Sunday, 14 August 2011

The strawberry fields

Only a relatively steady walk with Monty today through the "strawberry fields" owned by Hugh Lowe Farms on the Lower Greensand Ridge. The farm is rather well off for hedgerows and shaws, useful to shield the poly-tunnels they use to grow the strawberries in, from spoiling the long-distance views.

The farm is partly on the South-facing slope of the ridge, between West Peckham half way up the hill and Hadlow down on the Medway Floodplain. I parked at West Peckham, where they were playing cricket on the green in front of the pub, and walked downhill along the footpath with high hedges either side until I broke out into the open arable land just above the earth-bank reservoir put in to irrigate the strawberries, and Hazel Wood just alongside it.

I had a quick look at the reservoir hoping for some migrant waders, but only accidentally put up a young cormorant, which circled rapidly to gain height and then flew off. Along the tracks alongside the reservoir there were hundreds of Bristly Ox-tongue plants, Picris echioides, with remarkably variable degrees of green and red in their stems, ranging from one extreme to another in different plants just next to each other. Their bristly leaves are pretty characteristic, only Bristly Ox-tongue has these unusual prickly spines arising from raised white welts on the upper leaf surface, as well as many further spines on the margin of the leaf!


Of all the many plants I saw during this walk (between 4 and 6 p.m., in the late afternoon) only one flowerhead was open, presumably because of the time of day to which the individual plants are almost universally tied in their rythms. This was the still open flowerhead, with the Y-shaped styles of many of the florets still open, seeking pollination,


while all the other flowerheads were closed up ready for the cool and moisture of the night. At this stage the spiny inner and outer bracts are both held upright around the flower in protective "vases".


Once the individual florets in a head are fertilised each floret develops into a dry single-seeded fruit called an achene, each with its own built-in parachute attached above it for dispersal. The fruiting heads of the parachutes, each with dozens of individual achenes are similar to the well-known dandelion "clock", as shown in the photo of a Bristly Ox-tongue fruiting head below. There are very green stems on this particular plant in comparison to many others which are much redder. The other thing to notice is how the spiny inner and outer bracts have now both turned down, and the platform of the "receptacle" that all the achenes are sitting on has now been pushed up and expanded into a very flat dome, presumably all to allow the easier dispersal of the parachutes:


The individual achenes are much more clearly seen when half of them are removed, for example by the breeze, as in this particular fruiting head here


Specifically for Bristly Oxtongue, amongst half a dozen of its very similar-looking relatives, each achene has an extended neck about its own length again, connecting it to its parachute, which consist of many individually feathered plumes (the feathering is visible if you magnify the image further) to aid the "floating" effect that we all marvel at as they drift past us in the slightest breeze. I think that they are incredibly beautiful in their utilitarian design, when seen in this close-up detail!

A receptacle emptied of achenes has the abandoned look of a rusting launch-pad from which the rockets have been fired, and for which there is no more funding for future missions!


Note the very vibrant red in this particular plant's stems, so different from the green-stemmed plants photographed above!

The only butterflies I saw were Meadow Browns, with Gatekeepers and Small and Lrge Whites all in reasonable numbers. There were hardly any hoverflies about, and no dragonflies to be seen at all. There was however a small and predominantly orange solitary wasp seen on hogweed flower umbels on many of the field margins, which I think is new to me (STOP PRESS - this is a sawfly, and most likely to be the turnip sawfly, Agre rosae as only its shoulders are black, not the whole top of the thorax as in the rose sawfly Agre Ochropus - see next post !!!):


and there were plenty of blackberries, some of which I sampled!




Saturday, 13 August 2011

Butterflies at Queendown Warren

I attended the course on Kentish butterflies with Steve Weeks at the Kent Wildlife Trust headquarters at Tyland Barn today, and in the afternoon we all went off to Queendown Warren to put our new-found identification skills into practice!

We got into the swing of things on the more familiar butterflies, checking out the differences between the Meadow Brown and the Gatekeeper, and the Green-veined White and the Small White respectively. Then we got some of the more specialist and rarer prizes on offer and the first species up was a Silver Spotted Skipper, Hesperia comma, one of the descendants of those re-introduced to the Warren after the grazing programme had been disrupted and the old colony there become extinct many years ago. The re-introductions used stock taken from Lydden Down and Temple Ewell nature reserves near Dover, with similar earlier (1997) re-introductions also made to Wye Downs and Burham Down. The re-introduction to Queendown took place about ten years ago and the colony seems to be thriving. they don't fly far from their home colonies, so they need help if they are to spread out to re-occupy more of their former range. Here's one of the results of their reproductive efforts!


and here is another individual from an angle that more clearly shows that this skipper gets its name!


This butterfly looks as though its enjoying the nectar it is sucking up from this knapweed flower-head! The average life-span of an individual is only about 6 days, so they deserve every treat they can get!

The males spend most of their lives watching out for females and the females, once mated, spend most of the time looking for exactly the right clump of Sheep's Fescue, Festuca ovina, to lay their eggs on, while trying to avoid further male attention while they do so. Described as rare in the National Red Data Book these small butterflies are a specific treat wherever their colonies are still found.

The second chalk downland speciality was the Chalkhill Blue, Polyommatus coridon, and there were quite a few nearer the foot of the hill where it was a bit moister and also more sheltered, fluttering around on the lusher patches of marjoram. these were light blue, with some grey edging to the wings and hatching on the white margins.


