Cricket plays with bat on a hot wicket

Female Great Green Bush-cricket with large ovipositor

It has felt like a good summer so far with my tanned legs unrecognisable from the white etiolated versions that last year’s damp squib created. This exposure to the sun has been extended this year by traditional scything and hay-making on our new plot of land. One of the benefits of such a manual approach is the closer intimacy it affords to the land and greater observation of any emerging wildlife. I have been impressed by the volume and variety of invertebrates caught in the process and have tried to leave a large enough patch for them to continue to thrive. This week I was pleasantly startled by the leap of a viridescent grasshopper. On closer inspection it proved to be a Great Green Bush-cricket (Tettigonia viridissima), characterised by its large size, distinctive colouration and very long antennae - hence this group of Orthopterans previously referred to as ‘long-horned grasshoppers’(Chinery, 1977).  The top image shows an adult female with its threatening-looking down-curved ovipositor, but this is simply its egg-laying tool.

Bush crickets are more nocturnal than grasshoppers and so predatory bats become a much greater threat, particular species that can tune in to the insects song. It would appear however that Tettigonia viridissima is not quite a soft target and has developed some clever avoidant strategies by monitoring the echolocation calls of hunting bats. Schulze and Schul (2001) showed by experiments that the crickets varied their responses based on the intensity of the bats echolocation, from ‘steering away’ at low levels to a ‘sudden dive’.

So here’s hoping for the summer weather to continue and the cricket to keep playing for a while longer before my legs morph back to wan winter wickets.

Chinery, M (1977) A Field Guide to the Insects of Britain and Northern Europe. London: Collins.

Schulze, W. and Schul, J. (2001) Ultrasound avoidance behaviour in the bushcricket Tettigonia viridissima (Orthoptera: Tettigoniidae). The Journal of Experimental Biology 204: 733–740

A Chelsea Bastard

I had been informed by a local botanist that there was a rare plant in our Devon village called Bastard Balm (Melittis melissophyllum) and that it had recently come into bloom. This is a dead nettle standing at up to two feet in height with foxglove like flowers, cream-coloured with a pink-purple splash. So surely not too hard find for a well-trained eye. Indeed there were two of us scouring the shady hedgebanks in the locality it had been described. But no luck although the banks were vibrant with Yellow Archangel, Red Campion, Greater Stitchwort and die-back Bluebells. Some instinct dragged me back up the lane and there it was, a clump of Bastard Balm plants – how it missed it I cannot explain and it just made me wonder how many other wildflowers go “under the radar”.

Bastard Balm is a scarce and vulnerable species found very locally mainly in the south west where the steep Devonshire banks suit it very well; otherwise it is usually a rare escape from gardens (Stace, 2010). Supporting the interest from gardeners, Carol Klein wrote in the Daily Telegraph (2005) about how she included it in one of her Chelsea displays and that “the lower lip of the flower protrudes, and the broad, central, pink stripe gives the impression of a tongue being poked out rudely as though it could not care less what anybody thinks about its status.” Not that I noticed such botanical rudeness, which at least reassures me that the mini-stronghold we do have may therefore have a better chance of survival....or maybe I need an eye test!

Daily Telegraph (2005) How to grow: Melittis melissophyllum[Online] http://www.telegraph.co.uk/gardening/howtogrow/3335387/How-to-grow-Melittis-melissophyllum.html [Accessed 28/5/13] 

Stace, C.A. (2010) New Flora of the British Isles (3^rd edition). Cambridge: Cambridge University Press.

Town hall clock chimes with spring

Spine-tipped leaves of Moschatel

The many faces of the Town-hall Clock

Whilst the bitter winds this March have held back much of spring, some plants seem to have paid no heed to the cold. Many of these are woodland species that cannot afford to wait too long as they will suffer from closing leafy canopies cutting out much needed light. Walking this week through the local Penny’s Wood I was on the lookout for these early emergers and was drawn to a clump of Fumitory-like foliage carpeting an area at the base of a tree trunk. On closer inspection I noticed a few innocuous tiny yellowy-green flowers, but was still none the wiser as to their identity. At home I studied digital images I had taken using a macro lens and noticed tiny spines at the end of each leaf. However more curious was the arrangement of the flowers in cube-like formats at the end of long stalks with four side faces and one facing upward to ‘heaven’ - the unique feature of the plant, ‘Town-hall Clock’ (Adoxa moschatellina). It is perhaps therefore not surprising that this flower has been considered a symbol of Christian watchfulness (Martin, 1975). Now this is a plant that I have long wanted to see with its unusual flowers, but I had not foreseen that it would require a blown up image on a computer to recognise it. It is more commonly called Moschatel named after its musk-like smell - from the French moscatelle, from Italian moscatella, from moscato 'musk (Shorter Oxford English Dictionary). Other names include Five-faced Bishop and Muskroot.

Moschatel is one of a very small family of plants that are globally uncommon or rare (locally frequent to scarce throughout its U.K. range), and existing in small fragmented populations. It would seem that not a great deal is known about the ecology of this species. It flowers very early in the spring, but the foliage persists most of the summer so it is not considered a spring ephemeral. Holmes (2005) reports: that it is pollinated by a variety of day-flying and night-flying insects, none of which seem specialized for this species; flowering is sequenced for each cube flower unit, with staged openings of the top flower followed by opposite pairs, which might facilitate self-fertilisation. So this tiny flower remains very much a mystery and probably hidden from perception by all but those with an inquisitive botanical eye.  

