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Of irruptions and hazy days

12 Nov

For the more experienced (i.e. older) amongst us, cast your mind back to your childhood going on summer days out with your parents. I have vivid recollections of the windscreen getting covered in squashed insects leaving smears and all kinds of marks on the front of the car which my father would spend ages trying to clean off. I also seem to recollect you could buy plastic covers to go over the front of the car to stop the paintwork being damaged… (OK – where is he going with this one..)

The point being is that we simply don’t get the number of insects we used to and, as a consequence, there isn’t as much for food for insectivores (Shrews, Swallows, Blackcaps etc) – so we don’t have as many insect predators as we used to – so we don’t have as many higher level predators such as birds of prey and stoats. (This is what’s known in ecological circles at trophic layers). Given a chance nature can recover quite quickly from population declines but in reality nearly all our countryside is quite heavily managed especially when you compare it to rural France or Poland where there is still lots of messy and unimproved bits as there isn’t as much pressure on farmers.

The more long-term deeper concern is what our children will see a lack of insects as normal.

On a more positive note the autumn bird migration will be almost complete in November with the usual suspects here in good numbers such as Fieldfares and Redwings. Many other continental birds such as Starlings, Jays, Wood Pigeons and Goldfinches will have arrived. In some years the number arriving is quite incredible. For example in November 2010 some 161,000 Wood Pigeons flew over a site in Dorset in 1 day!! (This wasn’t a typo..). In 2014 some 50,000 Swallows also flew over a site in Dorset in 1 day and in 2011 some 10,000 Goldfinches flew over a site in Kent in 1 day.

Sometimes these large numbers are due to the shortage of food for the birds in their summer grounds, or having a couple of successful years breeding when the numbers of individuals can significantly increase. This is known as an Irruption and in some years some unusual birds can arrive here such as 3 years ago when we had lots of Waxwings in the apple tree next to the village school.

If this winter proves to be a cold one and, just having completed a great breeding season for most birds, we may get all sorts of strange immigrants in the village.

Something quizical..

22 Oct
We are now into the full flow of autumn with long queues at Westonbirt. The deciduous trees drop their leaves as a response to shortened day lengths and less sun so the ‘cost’ to the tree of maintaining it’s leaves is greater than the benefit it receives. The tree forms a layer of dead cells (called an Abscission layer) at the base of each leaf so it drops off. The leaves fall to the ground and start to make compost for following years while the tree shuts down for the winter ready for the spring.
The birds are also changing their behavior now that they have finished their post breeding moult. Many of the birds that stay here over the winter go into a full moult once the last chicks have fledged so during September they tend to skulk amongst the bushes keeping out of the way of predators as they can’t fly as well. They grow a new set of wing and body feathers ready for the winter. Birds which are very territorial during the summer such as Great Tits, become very social during the winter.
Some recent research on winter flocks of Great Tits has shown that individual behaviours affect their social lives. A project in Oxfordshire found they could identify Great Tits that were bold and those that were shy. The birds were electronically tagged and introduced into a new environment with sunflower feeders (which could read the tags). They found the bold birds tended to associate with other bold birds while the shy birds also formed flocks. If you see a flock of Great Tits (which can be up to 40 individuals) have a guess if they are a bold group or a shy one. Also bear in mind we do have 5 different species of Tit around the village – The Great and Blue Tits which you will regularly see on the bird feeders, Coal Tits which may occasionally appear, Long Tail Tits which tend to stay out in the countryside in flocks of 10 – 20 and the scarce March Tit (which I have seen in Grove Wood – see picture).
The plans for Wild Sherston are in hand set for 17th/18th May 2014 with Wiltshire Wildlife Trust, Butterfly Conservation and the Wiltshire Ornithological Society, amongst others, participating.
Finally the second contribution to the Sherston Museum of Slightly Odd Things has arrived (following the rabbit skull a couple of months ago) the identification of which forms the first ever quiz in the column. In September, Pat Smith who lives in Wood Close found her curly garden hose had been chewed through. As you can see from the picture (with a lens cover to give a sense of scale) something has gone to some effort to chew it to bits. Any insights as to what may have caused this please let me know – the prize is a mention is next months edition!. If the cause can’t be identified maybe I should send it to Chris Packham..Marsh Tit Nov 2012 2

Any idea what chewed this?

Any idea what chewed this?

