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Monthly Archives: March 2011

Shelducks take amazing journey for the eclipse

Sometimes forces outside my control conspire to make the penning of these little columns impossible within the deadlines set. Last week saw my little girl bravely fighting a nasty virus, covered in an angry rash and very much in need of daddy cuddles and not daddy on the word processor. It’s at times like these that I wish I had prepared a backlog of ‘anytime’ articles. Good, solid natural history pieces with little seasonality, which can be grabbed off the virtual shelf with an unseeing familiarity and dropped into an email to the editorial staff, in an attempt to make their excessivelybusy lives a little easier. Sadly, I am neither that well prepared or disciplined to havecollected such an archive, so I have to promise to bash something out later than any of us would like.

However, in the spirit of that need, the subject of this week’s article would have madean excellent choice for just such a prepared essay. No matter what time of year toventure down to the Axe Estuary or indeed the Exe or Otter, you are likely to see shelduck. A large, almost goose-sized bird with bold white plumage, dark bottle-greenhead and wing patch and broad chestnut coloured Breast band; they are hard to confuse with any other water fowl on our coasts.


Areas of estuary mud will be jealously
patrolled by shelduck, with interlopers treated with extreme intolerance. Wings flapping, head down, the intruder will be seen off immediately. In keeping with their normal placid nature, they soon settle back down, as ducklings are brought back down to the water almost as soon as the albumen has dried on their down.
Unlike other ducks, the males and
females are very similar in looks Nesting underground in burrows, its less important for the female to be cryptically coloured when sat on eggs. When you see them at distance, you need to look for the large red knob on the top of the male’s bill to identify him from his female counterpart. A duck of gregarious flocks, males and females pair for life and can normally be identified as partners, even in huge groups, by the way they tend to forage together. The gregarious attitude extends to nesting behaviour, as pairs will often congregate in areas to nest communally, sometimes even with more than one pair in a single burrow. However, when the breeding season is under way there is one element of territorial behaviour which the ducks are fiercely guarded; their food.

The sight of adult birds leading a line of fluffy black and white ducklings back to the water’s edge is a fabulous and endearing sight of the summer. Once back in the water, parent birds will quickly become somewhat intolerant towards their own chicks, chasing them away whilst still very little ducklings. The cast out young group together with broods from other birds and these crèches are looked after by adult birds which have not bred that year. While the ducklings are in the crèche, the parent shelduckswill fly off to one of two locations in Northern Europe to moult their flight feathers in massive flocks of up to 100,000 birds in north Germany, and nearer 4,000 birds a littlecloser to home in Bridgewater Bay.

Shelducks moult all their tail and flight feathers at the same time, in a process known as the eclipse, during which time they are rendered flightless. Most ducks go throughthis stage, many such as the mallard enter a dull plumage colouration which somewhat mimics the female. Shelduck eclipse lasts about four weeks and their strategy to get through the vulnerable time is to flock together. The urge must be strong, as they travel hundreds of miles to do so and leave their entire parental investment for the year in the charge of a few failed breeding birds.

Not that this strategy isn’t working. Numbers for shelduck seem to be on the increase in recent years so, as traumatic as it seems, it works for them. Once the new set of strong flight feathers have grown through their blood-filled sheaths and returned the bird’s ability to fly, so they return to the estuaries where they will spend the winter andraise next year’s young. The shelduck’s diet consist of all sorts of crustacea and molluscs gobbled from the surface of the estuary mud, but their name confusinglydoes not refer to their appetite for shellfish. Rather, it is a reference to the bird’s colour, “sheld” was a fourteenth century word meaning variegated and the “sheldrake” was a name given to any black and white water bird including shoveller and merganser.

So, next time you catch sight of a pair of big, black and white ducks feeding in tandem on the mud, give a thought to the amazing journey their lives take them on each year, in their fight for life.


 

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Posted by on March 30, 2011 in Uncategorized

 

The Flower Trap

On sunny hedgebanks and grassy slopes across the District, fabulous insects are on the march. A sure sign of spring, the glossy black sheen of an oil beetle is a sight to behold.

Oil Beetles at Seaton Marshes LNR, photo C Willerton

Emerging at this time of year to begin an elaborate life history, these beetles look a little like gigantic ants, with the females dragging a hugely engorged abdomen behind them. This massive tail-end is packed full of thousands of precious eggs, destined to be fertilised and buried in bare sandy soil, often along the edges of footpaths and other areas worn of grass.

The eggs are laid early to ensure the most elaborate coincidence in nature. Bare soil is essential to get as much of the weak spring sunshine warming them to maturity. Once the larvae inside have developed, they hatch from the egg in a few weeks time looking like a tiny louse-like creature, crawl to the top of a nearby flower stem and wait for the happenstance.

