Finding green hairstreaks

[Matsukaze]

Hi All,

I never find this species except by accident. Most of the places I know it from are a mix of scrub and flower-rich grassland, usually with bare patches. OK as far as it goes, but I do not find them in sunny sheltered spots on the ground, like I do with blues and the spring skippers. From other contributors' photos, they seem to spend a lot of time perching on large shrubs - but what sort of shrubs, at what height, and at what sort of aspect?

Finally, do we know what foodplants they use and what sort of microclimate they use for egglaying in limestone areas?

[NickB]

My sightings are all on chalkland; I have seen them on Hawthorn and Blackthorn (picture) hedges and bushes posing and nectaring and fighting for airspace.

They also seem to spread-out from these areas for basking on the banks of the Dykes and railway cuttings where they are found locally, angling themselves to the sun (which makes them difficult to get parallel when you try to get a shot ). I have also found them next to Small Blue, in a rough meadow next to a chalk quarry, ovipositing on Birds Foot Trefoil, though Common Rock Rose is assumed to be the primary larval food-plant on the Dykes I visit. A common feature seems to be that these places are sheltered and catch the sun.
Once you have found a colony - and they seem quite discreet, quite often no more than a dozen or so individuals - there are often others around in similar places close-by, perhaps within 100 metres or so. Each year these places seem to attract the males to display and fight - they were even seeing-off Peacocks that came too close this weekend - so I tend to go back to places I or others have found at this time of year. I suspect, but don't know, that the females are more-often seen away from these "master bushes" as they look for ovipositing sites, or check-out neighbouring displays(?).
I agree they are not often just found; I don't find many without this prior info - but I have been found kicking bushes and hedges at this time of the year in likely-looking spots or just sitting ,watching the tops of the bushes, for signs of activity in likely places....I think they are probably more widespread than we know, tho' my bush-kicking does not support this hypothesis so far

With regards to habitat and ecology - my local BC Branch is helping sponsor a project on the Devils Dyke and Fleam Dyke here near Cambridge:

* * * GREEN HAIRSTREAK PROJECT ON DEVIL'S DYKE * * *

Phil MacMurdie is undertaking a project (with all the necessary permissions and support etc.) into the ecology of the Green Hairstreak on the Fleam and Devil's Dyke. He would appreciate any sightings of Green Hairsteak (with a grid reference or location description, including any activity notes) which we will forward onto him.

So, if any UKB'ers are out on the Dykes, let Phil know of GH sightings via the Cambs&Essex BC web-site -
sightings@cambs-essex-butterflies.org.uk

N
Not much good for limestone ecology, sorry!

[Jack Harrison]

Phil MacMurdie is undertaking a project

I met Phil on Sunday.

survey.jpg (57.62 KiB) Viewed 740 times

As someone else commented – in jest I hasten to add – that the Green Hairstreaks in Cambridgeshire will not make good photographic subjects after the marking process.

I carried out a similar survey in the 1970s on Pearl Bordered Fritillaries in Rewell Wood, West Sussex being mainly interested in colony size. The methodology is easy. 100 (or whatever) are marked late morning (presumably after the emergence that day is likely to be complete – only males were counted) and released. Then another capture session follows with another (say) 100 males. These are marked in a different colour (to avoid counting twice). Now if for example, during the second session, 25 are caught that had been marked in the previous session, but another 75 are caught that were previously unmarked, this implies that approx a quarter of the population had been marked first time so that the total number of males in the colony can be estimated to be around 400.

I have used simple arithmetic here to illustrate. I have lost my records from that survey, but as best I can recall, the total colony size (males + females) of PBFs was around 160 (80 males – I assumed an equal number of females) – that today would seem an extraordinary number.

Jack

[IAC]

Hi all,
The Green Hairstreak is becoming a real conundrum here in South East Scotland. The distribution maps show a real void in Northern England- Southern Scotland, especially in the east. The nearest colony to were I live is 25 miles or so to the west. The habitats required are a little different to the ones you mention Nick. Here it is Billberry, Birch, moorland, dry slopes, scrub. We have plenty of that type of habitat, but no historical records of GH at all. Under recording ?...very possible..I have a task and a half faced with vast areas of possible sights and turning up nothing. I am convinced that they must exist somewhere locally..
The Bush kicking technique you mention Nick sounds interesting unorthodox...yes...but more than likely effective...as long as the bush does not kick back
With this particular species it seems a little luck is more than definately required.

Cheers

IAC.

[Lee Hurrell]

I've only ever seen one Green Hairstreak, about 20 years ago in a disused quarry near Kemsing in Kent that was surrounded by mature shrub, on which it was perched.

I'd dearly love to see another one!

Cheers

Lee

[Pete Eeles]

... but I do not find them in sunny sheltered spots on the ground ...

I must admit, I do find them close to the ground quite regularly - and not just ovipositing females. Yesterday, a male had set up a territory in a very sheltered area and flew between bushes at head height, and often perched on ground vegetation. Typically, however, the males (especially) will sit at around head height on a prominent bush / shrub.

... but what sort of shrubs, at what height, and at what sort of aspect?

