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Re: Large Tortoiseshell.
Posted: Mon Mar 10, 2025 8:39 am
by Allan.W.
I think its a natural occurence . Large Torts have been noted in many areas of East Kent over the last 3 seasons ,including several sections of the Orlestone block .Last season in the main area where the most sightings are coming from this March ie;Birchett Wood ,had a few sightings at the same time in 24' (actually slightly later ) and I also had a probable Gravid female in late July 24' (see Favourite photo thread,+LT picture thread ) ,2-3 were also noted at Park farm ,Kingsnorth , And along a byway near Woodchurch . A friend had several sightings in his garden at Brabourne ,including an individual late on which he released from an upstairs room .Its also worth mentioning that there were a few seen in the Blean near Canterbury ,possibly East Blean .....most interestingly was the discovery of full grown larvae there .Most of these records above have appeared at one time or another on various social media sites ......mainly facebook (which I don't use ).If they were being released locally ,surely they would have been released at a positive area holding plenty of Elm....which as far as i,m aware is missing or very ,very limited in Orlestone (not sure about the Elm situation in Blean).
In Orlestone there is plenty of Sallow......and my feeling is that the Large Torts are using Sallow as their food source . Don't have a lot of luck looking through records from The Kent Branch butterfly conservation site but i'd bet that Large Torts were seen in other parts of Kent in the recent past as well.
Re: Large Tortoiseshell.
Posted: Mon Mar 10, 2025 9:54 am
by Butterfly_Julian
Hi Allan, thanks for the post on the back ground to these sightings .
Julian
Re: Large Tortoiseshell.
Posted: Mon Mar 10, 2025 6:42 pm
by bugboy
Lawts wrote: ↑Mon Mar 10, 2025 8:15 am
Were there records from the Orlestone/Hamstreet area last year? I don't recall seeing any. I remember Knepp and Portland, I think it was but not here.
Also, how long might one expect to see them at this site, given the right weather conditions, before it goes quiet again?
Thanks.
viewtopic.php?t=11965
viewtopic.php?t=11681
Like most the adult overwinterers they'll probably remain active for a month or two yet, weather dependant obviously. Then a wait until July when any new ones will be emerging but that's just a short window of a couple of weeks before they go straight into hibernation.
Re: Large Tortoiseshell.
Posted: Mon Mar 10, 2025 9:19 pm
by Lawts
bugboy wrote: ↑Mon Mar 10, 2025 6:42 pm
Lawts wrote: ↑Mon Mar 10, 2025 8:15 am
Were there records from the Orlestone/Hamstreet area last year? I don't recall seeing any. I remember Knepp and Portland, I think it was but not here.
Also, how long might one expect to see them at this site, given the right weather conditions, before it goes quiet again?
Thanks.
viewtopic.php?t=11965
viewtopic.php?t=11681
Like most the adult overwinterers they'll probably remain active for a month or two yet, weather dependant obviously. Then a wait until July when any new ones will be emerging but that's just a short window of a couple of weeks before they go straight into hibernation.
Thanks for the info.
Re: Large Tortoiseshell.
Posted: Mon Mar 10, 2025 10:17 pm
by Lawts
What will be the outcome for these butterflies that have come out of hibernation following these recent warm temperatures, if there was a period now, of say two weeks where the temperatures might not get above ten degrees? The forecast is now for temperatures below the seasonal average. Notwithstanding as as been said, that these specimens could be about for a month or two, is that totally weather dependent?
Might they go back into a further mini hibernation, or now they've committed to coming out of hibernation, will they simply perish if temperatures were to stay consistently low?
Thanks.
Re: Large Tortoiseshell.
Posted: Mon Mar 10, 2025 11:30 pm
by bugboy
Lawts wrote: ↑Mon Mar 10, 2025 10:17 pm
What will be the outcome for these butterflies that have come out of hibernation following these recent warm temperatures, if there was a period now, of say two weeks where the temperatures might not get above ten degrees? The forecast is now for temperatures below the seasonal average. Notwithstanding as as been said, that these specimens could be about for a month or two, is that totally weather dependent?
Might they go back into a further mini hibernation, or now they've committed to coming out of hibernation, will they simply perish if temperatures were to stay consistently low?
Thanks.
As with all adult over winterers they've evolved to cope with the changeable weather patterns at this time of year. They'll simply go into torpor during these cooler, duller spells, using minimal energy, and return when things warm up again. The females will now most likely have been mated so all they'll need is a sunny afternoon to lay their eggs and the job is done. With the sun getting higher, even if the air temp is below 10 degrees, the radiant heat will be enough to keep them active on a sunny day, butterflies in temperate climes are experts at finding warm sheltered spots so as to remain active. If we get a sunny afternoon during this cool spell, I'd look for them on some east/west paths that will provide shelter from the northerly winds.
Re: Large Tortoiseshell.
Posted: Tue Mar 11, 2025 7:16 am
by Mark Tutton
Interesting article on Sussex BC by Dave Harris documenting breeding of LT in Sussex since 2021
https://sussex-butterflies.org.uk/down ... eshell.pdf
Kind Regards
Mark
Re: Large Tortoiseshell.
Posted: Tue Mar 11, 2025 7:21 am
by Lawts
bugboy wrote: ↑Mon Mar 10, 2025 11:30 pm
Lawts wrote: ↑Mon Mar 10, 2025 10:17 pm
What will be the outcome for these butterflies that have come out of hibernation following these recent warm temperatures, if there was a period now, of say two weeks where the temperatures might not get above ten degrees? The forecast is now for temperatures below the seasonal average. Notwithstanding as as been said, that these specimens could be about for a month or two, is that totally weather dependent?
Might they go back into a further mini hibernation, or now they've committed to coming out of hibernation, will they simply perish if temperatures were to stay consistently low?
Thanks.
As with all adult over winterers they've evolved to cope with the changeable weather patterns at this time of year. They'll simply go into torpor during these cooler, duller spells, using minimal energy, and return when things warm up again. The females will now most likely have been mated so all they'll need is a sunny afternoon to lay their eggs and the job is done. With the sun getting higher, even if the air temp is below 10 degrees, the radiant heat will be enough to keep them active on a sunny day, butterflies in temperate climes are experts at finding warm sheltered spots so as to remain active. If we get a sunny afternoon during this cool spell, I'd look for them on some east/west paths that will provide shelter from the northerly winds.
Thanks again for the info.

