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