Holmes, D.S. (2005) Sexual reproduction in British populations of Adoxa moschatellina L. Watsonia 25:265–273

Martin, W.K (1975) The Concise British Flora in Colour. Hong Kong: Ebury Press

An earful of Waxwing

Flock of Waxwing roosting on the side of Devon Expressway

Whether you are a fanatical wildlife watcher or casual observer of nature around you, there are iconic animals and birds that capture everyone’s imaginations. Polar bears, puffins and pandas all come to mind. But as a boy I was drawn to the mystery of the Waxwing (Bombycilla garrulus), a brightly coloured bird that sporadically irrupts into Britain on an Arctic chill; the polar opposite of the Hoopoe that butterflies in on the heat of a southerly breeze. But I saw neither of these as boy or young man. Eventually it took a trip to Easter Spain to be woken from a convent cell by the terracotta warmth of the Hoopoe.  Two decades later and under rather less enchanting circumstances I encountered my first Waxwing - I stood with Greg chilled between a ceramic industrial building and the roar of the Devon Expressway whilst an ‘earful’ of Waxwing teased us chattering through the February mist on the distant carriageway (hence the rather poor image!). The other collective nouns for Waxwing are more obscure, ‘museum’ and ‘grosbeak’.

Our rather sad looking specimens with much of their colorific splendour drained out by the enveloping greyness made occasional risky efforts to feed on the last abject rose hips on the central reservation. They are under better conditions very jazzy birds, featuring a punky hair-do, black eye mask and accessorised with red and bright yellow feathers. Their mystery lies in part to due to their occasional mass migrations (‘irruptions’) from Northern area such as Scandinavia in tens of thousands into mainly Eastern Britain. However the extreme cold weather this February would appear to have driven them further to the warmer West Country. Their apparent tameness means that they seem relatively unaffected by human activities and so they seem unabashed feasting in a Tesco’s car park, or in our case amongst heavy traffic. It was fantastic to get my first glimpse of these quirky birds, but I hope next time that I come to meet them at a more attractive feeding location and that I do not have to wait another half a lifetime.

Buzz-off

There was an excited call from my wife the other day when she spotted from our upstairs skylight a large bird in our neighbour’s garden. It turned out to be a Buzzard (Buteo buteo) standing slightly hunched and initially motionless in the grass. After a while it walked slowly to perch on a bench. On closer inspection with the neighbour it seemed unwilling or unable to fly even in the presence of two sizable Tom cats. Sadly a few hours later it died.

So what could have been the cause of death? My immediate thought was that it had hit the ground too hard whilst chasing prey or had taken a glancing blow from a car on the nearby A road, before coming to rest in the garden. However a friend informed me that there would appear to be a lot of poisoning of birds of prey occurring in Devon. There are certainly a lot of young pheasants to protect in our area and an over-zealous gamekeeper might be tempted to break the law. This is supported by the RSPB’s latest Birdcrime Report (RSPB, 2012), which shows Devon to be one of the worst areas in the UK for confirmed persecution of birds of prey. On this basis I rang the 'Predatory Bird Monitoring Scheme' (PBMS), who take in suspected cases of poisoning for analysis. However the chap I spoke to felt our Buzzard’s was more likely to be the result of injuries from a collision that had enabled the bird to initially fly away but later suffer from internal bleeding. He said this was supported by a number of specimens that had been sent into them and that without circumstantial evidence it would be hard to prove anything.

This is clearly an awful tragedy for the individual bird and we will never know now what caused its death. However the backdrop is of a bird species that has been very successful over recent years expanding into/returning to many areas of Britain. We appear to have a very strong local population and are lucky to have daily experiences of them perched or soaring over the landscape.

Predatory Bird Monitoring Scheme – See https://wiki.ceh.ac.uk/display/pbms/Home

RSPB (2012) BIRDCRIME 2011 - Offences against wild bird legislation in 2011[Online].  http://www.rspb.org.uk/Images/Birdcrime_2011_edit_tcm9-324819.pdf [Accessed 20/02/13] 

Strawberry-Ness

Strawberry anemone with tentacles retracted

For me rock-pooling transcends age and maturity. I get as much joy and excitement poking under rocks and in crevices as I did as a kid. In contrast I often find sandy beaches boring. Rocky seashores provide opportunities for startling discoveries and a glimpse into life under water. There was the time I came across a dogfish trapped in a rock pool and another when I first discovered blue-rayed limpets adorning kelp like miniature landing strips for alien sea craft.

Last week I was indulging in such activity at Ness beach near Shaldon, a hidden treasure only accessible by an original smugglers tunnel cut through the cliff (Smuggler’s Britain, 2013). The red cliffs enclose a mainly shingle beach, but at either end are large areas of rocky seashore. It was amongst these rocks that I found a real treasure clinging limply – A Strawberry anemone (Actinia fragacea), a large relative of the commoner Beadlet anemone (Actinia equina). These fruity creatures, strawberry red flecked with pip like greeny-yellow spots, can grow up to 10cm long (excluding tentacles). These are primitive carnivorous animals using stinging cells in their tentacles to capture prey (including small fish) that then pass the food into a simple stomach (Oakley, 2010).