I think they use a variety of shrubs depending on the site. But hawthorn is a favourite where they blend in perfectly! They also like sun, so clearly branches in full sunlight are chosen.

Finally, do we know what foodplants they use and what sort of microclimate they use for egglaying in limestone areas?

This species has the widest variety of foodplants of any British species. I've seen them lay on gorse, goose grass and rock-rose.

Cheers,

- Pete

[Padfield]

On close-cropped chalk downland they do readily come to ground, often to buttercups and other yellow flowers. But this is not at all a good way of finding them. Familiarity with the kind of outposts on bushes that they prefer is the best way. I find that in late morning (10.00am - 12.00pm) they occupy entirely predictable points on suitable shrubs, and frequently exactly the same place year after year. On Saturday I visited a particular bush at 11.00am that in previous years has invariably had a green hairstreak standing guard, so I could get a good portrait for my year list. Sure enough, a green hairstreak zoomed out at me, spun around the bush a couple of times and returned to the same place, allowing some nice shots:



As you can see from the glimpse of meadow in the background, these posts are often good vantage points, from which the hairstreaks will challenge any passing insects, butterflies or other.

Guy

[NickB]

Hi all,
The Bush kicking technique you mention Nick sounds interesting unorthodox...yes...but more than likely effective...as long as the bush does not kick back
Cheers
IAC.

...you should see the ones that DO
N

[Jack Harrison]

Tabloid headline: NICK KICKS BUSH

Jack

[Zonda]

Today i trudged the scrubby chalk downland all around the giant at Cerne Abbas (a noted GH site). Afterwards,, i trudged another Dorset chalky scrub reserve at Muckleford. Lots of blackthorn and gorse blossoming at both sites. I saw some frisky small Torts, and one Speckled wood, not a sign of a GH. All i got was a lot of leg ache. Tomorrow i'm heading for the acid heaths.

[Matsukaze]

Thanks folks - interesting food for thought!

[Dave McCormick]

I have found Green Hairstreaks in cutover or lowland raised bogs here in Northern Ireland. I found my first early last May and beat a large bush (it was around 11am or so when I did this, not sure if they are found more so in morning or not) and one flew out. I have been wanting to find if a colony exists at my reletives bog, they have not been recorded in area before, but it has the right habitat.

[Lee Hurrell]

Tomorrow's tabloid headline: DAVE BEATS BUSH

[Jack Harrison]

Lee:

Tomorrow's tabloid headline: DAVE BEATS BUSH

Don't you mean DAVE* BEATS ABOUT THE BUSH

* replace with your own choice.

Jack

[Chris Pickford]

They are fairly common most years around here (S.Oxon, Chalk Downland) in one or two specific spots. The best way I've found to see them is to go to prominent hawthorn bushes or small trees in sunny positions and wait. Groups of 3-4 GHs seem to move around over quite a large area, but will come back time after time to these prominent bushes and fly rapidly around in circles together on the sunny side of the bush, at say 10 - 20 feet above the ground. I presume this is either part of the mating ritual or males showing off. When the sun goes in, they tend to perch where they are and can often be photographed:-

Chris

[NickB]

Today i trudged the scrubby chalk downland all around the giant at Cerne Abbas (a noted GH site). Afterwards,, i trudged another Dorset chalky scrub reserve at Muckleford. Lots of blackthorn and gorse blossoming at both sites. I saw some frisky small Torts, and one Speckled wood, not a sign of a GH. All i got was a lot of leg ache. Tomorrow i'm heading for the acid heaths.

Just to let you know - You are not the only one to blank on a GH trip this last weekend; I went to another known site on the Devils Dyke on Sunday - but found NOTHING! My only thought is that it was perhaps 150-200 feet higher and more exposed than the first site, and hence just a bit behind...
N

[Susie]

I had a look around some likely spots at Denbies Hillside this morning where I have seen them in previous years but without luck. A jolly nippy wind was blowing this morning.

[Jack Harrison]

I have let Alex know (Sandringham thread) that I am provisionally planning to go to Holme NNR (near Hunstanton) on Friday primarily for Green Hairstreaks. It's a splendid place in any case, Green Hairstreaks or no Green Hairstreaks.

Jack

[Vince Massimo]

Today i trudged the scrubby chalk downland all around the giant at Cerne Abbas (a noted GH site). Afterwards,, i trudged another Dorset chalky scrub reserve at Muckleford. Lots of blackthorn and gorse blossoming at both sites. I saw some frisky small Torts, and one Speckled wood, not a sign of a GH. All i got was a lot of leg ache. Tomorrow i'm heading for the acid heaths.

Zonda - I hate to see a grown man cry. If all else fails try Ballard Down (which I think is quite near you). It is a good reliable site for Green Hairstreak and they are always in the same place. You should also see Dingy Skipper and possibly Brown Argus, but best to leave it at least a 10 days to be sure. I can provide more details if required.

I trust you know that the Cerne Abbas giant is also good for Marsh Fritillary at the end of May and beginning of June.

Good hunting,

Vince

[Zonda]

Thanks Vince, i am a grizzler aren't i? On Friday i'm doing the eastern heathland and Durlston, which may give better result. The weather is set to warm up at the end of the week.