Searching for Odonata on Dartmoor

Scarce Blue-tailed Damselfly (male) - near Cadover Bridge. The pattern of blue on the tip of the abdomen is different to Blue-tailed (see below).

 

One of my aims this summer is to learn about dragonflies and damselflies, so with that in mind I spent a very pleasant morning searching some sites on Dartmoor. It was great, not least because I so very rarely get up there these days. My targets were Southern Damselfly and Scarce Blue-tailed Damselfly - both scarcities and both species I've never seen before. I started at Prewley Moor, not far from Okehampton, and then followed the picturesque A386 south'ish, through Tavistock, and on to Cadover Bridge. I came back along the A38 which meant I pretty much circumnavigated the whole of Dartmoor. I failed to find Southern Damselfly (it's perhaps a bit too late in the season) but otherwise did pretty well.

Bird-wise there were a couple of surprises with a calling Willow Tit along the Granite Way at Prewley Moor, and a presumed migrant juvenile Sedge Warbler in a runnel on high moorland, close to Cadover Bridge. Once again a big thank you to Dave Smallshire for the site information. It was hugely helpful!

View from Prewley Moor looking up towards Sourton Tors.

Azure Damselfly - Prewley Moor. No Southern Damselfly at this site but I did see Small Red Damselfly, a small number of Keeled Skimmers and a Golden-ringed Dragonfly.

Common Emerald Damselfly - one of two seen near Cadover Bridge. Other Damsels included one Scarce Blue-tailed (see above), c10+ Blue-tailed, 3 Large Red and several Common Blue.

Common Hawker (immature male) - near Cadover Bridge. This is a new species for me. According to Dave, this wing damage is likely to have been caused by the recent brief spell of stormy weather. It sadly means that this individual is unlikely to be able to fly. Note the yellow costa (front edge of the wings) which is diagnostic of this species.

Female Blue-tailed Damselfly - form rufescens with a pink thorax

 

Black Darter - the only shot of a male that I managed. After taking this photo I moved to try for a better angle but it disappeared.

This immature male Black Darter was much more obliging. I wasn't expecting this species to be so small. This individual also has some wing damage but it seemed to be flying pretty strongly. A few Common Darters and a probable Emperor Dragonfly were also seen at this brilliant site, near Cadover Bridge.

Tricky Yellow-legged and a nice easy Juv

The long-winged, high-chested, long-legged and small, round-headed appearance sent me down the 'Caspian' path. The positioning of the small dark eye looked promising too. Although the bill is undeniably thick-based I felt it tapers to more to the shape of Caspian as opposed to the oft-quoted 'hatchet' bill of a Yellow-legged Gull (created by steep gonydeal angle).

 

I thought I was on to a Caspian Gull this morning. The bird was resting on Exmouth cricket pitch and was easily picked out by its darker grey upperparts. It's a second-summer bird and I felt that structurally it was a better fit for Caspian. With a bird of this age, and in this state of moult, there are no real diagnostic features to go on, but it should ideally show a small white mirror on p10 and this bird most certainly doesn't. That feature can however be absent on Caspians, but arguably would make this more likely a hybrid and therefore less safely identifiable as Caspian. Mike Langman has seen the photos and agrees it looks structurally ok for Caspian, but he was concerned about the thickness of the bill, and of course the lack of white mirror on p10. Tim Worfolk managed to see the bird before it flew, and cautiously felt it looked ok for Caspian (though a little thick-billed), but wanted to look more closely at the upperwing pattern before committing to an id. And finally, thanks to Tim, Martin Elliot has seen photos of the bird and thinks it's just Yellow-legged Gull. Gulls are rarely straightforward but rest assured I won't be submitting this as a Caspian!

Otherwise a couple Mediterranean Gulls and another juvenile Yellow-legged Gull were present earlier on.

It's so tricky judging size and structure of gulls. To my eye this looks to have long tibia and a small rounded head. It lacks the brow and fierce look that I normally associate with Yellow-legged Gulls, and I'd expect the eye to look paler. Gulls however are so variable, that none of these features hold much weight, and may be interpreted completely differently by other observers.

