Mapping the social networking of birds

Sep 12, 2012
The social networking of wild birds has been mapped in unprecedented detail, using cutting-edge technology.

(Phys.org)—A team, led by researchers at the Universities of St Andrews and Washington, used novel radio-transmitters to study the social networks of New Caledonian crows, a species renowned for using sophisticated foraging tools.

Data downloaded from the miniature tracking devices, which were attached to the birds as back-packs, enabled the researchers to infer their birds' , revealing a surprising amount of contacts.

Unlike conventional wildlife radio-tags, these new devices can both transmit and receive radio-signals.

Crucially, at the analysis stage, this allows the researchers to infer from the data how close two birds were to each other, based on the basic premise that close tags should exchange stronger radio-signals than tags that are farther apart.

The study is a crucial step towards understanding how tool-related information may diffuse in wild crow populations. A report of the research is published this week in .

are the most prolific avian tool users. In the wild, they use at least three distinct tool types to extract invertebrate prey from deadwood and vegetation, with some of their tools requiring complex manufacture, modification and/or deployment.

Some scientists have suggested that certain aspects of these crows' sophisticated tool-use behaviour may be the outcome of social transmission processes, where birds observe, and learn from, other individuals.

The study, which was funded by the UK's Biotechnology and Biological Sciences Research Council (BBSRC), examined whether such 'tool cultures' could exist in wild crow societies.

Dr Christian Rutz, a world-leading expert in the use of miniature for studying the behaviour of (known as biologging) led the project.

He said: "Whenever two marked crows get close to each other, their tags exchange . It is as if the birds are swapping business cards when they meet."

Plotting the social network revealed a highly interconnected population, in which most individuals associated at very close range with non-family members within just a few days. This illustrates considerable potential for the diffusion of social information in crow populations.

Dr Rutz, Reader in the School of Biology at the University of St Andrews, compared this to friendship networks in humans.

He added: "We all know how fast fads can spread, whether it is fashion or music preferences, or new consumer products. But, importantly, successful diffusion depends on people's ability to observe and copy other individuals' choices and behaviours.

"This is why we wanted to know how often crows meet other crows in the course of a week."

Dr Richard James, a physicist at the University of Bath who collaborated on the analysis of the data, said: "These tags produce the kind of information theoretical biologists have been waiting for.
"Datasets in our field are usually quite sparse, because of the difficulty of observing wild animals."

Dr James St Clair, a Postdoctoral Fellow in the School of Biology at the University of St Andrews, said: "In this study, we have been able to look at association patterns minute-by-minute, building an unusually comprehensive picture of these birds' social lives."

Dr John Burt and Professor Brian Otis from the University of Washington, invented the tracking technology employed by the study, called "Encounternet".

This new technology is likely to revolutionise the fast-moving field of animal social network analysis, and has considerable potential for a wide range of other applications.

Dr Burt said: "It was fantastic for us to see these tags being deployed on wild animals. The technology worked beautifully and generated some fascinating new insights into the biology of these remarkable birds."

The results of the present study show that crows indeed have plentiful opportunities to learn from other , even unrelated individuals. The next step will be to investigate whether social transmission of information actually takes place during encounters.

Explore further: Genome yields insights into golden eagle vision, smell

Related Stories

Crows demonstrate their cleverness with tools (w/ Video)

Apr 22, 2010

(PhysOrg.com) -- New Zealand scientists studying New Caledonian crows have found they can use three different tools in succession to gain a food treat. The crows are known to solve problems and fashion and ...

Crows found able to distinguish between human voices

May 16, 2012

(Phys.org) -- Researchers at the University of Vienna have discovered that carrion crows are able to distinguish between familiar and unknown human voices. They also found, as they write in their paper published ...

Wild crows reveal tool skills

Jan 11, 2010

(PhysOrg.com) -- A new study using motion sensitive video cameras has revealed how New Caledonian crows use tools in the wild, Oxford University scientists report.

Crows can use 'up to three tools'

Aug 05, 2009

(PhysOrg.com) -- New experiments by Oxford University scientists reveal that New Caledonian crows can spontaneously use up to three tools in the correct sequence to achieve a goal, something never before observed ...

Recommended for you

Genome yields insights into golden eagle vision, smell

10 hours ago

Purdue and West Virginia University researchers are the first to sequence the genome of the golden eagle, providing a bird's-eye view of eagle features that could lead to more effective conservation strategies.

User comments : 0

More news stories

Ocean microbes display remarkable genetic diversity

The smallest, most abundant marine microbe, Prochlorococcus, is a photosynthetic bacteria species essential to the marine ecosystem. An estimated billion billion billion of the single-cell creatures live i ...

Genetic code of the deadly tsetse fly unraveled

Mining the genome of the disease-transmitting tsetse fly, researchers have revealed the genetic adaptions that allow it to have such unique biology and transmit disease to both humans and animals.

Cell resiliency surprises scientists

New research shows that cells are more resilient in taking care of their DNA than scientists originally thought. Even when missing critical components, cells can adapt and make copies of their DNA in an alternative ...