Scattered amongst the Chalkhill Blues were some Common Blues, Polyommatus icarus, some of them looking a little tatty. These were more overall lilac in colour on the uppersides, with no grey edging and no black hatching on the white edge of the wings.


And then there was the butterfly speciality of this internationally important site, the Adonis Blue, Polyommatus bellargus, and here is a good one I saw just as we all left the reserve main bank at the top of the hill:


Wednesday, 10 August 2011

Bourne Valley

Just a slow walk with Monty today between 2:30 and 4:30, through the housing estate to Marshall Gardens and across to the River Bourne to the West via Hope Meadow, then back South down to Mill Close and East back to School Lane and home. I should have taken some landscape shots, but they will have to wait until another day.

As I walked from Marshall Gardens to the Paddock alongside the horses grazing in Williams Field (amongst all the ragwort!) I saw my first hoverfly of the day, a gorgeous possible Leucozona, a species I've never seen before, but as I was still in the housing estate I didn't have my camera to hand, so no confirmation and no pictures! Botheration, but never mind!

The wheat field must be so close to harvest now, with the ears rattling in the wind. The land is dry and there is very little moving apart from Greenbottles on the path, present for obvious reasons. The first signs of nature apart from the occasional weed such as hedge mustard came when we reached the first ditch, trickling down the side of the valley from Spring House. A small patch of Figwort and Greater Willowherb in the bottom of the ditch was full of bees, wasps and flies, pollinating away like mad. All the activity made the surrounding wheat look a bit lifeless in comparison.


A median? wasp feeding from a figwort Scrophularia nodosa flower

Well on the way back and coming up the sheltered holloway of Mill Close from Hope Mill on a sunny sheltered bank of ivy, bramble and other flowers I suddenly spotted a bee flying in a fly-like fashion - golly, yes it really was the bumblebee mimic I have been hoping to spot for quite a while now, the hoverfly Eristalis tenax, the drone fly. Focussing in on it, the obvious fly features of the eyes, antennae and the V-shape of its wings confimed that certainly wasn't the bumblebee it superfically remembers. How nice to be able to recognise an insect for the first time from its photographs in books and on the web!

As we came up along the School Lane path approaching the back of the house, I saw a small thin hover on the leaves at about waist height, and got a few shots of it from different angles as it seemed quite relaxed - Syritta pipiens another new species for me (or have I seen it once before?), said to be very common, but a little beauty. I couldn't see any orange bar on the hind femur as described in Stubbs & Falk, but this is a variable character anyway. This male fitted most characteristics quite well, and was really nice to see, and exciting to identify!


The swollen hind femurs are more obvious in the photo below taken more from the side.


And home at last! What a nice thing to find Syritta so close to the house!

Friday, 5 August 2011

Whetsted gravel pits

Scaeva pyrastri on tansy on the South bank of the Medway. This is a lovely insect and a relatively easy species to identify compared to some groups of hoverflies.

Only one Scaeva seen today, on the beautiful tansy (Tanacetum vulgare) flowers by the South bank of the river to the East of East Lock - this is the only site where I am currently aware of tansies growing apparently in the wild in the parish. The common tansy releases a camphor-like essential oil. In excess it is certainly toxic to humans, and it may also be used as an insect repellent

Thursday, 4 August 2011

Bat evening at Dunorlan

Turned out on a slightly chilly and breezy evening to support Val on a bat walk for the High Weald Project. Pam was also there so we compared notes on our first Daubenton's Bat survey last night, and reported back to Val.

Pam is also working with Ightham Mote to set up some bat walks there, and so I have offered to help out with those as well.

We did quite well tonight, and although the Noctules didn't shows quite so clearly as last week, I certainly got better views of the Daubenton's bats skimming over the water - really spectacular! Good numbers of both Soprano and Common Pipistrelles heard and seen - it really is a great place for a bat walk.

Tuesday, 2 August 2011

A quick post to mark a flying visit to North Wales and half an hour at the car-park between Foel Fenlli and Moel Famau, on a breezy slightly chilly evening

Monday, 1 August 2011

A damp field corner

How excellent that some farmers still go with the flow and don't try to push production to unrealistic and perhaps unsustainable limits. Right next to the River Bourne there's a small patch of damp land that holds some nice plants and who knows what else. At the end of a long day I took Monty down to have a quiet wander and in the still of a hot muggy evening the first thing I noticed was that the Common Fleabane heads have only just started to open up, attracting pollen beetles, hover-flies and a wide range of other odds and ends from the insect world. This hover-fly looks a bit like Sphaerophora, and possibly S. scripta, which I've already seen some days ago up at Dene Park.



The Fleabane (Pulicaria dysenterica) is seen in good stands along the damp edges of rides in nearby woods like Dene Park (where I saw the first heads open yesterday), as well as on the damp alluvial soil down here by the river. The plant's common name comes from its use to repel insects (the sap is astringent), while its specific name comes from a previous use as a supposed cure for dysentery - note the spelling!

Other plants noted were a fine stand of prickly ox-tongue, water mint, marsh woundwort, Birds-Foot Trefoil and smooth tare, all competing well with a wide range of grasses on this heavy low-lying land to form a colourful damp meadow.

There were quite a few hover-flies and bees together with other insects wandering around at knee height although it was already 6:30, and the heat of the day was vanishing quickly. This is an unknown species of Ichneumon wasp.


and this is a quick photo of a Gatekeeper butterfly.


and finally this is a view of a hover-fly I can't identify! I do wonder whether it might be a very fresh S.scripta, its just got that sort of feel about it (and the wings don't look as though they are going to reach the end of the abdomen!