Eye don't want you here: new research at Sidney

Sidney graduate student Gabrielle Davidson’s research shows jackdaws with bright eyes may be better at deterring intruders to their nesting sites.

Gabrielle's research, conducted with colleagues at Cambridge and the University of Exeter, was published recently in the Royal Society’s journal Biology Letters.  It reveals how the colour of jackdaws' eyes might help them better defend their nesting sites from intruders.

The team set up video cameras in over eighty boxes around the Cambridgeshire village of Madingley to record the number and duration of visits that birds made and to monitor their response to a variety of digitally manipulated images of other jackdaws that were displayed by the entrances to the boxes. These included birds with a range of different bright or dark irides (or irises).

The findings revealed that the images of jackdaws with the brightest irides appeared most successful at deterring potential intruders. Jackdaws were also likely to spend less time around the boxes that contained the images of the birds with brighter eyes.

The findings thus raise interesting questions about the connection between eye colour and evolution, as Gabrielle recently explained to the BBC Nature. And the research has also enjoyed widespread media attention.