So an oak is an oak – yes?

Think again – Dartmoor (and the UK generally) has in fact got two species of native oak (Genus Quercus). One species the Pedunculate or English oak (Quercus robur) is the species of  lower more nutrient rich ground whilst the Sessile oak (Quercus petrea) is an upland species found on nutrient poor soils. Sessile oak is the quintessential species of Dartmoor’s river valleys (e.g. the Teign, the Dart and the Lyd). With a bit of practice and knowledge it is quite easy to tell the two species apart.

 These are the leaves of Pedunculate oak (Q. robur) – note the leaves have very short stems where they meet the twig/branch and have little ears called auricles where they meet the twig – you can see the auricles at the centre of this photo where the four leaves join the branch

 A single Pedunculate oak leaf – note no stem to the leaf – the auricles are at the left end of the leaf in this picture. In addition the underside of the leaf and its veins are hairless.

These on the other hand are the leaves of the Sessile oak (Q. petrea). Note there is a stem over 1cm long which joins the leaves to the twig

A single leaf of Sessile oak – stem and no ears! On the underside of the leave along the veins are numerous star shaped hairs.

There is another essential difference between the two species but one which I won’t be able to show you until the autumn – this involves the stalk on the acorns. The Pedunculate oak has a long stalk to connect the acorn and cup to the twig whilst the Sessile oak’s acorns and cups are stalkless.

In summary then….

Pedunculate oak: short stems to the leaves, auricles, hairless and long stalk on the acorns
Sessile oak: long stems to the leaves, no auricles, star like hairs on the undersurface veins, no stalks to the acorns

Where to see the two species:  there are plenty of Pedunculate oaks at Parke (but beware the parkland contains a number of exotic species of oak too (e.g. The Lucombe Oak, Turkey oak and Holm oak) but they look very different. You can find Sessile oaks in the Teign Valley including Fingle Woods, Lydford Gorge, Hembury Woods and Holne Woods. These woods also contain some Pedunculate oak so are perfect places to practice your ID skills!

A fox in the garden

Got home from work last night and rather surprisingly there was a fox in our garden eating the  seed  and peanuts that had fallen out of the bird feeders! Here are a few pictures.

Birds are messy feeders – lots of the seeds and nuts fall to the ground and the fox is hoovering them up

Ever alert – distracted by a car

The sun catches his fur

I’ve been spotted

I’m looking at him and he’s looking at me

Rather magical!

Parke’s longhorn beetles

I like longhorn beetles – they are large, relatively easy to identify and are found only occasionally so always cause me some excitement! They are not species I specifically go looking for – I normally just bump into them or as happened yesterday they bump into me. Whilst I was a Parke yesterday a large insect flew into me and then landed on an adjacent ash tree. I immediately caught it to see what it was. It turned out to be the black-spotted longhorn beetle Rhagium mordax.

I photographed it in my office on the carpet – it was quite flighty and I was keen to get a picture before it flew off

Here is another picture of the same species also found at Parke in 2009.

Here is Rhagium mordax‘s national distribution – it is quite a common species.

Longhorn beetles have interesting and long lives. The adult female beetle lays eggs into the outer sapwood of rotting stumps (oak predominantly for R. mordax). The larvae then feed on the rotting wood for 2-3 years before emerging as an adult. The adult R. mordax metamorphose in August and stay within the pupal case only emerging in the following April!

This is the closely related species Rhagium bifasciatus – the two-banded longhorn beetle. Again recorded at Parke in 2008. It is a species most often associated with Scots Pine.

Again quite a common and well distributed species nationally

 This species, found at Parke in 2008 is the golden-haired longhorn beetle Leptura aurulenta. The larvae for this species can spend up to 4 years feeding on the dead wood of various trees – most usually oak.

Golden-haired longhorn beetles are much rarer than the previous two species and are largely restricted to Cornwall, South Devon, Hampshire and West Sussex. It has a rarity rating of Nationally Scarce A – a good find at Parke.

This species is a large one known as the Tanner beetle Prionus coriarius. This individual was trapped at Parke last year during a moth trapping evening on the 25th July when the highlight of the evening was the capture of a Ringed Border moth – a first for Devon! (see here and here for further details). The Tanner beetle larvae live for up to four years on the roots and rotting stumps of old deciduous trees. The adults are out and about between July and September – they are crepuscular which means they fly at dawn and dusk and are often attracted to light. Thank you to Nicola Bacciu for allowing me to use her excellent photograph of the Parke specimen.

Again another sparsely distributed species which is categorised as Nationally Scarce A – another excellent record for Parke.

 

The final species I have recorded at Parke is Rutpela maculata – the black and yellow longhorn beetle. I found 4 individuals last July at Parke – see here. The larvae are fond of rotting birch and can live for 2-3 years. The adults are quite conspicuous as they are often found feeding on umbellifer flowers.

Quite a common species nationally.

Longhorn beetles are good indicators of species rich parklands, woodlands and dead wood habitats – they are species of conservation interest – the more species – the better the habitat. There are records of three other species from Parke – Grammoptera ruficornis  the common Grammoptera, Leptura quadrifasciata the four banded longhorn beetle and Pogonocherus hispidulus the greater thorn-lipped longhorn beetle – all are quite common nationally. I am sure there are many more species of longhorn beetle here at Parke and over time they will be recorded. If you have any records of longhorn beetles from Parke or any other National Trust properties I would love to hear from you.

All maps are courtesy of the National Biodiversity Network – see here where you can access (for free) distribution maps of all UK species of wildlife – an amazing resource built largely on the efforts of amateur naturalists who share their records for the greater good.