Like its namesake this anemone enjoys a warm climate, being a southern species  present in the Channel as far east as Brighton, but is expected to respond to climate change in UK waters (Kendall, et al., 2004) – it otherwise commonly occurs in Mediterranean and West Africa. So as global temperatures rise we are likely to see more of these gems smuggling onto our rocky shores - happy hunting.

Kendall, M.A. , Burrows, M.T., Southward, A.J & Hawkins, S (2004). Predicting the effects of marine climate change on the invertebrate prey of the birds of rocky shores. Ibis (146): 40-47

Oakley, J. (2010) Seashore Safaris. Cardiff: Graffeg Books

Smugglers Britain (2013) The South Devon Coast [Online]. http://www.smuggling.co.uk/gazetteer_sw_10.html [Accessed 9/02/13]  

 

Barnacles uncovered

On New Year’s day I was drawn to the sea for a walk to clear the toxins of the previous nights festivities. The long sandy beach at Slapton eventually made way for some rocks where we rested to enjoy a lunch of leftover Scotch eggs and shortbread. Whilst relaxing, my eyes became focussed on a more macro world of animals on the rocks as the tide went out.....

 

Acorn barnacles with limpets

....Most people have had the painful experience of barnacle encrusted rocks whilst rock pooling at the seaside. These creatures commonly coat rocks alongside other shelled animals, but are in fact very different in origin. Molluscs such as limpets and periwinkles are relatives of snails using a muscular foot to move and graze the rock surfaces whilst carrying their protective shells with them. The barnacles that hurt our feet are the static adult forms that await the tide to come in to feed, using feathery legs (cirri) that emerge when their opercular plates are opened, like a scene from Dr No. These cirri are thrown out and back like thin clawing hands, netting plankton and detritus. It is however the young barnacles that give themselves away as crustaceans, relatives of crabs, prawns and shrimps. The free-swimming larvae travel with other sea plankton, moulting several times before settling down to a ‘fixed’ life on a rock. They literally cement themselves down head first once they have selected a spot, ideally rough and shaded, orientating themselves across the current to maximise feeding (Yonge, 1976).

The commonest forms of barnacle on British shores are various types of acorn-barnacles. The species are distinguished by the number of shell plates (six in British spp as opposed to four with the Australian invader, Elminius), and the shape of the opercular openings which vary from oval to kite to diamond (Oakley, 2010). The image is probably of Chthamalus sp with kite shapes. One of the commonest British species is Semibalanus balanoides, which has a fascinating sex life - To overcome the reproductive challenge of separate sexes, each glued down and surrounded by armour plating, the male organ is gigantic (equivalent to 20 metres in human terms) – once the males have completed copulating with the females fertilizing up to 8000 eggs the mighty organ withers away and the males turn into females for next season (The Seashore, 2013).

Oakley, J. (2010) Seashore Safaris. Cardiff: Graffeg Books

The Seashore (2013) [online] www.theseashore.org.uk  [Accessed January 10^th 2013]

Yonge, C.M. (1976) The Sea Shore (The New Naturalist series). London: Collins

Stunning bird!

A few weeks ago I was with my wife in the Buckfast Abbey cafe after a long walk, enjoying an Earl Grey tea and admittedly a rather indulgent cake. The cafe has an external patio area with a glass screen to enable views of the grounds. We watched a pair of busy Pied Wagtails (Motacilla alba) that seemed to be enjoying chasing each other around the gardens below. Suddenly one of them hit the glass with quite a thud, rousing tea drinkers from their afternoon stupor.  The bird landed on a roof below and stood almost motionless, panting with its beak wide open. It stayed like this in apparent shock for over 10 minutes and remained that way as we left.

This type of occurrence is commoner than I realised. A US report claims that collisions with clear and reflective materials such as glass are the second highest man-made mortality factor for birds worldwide, only superseded by habitat destruction (Klem, 2008). This amounts to billions of deaths from head trauma; far higher than hunting, road kill, and domestic cats. There have been many prominent campaigns against hunting birds and more recently wind turbine objectors have frequently cited bird kill as an argument against their installation, and yet the far greater toll from glass gets conveniently ignored. The birds appear to treat these barriers as invisible. This type of death is no discriminator of an individual’s level of fitness, unlike more natural mortality factors. The RSPB recommends the use of silhouette images of birds of prey on windows to deter birds, particularly on large glass areas such as patio doors, or where birds might perceive a clear pathway through structures. Other solutions include netting or hanging objects in front of windows, placing feeders closer to windows to reduce the speed of impact, angling windows at 20-40 degrees also to reduce impact, and more novel use of one-way films that create patterns and shades rendering them relatively opaque (Klem, 2008).

Meanwhile at home I accidently discovered last year that my stuffed Barn Owl place on one of our deeply recessed window ledges appeared to be putting off birds coming anywhere near the back of our house – perhaps not a practical large scale solution!

Klem, D (2008) Avian mortality at windows: The second largest human source of bird mortality on Earth. Proceedings of the Fourth International Partners in Flight Conference: Tundra to Tropics. 244–251

Last summer rays

Back in early September I was in North-West Wales enjoying a late burst of summer warmth in the shadows of Snowdonia. Walking some of the lanes I was struck by the number of Goldenrod (Solidago virgaurea) plants and how unfamiliarly small some of them seemed. I have since learnt that this species is very variable and can appear in dwarf-like forms (Stace, 2010). More recently I came across the bright yellow burst of this late flowering plant nearer home on the side of a Devon stream (see image).

