Today’s my last day. Tomorrow I take off for Co Derry, and home. In the way of academic holidays, our building is like a ghost town, just myself and a few hardy stalwarts, ie, fellow workaholic PhD students, remain. Only one will still be around tomorrow: somebody’s actually running an experiment right up until Christmas! Whoever said students were carefree and lackadaisical? I’ve never mixed with a crowd as obsessed with work as this lot, with the possible exception of teachers, and with teachers it was always seasoned with real concern for the students, and the inevitable pressure of having to perform in public for six hours a day. Of course there’s performance anxiety wrapped up the doing of the PhD, but there’s also obsession of the best sort: having your own project to run, having total control; and whatever about the long hours, you can at least set them to suit yourself.
Anyway, I’m delaying my departure until Saturday morning for, among other reasons, the protests (http://www.bbc.co.uk/news/uk-northern-ireland-20763350). Every morning they’re the first topic of conversation in the office. Where will they be tonight? What’s the best website to find out? Will the Christmas market survive next year? How can socialising be managed around their inconvenience? I refuse to drive in Belfast at night for the time being. It’s like the old days, and I find myself fantasising about emigrating. I further refuse to live through the Troubles twice.
Back to my PhD: I got my four-and-twentieth blackbird finished yesterday. My eyes are burning from staring at spectrogram windows. If I hear another blackbird, believe me, into the pie he’s going. At least until spring. That’s the bulk of my measuring over. I still have three species to complete. Song thrush. Robin. Chiffchaff; but not full analyses. At absolute tops it’s six weeks work, a fortnight per species. But it hopefully won’t even be that long….
Unfortunately, London (http://asab.nottingham.ac.uk/meetings/index.php) was not what I’d hoped. I made only one day of the conference, thanks to some mysterious infection. I spent the second day of the conference in bed. I didn’t make a show. I was just about well enough to travel home. Grrr.
However, that one day alone was worth the trip. The conference theme was Cognition in the Wild, and many of the talks highlighted how animal behaviourists have moved out of the laboratory or the captive state, to assess the cognition of wild animals in their natural settings. One of the first speakers was Karen McComb (University of Sussex, England). My first impression of her was how physically like the poet Mary Oliver she was! (I had the pleasure of meeting Mary Oliver – I have autographs to prove! – when she gave a reading in Wellfleet, Massachusetts, in 2005). Karen had the same stiff grace, assured awkwardness. At ease in her skin. She talked of how playback experiments on African elephants in Amboseli (Kenya) and Pilanesberg (South Africa) National Parks give insight into the contribution of matriarchal age and experience to the knowledge base and thus the behaviour of the herd. How older matriarchs can discern the difference in male and female lion vocalisations. As males are a bigger threat, their voices provoke a more immediate and stronger bunching response, the main purpose of which is to protect the youngsters. So far, so predictable. There’s more. Older matriarchs are also able to distinguish male and female human voices, and, wait for it, different human languages! They show the greatest fear response to the Maasai language, a language of hunters, spoken by men, than to the Kamba language, the language of an agrarian people. Karen also showed how the Pilanesberg population, which was formed out of what were translocated refugee elephants, originally from populations which had suffered greatly from human hunting, showed a far less modulated response to different threats. Basically they spooked at anything. The take-home message was that age matters. The older matriarchs, the more judicious leaders, are at least 55 years of age.
Theresa Burt de Perera (Oxford University, England) illuminated how animals which can move in three dimensions (the swimmers and the flyers, basically), that is, with six degrees of freedom, represent the vertical and horizontal dimensions of space separately, and furthermore, in fish at least, give priority to the vertical. This contrasts with ‘surface-constrained’ terrestrials like ourselves, which inevitably prioritise the horizontal, and is probably related to hydrostatic pressure-dependence of fish on their swim bladders. It made me wonder, however, about the brain-changes that presumable occur in the transition of metamorphic species such as amphibians from an aquatic to a terrestrial environment, as they mature from, eg, tadpoles to frogs.
