RSS

Monthly Archives: April 2011

A compromising position

My workplace, like so many others in the UK has a very tight policy regarding internet and email use. The policy document is good and thick and everyone who uses computers, which is all of us, must abide by these guidelines to ensure our conduct is above board.

In the normal course of events things run like well-oiled clockwork; information passes into me and I churn a multitude of things outward. Sometimes however, things get caught inadvertently in the net. The way in which computer security systems work means that some documents I receive will contain flagged words, for example  I was once sent a highly scrutinised report about woodland birds which contained too many references to the perennial favourite Parus major.

There are also some photos which are sent to me containing a large percentage of flesh tones. Autumnal heaths are notoriously tricky subjects for photo composure, and if some of the more heavy-handed IT filter systems are to be believed, they are also a hotbed for carnal  imagery too. Seldom the case with the photos I receive, I assure you.

Sometimes however, a photo evades the censor’s scrutiny and I gets through to my inbox. One such snap dropped in to my email system last week from a trusted source, which I was only glad I opened in a deserted office, such was its content. I was moved to send it in to the local paper.

So what caused all the hubbub? This fabulous picture of a pair of mating lizards, that’s what.  Despite their name, the common lizard is anything but common, and this behaviour is seldom seen, let alone captured on camera. The lucky cameraman photographed the pair in his garden, which is a timely reminder of the value of our backyards for wildlife.

Common Lizards mating - Bob Dark

As with another reptile which lives in northern climes, the adder, common lizards give birth to live young rather than lay eggs like most reptiles.  Viviparity, the birth of live offspring, allows the lizard to control the temperature at which the developing young are exposed to, through behaviour of the gravid female. If she detects that her core tempertature is low, she can bask in an open position to raise her body temperature. If she is too hot, she will retreat to a shady spot and let herself cool down. In the cool climate of the UK, it is seldom overheating which is the problem!

The young are born in July, between 3 and eleven individuals in thin eggs sacks which split as soon as the female has deposited them. The tiny, dark coloured babies are immediately very agile and will dash off into their habitat to develop unaided by the parent.

Males and female common lizards can be told apart by the pale, less speckled body colour, and the female’s wider belly size, which can be seen to physically bulge with developing young towards the end of June.

If you are lucky enough to see a common lizard handled, then the brightly coloured belly of the male is stark contrast to the female’s paler and un-speckled tum. However, you should never attempt to handle a lizard in the wild, as they are very delicate, fast-moving and difficult to catch safely and unless you are well-practiced you are very likely to harm the animal if you try to grab at it.

Better to sit quietly and watch the lizard through binoculars. If you approach slowly and calmly, a common lizard will often allow you to approach it in its favourite basking position to within a few metres. Got too close, too quickly however and the lizard will disappear out of view into the vegetation nearby.  However, do not lose heart, as they are dependable in their ensuing behaviour too. Back up a little and wait for the lizard to reappear. If you remain still, it will not notice you and will return to the same basking position as you found it in.

So to any of you budding photographers out there, by observing a little patience and guile,  you can capture good close up photographs of lizards without the need to get too close or interfere with them. Just sit tight and wait for them to come back to you.

East Devon is blessed with many very good places for reptile watching, the pebblebed heaths are a haven for many species of reptile, particularly this little fellow. Look for them on prominent features, low to the ground like rocks, or logs in sheltered spots on south-facing exposures. As ever with wildlife watching, you will need to wander about sites slowly to increase you r chances of seeing anything, and listen out too as the characteristic sound of a common lizard dashing into heather is often the first clue to a lizard’s whereabouts.

Advertisements
 
Leave a comment

Posted by on April 18, 2011 in Birds, Heathland, Reptiles

 

Snakes and adders

One of the most exciting sights in the East Devon countryside in spring must be the glimpse of an adder. Perhaps it’s a diminutive steely-grey male, with golden eye and flicking black tongue or a larger, bronzed female, opulently basking in the early spring sunshine. Whenever I see one of these beautiful animals, it sets my pulse racing.

Adders have been persecuted for years, largely due to the misconception that they pose us serious harm. However, since the killing of adders was prohibited by law their populations have continued to decline and this has got so serious in recent years as to move scientists in Oxford University to examine their genetic diversity in an attempt to unravel the mystery.

Adders are a top predator in the habitat in which they live. Feeding on small mammals and lizards, adders can only thrive where populations of these prey items are abundant. However, adders are also very slow to move into new areas, colonising – or recolonising – territories at a very slow pace. As reptiles, adders live at the northern limits of their range in our temperate climate, and so their ecology is somewhat slowed. They live a long time, and are only able to reproduce every two years, such is the stress to produce offspring. This means that with a few young being produced every other year, recruitment to the population is very slow. So once you’ve lost an adder from a site, it’s a very long time before they are likely to return.

As adder numbers wane, so populations become isolated and small clans are all that remains. Recent reports of adder malformation and abnormalities have raised concerns amongst herprtologists (scientists who study reptiles and amphibians) that this isolation could have led to genetic abnormalities through in-breeding. If a population has become so isolated that the same few adult animals are reproducing each year, and no new bloodlines are being introduced from adders nearby, for the simple reason that there are no adders nearby, then the decline of the population will be terminal.

A simple monitoring scheme has been running on Fire Beacon Hill Local Nature Reserve for three years now, keeping an eye on adder numbers, ratios of male and females and general health of the population with a series of monitoring refuges. I organise a number of reptile rambles through the year for members for the public to join in surveying the traps, giving people the chance to meet an adder often for the very first time.

