We finally know when birds lost their teeth

Open wide. (Olga Maltseva/AFP/Getty Images)

Scientists have figured out when and how birds lost their pearly whites — and it wasn’t a prehistoric fist fight, according to a paper published Thursday in Science.

As the modern descendants of dinosaurs, birds must have once had teeth. We’ve known this since 1861, when paleontologists uncovered Archeopteryx, a 150-million-year-old bird fossil with teeth. But now, as you probably know, all birds have got beaks instead.

Fossil records are too spotty for scientists to pinpoint when the shift occurred. Until now, so was genetic information.

But because of the newly reported sequencing of 48 different bird genomes (representing at least one species from each major lineage), we can now trace beaks back to their origin.

Eagle research soars via GPS trackers

A wedge-tailed eagle is being tracked by a solar GPS satellite transmitter. Credit: Simon Cherriman

A world first study tracking wedge-tailed eagles (Aquila audax) via GPS satellite transmitters has led one researcher into uncharted territory after a female appeared to have her partner stolen by a new bird, challenging a long-held belief that this species mates for life.

Perth Hills-based ornithologist Simon Cherriman used the solar GPS technology—Platform Terminal Transmitters (PTTs)—to track the birds to map out new inroads into raptor research.

Each PTT was programmed to record a GPS fix at almost every hour of daylight and was fitted to two adult and two juvenile eagles at the Lorna Glen proposed conservation reserve in the Murchison.

Highly sociable Australian birds show us the effects of social conformity

Scientists from LJMU have published research that provides a unique opportunity to investigate how personality can be affected by social context.

Dr Leah Williams and Dr Claudia Mettke-Hofmann of the School of Natural Sciences and Psychology, published work in the journal Animal Behaviour which reveals that the Australian Gouldian finch birds adjust their behaviour according to the personality of their partners.

When tested alone, a Gouldian finch’s personality correlates with its head colour. This finding together with its highly social nature makes Gouldian finches ideally suited to investigate the effect not only of other individuals but also of individual identity (head colour) on personality expression.

Noise forcing songbirds chorus pre-dawn

Noise forcing songbirds chorus pre-dawn

It is the sound synonymous with the start of a new day. But because of increased urbanisation and man-made noise levels, birds are having to begin their dawn chorus long before sunrise to make themselves heard.

Robins, blackbirds and nightingales are among species which are altering the time of their morning song so their efforts are not in vain, a study has found.

In some cases, birds are starting their dawn chorus two hours before sunrise, potentially putting themselves at risk from predators. A study conducted at five airports found that birds were anticipating the morning rush of planes, which start taking off at 6am, and changing their song times to avoid it.

Milk bottle-raiding birds pass on thieving ways to their flock

He’s gotta lotta bottle. Credit: David Darrell-Lambert

Great tits are opportunistic copycats. Entire populations can be found performing the same arbitrary behaviour simply because birds copy one another, following a fashion. And it’s this behaviour, reported in a paper published in Nature, that explains the great milk bottle raids that baffled milk drinkers in Britain almost a century ago.

Back in 1921 residents of the small town of Swaythling in Hampshire found their milk bottles vandalised on their doorsteps, the foil caps pierced. The culprits turned out to be birds of the tit family, and this milk thievery spread quickly, with people all over Europe noticing tits pecking through the foil caps of the milk bottles on their doorsteps to reach the cream underneath.

Birds conform to local ‘traditions’

Birds learn new foraging techniques by observing others in their social network, ‘copycat’ behaviour that can sustain foraging ‘traditions’ that last years, according to a study of how innovations spread and persist in wild great tits (Parus major).

The study involved experiments with eight local populations of great tits in Wytham Woods, Oxfordshire (UK). In five of the populations two male birds were trained to slide a puzzle box door either to the left or to the right. In three control groups two males were captured but not trained. The birds were then released back into their original populations to act as ‘innovators’, together with puzzle boxes that revealed a tasty mealworm reward when opened from either side. Electronic tags on the birds recorded how the two box-opening methods spread in each of the local populations through social network links.

Despite both methods working equally well, the team, led by Oxford University researchers, found that each experimental population strongly favoured the puzzle-solving solution that had been introduced by the trained birds. The preference for this arbitrary solution increased over time, forming a stable tradition. In the control populations, by contrast, it took much longer for birds to learn to solve the puzzle box.

When the experiments were repeated a year later each population still favoured their own ‘traditional’ method even though only 40% of each population of 75-100 birds were survivors from the previous year. The researchers were able to show that, even when birds discovered both ways of opening the puzzle-box, they were much more likely to use the behaviour that was dominant in their local population; in other words, they conformed to the behaviour in their local population.

The research, reported in this week’s Nature, is the first experimental demonstration of the spread of culture, and the operation of conformist learning in a wild non-primate. The team included scientists from the University of Ottawa, Canada, the Australian National University, Canberra, Australia and the University of Exeter, UK, and was supported by the Biotechnology and Biological Sciences Research Council (BBSRC), the Natural Environment Research Council (NERC) and the European Research Council (ERC).

‘In humans, new traditions arise when novel behaviours spread through social network ties via a process of observational learning. But we really have very little knowledge if similar processes are happening in animal populations,’ said report author Dr Lucy Aplin of Oxford University’s Department of Zoology. ‘We were able to experimentally demonstrate that sustained foraging traditions can occur in wild great tits. This appears to have been partly due to a process of conformity – the birds were preferentially copying the majority behaviour.’

Read the whole article on Physorg