The genus name, Solidago is derived from the Latin meaning to ‘make whole’ and  Goldenrod has certainly a long history of traditional medicinal use, particularly as a diuretic and urological disease. Hawes (2010) suggests harvesting the whole flowering plant and dry for use with herbal infusions for urinary problems with regular doses helping to reduce the risk of kidney stones. Other suggested uses included a hot dose to treat runny nose symptoms of colds and a tincture for catarrh and hayfever. More contemporary studies by scientists have shown some anti-cancer potential of Goldenrod (Gross, et al., 2002). I do wonder at the contrast of traditional and modern medicine and how different health benefits have been discovered over the ages. How did people learn to test different plants for the varying ailments as they evolved in their communities? Was it simply trial and error or did they have better developed intuition that they learnt to trust.

In the meantime the Goldenrod plants are now slowly being absorbed back into the autumnal earth to hide their powerful secrets until next spring.

Gross,S.C., Goodarzi,G., Watabe,M. Bandyopadhyay,S., Pai,S.K. and Watabe, K. (2002)  Antineoplastic Activity of Solidago virgaurea on Prostatic Tumor Cells in an SCID Mouse Model. Nutrition and Cancer, 43(1): 76–81

Hawes, Z (2010) Wild Drugs – a forager’s guide to healing plants. London: Octopus Publishing Group Ltd.

Stace, C.A. (2010) New Flora of the British Isles (3^rd edition). Cambridge: Cambridge University Press.

Four and twenty blackberries

It is that time of the year that the hedgerows are bursting with the black-ripe fruits of Blackberry and elder, ink-blue sloes, bright red haws and browning hazelnuts. But not this year. The few blackberries I have seen are mean looking, grizzled and diminished. Flies hungrily surround the few succulent fruits. Hazelnuts that I scooped up in handfuls last year, cracked and roasted for my morning muesli with blackberries, are all but absent. A quick scan of the internet revealed that I am not alone in noticing the poor crop this year of blackberries. The Guardian (2012) reported on this a few days ago, “the cool, wet spring and summer has delayed the season for berries on bramble, blackthorn, elder and other bushes, and these are only beginning to ripen. They also seem to be smaller than usual.”   

So what is actually causing such low yields in much of Britain? Could it be that the prolonged poor weather reduced insect activity so much that many bramble flowers were simply not pollinated? I know anecdotally that local beekeepers in unprecedented action had to feed their bees this spring/summer on sugar solution, as they were starving from not being able to go out and forage. Combine this with a lack of warm temperatures to ripen the fruit, and it is hardly any wonder there is such a low yield.

What will the impact on wildlife that feast on this autumn harvest? Blackberries are a vital food supply for a wide range of mammals such as badgers, dormice, hedgehogs and foxes; birds like blackbirds, bullfinches, chaffinches, magpies and song thrushes; and insects including butterflies, wasps and moths (BBC, 2012). I will therefore be leaving what’s left of the sad blackberry crop to these creatures and adapt my muesli mix, making use of some garden autumn golden raspberries planted this year. Let’s hope our British wildlife can be equally adaptive.

BBC (2012) Blackberry crop threatened by record dry spring [Online]   http://www.bbc.co.uk/blogs/natureuk/2011/06/blackberry-crop-threatened-by.shtml [Accessed 26/09/12]

Guardian (2012) Plantwatch: This autumn likely to provide a brilliant display of colours [Online]  http://www.guardian.co.uk/science/2012/sep/21/plantwatch-autumn-leaf-colour?newsfeed=true [Accessed 26/09/12]  

The knock out nuptial gift

What a washout of a summer. As I sit typing this blog the rain is lashing against the skylight – again! It’s not just the volume of water that this summer has thrown at us that has turned the British summer into a damp squib, but the wind ripping through plant and canvas. We were seriously concerned about my brother camping a couple of weeks ago in nearby Brixham, wondering if their new tent would take the pounding. It’s easy for the human species to hide from the worst of the elements, but think of more delicate nature accustomed to light summer breezes and warm nectar. Honey bees have been so short of food that many beekeepers have had to take the unusual step of feeding them this summer with sugar solution. But what of other not so pampered invertebrates, such as butterflies and moths. No doubt we will feel the impact for years to come.

There have been a few decent interludes and I have tried to get to the coast for the occasional walk. The resilience of nature to grab these weather opportunities is somewhat reassuring. One species that has particularly drawn my attention are Six-spot Burnet moths (Zygaena filipendulae), whizzing from one purple flowered Knapweed to another. These day flying moths make the most of heat and sunshine. My friend Mary from Nottinghamshire spent years protecting and observing a ‘colony’ of Burnet moths living precariously on a busy verge, noting the emergence of the black & red adults on hot days. The caterpillars are equally colourful, yellow with broken black lines running the length of their body. However they are adept at protecting themselves by turning themselves into living cyanide pills for any unwary predators. Many plants produce cyanogenic glucosides to deter grazing animals, but these caterpillars are able to biosynthesise these chemicals for their own defense (Zagrobelny, et al., 2008). Perhaps more fascinating, when adults mate the males transfer a ‘nuptial gift’ of cyanogenic glucosides to virgin females, which it is suggested by researchers is then used for her own defence or to protect her eggs (Zagrobelny, et al., 2008) – indeed further experiments indicated that females can detect how much the males possess and reject those with low concentrations.