Erica van de Waal (University of St Andrews, Scotland) elucidated how food preference, which had been induced by means of colouring maize with food dyes, is influenced by the culture of the local group in vervet monkeys. When young males immigrated to a group that had a different colour preference to that which they’d grown up with, the young immigres soon switched preference to that of their new group. The only exception was one male who had been of high status in his original group. He was not swayed by the vagaries of a new fashion. An illustration perhaps, of the primate need to belong on the one hand, and how high self-esteem may buffer against group think on the other.
That social interactions can prompt gene expression was indicated by the work of Rui Oliveira and colleagues (ISPA-Instituto Universitario, Lisboa, Portugal). Working on cichlid and zebra fish, they showed how social context, as they put it, their salience and valence, triggers not only neural and endocrine responses, but actually switches genes on or off. In other words, there are socially-regulated genes, an amazing demonstration of how DNA is not an inert sacrosanct template, forever locked into the nucleus, but responds itself not just to the predictable events of development, but can also mediate transient social events; a truly fundamental response mechanism.
There were a lot of talks on birds. Richard Holland (Queen’s University, Belfast, Northern Ireland) gave another excellent talk on migration. Because we’re both based at the same University, I’ve heard Richard’s talk, or versions of it, several times, but it never palls. That tremendous directional impetus, the overriding sense of purpose it confers, always inspires wonder. The evidence is for birds’ reliance their surreal sense of the earth’s magnetic field for at least some aspects of their migratory behaviour. Some magnetic receptors are even found in their olfactory mucosa. They can smell magnetism! What is also clear, however, is that a variety of mechanisms may be called up to guide birds on their various epic transcontinental and oceanic voyages. I was reminded of my summer sojourn to Achill when Richard named one individual wheatear, which thanks to advances in (mainly the diminutisation of) tracking technology, has been monitored on its biannual journey from Africa to the Canadian arctic – twice! As Richard pointed out, while social factors, i.e., migrating in family groups may largely explain the successful journeys of juvenile geese and waders to their wintering grounds, how are we to explain the first migration of brood parasites, such as the cuckoo, which never meet their biological parent, and even where its adoptive parents such as reed warblers also migrate, the adoptive parents don’t have the same wintering grounds anyway. Nevertheless young cuckoos, just fledged, make their way to Africa under no instruction or guidance whatsoever. How to explain that level of instinct?
Orientation at a more local but still phenomenal level was illustrated by the renowned ability of the Clark’s Nutcrackers – a corvid, so not surprising that they’re bright (http://en.wikipedia.org/wiki/Clark’s_Nutcracker) to locate the thousands of seeds they’ve cached for the winter as that season progresses. Debbie Kelly (University of Manitoba, Canada) took us through the cues that the birds use to locate hidden food, concluding that it was a geometric spatial sense, rather than precise featural cues that is used to unearth the treasure often months after it’s been hidden. Debbie finished with a photograph of the same Canadian scene winter and summer which dramatically brought home why geometry rather than landmarks might be more useful in a habitat that undergoes such dramatic seasonal change.
Andy Hurly (University of Lethbridge, Canada ) has done similar work on hummingbirds, to show, again, at the very localised scale of a summer meadow, hummingbirds rely on their sense of spatial geometry to locate fresh flowers, and avoid revisiting the same ones too soon. Given their unimaginably high metabolic rate (a heart that beats 1000 times a minute; wings blurred to invisibility by beating 80 times a second), it isn’t surprising that such finely-tuned physiology demands unequivocal decisions. There really isn’t any energy to spare for mistakes.
I have a soft spot for bowerbirds anyway (http://en.wikipedia.org/wiki/Bowerbird), but Jess Isden’s (University of Exeter, England) talk on their problem-solving abilities only confirmed my affection. Bowerbirds have exported sexually selected traits to outside of their own bodies, an extended phenotype as it’s described, behaviour not unlike our own with regard to mate attraction. Males haven’t impressive plumage, and don’t really sing. But they do build and decorate bowers. What I didn’t know is that different species have different colour preferences. The ‘cognitive tests’ that Jess and her colleague Joah Madden have devised (a clear way of upsetting the bird’s egregious sense of interior design) is to plant items of, quelle horreur, the wrong colour within the boundaries of the bower. These hideously hued objects are covered by a clear plastic basin so the birds can see them but have to figure out how to remove them. Others are fixed so the birds find it physically impossible to remove them. They solve this problem, eventually, by thoroughly covering them up, hopefully before any prospecting females catch a glimpse and forever bin the bower-builder (yes, the skinnies are back, us 80s children can use this metaphor again) into the flared-jeans = loser category. These birds are a scream.
