The eyes have it

Researchers in Cambridge and Exeter have discovered that jackdaws use their eyes to communicate with each other – the first time this has been shown in non-primates.

Unlike their close relatives, rooks and crows, jackdaw eyes are almost white and their striking pale irises are very conspicuous against their dark feathers.
Gabrielle Davidson

While what humans do with their eyes has been well studied, we know almost nothing about whether birds communicate with members of the same species with their eyes.

The new study, published today in Biology Letters, shows that jackdaw eyes are used as a warning signal to successfully deter competitors from coming near their nest boxes.

Gabrielle Davidson of the University of Cambridge, who led the study, said: “Jackdaw eyes are very unusual. Unlike their close relatives, the rooks and crows – which have very dark eyes – jackdaw eyes are almost white and their striking pale irises are very conspicuous against their dark feathers.”

While most birds have black or dark brown eyes, bright eyes are not unknown in the avian world, and around 10% of passerines (perching birds) have coloured irises. The question Davidson wanted to answer was do jackdaws use their bright eyes to communicate with fellow jackdaws?

Just before the spring breeding season arrived last year, Davidson installed one of four different pictures in 100 jackdaw nest boxes on the outskirts of Cambridge. The pictures were either black (the control), a pair of jackdaw eyes, a pair of jackdaw eyes in a jackdaw’s face, or a jackdaw’s face with a pair of black rook eyes. She then filmed the effect the different pictures had on the birds’ behaviour.

“Jackdaws are unique among the crow family in that they nest in cavities in trees. These hollows are natural – the birds cannot excavate their own nest cavities as some woodpeckers do – so they have to compete for a limited resource. And because jackdaws nest in close proximity to each other, they fight a lot to gain the best nesting sites,” she explained. Often what initiates these fights are jackdaws approaching nest boxes that are not their own.

After analysing 40 videos of jackdaws peeking into each other’s nest boxes, she found that compared with the other nest boxes, those that contained the picture of a jackdaw with its bright eyes was much more likely to deter the birds from landing on it, and that the birds spent less time near such a nest box.

Davidson’s study is the first to show the eyes being used as a means of communication between members of the same species outside primates.

“Before now we knew very little about why some birds have brightly coloured eyes. In jackdaws, the pale eyes may function to improve their ability to defend their nest and chicks from competitors. It also raises the question of whether this is unique to jackdaws, or if other cavity nesting birds also use their eyes in a similar way,” she added.

The field research took place at the Cambridge Jackdaw Project, which was established by Dr Alex Thornton of the University of Exeter.
- See more at: http://www.cam.ac.uk/research/news/the-eyes-have-it#sthash.9zmy6Leu.5GyURMaP.dpuf

Julian Bream

Bream was born in London and brought up in a musical environment. His father played jazz guitar and the young Bream was impressed by hearing the playing of Django Reinhardt.

Bream began his lifelong association with the guitar by strumming along on a small gut-string Spanish guitar at a very young age to dance music on the radio. The president of the Philharmonic Society of Guitars, Dr Boris Perott, gave Bream lessons, while Bream's father became the society librarian, giving Bream access to a large collection of rare music.

On his 11th birthday, Bream was given a guitar by his father. He became something of a child prodigy, at 12 winning a junior exhibition award for his piano playing, enabling him to study piano and cello at the Royal College of Music. He made his debut guitar recital at Cheltenham in 1947, aged 13.

He left the Royal College of Music in 1952 and was called up into the army for national service. He was originally drafted into the Pay Corps, but managed to sign up for the Royal Artillery Band after six months. This required him to be stationed in Woolwich, which allowed him to moonlight regularly with the guitar in London.

After three and a half years in the army, he took any musical jobs that came his way, including background music for radio plays and films. Commercial film, recording session and work for the BBC were important to Bream throughout the 1950s and the early '60s.

In the years after national service, Bream pursued a busy career playing around the world, including annual tours in the U.S. and Europe for several years. He played part of a recital at the Wigmore Hall on the lute in 1952 and since has done much to bring music written for the instrument to light.

1960 saw the formation of the Julian Bream Consort, a period-instrument ensemble with Bream as lutenist. The consort led a great revival of interest in the music of the Elizabethan era.

His first European tours took place in 1954 and 1955, and were followed by extensive touring in North America (beginning in 1958), the Far East, India, Australia, the Pacific Islands and other parts of the world. Bream performed for the Peabody Mason Concert series in Boston, first solo in 1959, and later with the US debut of the Julian Bream Consort.

In addition to master-classes given in Canada and the USA, Bream has also conducted an international summer school in Wiltshire, England.

The Big Egg Hunt returns for Easter week

Eggs from the London Egg Hunt 2013. There are over 101 eggs scattered around the city, all of them very pretty. This is the exhibition at Covent Garden, London.

Maggi Hambling

Oxford in Voice : The Voices

Oxford in Voice (1/6): The Choir
 Oxford in Voice (2/6): The Organ 
 Oxford in Voice (3/6): The Mind 
 Oxford in Voice (4/6): The Composer