I just hope that these stunning moths are as adept at coping with the vagaries of the increasingly volatile British summers as they are at developing chemical weapons.

Zagrobelny, M., Bak, S., Møller, B.L (2008) Cyanogenesis in plants and arthropods. Phytochemistry, 69:457–1468

The pharmaceutical poppy

There was no mistaking the identity of the Yellow Horned-poppy (Glaucium flavum)  scattered liberally along the shingle of nearby Slapton beach last week. The large yellow flowers are dwarfed by the extravagant sickle-shaped, horn-like seed pods that grow up to a foot long.

This predominantly coastal plant has been adopted for centuries as a traditional medicine, including use by the Vikings of Norway and Denmark (Psychoactive Herbs, 2012).  Over more recent decades, scientists have developed techniques to extract alkaloids from this plant, the main representative being glaucine (named after the plant). This has led to pharmaceutical use in drugs as a cough suppressant, anti-inflammatory and analgesic. There has also been a degree of recreational use due to its opiate like effect (Psychoactive Herbs, 2012).  A more innocent application is as a fuel for lighting by using oil from the seeds (PFAF, 2012). A recent development is the use of glaucine based creams as a cosmetic treatment for cellulite. The glaucine appears to impact fat cells by causing them to release fat as well as inhibiting new fat cells in favour of collagen-producing cells, resulting in “fat being replaced by firmness” (Lipotherapeia, 2012).

So as the Vikings landed on British beaches did they seek out the Yellow Horned-poppy to; stop coughs, get pain relief, have some fun or simply to firm up their buttocks?
 

Lipotherapeia (2012) Is glaucine, an extract of the common yellow poppy, the ideal anti-cellulite cream ingredient? [Online]  http://www.lipotherapeia.com/cellulite-questions-answers/is-glaucine-an-extract-of-the-common-yellow-poppy-the-ideal.html [Accessed 13/07/12]

Psychoactive Herbs (2012) Yellow Horned Poppy Extract, Glaucium flavum. [Online]  http://psychoactiveherbs.com/catalog/index.php?cPath=170_193 [Accessed 13/07/12]

Plants for a Future (PFAF) (2012) Glaucium flavum – Crantz. [Online]   http://www.pfaf.org/user/plant.aspx?LatinName=Glaucium+flavum [Accessed 13/07/12]

The pretty hungry caterpillar

We have been watching a group of very colourful caterpillars in the garden over the last few days. Many of you will recognise these caterpillars from the image, but perhaps have wondered what species it is and whether the adult is equally visually stunning. A strong clue to the caterpillars identity is its favourite food plant, Mullein, and hence its name the Mullein Moth (Shargacucullia verbasci). Our particular caterpillars featured are feeding on Great Mullein (Verbascum Thapsus) with its distinctive velvety elephant ear-like leaves - or what’s left of them. This moth will also feed on other Verbascum species, but also Figwort (which I have more frequently observed) and Buddleia.

The caterpillars seem unconcerned with their high visibility ‘jackets’, almost advertising their bright yellow and black markings – this is presumably to warn any predators not to eat them because they taste bad. This stunning colouration is in stark contrast to the adult moth form which at rest appears to mimic a dead plant stalk.

Many gardeners are all too acutely aware of how prone their Verbascums are to attack by the caterpillar of the Mullein Moth, which can consume much of a plant's entire foliage in a day. I counted only about three caterpillars on our Great Mullein and today we are left with little more than a stump. However this is where their colouration works against them as they are easy pickings for green-fingered predators!

A Lizard's tale

A few weeks ago I was lucky enough to spot a Grass snake (Natrix natrix) crossing our local country lane. I managed to grab it momentarily to get a good look before releasing it into the hedge. Then last week during the warmer weather I spotted another much smaller snake-like animal, a Slow worm (Anguis fragilis)- the Anguis is taken from the Latin, 'slim' and 'snake'. However, as many of you will know it is not a snake, but a legless lizard, being distinguishable by its closable eyelids which is why it is also called the Blind-worm – snakes do not have any eyelids.

This particular specimen was behaving rather too true to its name, being rather sluggish and easy to catch. I was concerned about its safety as we have a high cat population locally, one of its not uncommon garden predators. Like other lizards the Slow worm does have a curious defence, the ability to lose its tail to escape predation using a mechanism known as ‘caudal autotomy’. By detaching a section of its body that then independently writhes vigorously it distracts its predator whilst it makes its more genteel escape. Perhaps it is this tail breaking trick that provides the ‘fragilis’ part of its Latin name. I have witnessed this phenomena and it is quite a sudden and amazing sight, with the tail demanding attention. Theseverance of its tail is a reflex achieved using a fracture plane (‘line of weakness’) in the caudal vertebrae. However it can only do this once and the new tail grows back significantly shorter than the original (Fuke, 2011), and can take several years (Bryant & Bellairs (1967). Despite the immediate advantage of surviving an attack, the tail loss has potential significant costs such as reduced locomotion and it has been shown to have a negative impact on reproductive success (Maginnis, 2006).

This all leaves me pondering the question, how does an individual Slow worm that can live 20 years plus determine the significance of every one of the many threats it will experience and decide on each occasion whether to play its one 'joker’.

