UK - Lang’s Short-tailed Blue (1 Viewer)

[Bismarck Honeyeater]

Was fortunate enough today, to be invited to see a Lang’s Short-tailed Blue that had entered a house in Berkshire a week or so ago. Also saw it get released. The house owners said they have not bought any legumes lately, and it seems this individual came in through an open window.

A friend recently back from Spain has told me that LSTB’s were 3x more common than is usual. The supporting cast of vagrant Southern Moths and Swifts lately is also good circumstantial evidence for a genuine migrant, in my opinion.

Does anyone have knowledge of any movements recently in northern France, or elsewhere?

 

[Andy Adcock]

Not sure a vagrant would be sporting such long and intact tails?

 

[Farnboro John]

Not sure a vagrant would be sporting such long and intact tails?

Depends more on how old it is and how fast it travelled than vagrancy per se: quite probably the risks during migration flight at sufficient altitude to clear obstacles are lower than when bumbling about round flowers in among insect-eating birds. The first Long-tailed Blue I saw in Britain was tatty but subsequent ones have been stunning.

A lot of the transatlantic butterflies and dragonflies have been in perfect nick on arrival.

John

 

[Andy Adcock]

Depends more on how old it is and how fast it travelled than vagrancy per se: quite probably the risks during migration flight at sufficient altitude to clear obstacles are lower than when bumbling about round flowers in among insect-eating birds. The first Long-tailed Blue I saw in Britain was tatty but subsequent ones have been stunning.

A lot of the transatlantic butterflies and dragonflies have been in perfect nick on arrival.

John

Not sure I've seen one here with such complete tails, don't doubt they exist though.

 

[Owene]

Not sure I've seen one here with such complete tails, don't doubt they exist though.

Maybe one in 10 was like that of the ones I saw when I was out there first week of November but I don’t think the actual vagrancy would have much impact.

 

[Andy Adcock]

Maybe one in 10 was like that of the ones I saw when I was out there first week of November but I don’t think the actual vagrancy would have much impact.

Really, why not, they're much more fragile than birds feathers which are fairly often abraided when occuring as a migrant ?

 

[dantheman]

Depends more on how old it is and how fast it travelled than vagrancy per se: quite probably the risks during migration flight at sufficient altitude to clear obstacles are lower than when bumbling about round flowers in among insect-eating birds. The first Long-tailed Blue I saw in Britain was tatty but subsequent ones have been stunning.

A lot of the transatlantic butterflies and dragonflies have been in perfect nick on arrival.

Getting a good tailwind helps?

 

[Jos Stratford]

Really, why not, they're much more fragile than birds feathers which are fairly often abraided when occuring as a migrant ?

I've seen fresh Lang's with abraded tails and, on occasion, absolutely tatty Lang's where the tail has managed to remain intact. However, I would also be of the opinion that a migrant butterfly would not necessarily be any more tatty than any other butterfly. Painted Ladies are perhaps an example of pristine condition migrants - all Painted Ladies in Lithuania are migrants and most tend to be very good condition when they first appear, gradually thereafter becoming more tatty.

 

[dantheman]

(Abraded not abraided)

Butterflies don't usually have ponytails.





Agree there is usually no reason migrants have to be in poor condition - presume they may be if they have encountered bad weather (hail/rain?) but that doesn't necessarily have to happen (and anyway if the rain etc is happening if the same direction as the animal concerned may have no effect). Something physical has to have affected them en route (dust can also be abrasive), or before setting off. With birds that turn up in poor condition this could be moult etc before they left or even just in poor condition. Any number of small yank passerines have turned up here in pretty pristine condition (travelling through or between fronts, sometimes involving lots of weather?) ...

 

[Owene]

Really, why not, they're much more fragile than birds feathers which are fairly often abraided when occuring as a migrant ?

I thought a lot of abrasion was from plants and predators. Just getting caught in a weather pattern and blown away maybe less so as John says a lot of pristine vagrants turn up.