studies of other birds show very clearly that they feel pain, even if they don’t show it in a way we comprehend.
The guillemots that have played such an important role in my research—I’ve studied them since 1972—breed at exceptionally high densities, and the proximity of neighbors is the key to their success since it enables them to avoid attacks on their eggs and young from gulls and ravens. A phalanx of guillemot beaks can deter most predators, but to be effective the birds have to be tightly packed together. Guillemots breed at exactly the same tiny site, just a few centimeters square, year after year—sometimes for 20 years or more. Not surprisingly, they get to know their immediate neighbors very well, and specific relationships develop—friendships possibly—mediated by mutual preening (referred to as allopreening). Sometimes these friendships pay off in an unexpected way. Occasionally, as a greater black-backed gull attempts to take guillemot eggs or chicks, I have seen an individual guillemot rush from the back of the group to attack the gull. This is an extremely risky venture since these huge gulls are quite capable of killing adult guillemots.
Guillemots also look out for one another’s offspring in another way. If a parent guillemot leaves its chick unattended, a neighbor will usually brood the chick—keeping it warm and safe from predatory gulls. This form of communal care is rare among seabirds, and in most other species unattended chicks would simply be eaten.
For guillemots breeding in 2007 on the Isle of May, on the east coast of Scotland, something extraordinary happened. The sandeels they rely on to feed themselves and their chicks disappeared, and there was nothing else to eat. In hundreds of field seasons of guillemot watching by dozens of researchers at many different colonies, nothing quite like this had been seen before. As the parent birds on the Isle of May struggled to find food for their starving chicks, their normal harmonious behavior disintegrated into chaos. Many adult guillemots were forced to leave their chicks unattended as they searched farther afield for food, but their neighbors, instead of sheltering and protecting the unattended chicks, attacked them. My colleague Kate Ashbrook, who was studying the guillemots there, watched in horror as chicks were picked up by neighboring adults and swung around in the air before being tossed off the cliff and into the sea—attacks that were both shocking and tragic.
This unprecedented antisocial behavior seems to have been a direct result of chronic stress caused by the severe lack of food. In the following years, the food situation improved, and these same individual adult guillemots returned to their normal amicable behavior. The human parallels are far too obvious.
On a more positive note, seeing a long-tailed sylph hummingbird in Ecuador for the first time gave me the most extraordinary “buzz,” which lasted several days. The sylph was so exquisite I wanted to possess it, to capture and hold on to its beauty. A photograph can’t do the bird justice. I understand now why Victorians wanted to fill cabinets with the still sparkling if lifeless bodies of hummingbirds. For an ardent birder, seeing a rare or beautiful bird is a little bit like falling in love. In such situations, neurohormones are released, stimulating the brain’s reward centers.
The reward system is central to everything we as humans do. It is what keeps us going: why we eat, why we have sex, and why some of us watch birds. The greatest pleasures that (most) humans can experience, however, are the emotional experiences associated with love and lust. Love can be both romantic and parental, and both forms involve “attachment,” or bonds. Romantic love, of course, usually leads to physical desire and lust. It is easy to propose an adaptive explanation for love: A pair of individuals working together are more effective than an individual when it comes to rearing offspring.
Birds, too, are famously monogamous, by which I mean they are unusual among animals in that they breed as pairs—a male and a female working together to rear offspring. Although there is likely to be an emotional dimension to bonding, the problem is that, so far at least, we have no way of unambiguously demonstrating such an effect.
Here is how it might work. There are several things that birds do that we know are tightly associated with social relationships, both with partners and, in cooperatively breeding species, with other group members as well. These include greeting ceremonies, certain vocal displays, and allopreening.
Whether the goose whose partner was shot near Resolute in northern Canada experienced any emotional response to its loss is something we do not know. Geese are normally long-lived, with long-term pair bonds and strong family ties—the young remain with the parents for several months and the family even migrates together. When pair members are temporarily separated, they typically perform a greeting display or “ceremony” on being reunited. Such displays are widespread among long-lived birds and are particularly protracted when pair members are reunited after a winter’s separation, in birds such as penguins, gannets, and guillemots. Throughout the breeding season, pair members greet each other, even after a relatively short absence when one bird returns after a foraging trip. Strikingly, the duration and intensity of these greeting displays is closely tied to the length of time the pair members have been apart.
One expert, Bryan Nelson, calls the North Atlantic gannets’ meeting ceremony “one of the finest displays in the bird world.” If you visit a gannet colony, such as Cape St. Mary’s in Newfoundland, you can see it easily. As one member of the pair returns to its partner at the nest, the two birds stand upright, breast to breast with outstretched wings, their beaks pointing skyward. In a frenzy of excitement they clash their bills together, each intermittently sweeping its head down over the neck of its partner, calling raucously all the time.
Under normal circumstances this greeting display lasts a minute or two, but Sarah Wanless, who studied gannets at Bempton Cliffs, in northern England, observed a particularly prolonged instance. At one of the nests she was regularly checking, the female of the pair disappeared, leaving the male to care for the tiny chick alone, which, against all odds, he did. One evening, the female returned after a remarkable five-week absence, and luckily Sarah was there to witness it. To her amazement, the two birds performed an intense greeting ceremony that lasted a full 17 minutes! Because the greeting ceremonies of humans (like kissing and hugging) are also more elaborate the longer the participants have been apart, it is tempting to assume that birds experience similar pleasurable emotions on being reunited.
Our best hope for understanding the kinds of feeling birds might experience is through a combination of careful behavioral and physiological studies that measure responses to what are likely to be emotional situations, such as greeting displays, allopreening, and separation of partners. Physiological measures include changes in the heart rate and breathing rate, the release of neurohormones from the birds’ brains, and changes in brain activity, as visualized by scanning technology. None of this is easy, and at the present time cannot be done on free-living birds. Yet I imagine that in the not-too-distant future, it will be possible to measure at least some of these responses in wild birds. My prediction is that when we do, we will discover that birds have an emotional life more dynamic than that which we have so far imagined.