Ey up, sing reet
Question: Do birds have regional accents? Do blackbirds on mainland Europe sing the same song as those living in Britain? If they do sound the same then why don鈥檛 we?
Answer: Many species of songbird do indeed show regional accents, or dialects. One of the best known examples is the white-crowned sparrow found around San Francisco Bay. It is said that practised ornithologists can tell to within a few kilometres which part of the bay area a bird has come from by its song.
Bird song seems to have a hard-wired genetic component and a learned component. The learned element is important in promoting dialects: nestlings learn the dialect sung by their parents and neighbours, and if they are isolated in an experiment and exposed to song from another area, they will grow up to sing the dialect of the new area.
Advertisement
The length of the critical period during which the nestlings can learn song varies between species. In some it lasts for only their first few weeks, but others retain the ability to learn and incorporate new elements into their song throughout their lives. The blackbird has this talent, and adults from nearby territories learn song phrases from each other, promoting the formation of local dialects.
Jonathan Wallace
Newcastle-upon-Tyne
Answer: There is evidence for geographical dialects in songs of some species of bird such as finches, while others such as cuckoos show no variation. There is also a connection between whether birds show dialect variation and the degree to which their songs are learned while young: cuckoos reared in isolation still sing normally, whereas finches don鈥檛. In some cases dialect allows individual birds to recognise close relatives and to be aggressive to strangers.
What鈥檚 more, the brains of at least some species with regional dialects show some degree of hemispheric specialisation in the way communication and vocalisation are represented.
Bird dialects have interesting parallels with language in humans: unlike other apes, humans require post-natal exposure to successfully acquire language, and human language exhibits geographical variation. This sets us apart from other apes.
Obviously, an entirely innate behaviour will only show substantial geographical variation if there is corresponding genetic variation, whereas behaviours that require some degree of learning can exhibit geographical variation without accompanying genetic variation. Some human communicative behaviours, such as crying and smiling, aren鈥檛 acquired in the way language is, and show little geographical variation across the species.
D. Ladd
Department of Theoretical and Applied Linguistics University of Edinburgh
Answer: When I was a child I lived in north London. Our garden was frequented by a family of blackbirds, and over the years I learned to mimic their calls and songs. Eventually I was able to fool some of them into thinking a family member was calling. I also noticed that their songs changed according to the time of day and the seasons.
I now live in Canberra and we have a population of blackbirds. Although there are similarities, they definitely sing a different tune and attempts to entice them into my garden using the London blackbirds鈥� song have failed. In fact they just sit there and look bewildered. Perhaps they can鈥檛 understand a Pommy accent.
Ian Middleton
Canberra
Does my bum 鈥�?
Question: I recently remarked to a female friend of mine that a lot of the girls in Swindon wear black trousers and denim jackets. She told me it was because black trousers 鈥渕ake your bum look smaller鈥�. Is this true? Can it be scientifically proven?
Answer: Yes, your bum does look smaller when you dress in black, at least if viewed from behind.
The reason is that we can only perceive shapes if what we see appears in different shades or colours. If one wore white trousers the shape of your behind could be inferred from the slight shadows cast by its contour. In black clothing, the shadows are invisible and the shape appears flat.
This is the reason why people with dark skin often seem to age well compared to pale-skinned people. Wrinkles and lines, which are visible mainly by virtue of the fact that they create shadows, are harder to detect on darker skin. It is also the reason why facial features need to be greatly exaggerated on dark bronze sculptures.
Of course, your bottom will reveal its true size in profile, but black, especially matt, will save you a lot of exercise and dieting.
Glyn Hughes
Industrial designer and sculptor Adlington, Lancashire
Answer: The claim is true and it is because of the uniform dark colour of the clothing. Our perception of the shapes of surfaces, among other things, depends on minute shadows and patterns on the surface. See how much easier it is to notice wrinkles on a light shirt than on a dark shirt.
Patterns also play a part. For example lines that start off parallel, then move away from each other and then return to parallel in a fisheye effect give the perception of a bump on a smooth surface even if one is not present. In the case of uniform dark trousers, it is very hard to make out the shadows and any pattern, and that鈥檚 why it鈥檚 difficult to perceive the exact size of the bump.
Lakshmi Chakrapani
Atlanta, Georgia
Answer: This isn鈥檛 a scientific answer but it is evidence in favour. In Star Trek, some female cast members supposedly wear padding to increase their female allure. They have two different sizes of padding, and the larger of the two is used for when they are wearing dark clothes.
Rob Ives Maryport
Maryport, Cumbria
Answer: A similar illusion occurs with striped clothing, but it depends on whether the stripes are horizontal or vertical. Horizontal stripes give the illusion of widening while vertical stripes make a person taller and more compact. So a larger person wearing vertical stripes will take on a more flattering shape. But if they wear horizontal stripes, their proportions will be accentuated鈥ideways.
Colin Vasey
Austin, Texas
This week鈥檚 questions
Off your trolley: Last week my shopping trolley ground to a halt when I tried to push it beyond the confines of the store car park. The security guard told me that the trolley was protected against theft, and that once beyond a certain point, its wheels ceased to function. How does such a system work?
Kirsty Subbet
Edinburgh
Green death: Animals have a point of clinical death. Do plants, and if they do, how is it determined?
Matt Price
Seattle, Washington