 

Lack of a mirror on p10 raises concerns about the identification. Otherwise the black band on what is apparently p5 is ok for both Caspian and Yellow-legged, so isn't really of any help.

 

50% of the small gulls on the cricket pitch were Meds.

 

Second summer Mediterranean Gull.

 

Juvenile Yellow-legged Gull (with a juvenile Herring Gull to its right).

YLG

 

Juvenile Yellow-legged Gull on Exmouth cricket pitch.

 

A sea-watch from 0540 to 0630, from Orcombe Point, was breathtakingly bad. Just one shearwater past in all that time, and it was either Manx or Balearic. Otherwise, a single Fulmar east and 4 Mediterranean Gulls east, with a trickle of Black-headed Gulls. Gannets didn't even reach double figures! I left to look at the gulls on the cricket pitch, noting 1 juvenile Yellow-legged Gull, about half a dozen Lesser Black-backed Gulls and 7 Mediterranean Gulls, amongst the Herrings and Black-heads.

A glance out to sea again, sometime after 10am, revealed two shearwaters together which were almost certainly Balearics - direct flight, no shearing etc. The visibility has been dreadful this morning.

 

Behind three juvenile Herring Gulls.

 

 

Juvenile Mediterranean Gull. Meds are everywhere you look in Exmouth at the moment, although I haven't seen the numbers they've had at the Warren.

 

Juvenile Yellow-legged Gull

Emerald Damselfly

Hummingbird Hawkmoth caterpillar on Lady's Bedstraw, near the Lifeboat Station. One of two larvae found on a quick search of the usual spot.

 

Emerald Damselfly - Stover Country Park - an exquisite insect and a brand new one for me. Hoping to find Southern and Scarce Blue-tailed Damsels next...

 

Tortoise Shieldbug. Never seen one of these before either. What a fantastic looking and aptly named creature!

 

Mandarin - Stover CP - one of four or 5 seen in the area where the ducks are regularly fed.

Juvenile Peregrine on Black-headed Gull kill - Mudbank

Lesser Wax Moth and White-legged Damselfly

Lesser Wax Moth - a new one for me, though not a scarce species. The name comes from the fact that the larvae feed on wax in old honeycombs. Was gutted to lose a presumed Acleris emargana from the trap which would have been another new one. Immigrant species included a small number of Silver Y and one or two each of Rusty Dot Pearl and Diamond-back.

White-legged Damselfly - male - a big thank you to Dave Smallshire for helping me track this species down. Just as he suggested, I found them resting in nettle beds. Apart from the white legs this species has a narrower head than its close relatives, and the markings on the abdominal segments are quite different. Colour-wise it's much paler than Common Blue and Azure Damselflies, and I thought it looked almost turquoise in flight

 

White-legged Damselfly - female

 

 

Southern Hawker - female

 

 

Marbled Green

Common Mompha and Some Dragon/Damselflies

Common Mompha - Mompha epilobiella

 

Ox-tongue Conch - Cochylis molliculana

Black-headed Conch - Cochylis atricapitana

Marbled Conch - Eupocilia angustana

Micro sp - possibly Homoeosoma nebulella or a Phycitodes species.

Holly Blue

Small Red-eyed Damselfly - male

Blue-tailed Damselfly - male

 

Red-eyed Damselfly - male

Red-eyed Damselfly

Jersey Tiger

Banded Demoiselle - male

Banded Demoiselle - female

 

Common Darter

Scarce Chaser - male

Common Blue Damselfly - male

YLG and Pebbles

Juvenile Yellow-legged Gull. This individual left a huge feeding throng of gulls offshore, early this morning, to rest briefly on the beach. Also noted in the feeding flock were several Mediterranean Gulls and my first juvenile Lesser Black-backed Gulls of the season. A Dunlin and  Little Egret were also noted during my brief early morning visit.

I fluffed the open wing/tail shot. One outstretched wing was the best I could manage.....

Pebble Hook-tip - my first this year.

Pebble Prominent

 

 

Black Arches - another first for the year.