When I set off on the site to lead my first ever reptile ramble, I have to admit my heart was in my throat. Was I being reckless taking a group of people onto a site which has adders, on a hunt to see… adders? I went through an extraordinarily extensive briefing before we set off, I was in serious danger of losing a few participants to boredom before we had left the car park, such was the length of my Health & Safety spiel. But eventually we got underway, and a fabulous time was had by all. As I lifted reptile traps in turn, the children at the front, adults behind, the thrill of expectation was palpable on each occasion.

Each time you lift a piece of roof felt which comprises a reptile ‘trap’ there is great anticipation for what might lie beneath. All too often it’s a large colony of ants, which means nothing else will be there. But sometimes there’s a slow worm, sometimes a common lizard and occasionally there will be the ultimate prize of an adder peacefully soaking up the heat. As long as everyone remains still and calm, gently lifting the lid on a slumbering snake will mean that it stays in its coiled position to be admired by onlookers. If people push forward to get a better view the snake will disappear into the heath behind the trap, and I will not grab out at it to pull it back into view.

The snake has done its bit and it now deserves its sanctuary, I then attempt to persuade everyone that we’ll get a better view next time if people stay still and don’t rush forward! It’s hard to convince people, but with reptiles its movement that they react to more than shape. If you stay still when reptile watching you will get far better views than by attempting to move close in. The only time in which I would intervene is if the adder decided to make good its escape toward the onlookers, which could prove rather interesting! If this happens then I’ll gently lift the snake and turn it to move away from the crowd rather than into it.

At the beginning of this article I mentioned that persecution stemmed from a misconception that adders are harmful. This is of course relative, in the same way that heights are not harmful if you do not fall from them. Adders have a venomous bite, and in certain circumstances this bite can prove dangerous. You should never attempt to pick up a snake you find in the wild, you will get much better views of it by remaining a respectful distance from it. And if you stumble upon one by chance, try to remain calm and back away gently, remember – the snake will be far more terrified than you by your sudden appearance. There, safety lecture over!

 
Leave a comment

Posted by on April 18, 2011 in Heathland, Reptiles

 

Long-tailed wonders

As regular readers of this column will already know, there is one garden bird with a particular place in my heart; long-tailed tits.

 

These tiny, industrious little balls of fluff have a wonderfully engaging manner. They move through gardens and woodland in a bustle of peeping conversation, calling with a short morse code trill as they scour every tiny crevice, nook and cranny in search of little invertebrates to eat. Being so small they are a little shrew-like in their behaviour, always hungry, always on the look out for a meal.

I’ve been very happy to watch the long-tailed tits visit my garden feeders through the winter, and this morning I saw some activity which really made my heart leap.

 

Along the hedgerow, where I had put a potted plant in a gap to stop my dog from nipping into the neighbour’s garden, I found a pile of feathers. Without yet seeing one in this new home, I had a new bird to add to the garden list – a sparrowhawk. The blackbird’s feathers were strewn within the shallow depression in the hedgerow, a jumble of downy breast feathers and wing feathers. All the feathers bore the characteristic mark of a sparrowhawk kill, the shafts were complete, with a little bend near the base. This is due to the fact that hawks pull feathers from their kill, while carnivorous mammals, such as foxes, will shear the feathers quickly with their scissor-like molars.

 

So, my garden blackbird had met his match, but nothing was to go to waste, as is so often the case in nature. The sparrowhawk had made off with the carcass after shedding most of its feathers in the privacy of my garden hedge, probably to a favoured feeding perch or a nest of young in the woodlands further up the hill.

 

This morning the down feathers were being gathered by the dear little long-tailed tits to act as a snug duvet to line their nest. So the birds which I have fed through the winter are nesting somewhere nearby – what a thrill!

 

A lot of research work has been carried out on long-tailed tits, mainly in the world-famous Oxfordshire woodland in which so much bird ecology has been scruitinised, Wytham Woods.  Males set up breeding territories and weave the most amazing nests; a wonderful creation for such a tiny bird. A sphere of moss and spider silk, with a small round opening, is woven in the depths of a bushy hedge or shrubby tree. It is lined with up to 2,600 feathers and camouflaged with up to 3,000 flakes of lichen! So the few feathers this little tit was collecting from my garden is just the start of a massive effort. Even with all this endevour to remain illusive, breeding success is as low as 17% with most nests being preyed upon.

 

This high failure rate is turned into a positive, with failed breeding birds assisting with the feeding of chicks in nearby long-tailed tit nests. Its hard not to imply a human character on these endearing little birds, they are simply adopting the most effective strategy to secure the future of their species, but it would be a very cold-hearted naturalist to not indulge an inward smile at these altruistic uncles and aunts.

 

With such fragile success rates I would encourage you not to go in search of long-tailed tit nests. Even if your intentions are benign, by locating the nest you could potentially alert nest predators such as magpies, crows, woodpeckers and the rest, to its whereabouts, and with only 17% of the nests successfully raising a brood, they need all the help they can get.

 

Do keep a lookout later in the summer though, when breeding has finished you may be lucky enough to find one of these spherical masterpieces. If you’ve got time, count how many lichen flakes have been delicately stitched to the outside with spider’s silk!

 

Keep an eye out over the coming weeks for other signs of bird breeding in the District. The early starters, rooks and herons are already brooding, and blackbirds have been seen locally feeding fledged chicks – a very early gamble! If the parent birds are able to find the early glut of catterpillars in sufficient quantity to raise the chicks to independence, it will give them a good chance of cramming in one or even two more broods to replace those individuals that are being picked off by the local sparrowhawks.

 

Keep up the good work blackbirds, that little long-tailed tit needs another 2,548 chest feathers to line its nest please!

 

 
Leave a comment

Posted by on April 6, 2011 in Uncategorized