Here’s looking at you: research shows jackdaws can recognise individual human faces

jeh98 — Tue, 11 Aug 2015 15:28:20 +0000

Researchers Alex Thornton, now at the ̽��ֱ�� of Exeter, and Gabrielle Davidson carried out the study with the wild jackdaw population in Madingley village on the outskirts of Cambridge. They found that the jackdaws were able to distinguish between two masks worn by the same researcher, and only responded defensively to the one they had previously seen accessing their nest box.

Over three consecutive days Davidson approached the nest boxes wearing one of the masks and took chicks out to weigh them. She also simply walked past the nest boxes wearing the other mask. Following this she spent four days sitting near the nest boxes wearing each of the masks to see how the jackdaws would respond.

̽��ֱ��researchers found that the jackdaws were quicker to return to their nest when they saw the mask that they had previously seen approaching and removing chicks to be weighed, than when they saw the mask that had simply walked by.

They also tended to be quicker to go inside the nest box when Davidson, wearing the mask, was looking directly at them rather than looking down at the ground.

“ ̽��ֱ��fact that they learn to recognise individual facial features or hair patterns so quickly, and to a lesser extent which direction people are looking in, provides great evidence of the flexible cognitive abilities of these birds,” says Davidson. “It also suggests that being able to recognise individual predators and the levels of threat they pose may be more important for guarding chicks than responding to the direction of the predator’s gaze.”

“Using the masks was important to make sure that the birds were not responding to my face, which they may have already seen approaching their nest boxes and weighing chicks in the past,” she adds.

Previous studies have found that crows, magpies and mockingbirds are similarly able to recognise individual people. However, most studies have involved birds in busier urban areas where they are likely to come into more frequent contact with humans.

Jackdaws are the only corvids in the UK that use nest boxes so they provide a rare opportunity for researchers to study how birds respond to humans in the wild. Researchers at Cambridge have been studying the Madingley jackdaws since 2010.

“It would be fascinating to directly compare how these birds respond to humans in urban and rural areas to see whether the amount of human contact they experience has an impact on how they respond to people,” says Davidson.

“It would also be interesting to investigate whether jackdaws are similarly able to recognise individuals of other predator species – although this would be a lot harder to test.”

̽��ֱ��study was enabled by funding from Zoology Balfour Fund, Cambridge Philosophical Society, British Ecological Survey, and BBSRC David Philips Research Fellowship.

Inset images: Mask (Elsa Loissel).

Reference:

Davidson, GL et al.,Wild jackdaws, Corvus monedula, recognize individual humans and may respond to gaze direction with defensive behaviour Animal Behaviour 108 October 2015 17-24.

When you’re prey, being able to spot and assess the threat posed by potential predators is of life-or-death importance. In a paper published today in Animal Behaviour, researchers from the ̽��ֱ�� of Cambridge’s Department of Psychology show that wild jackdaws recognise individual human faces, and may be able to tell whether or not predators are looking directly at them.

̽��ֱ��fact that they learn to recognise individual faces so quickly provides great evidence of the flexible cognitive abilities of these birds

Gabrielle Davidson

Richard Woods

Jackdaws on nest box

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̽��ֱ��eyes have it

jfp40 — Wed, 05 Feb 2014 00:01:00 +0000

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.

̽��ֱ��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 ̽��ֱ�� 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. ̽��ֱ��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. ̽��ֱ��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.

̽��ֱ��field research took place at the Cambridge Jackdaw Project, which was established by Dr Alex Thornton of the ̽��ֱ�� of Exeter.

To see the research in action, view video below:

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

Richard Woods. Homepage banner credit: Вых Пыхманн

Jackdaw

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̽��ֱ�� of Cambridge - Gabrielle Davidson

Here’s looking at you: research shows jackdaws can recognise individual human faces

̽��ֱ��eyes have it