I was so sorry to miss Joah’s talk the following day which I understand to have been about the development of more abstract ways of testing cognitive abilities in bowerbirds, given that, as Jess put it, cognitive testing of wild animals could be improved by moving away from tests that are linked directly to natural selection. This makes sense to me. While abilities based on solving the sorts of problems animals will encounter in the wild can yield valuable information, when we think of ourselves, so much of our problem solving abilities may be assessed by situations or contexts that have little immediate survival value in themselves but which may nevertheless reflect our basic intelligence. The abstraction of psychological tests could discriminate or tease out such native abilities in other species as well. Thus, cognitive testing of wild animals could be improved by moving away from tests that are linked directly to natural selection especially as complex multicomponent displays, such as bowers, probably have multicomponent explanations.
Two of the bird talks were right up my street. Christopher Templeton (University of St Andrews, Scotland) is working on the Mexican happy wren (yes, they’re really called that). Being a non-temperate species, the happy wren does not exhibit the northern hemisphere-typical singing behaviour whereby, in the main, males do the singing and females do the judging. As is typical of many equatorial or tropical species, both sexes sing, duet, together. In happy wrens, this duetting shows a staggering temporal exactitude, so that it sounds a single song. When Christopher showed us a colour-coded spectrogram and played it, both as one, and then the male and female parts separately, there was literally a murmur in the room. As Christopher said, communication involves cognition and the complexity of birdsong may be an indicator of overall cognitive ability as it involves social learning, information processing, imitation and memory. Obviously happy wrens utilise these abilities to an enormous degree. The wrens form long-term mated pairs, and not only have sex-specific song elements but also a large repertoire of 30-40 song types. Either sex may initiate singing bout, and within milliseconds the responding partner not only has to recognise that song type and part, but produce the appropriate response. As an act of memory and recognition, it’s an impressive feat.
What is the purpose of such duetting? Singing in temperate species has long been recognised as a way of defending territory and attracting mates, but the duets of happy wrens appear to be largely use to signal co-operation between the singers, which must reinforce their pair-bond, rather than as aggressive signals. Christopher’s talk was further indication of the endless fascination of bird song; why it has evolved; what it is for; how it is shaped by its environment.
Marc Naguib (Wageningen University, Netherlands) also discussed how birdsong may be used as an indicator of cognitive ability, conveying relevant spatial and social information within a species. A lot of his discussion focussed on European species and was therefore relatively familiar to me but his overview of how tracking technologies combined with acoustic work was pointed the way to how we may glean further insight into the strategies birds use to extract relevant information in a social network.
It was a very full day, and there were other interesting talks on, eg, how the poisonous Cane toad (http://en.wikipedia.org/wiki/Cane_toad), a South American native but invasive to Australia (Calum Brown, Macquarie University, Sydney, Australia) has caused a generalisation response in native Australian predatory fish, whereby the fish now avoid consuming local palatable tadpoles. This, of course, has further knock-on effects in the food web. There were also talks on spatial sense in insects(Matthew Collett, University of Exeter, England) , and the effects of habitat and social complexity on brain structure in rodents (R. Sobrero, Pontifica Universidad Catolica de Chile, Chile). The following day’s program looked equally good, but unfortunately I didn’t make it, and will have to make do with the abstracts.
The variety and range of research was inspiring, as was simply being at the conference, mixing with that community whose parallel work offers such insight into the cognitive processes of the other species with which we share this planet. It reminded me again of how the differences between them and us are along the same continuum in many instances, but also the exciting variety of sensory processing and cognitive ability across species, shaped inevitably by the environment to which they are adapted. As Susan Griffin (http://www.poetryfoundation.org/bio/susan-griffin) put it so well, we are all, all of us, each and every species, made from this earth, and organisms respond to that that earth’s making and shaping in as much variation in their brains and behaviour as in their bodies.