Bryant, S.V. and Bellairs. A. (1967) Tail regeneration in the lizards Anguis fragilis and Lacerta dugesii. Journal of the Linnean Society of London, Zoology, 46(310): 297-305

Fuke, C. (2011) A study of a translocated population of Anguis Fragilis in Cornwall, UK. The Plymouth Student Scientist,4(2):181-221

Maginnis, T.L (2006) The costs of autotomy and regeneration in animals: a review and framework for future research. Behavioral Ecology, 17(5): 857-872.

Classy jumper

The recent improvement in the weather has triggered a burst of insect life as they respond to the early summer heat. This has shifted the hazards as I run the local lanes, from leaping giant puddles to avoiding swallowing the local insect fauna. Whilst on a slower ecological circuit, I was drawn to the numbers of flies, beetles and bees feasting on the abundant Alexanders flowers and other plants. It was however a red and black ladybird-coloured insect that particularly caught my eye, poised on a nettle. I took a couple of images before my macro lens became too intimate with the beast and in a flash it was gone. Back at home I was quickly able to identify it as one of our most visual frog hopper species, the Red-and-black Froghopper (Cercopis vulnerata). These bugs are also known as ‘spittle bugs’ and cuckoo-spit insects’, due to their nymphal stage habit of living in a protective mass of froth or spittle (Chinery, 1977).

When it comes to jumping stakes, few would bet against the flea when taking account of relative body weight. It turns out that froghoppers, such as C. vulnerata, produce a substantially better jumping performance. Starting with my puddle leaping efforts with a take-off force of about 2-3 times my body weight, the flea manages about 135 times, and froghoppers more than 400 times (Burrows, 2006). This is a very useful if you want to avoid predation or being eaten by a grazing cow. Researchers have shown that the key to this jumping performance is a spring-loading mechanism called the ‘pleural arch’, which the insect compresses like an archer’s bow in readiness for leaping to safety (Patek, et al., 2011). It is even cleverer than this when you consider the materials used to form the pleural arch; a sophisticated combination of chitinous material to store energy and ‘resilin’ to provide flexibility and shape restoration, has drawn comparisons with high performance composite bows (Patek, et al., 2011).

Such innovative mechanisms adopted by insects has inspired engineers and biologists to consider applications for human inspired devices. If we get another wet spell as bad as this April, I would be interested in a ‘human friendly pleural arch’ device to better avoid the puddles.

Burrows, M. (2006) Jumping performance of froghopper insects. Journal of Experimental Biology, 209: 4607-4621.

Chinery, M (1977) A Field Guide to the Insects of Britain and Northern Europe. London: Collins.

Patek, S.N., Dudek, D.M. and Rosario, M.V. (2011) From bouncy legs to poisoned arrows: elastic movements in invertebrates. Journal of Experimental Biology, 214:1973-1980.

Limestone lovers

Berry Head in South Devon is quickly becoming one of my favourite haunts with its rich botanical landscape and marine wildlife. Last September I blogged about one of its specialities, the White Rock-rose (Helianthemum apenninum), a nationally rare species (see http://nicksnaturenotes.blogspot.co.uk/2011/09/last-white-rock-rose.html). The unusual mix of physical geography and chemistry provided by the Devonian limestone sea cliffs of Berry Head provide conditions for the White Rock-rose shared only by a handful of other sites in the South West. I was visiting it again this weekend with friends and showed off the White Rock-rose amongst other more common plants. Towards the end of the afternoon we wandered up to the remains of the fort in search of summer migrant birds amongst the scrub. Resting my arms on the battlements and enjoying a Whitethroat and possibility of Cirl Buntings, I became curious about a stunted-looking plant which I had almost leant on. Closer inspection revealed what looked like a bonsai version of an umbellifer, a dwarf parsley or carrot plant. My companion with much pleasure eventually identified it as Honewort (Trinia glauca), which is indeed a member of the carrot family and another local limestone specialist. Apparently, in turf closely grazed by rabbits, plants of Honewort grow to no more than a few centimetres tall (BRC, 2012), as was the case with many of the Berry Head plants that we observed.

When I got home I looked at the distribution map on the National Biodiversity Network's Gateway (see http://data.nbn.org.uk/gridMap/gridMap.jsp?allDs=1&srchSpKey=NBNSYS0000003662) and fascinatingly it is found in almost the same isolated areas as the White Rock-rose. These rare fragmented habitats of dry limestone, with short-grazed south facing aspects have created almost identical conditions for such specialists to cling on to their slopes. However their hold is truly precarious, the species being listed as ‘Near Threatened’ (BRC, 2012). The challenge for the Honewort is made more challenging as it is dioecious (having separate male & female plants, requiring cross-pollination) and has poor seed dispersal, most likely reliant on ants (Carvalheiro, et al., 2008).

These two limestone loving species are literally hanging on in Britain, exposed to human disturbance.  This makes it all the more important to value these wonderful wildlife hotspots and for me to take more care where I lean my tired ‘binocular-ed’ arms.