It’s that time of year again.

29 Sep
Autumn is upon us with a rush of changes underway. Numerous birds that were here for the summer, such as Chiffchaff‘s and Blackcaps, are on their way south (although a few may remain) while we should start to see the birds that migrate from Scandinavia starting to arrive. The commonest migrants in the winter are Redwings and Fieldfares. Basically these are similar to Song Thrushes but bigger and tend to congregate in flocks in fields – it’s not often you will see them on the village itself.
A Redwing is red under the wing and has a clear stripe across the eye while a Fieldfare is grey across it’s back with brown wings and a streaked chest. The name probably comes from an Anglo-Saxon word, which dates back to at least the the eleventh century, feldefare which means ‘traveler through the fields’. They are often together in quite large flocks.
With autumn in full flow there are so many foods available free in the hedgerows. While the Blackberries may be over its time to get out and have a look whats there – for some inspiration have a look at the web site – http://hedgerowharvest.org.uk/
This year has been great for butterflies with up to 14 species on the Cliff at any one time and, after last years really bad weather, it shows that nature can rebound if given a chance.
I have just got back from Botswana and, being lapsed Geologist, realised that the crocodiles you see there today are actually similar to creatures living around Sherston when the rocks were deposited. Around the village the underlying bedrock is Oolitic Limestone about 165 Million years old deposited during the Bathonian Stage of the Jurassic Period. The Jurassic is best known for the dinosaurs which were alive and well at the time so we could have had residents like the one in the picture. If you do happen to see one on the Cliff do let me know!
Crocodile. Chobe National Park, Botswana

Crocodile. Chobe National Park, Botswana

Finally – start thinking about feeding the wild birds. While there is more than enough food out in the countryside, when winter starts to arrive the birds do appreciate the peanuts, fat balls etc we provide.

A couple of gems

17 Nov

With long winter nights giving the birds less time to feed together with the leaves falling from the trees it’s a good time to be out and about.

Over the past week or so I have spotted a couple of less common inhabitants of wood and field – a Barn Owl and a number of Marsh Tits.

In spite of my amateur efforts to photograph the owl, as it was out hunting along a local river bank, Nick Holland got the good one…… as usual.

Barn Owl – Sherston. Courtesy of Nick Holland

…and my effort….. (it was one of the better ones – my excuse was lack of light even with an ISO at 4,000)

 

While walking through Grove Wood I came across a small number of Marsh Tits. While not uncommon they are quite hard to spot in woodland light. It takes a couple of seconds to realise they are not Blue Tits or Great Tits.

 

 

Till next time…

 

 

It’s that time of year again.

15 Oct

The winter migrants are arriving, nights are getting longer, it’s dark around 6.30pm and its getting colder.

It’s time to go into the garage and clean and fill the bird feeders ready for the winter. If you have any peanuts left over from last winter you want to check then very carefully for any mould – they can have some quite nasty things growing on them which could harm the birds.

There are some accounts of the poor summer in Scandinavia and Russia resulting in low levels of fruit and berries over there – this will encourage (or force more likely) more birds to migrate looking for new sources of food. We may get the Waxwings back!!

You could also clean out nest boxes but replace them. They could have birds roosting in them in cold nights. Some birds such as Redwings and Wrens all pile in together to keep each other warm.

They are out there – at night…

15 Oct

The migration of our summer visitors is almost complete – the most obvious example being the absence of Swallows and House Martins who have left for north and sub-Saharan Africa.

Just arriving, amongst other birds,  are the thrushes – Redwings and Fieldfares and Mistle Thrush. They migrate from Norway, Sweden, Finland and Russia to spend the winter here in our warmer climes.

They migrate at night in flocks so if you go out into the garden (or on the way home from the Rattlebone..)  you may hear a soft but sharp ‘tseep’ coming from above. This is a Redwing calling to the other birds in the flock keeping distance and direction.

You may also hear a very different sound – a ‘shack’ or ‘shack-shack’  delivered with some urgency. This is a Fieldfare calling on migration.

It needs to be dark, little cloud and, ideally, quite still.

Less than 1 in 50 birds in a migrating flock call so if you hear say 4 calls in the space of a minute that could equate to some 200 birds passing over.

Reports from Scandinavia suggest that the supply of fruits and berries may be quite poor (another effect of the wet summer) so we may get more than usual this winter.