Sitting in the corolla of the flower the larva, known as a tringulin, is waiting for a lift to the next location for its development. Larval oil beetles feed exclusively on solitary bee grubs, and it’s the adult bee which carries the hungry interloper to its waiting brood. As a solitary bee lands to feed on the flower’s nectar, so the larva latches on with strong claws and hitches a ride to the underground burrow of the bee. The bee has no idea what is happening.

Once in the nest, the tringulin feeds immediately on the first clutch of bee eggs, before moving on to the pollen and nectar stores provided for the developing bee grubs. The larva feeds in the sanctity of the bee burrow, safe from all disturbance or predation, being guarded by the protective instincts of the adult bee.

Once the larva has developed sufficiently, growing through various larval stages within the bee’s nest, it pupates into the adult beetle towards the end of the summer, ready to burry itself and remain dormant through the winter to begin the cycle once again.

Members of the blister beetle family, oil beetles are so called because of their ability to secrete noxious heamolymph from their joints. This greasy fluid contains chemicals which are foul tasting, and means these sluggish and highly visible beetles remain unmolested by passing birds.

The oil beetle might be Meloe by name, but its anything but mellow by nature!

This year the invertebrate charity Buglife are carrying out a survey of these fascinating little creatures. Anyone who would like to get familiar with an entire family of insects would do well to chose this one to specialise in, as there are only four species found in Devon! Meloe proscarabaeus, or the black oil beetle is the one found littering the footpath to Seaton Marshes bird hide, and the species I found there last week totaling 23 individuals on a brief walk-past.

The violet oil beetle, Meloe violaceus is the other commonly encountered oil beetle, and is distinguished by a characteristic chink in its pronotum. Finally, the two other oil beetles – the rugged and the short-necked oil beetles are only known from two sites in the county, so you’re unlikely to find these. The brilliant wildlife artist John Walters has produced an identification guide to these beetles, available free of charge from the Buglife. All the charity asks for in return is records of these beetles if or when you see them.

Visit www.buglife.org.uk for more information, or to report a sighting.

As these beetles tend to gather alongside footpaths, they are liable to being trodden on by walkers, so this year we will be putting up “watch out for beetle” posters, based on the toad crossing road signs we see cropping up at this time of year. If you spy one of these posters when visiting an East Devon District Council nature reserve, keep your eyes peeled in the grass for these brilliant little beetles. But be careful, unless you want that unpleasant liquid on your hands, don’t be tempted to pick them up.

Local naturalist Nigel Pinhorn was leading a guided walk to Seaton Marshes Local Nature Reserve on valentines day and recorded five of these beetles, thought to be the earliest record yet of oil beetles in the County!

Another spring favourite to look out for while you stroll down to the bird hide at Seaton Marshes, is the wheatear. A really interesting bird which demands more treatment than I have room for here, they have a habit of flitting along the fence posts a few metres in front of you as you walk to the hide. Watch out for their bright white tail feathers, which give this bird its name. Wheatear is in fact a cleaned-up version of their traditional English name of White Arse!

 
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Posted by on March 25, 2011 in Insects

 

Silence, not always golden

Recent studies of killer whale hunting behaviour off the coast of Alaska have shown that as a pod of these incredible animals hone in on their prey, they switch to “stealth mode” and hunt without noise. No more contact calls between orcas, they swim silently. The first thing a seal would know of the imminent attack is when those crushing conical teeth are doing their terrible best. All very interesting, but what bearing does this have on the pastoral beauty of East Devon? Good question, let me reach for the crowbar.

Silence is often assumed to be the best approach when wildlife watching, doing as little as possible to bring attention to oneself. If you are hidden from view then this is indeed a good policy, but more often than not the animals have seen you coming well before you spot one of them, in which case, keeping silent and behaving like a predatory killer whale will do you no favours at all.

Of course, this does not mean the reverse is the case. Dashing about shouting at the top of your voice will clear all but the fattest, laziest, most humanised pheasants into the nearest convenient piece of cover. However, when out and about, consider whether you are in stealth mode, or if it’s more appropriate to act nonchalantly but make no attempt to cover your whereabouts. At this time of year (and here’s how we tenuously link the introduction to the body of the article) its the perfect time to be out there watching woodland birds and putting this theory to the test.

Spring is in full swing now and birds have dusted down their vocal chords and are belting out the romantic ballads and territorial standards at full throttle. Trees, on the other hand, are playing catch up for the next few weeks; leaves are only just budding and the canopy is still visible from our lowly vantage point on the woodland floor. Soon enough a shroud of verdant foliage will obliterate the view until the last few days of autumn, so a bit of swatting up on bird call identification now will stand you in good stead for woodland birding through the rest of the year.

