Index – Intro – Ch.1 – Ch.2 – Ch.3 – Ch.4 – Ch.5
Ch.6 – Ch.7 – Ch.8 – Ch.9 – Ch.10 – Ch.11 – Ch.12 – Ch.13
Why is it that I can see buzzards, red kites and kestrels but no other birds of prey? Two words: search image. Or what birders call “jizz”. Being able to tell from a casual glance out of the corner of your eye that this half-glimpsed movement in the bushes is [fill in your own preference].
To me the words “search image” immediately call up a story related by Stephen Jay Gould in his collection of Natural History essays entitled “Eight Little Piggies”‡. He was explaining how, when he was the guest of Richard Leakey at one of his hominid excavation sites, he had trouble seeing vertebrates remains from mere rock outcrops, but being a gastropod specialist, spotted snails where everyone else had overlooked them:
I couldn’t see bone fragments worth a damn – and Richard had to direct my gaze before I could even distinguish the skull from surrounding lumps of sediment. But could I ever see snails, the subject of my own field research – and no one else had ever found a single snail at that site. So I rest content with my minuscule contribution, made in character, to the collective effort. At the top right of page 143 in the November 13, 1986, issue of Nature – the article that describes the new skull – a few snails are included in the faunal list of the site, some added by my search image. (I also found, I believe, the first snails at the important South African hominid site of Makapansgat in 1984 – where I also couldn’t see a bone. I think I am destined to be known in the circle of hominid exploration as “he who only sees the twisted one.”)
Anyhow, back to my story, and what search image means to me. First of all, I can’t have a search image of something that I have never seen with my own eyes. Just looking up a bird in a field guide, or listening to its song or call from a recording just isn’t the same. This raises another conundrum, i.e. how would I know that the bird that I think I can identify as a buzzard is in reality not a different type of raptor that I’ve just mistaken for a buzzard. Granted, I’ve seen many buzzards, and even the ones that I was doubtful about turned out to be buzzards when I asked the friendly people on the Bird Forum. But how can I be sure that it’s not one of the many rarer raptors that I haven’t seen, and as such can’t exclude from my ID parade because I’ve never had the opportunityof getting a feel for the bird in real life.
Which brings me to the second point: knowledge of your area. I know, that’s not much use once you start birding further afield, or if you’ve just started out as a learner birder, but at least it helps narrowing things down in your local patch / area / region / country. If you can’t deal in certainties when it comes to identifying birds, then at least you can assign probabilities and narrow down the options. Is this bird common or rare? If it’s common, then chances are that you already know it, or have a good chance of becoming familiar with it. If rare, then at least you can start comparing it with its more common relative, and find reasons why it’s probably not the common. In addition, you need to familiarise yourself with the where and when of certain birds. Does it frequent wooded areas? Flooded grasslands? Suburban gardens? Riverbanks? Or are they pretty catholic in their tastes? Are they around all year round, or only in certain parts of the year? Some knowledge of the seasonal coming and goings of birds will help you avoid the “nightingale in November” mistake.
Take for instance the five thrushes that are commonly found in the UK: blackbird, song thrush, mistle thrush, redwing and fieldfare. The blackbird should be obvious to even non-birders as the familiar black bird with the orange bill of parks and gardens. Maybe more puzzling are the females and youngsters, because their dark brown plumage and lack of an orange bill seem to lack the obvious features that call out “blackbird”, but at least they’re not likely to be confused with the other thrushes. Two more (redwing and fieldfare) are restricted to the winter months, so outside the period October to March you can forget about them – btw, redwings are the ones with the prominent stripe above the eye, and fieldfares are the ones with a grey head. Mind you, once you leave the British isles things are less clearcut: as I found out from personal experience, fieldfares DO occur on the continent (in this case Germany) during the summer.
Which leaves the classic conundrum of song versus mistle thrush. And that’s where my inexperience as a birder shows, because in the field I can’t always be sure which is which. Granted, the mistle thrush is larger and its plumage more greyish brown, but if observation conditions aren’t ideal then those features are not always obvious. Likewise the difference in the shape and position of the spots on its front is not always that obvious, especially if you didn’t bring your binoculars. So how to solve the conundrum? Try and find other clues, such as song thrushes having a preference for hedges while mistle thrushes are more likely found in trees. Or the distinctive rattling alarm call of the mistle thrush. Basically at this stage I work in probabilities, and if I can manage to take a photograph then that’s fine for subsequent armchair identification.
One of the few birds that I’m pretty confident I can identify under most circumstances is the magpie. You’d think that a bird like the robin would be a prime candidate for this distinction, but you would be surprised by the number of times that I misidentified or failed to identify a robin when the circumstances for observation were less than ideal. So what makes a magpie stand out in a way that few other birds do?
- Decent size: even when viewed from a distance, there’s enough bird to be taken in for a positive identification. This stands in contradiction the various little brown and other jobs, which you only notice when they race across your path from one hidden perch to the next. Or the ones that sit so high up in a tree that all you can see is a dark blob against the clear sky, without any identifying features that can be observed without binoculars.
- Ubiquitous: where I live magpies are two a penny and can be observed throughout the day in a variety of postures. That way you quickly become familiar with the way they hop, fly or perch. You also become familiar with the various sounds they make,especially the sound that is akin to that of a toy machine gun.
- Distinctive: there are no other birds that look sufficiently like magpies that might be mistaken for them. Their black-and-white livery, the way they trail their tail behind them in flight or flick it to balance on a branch, and the sounds they produce make them stand out from the rest.
This is in contrast with the quartet of their black-feathered cousins, the raven, carrion crow, rook and jackdaw (I’ve left out the chough, since it is less common, and not totally black either). Although about the same size as a magpie, and fairly common, they are far less distinctive for easy recognition in all circumstances. Viewed from a distance, the difference in size and the various distinctions of bill shape are not always that obvious, and even from relatively nearby I still struggle to tell a raven from a carrion crow.
Together, size, ubiquity and distinctiveness make for a recognition time that is measured in fractions of seconds, whereas other birds, depending on the quality of the observation window may take several seconds, or in the case of little brown jobs, the time required to identify the bird may exceed the size of the observation window.
Take for instance a wood pigeon, which under good observation conditions is fairly straightforward to identify: sometimes it is not clear whether it is a bird of prey of similar size seen from an unusual observation angle, or a jay which under certain types of light can seem fairly similar. Longer observation times may enable the viewer to spot movements or behavioural traits that make it clear which is which, such as the shape or the size of the bill, the way a pigeon landing on a branch is heavier than that of a jay, or the style of wing movement during flight.
Index – Intro – Ch.1 – Ch.2 – Ch.3 – Ch.4 – Ch.5
Ch.6 – Ch.7 – Ch.8 – Ch.9 – Ch.10 – Ch.11 – Ch.12 – Ch.13
(‡)Stephen Jay Gould 1993 – Eight Little Piggies, p.293 “The Declining Empire of Apes”
Marnix's Bird Gallery 