BRC (2012) Online Atlas of the British and Irish flora [online] http://www.brc.ac.uk/plantatlas/index.php?q=plant/trinia-glauca [Accessed 7/5/12]

Carvalheiro, L.G., Barbosa, E.R.M. and Memmott, J.(2008) Pollinator networks, alien species and the conservation of rare plants: Trinia glauca as a case study. Journal of Applied Ecology, 45: 1419–1427

National Biodiversity Network's Gateway  (NBN) (2012) Grid map of records on the Gateway for Honewort (Trinia glauca) [online] http://www.brc.ac.uk/plantatlas/index.php?q=plant/trinia-glauca [Accessed 7/5/12]

Windless anemones

Over the last few weeks our local Devon woodlands have sprung to life with the white starlight flowers of Wood Anemone (Anemone nemorosa), carpeting the open floors. I’ve also recently been to the beach a couple of times and I have become curious about the marine namesakes, such as the Snakelocks Anemone (Anemonia viridis) pictured above. What is the commonality of the name, ‘anemone’?

Looking up in the dictionary, 'Anemo’ is Greek for wind, which I could have guessed from knowing that an anemometer is an instrument to measure wind. The Shorter Oxford Dictionary (1952) defines ‘Anemone’ as “daughter of the wind” and the Wood Anemone as “the wind-flower”. Other sources state that the wind God, 'Anemos' sent Anemones early to herald his early coming in spring - the Wood Anemone is certainly one of our earliest flowering plants. However there does not seem to be any evidence that wind plays much of a part in the life history of this plant. They spread mainly via underground rhizomes as long-lived clonal groups, and pollination is via insects (Stehlik and Holderegger, 2000). An alternative name is ‘Smell Fox”, which is explained by the musky smell of the leaves (Woodlands.co.uk, 2012) – a bit a blunt and ‘to the point’ of a name, but at least more descriptively accurate.

The link with sea anemones seems more straightforward – these sea creatures resemble flowers with their brightly coloured spreading tentacles – hence the Strawberry Anemone (Actinia fragacea) which is reddish with flecks like pips on a strawberry. Indeed, until modern times many believed that sea anemones were actually plant species. However the resemblance of the large variety of sea anemones does not seem particularly reminiscent of plant anemone species – many look more like colourful sunflowers or daisies.

So, in pedantic summary the anemones don’t have much in common with wind, and sea anemones don’t look any more like anemones than many other flower genera. This should not however stop us admiring the wonderful beauty of anemones, plant or animal.

Onions, C.T (1952) The Shorter Oxford English Dictionary on Historical Principles. Oxford: Clarendon Press

Stehlik, I. and Holderegger, R (2000) Spatial genetic structure and clonal diversity of Anemone nemorosa in late successional deciduous woodlands of Central Europe. Journal of Ecology, 88 (3): 424–435

Woodlands.co.uk (2012) [online] Wood Anemone-  http://www.woodlands.co.uk/blog/woodland-flowers/wood-anemone/  [Accessed 22/04/12]

Painted shells

In nature shells provide varying forms of protection, from snails that use them to shelter their soft bodies from predation and drying out, to bird’s eggs that defend the growing embryo. This week I picked up a discarded egg shell of a Song Thrush (Turdus philomelos), characteristically a stunning summer sky-blue with sparing dark speckles. A couple of weeks ago I was dazzled by brightly coloured Painted Topshells (Calliostoma zizyphinum) dotted about on low tide rocks near Torquay. This led me to wonder at the biological function of some species having such visually distinctive shells that might make them more prone to predation.

Considering the Song Thrush there is some consistency with other birds that make their nests in darkened habitats and pale blue eggs. The Song Thrush chooses either a thick hedgerow, hollow in a creeper, or rarely if on the ground in a shady well-hidden site. It was believed that the distinctive colour may help the adults locate them more easily (Harrison, 1975). Many alternative theories of why thrushes lay blue eggs was summarised by Gotmark (1991): they may be cryptic and provide camouflage by imitating spots of light on green leaves; egg parasites such as cuckoos might have exerted selection pressures historically; the pigmentation of eggs enhances the strength of the egg shell and therefore its resistance to cracking; egg coloration influences egg temperature helping with its regulation. More recent research has tried to test whether the blue-green egg colouration of many bird species provides a health indicator of the female to allow males to modulate their parental investment. However it would appear that researchers are still really none the wiser and so we can only assume that the cost of producing blue pigment is outweighed by some unclear benefit that may no longer be relevant, or that it is simply maladaptive.

The Painted Topshell is the most colourful example of these intertidal molluscs in the UK. The colour varies from yellow or brown to pink or purple and is overlaid with irregular dark purple or red markings. The purplish blotches spiralling around the almost perfect conical shell give the illusion of a spinning top. There is also a white ‘morph’ form which is considered by some to be a separate species. This Topshell is also notable for its frequent shell-wiping behaviour, which would appear to both prevent surface fouling and top up its food intake by as much as a fifth (Holmes, 2001). Despite this interesting colour variation I can find no explanation to its cause. So whilst scientists continue to hypothesise I humbly suggest that we simply sit back and admire nature showing off its surprising beauty.

Gotmark, F. (1991) Blue eggs do not reduce nest predation in the song thrush, Turdus philomelos. Behav Ecol Sociobiol,  30:245-252

Harrison, C (1975) A Field Guide to the Nests, eggs and Nestlings of British & European Birds. London: Collins.

Holmes, S.P., Sturgess, C.J. Cherrill, A. Davies, M.S (2001) Shell wiping in Calliostoma zizyphinum: the use of pedal mucus as a provendering agent and its contribution to daily energetic requirements. Marine Ecology Progress Series, 212:171-181

Spurge-laurel - a healthy pungent purge or scourge?