These are a few top tips for spring bird watching.

Firstly, do yourself a favour and get up early. Make the most of the lateish morning sunrise and get to your intended woodland nice and early to appreciate a slightly more sociable dawn chorus. Walking slowly round the wood will give you the chance to listen out for birds throughout the patch, and also this is the time to identify your quiet sitting spots. The only reason to be quiet at this stage is to give you full chance to hear everything that is going on above your head, you’re not fooling anyone, every step is being watched by some vigilant bird or another.

I like to position myself at the mossy base of trees, as this not only gives me a comfortable back rest, but also breaks up the human outline and blends my profile into the background. It goes without saying that your 1980s neon shellsuit should be left at home for this activity and, while full camouflage gear is unnecessary, wearing muted natural tones is important. Get yourself into a good position and sit quietly for some time. The importance of being comfortable means that you are less likely to squirm about and shift position, another reason why adults are a bit better at this activity than children.

Soak it up. Try and take in every movement, every sound. You might not be able to identify or translate all that you notice, but open your senses to their full and get every minute bit of data from what is around you. Our brains are very good at filtering out information before we have a chance to process it, switch that particular function off for this, you want to see; hear; smell and feel everything that is going on within your sphere of perception. With time, that sphere will grow. To begin with you might only pick out sounds or movements from within a few metres of your location, but with practice you can develop the ability to “see” deeper within the trees and interpret what is going on. It’s a fabulous feeling.

Try a variety of positions and locations, but linger at each, take your time. Another favourite location of mine is, again, at the base of a tree, feet to the trunk looking up into the branches. This is such a novel position to find humans that I have almost been trodden on by startled roe deer on a number of occasions, as they have simply not identified me as a person, no sarcastic comments please. Before the leaves burst, this is the time to get the full impact of this position. Notice how the flocks of great tits, blue tits and finches are joined by an entourage of smaller feeders, goldcrests bringing up the rear. Long tailed tits will flit through the branches overhead, giving you plenty of prior warning of their arrival with their constant chatter of bell-like calls. Nuthatches have a singular tweeting call which once spotted coming from the beak of a nuthatch, is never forgotten or mistaken.

Finally, don’t try and cram this in before another important date in your diary. Don’t rush. On a normal guided walk around Holyford Woods I reckon to take between an hour and two hours to complete a basic circuit with a couple of stops for questions and talking. When I am exploring by myself, I can easily lose three hours to the woods, and that doesn’t even involve me pontificating for any length of time.

Ah, woodlands at this time of year are an absolute thrill.

 
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Posted by on March 11, 2011 in Birds

 

What a load of Bullfinch!

Last week I looked in on a little nature reserve, tucked away in a sleepy corner of the District , on the hunt for a couple of my favourite birds.

Lying to the north of Honiton, about half a mile along the farway road from the Hare & Hounds pub, Knapp Copse is a woodland, boggy mire and grassland site, whose beauty defies its history. In the seventies this steep valley was an active landfill site. Someone a few years ago had the bright idea that the head of a valley, on a precipitously sloping  gradient, was the ideal spot to dump all manner of rubbish and refuse, which could be quietly capped off with a bit of topsoil and no one would be any the wiser.

Through the intervening years a number of pollutants were traced back to this site and massive work was carried out to secure the landfill and stop the leaching. This was done successfully I am pleased to say and now, forty years on, it is an idyllic little spot if you are fit enough for the hills!

The site lies on the route of the East Devon Way, the gargantuan long-distance walking route which weaves its way sinuously through the District from West to East. However, for those of you who will be puffed out quite enough by the slide down and climb back from exploring the site, its good to know there is also a convenient car park with permissive footpaths leading across the site.

Every so often at work I am able to indulge in what is termed ‘general rangering’. This is when I have no specific errand or job to carry out on a site, but a visit to checkup on the place is necessary nonetheless. Quite apart from anything else, this column would take some filling if I were never to venture out of the office! Last week’s visit turned up some broken fencing in need of urgent attention, and a host of wildlife treats for me to report back on.

For me, the highlight of this site is normally encountered in the first few hundred yards from the car park. The hedgerows and fields up here on the top of the East Hill escarpment are bursting with birds; there is always something exciting to be seen.

The gateway you pass through, shortly after negotiating the kissing gate out of the car park, has never failed to be filled with one of my favourite little birds, the bullfinch. A specialist seed feeder, it is often encountered up here with charms of goldfinches, another seed-specialist. While the goldfinch’s beak is quite long and needle thin at the end, evolved to pluck from a diet of thistle and teasel seeds, the bullfinch has a big heavy bill adept at tackling far bigger items.

