News archive

December 2014

Tuesday, 16 December 2014

Great tit perched in small tree

Great Tit tweeting!

A new study has revealed that birds don't always act instinctively, but have their own social networks and cultures too.

It now seems ironic that one of the most popular forms of social networking the world over is called Twitter, which is done by sending tweets with the icon of a small bird - when small birds themselves are busy socially networking anyway.

Lucy Aplin, a researcher in Oxford's Zoology Department, has shown that birds learn through imitation, inside a closely-knit social network. She did it with the great tits of Wytham Woods just outside Oxford, which have been the subject of continuous study since 1947, and many of which are electronically tagged and can be tracked.

They form distinct sub-populations, and from five of these, Dr Aplin captured birds and taught them a trick - how to open a box, to get a tasty mealworm just inside. They could do it by sliding a door to the left, or to the right. The captured birds learned to do it one way or the other - although both ways worked equally well - and were then released back into their communities.

And what Dr Aplin found was that in a community where the returning bird had learned to slide the door to the left, virtually the whole community picked up on that and started doing it - while in a community with a bird coming back favouring the right hand slide, all its fellows imitated, and started sliding rightwards as well.

In each of these sub-populations, a "tradition" was established, to which all the birds conformed.
When the experiments were repeated a year later each population still favoured their own "traditional" method even though only 40 per cent of each population of 75-100 birds were survivors from the previous year. Dr Aplin and her colleagues were also able to show that, even when birds discovered both ways of opening the box, they were much more likely to use the method that was dominant in their local population; in other words, they conformed to the behaviour of their own social network.

The research has just been published in the scientific journal Nature. Dr Alplin's boss, Professor Ben Sheldon, head of the Zoology Department's Edward Grey Institute, commented: "Our work shows that once a majority in a group adopt one way of doing things, these cultural traditions are passed on to the next generation and may persist over years."

Dr Aplin herself said: "Even when a great tit already has experience of using one method, if it moves to a new area which favours the alternative solution, this bird is likely to adopt the method preferred by its new group. It's as if its own personal experience is being over-written by the majority behaviour."

Sunday, 7 December 2014

News from the RSPB's Weald reserves, Broadwater Warren and Tudeley Woods.

News from the RSPB's Weald reserves, Broadwater Warren and Tudeley Woods.

Broadwater Warren
The big machinery at Broadwater has been working rapidly to get the conifer felling and thinning work finished this winter. The recent wet weather and delayed start to the job has resulted in much more 'ground disturbance' than anticipated with the main track from the car park down the hill to the woodland being particularly treacherous, so please take care! This will be fixed when the work is complete and apologies for the inconvenience until then.

You may have noticed high stumps left by the harvester after cutting down the conifers in the newly cleared areas. These are helping to mark out and protect the archaeological features from the forwarders as they pick up the processed timber and leafy tops (brash). Broadwater has over 450 identified features now, with more being uncovered as the restoration work progresses. They help us 'read' the historic landscape and find out more about past uses. We already know about its extensive use as a training ground in both World Wars, and there is some old graffiti carved into one of our veteran beech trees. You can just make out the date 1941 and a reference to Canada which has stretched and warped as the tree has grown, possibly from the Canadian troops who were training at Broadwater at the time.

As many as 50 siskin and redpoll have been seen together as they feed on the catkins at the tops of birch trees. Groups of about 30 woodlarks and meadow pipits are still feeding out on the open heath, foraging on the ground for seeds and insects. A raven flew into the north-east of the reserve on 25 November and settled in the top of a tall conifer until it was mobbed by a group of crows; jackdaws and crows can be seen flying en masse across the western heath and delightful looking jays seem to be everywhere as they gather acorns for their caches. They can store up to 400 acorns in one winter!

Out in the open, several snipe have been flushed from the wet heath areas, and last week three woodcock blasted out from the undergrowth scaring the life out of Matt as he was orientating himself around his new reserve!

The volunteers have been busy taking down the redundant 'dormouse corridors' at the edges of the heath compartments. These thin screens of trees and shrubs were left as the major work was carried out to let dormice move through on their way into the retained woodland areas. The conifer removal work was carefully planned with the advice of our dormouse consultant, and done in an order to make sure there were no isolated populations. Now they are dormouse-free, the screens can be reduced to open up the amazing panoramic views across the heathland.

Tudeley Woods
Last week Tudeley hosted a demonstration for biomass harnessing to launch a project along with partner organizations in an effort to make land management practices more sustainable. Heathland and grassland management has always required the removal or reduction of invasive bracken, scrub and gorse. In past centuries, people used this material in everyday life: bracken was cut for animal bedding; gorse was used in fires as it burns so hot; young saplings were used for a multitude of things from besom brooms to pea sticks. Now, there is no market for this 'waste' material but it still needs to be removed and often costs a lot of money to do so. This project involves using new specialist machinery to cut, mulch and compress the waste material into briquettes for bio-fuel, once again providing a use for it.

While he was there for the demo, Matt had this year's first record of the Dartford warbler which has returned to Pembury Heath for the winter. Listen and look out for this energetic little brown bird as it zips between gorse bushes.

The Tudeley volunteers have been battling away with the more established scrub encroachment in the valley mire. They have been cutting the invasive birch and alder regrowth to once again open up the delicate wet heath along the stream, as well as reducing the scrub in other heathy areas. It's an ongoing battle and they're doing a mighty fine job!

Events
In January we will be hosting two 'New Year Work Parties', one at each site. If you've not tried your hand at volunteering with us yet - this is the opportunity! Join us for a morning of practical reserve work before eating a bonfire-cooked jacket spud then a casual winter stroll around the reserve to do a bit of wildlife spotting looking at how the volunteers excellent work makes a difference.
It's free; you just need to book a spot so we bring enough potatoes!

Join us at:
o Broadwater Warren on Saturday 10th January from 10.30 am until 3pm
o Tudeley Woods on Sunday 18th January from 10am until 3pm

Please get in touch if you'd like more information about these days, or indeed any volunteering opportunities.