If you want to know more about longhorn beetles I can recommend the excellent Identification articles in British Wildlife Magazine.

Identification: Longhorn beetles part 1: British Wildlife (2007)  vol 18 pp406-414 Andrew Duff & Richard Lewington
Identification: Longhorn beetles part 2: British Wildlife (2007)  vol 19 pp35-43 Andrew Duff & Richard Lewington

See here for more details on British Wildlife Magazine – an essential read / subscription!

 

A wet meadow

The wet meadows in the Bovey Valley at Parke are looking great at the moment – awash with the colour of buttercups, ragged robin and cuckoo flower. Restoring these meadows is currently one of our priority conservation projects.

Buttercups and cuckoo flower

Ragged robin – a good indicator of a quality unimproved wet grassland

A couple of red and black froghoppers Cercopis vulnerata – instantly identifiable!

This is the distribution of the froghopper – not many records from Devon and it looks like the Parke record is a new one

This is a thick knee flower beetle Oedemera nobilis – very common on buttercups at the moment – note the bulges on the knees and the ‘split’ wing cases

Common – but not that common in Devon – have been recorded before at Parke

Lydford’s grey wagtail chicks take to the wing

Yesterday lunchtime I had a quick walk down into Lydford Gorge. I was lucky to find a noisy family of grey wagtails –  in the last couple of days the chicks have left the nest and are now flying around the river but are still being fed by their parents. Here are a few photos

Grey wagtail fledgling (the name given to a chick which has now learnt to fly)

Lots of light grey and a hint of yellow around the tail

Every 5-10 minutes the adults would come and feed the birds who were constantly calling

I saw two fledglings – one on each side of the river

 

Lydford Gorge and the Lyd – its like going up the Amazon!

The Cauldron was quite lively yesterday

A male fern frond unfolds

Teign Valley specialities

A number of rare and uncommon beasties are now out and about in the Teign Valley below Castle Drogo. The other day when I was there I saw the following species.

This is the nationally rare and declining pearl bordered fritillary – populations on Dartmoor are bucking the national trend and are increasing

This is a small heath butterfly – a fairly common species

This is a Wall Butterfly – nationally uncommon and declining

This is the very rare ground beetle – Kugellan’s Ground Beetle – every year I try and monitor how this major rarity is doing in the Teign Valley. I have written about this species before – see here.

 

 

Orange tips at Parke

The last few weeks of glorious weather has really brought out the butterflies. At Parke there has been a large emergence of orange tips.

This is a male orange tip – in my view of of the most spectacular of of native species

The main food plant for the orange tip is the cuckooflower (Cardamine pratensis) along with other members of the cabbage family. There is a good population of cuckooflower in our wet meadows along the River Bovey

Cuckooflower has four petals (a chracteristic of the cabbage family) and the flowers have a lovely pink hue

I have written quite a bit about oil beetles and their larvae which are called triungulins – see here, here and here. The other day when I was looking for fritillaries at Parke (sadly no sign yet) I counted 35 flowers with oil beetle larvae in a area 20m x 30m – amazing – they are having a good year!

Triungulins on lesser celandine (Ficaria verna)

And more of dandelion (Taraxacum officinale)

 

Violets at Hembury Woods

From a distance it looks as if the bluebells are out – they are not – it is still too early. When you get closer you see they are violets – thousands and thousands of them.

Violets flowering amongst the bluebell leaves

Good to see so many – violets are the food plant for our pearl bordered and small pearl bordered fritillary butterflies

A close up shot

Comma

I photographed this lovely comma butterfly at Parke a couple of days ago. Commas are pretty common butterflies in the woodlands and meadows of Dartmoor. This individual has hibernated overwinter and is now active on the wing enjoying the sunshine. You can see that its wings are a little worn at the edges.

The food plant for the comma is predominantly the common nettle – the eggs laid on the leaves resemble bird droppings as a means of cryptic camoflage.

Last century the comma declined considerably and since then has made a dramatic recovery. It is a flexible species now which is able to respond quickly to favourable conditions and expand quickly.

So far this year I have now seen 7 species of butterfly (red admiral, peacock, orange tip, brimstone, speckled wood,  small tortoisehell and the comma). In the next few days pearl bordered fritillaries should start emerging.

A fly and a beetle that are beastly to bees

At Parke yesterday I managed to photograph a fly and a beetle which have life styles where their larvae predate the larvae of solitary bees.

This is the bee fly Bombylius major – a really attractive fly which mimics a small bumblebee – here it is feeding on the nectar inside a primrose flower

 Another picture showing the long ‘nose’ which reaches deep into the flowers.

The adult bee flies are vegetarian but they lay their eggs immediately outside the burrows of solitary bees – these then hatch and crawl into the nest and feed on the bee’s larvae. See here more details.

These are tiny oil beetle larvae sitting on a dandelion flower – these larvae are also known as triungulins.

As you can see there are quite a lot of larvae in the one flower.

Here is a close up – the triungulins are waiting for a solitary bee to visit the dandelion flower – a single triungulin will then attach to the bee’s leg and be transported back to its nest where it will then detach and feed on the larvae of the bee

This is what adult oil beetles look like when they emerge from the bee’s nest – these were both photographed last May again at Parke. The animal at the top of the picture is a female and the one at the bottom is the male.

Buglife in partnership with the National Trust is carrying out a survey into oil beetles – see here for details on how you can get involved.

Whilst the life styles / behaviours of bee flies and oil beetles might seem disturbing – remember that both bee flies and oil beetles are pretty rare whilst solitary bees are pretty common – if the balance were the other way around it just wouldn’t be sustainable!