Not quite in the league of the hawfinches which are seen around here every so often, a bullfinch beak is still an impressive piece of natural engineering. A deep base gives the power needed to bite down on rock hard pips, while razor sharp edges assist in the cracking of big seeds, fruit pips and their favourite: tree buds. A long-standing foe of the fruit grower, bullfinch numbers were in dramatic decline for much of the second half of the twentieth century. However, if you know where to look, you can still find these dazzling birds flitting about in trees and hedges adding a splendid splash of colour to the greyest of winter days.

The female is a rather drab bird, poor thing. Brown, off-brown and grey-brown is about  the limit to her wardrobe palette. The male on the other hand makes a robin look tawdry. A jet black cap gives way sharply at the cheek to a bright pink face and chest, black tail with ID-clinching white rump and broad dark wings. Even if you don’t spot the pink, this dandy chap is easy to identify, even in flight.

A little way on from the bullfinch hedgerow, the field to the northwest of the reserve was crammed with hundreds of starlings and fieldfares, lit up beautifully against the frosty grass. In the coming months, as temperatures begin to rise and days begin to lengthen, it will be time for the fieldfares to return to Scandinavia to breed. It’s been a particularly plentiful year for them in the south west, due to the exceptionally cold weather we have been treated to. I have grown quite accustomed to having them about.

But the good news is as these guys move on, their place in the birding landscape will be filled by a host of migrating birds en route to northern sites, and then our own summer visitors will be back, some from as far away as Namibia!

 
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Posted by on March 2, 2011 in Uncategorized

 

Things to do in March – go butterfly spotting!

March isn’t the normal month you associate with looking for butterflies. But, if you want to find evidence of one of our more rare species, this is exactly the time of year you should be out there looking.

The brown hairstreak is our largest native hairstreak butterfly and arguably the prettiest of this fabulous group too. Golden underneath with a double white line on the hind wing, dark chocolate upperwings with orange splodges and the tiniest of wingtails, the brown hairstreak is a lot more attractive than its name implies.

However very few people ever get to see this beautiful butterfly. This is due to its short adult lifespan and irritating behaviour of spending the vast majority of the eight or so weeks it is on the wing, flying merrily about high in the treetops. Another reason why this butterfly is seldom seen is due to the fact that its numbers and distribution are declining through its range, which is already biased toward the south west of the UK.

As ever with species loss, the reason for its decline is due to habitat loss; a palatable way of saying, it’s our fault. The brown hairstreak lays its tiny white eggs in singles or pairs on the outer branches of blackthorn. Our prodigious stretches of blackthorn hedge provide a refuge for the species in the country, however its habit of laying eggs to overwinter on the vey outermost branches of the shrub, are the key to its downfall.

The eggs are tiny white specks, with a jazzy pattern all over them. They are so small however, that you have to have pretty good eyesight to make out the design. The adults lay the eggs at the base of the previous year’s growth, where the two-year-old branch joins with last year’s new shoot. This means the eggs are out on a limb, both literally and metaphorically.
In our ambition to have neat, safe hedgerows, lining roads and lanes around the district, a familiar sight is the tractor and flail neatening things up and squaring hedges up. The hedge season is also timed so as not to disturb nesting birds, and rightly so, but this means the little tough eggs which are overwintering the caterpillars, are in the firing line. Sadly this practice strims off exactly the growth which the adult butterfly hones in on to lay its eggs and many hundreds of thousands of eggs must have been lost over the years.

So, its a bit of a rarity, and you are not likely to see the beautiful adult unless you spend a deal of time hanging about in the canopy. So why bother?

I suppose this conundrum gets to the heart of all naturalists, to know something is there is as good as seeing it for yourself, and one stage of the lifecycle is as enjoyable a view as the next. So here’s a few tips to spotting brown hairstreaks… in winter.

Scrutinise the south facing sides of hedges, and make sure you are looking for blackthorn growth of one and two years. Look closely at all branches within reach, but pay particular attention to the junction between the two year’s growth. Its important to look closely, as even if you do think you’ve spotted an egg, they can often be very hard to differentiate from small spots of lichen, so look closely!

Who knows, if the volunteer army is there, perhaps we’ll see a time when all blackthorn hedges are screened prior to being cut, and all of their precious Devonian cargo is transferred to a safe location before the flail descends? It would be a lot of effort, but what price is too great to reverse species loss?

 
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Posted by on March 1, 2011 in Uncategorized