LONG before the GPS was invented, bees learnt how to navigate the shortest possible route when they buzz from flower to flower.

British researchers have attached tracking devices to the backs of bumblebees – which live for about a month – and found that they use trial and error to determine the ideal flight path from one food source to another.

Developing an efficient route between scattered feeding sites – to save both time and energy – is the goal of many species including ants, bats and hummingbirds.

But scientists have struggled to understand how animals achieve this feat in the wild.

“[It’s] analogous to the well-known travelling salesman problem – finding the shortest route to visit a set of locations once and return to the origin,” the study leader, Lars Chittka, said.

The London psychologist from Queen Mary University and his team arranged five artificial flowers, each filled with a few drops of sugar and fitted with motion-sensor cameras, 50 metres apart on an open field to prevent the insects navigating the shortest distance by sight.

They also attached tiny transponders on the backs of five bees to track them as they foraged for food.

When released from their hive, all bees found the closest flower first. After several foraging trips they found the other sites.

Between their first and last attempts, the bees reduced their travel distance about 80 per cent, from 1953 metres to 458 metres, in one day. Measured by a computer, the shortest path was 314 metres.

Of the 120 possible routes between the five flowers and the nest, the bees tried only 20, on average, before finding the shortest.

Because it takes too much time for the bees to explore all the possible routes between food sources, the team suggests that the insects learn the best flight path through experience, abandoning a previous route if they happened upon a new, shorter path. On average, it took the bees 26 trips to figure out the ideal journey.

While the researchers were surprised how quickly the bees could find the best route, given the number of possible solutions, their technique was “simple and elegant”.

“It sounds simple to keep exploring even when you’ve found what looks like a good solution and, if you do find a new route, compare it with your previous one and then stick with the better of the two – but it’s robust and it works for an animal with a brain the size of a pinhead,” said Professor Chittka, whose findings were published in the journal PloS Biology.

When the researchers moved one flower to another location the bees’ distance increased before they incorporated the new location into their ideal circuit.

Read more: http://www.smh.com.au/environment/animals/from-a-to-bee-first-a-stumble-then-its-a-direct-flight-to-nectar-20120920-269q7.html#ixzz28N0d3FTA

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The world needs to do more to prepare for the impact of a rapidly ageing population, the UN has warned – particularly in developing countries.

Within 10 years the number of people aged over 60 will pass one billion, a report by the UN Population Fund said.

The demographic shift will present huge challenges to countries’ welfare, pension and healthcare systems.

The UN agency also said more had to be done to tackle “abuse, neglect and violence against older persons”.

The number of older people worldwide is growing faster than any other age group.

The report, Ageing in the 21st Century: A Celebration and a Challenge, estimates that one in nine people around the world are older than 60.

The elderly population is expected to swell by 200 million in the next decade to surpass one billion, and reach two billion by 2050.

This rising proportion of older people is a consequence of success – improved nutrition, sanitation, healthcare, education and economic well-being are contributing factors, the report says.

But the UN and a charity that also contributed to the report, HelpAge International, say the ageing population is being widely mismanaged.

“In many developing countries with large populations of young people, the challenge is that governments have not put policies and practices in place to support their current older populations or made enough preparations for 2050,” the agencies said in a joint statement.

‘Cast out’

The report warns that the skills and experience of older people are being wasted, with many under-employed and vulnerable to discrimination.

HelpAge said more countries needed to introduce pension schemes to ensure economic independence and reduce poverty in old age. It stressed that it was not enough to simply pass legislation – the new schemes needed to be funded properly.