Very few plants put energy into flowering in the winter due to the cold and lack of sunshine and pollinators. There are some obvious exceptions such as Snowdrops and Winter Aconites. Less obvious is the evergreen shrub, Spurge-laurel (Daphne laureola) which I spotted inadvertently last week in one of our local hedgerows. The origin of the Latin name Daphne apparently comes from the water nymph whom the Gods turned into a laurel-bush to hide from the advances of Apollo (SAPS, 2012). Well in keeping with concealment you would be forgiven for not spotting its flowers, with petals absent and small camouflaged yellow-green sepals. The plant flowers appear from January, a welcome source of nectar for early emergent moths and bees attracted by their strong scent rather than visual cues. But don’t let the sweet fragrance fool you – all parts of a Spurge-laurel plant are poisonous to humans, particularly the bark and berries. It can cause stomach pain, nausea, vomiting, bloody diarrhoea, delirium, collapse and death; even external contact between plant and skin can cause blistering. (Eland, 2012). Some tribes in northern Africa still use a bark extract to poison fish (Eland, 2012). This all serves a useful service for the Spurge-Laurel, as its production of powerful toxic compounds such as coumarin results in a “well defended plant” with very few animals able to eat it (Alonso, 2009).

Interestingly it is not universally toxic to animals; for instance the black berries are eaten by birds like greenfinches without any harm (SAPS, 2012), and in the past used as a veterinary cure for horses (Eland, 2012). It has also been used occasionally in the past for medicinal purposes, such as folk treatments for cancer, toothache and rheumatism (Eland, 2012). Johnson (1856) refers to a “decoction of the root and bark being recommended for children afflicted with worms”, but goes on to warn that “it should never be used, being one of those remedies that can only be employed at the risk of life”. He continues with a more strident note –

“The Lady Bountiful of the village would do more good by confining her benevolent practice to the issue of nourishing food and warm clothing, where necessary, than by trying to combat disease by remedies of which the action is equivocal, if not, as in this instance, dangerous in the highest degree.”

In modern times opinion of Spurge-laurel very much leans towards Mr Johnson’s – well at least botanically rather than his gender insinuations.

Alonso, C., García, I.M, Zapata, N. and Pérez, R.(2009) Variability in the behavioural responses of three generalist herbivores to the most abundant coumarin in Daphne laureola leaves. Entomologia Experimentalis et applicata, 32(1):76-83

Eland, S. (2012) [online] Plant Biographies http://www.plantlives.com/docs/D/Daphne_laureola.pdf  [Accessed 7/03/12]
Johnson, C. (1856) British Poisonous Plants. London: Taylor & Francis.
Science and Plants for Schools (SAPS) (2012) [online] http://www-saps.plantsci.cam.ac.uk/trees/laurels.htm [Accessed 7/03/12]

A Devilish Mis-Tor-y Tour

Over the last few weeks as the weather has turned colder I have felt a compelling draw towards Dartmoor. Most days I glimpse this wild plateau, discrete in the distance; a feint hint of something awesomely ancient, soaked in legend and mystery. Last week we paid a quick visit to the highly accessible Haytor, cloaked in snow and ice. However I yearned for something more remote and wild and so geared up yesterday to do a circular walk around Great Mis Tor on the west side of the moor. Driving to our starting point we crossed an iced and undulating landscape, intermittently crested by tors, the granite outcrops resembling the broken teeth of giants or fossilised horse dung. Mis Tor is aptly named, frequently wrapped in mist as it was yesterday, filling the whole of the Merrivale Valley. Undaunted we trudged up the icy track barely able to see more than a few yards ahead, until quite unexpectedly loomed a huge grotesque visage out of the mist - a contorted ugly witch-like head, featuring a hooked nose, goitre and warts (see image above). This was Little Mis Tor glaring upwards to its more foreboding fellow. It did not take much longer to find Great Mis Tor, or at least its large collar of broken stones. There is apparently a notable rock basin on the peak, Mistorpan or ‘the Devil’s Frying Pan, which has led to “speculation about sacrificial rituals, with blood collected in the basin running out along an [adjacent] groove” (Sale, 2000). There is a more logical geological explanation about natural erosion but don’t let this get in the way of a good story.

Down on the slopes my eye was caught by the striking red of the lichen Devil’s Matchstick (Cladonia floerkeana) (see image below), an apt discovery on this spooky walk. The Cladonia genus of lichens are common on heathlands, enjoying the clean air of such habitats. The name is derived from the Greek ‘’cladon’, meaning branching – these are easy to recognise lichens with their brightly covered fruiting bodies (ascocarps) borne on the top of the podetia (Cladonia Resources, 2012).

As we descended into the Merrivale valley, crossed the rushing brook, and climbed the other side we found ourselves in the middle of a Bronze Age settlement. Standing within the remains of an ancient hut circle we tried to imagine a thriving community looked down on by the imposing tor. Our final mystery lay above this settlement; a stone circle, or at least what remained after past misdemeanours of troops using it as target practice during the Second World War (Sale 2000). By this time the sun had broken through the mist to show us the full breathtaking beauty of an aged landscape decorated by human antiquities; geology merging with mis-tor-y!

Sale, R (2000) Dartmoor – Collins rambler’s guide. London: HarperCollins.

Cladonia Resources (2012) [online] What is Cladonia? http://www.cladonia.co.uk/component/content/article/10.html [Accessed 13/02/12]