Re: Large Tortoiseshell.
Posted: Tue Mar 11, 2025 7:17 pm
by essexbutterflyer
Thank you Lawts for asking a question I had been wondering about and thank you Bugboy for answering it! I had initially resigned off this week but after reading this perhaps a little search in a sunny spell won’t do any harm
I’m a little late to the Large Tort party but am hoping to travel down in the next good spell of weather… hopefully they’ll still be there

Re: Large Tortoiseshell.
Posted: Wed Mar 12, 2025 11:31 am
by David M
essexbutterflyer wrote: ↑Tue Mar 11, 2025 7:17 pmI’m a little late to the Large Tort party but am hoping to travel down in the next good spell of weather… hopefully they’ll still be there

They ought to be, Zayed. March is a very active month for them with the males holding territory.
Re: Large Tortoiseshell.
Posted: Wed Mar 12, 2025 12:10 pm
by essexbutterflyer
David M wrote: ↑Wed Mar 12, 2025 11:31 am
essexbutterflyer wrote: ↑Tue Mar 11, 2025 7:17 pmI’m a little late to the Large Tort party but am hoping to travel down in the next good spell of weather… hopefully they’ll still be there

They ought to be, Zayed. March is a very active month for them with the males holding territory.
Thanks David. Just waiting for the weather to improve now... may have to wait a while

Re: Large Tortoiseshell.
Posted: Wed Mar 12, 2025 12:25 pm
by bugboy
essexbutterflyer wrote: ↑Wed Mar 12, 2025 12:10 pm
David M wrote: ↑Wed Mar 12, 2025 11:31 am
essexbutterflyer wrote: ↑Tue Mar 11, 2025 7:17 pmI’m a little late to the Large Tort party but am hoping to travel down in the next good spell of weather… hopefully they’ll still be there

They ought to be, Zayed. March is a very active month for them with the males holding territory.
Thanks David. Just waiting for the weather to improve now... may have to wait a while
The weekends looking promising, particularly Saturday (at least on the apps on my phone!)
Re: Large Tortoiseshell.
Posted: Wed Mar 12, 2025 12:43 pm
by Lawts
In addition to the grid reference provided up thread, does anyone have any more grid references or directions for any of the others seen in the area, particularly the site where six were reported on Birdguides.
Wasn't clear if the six were together, or a summation of a few records in the general area.
Thanks.
Re: Large Tortoiseshell.
Posted: Wed Mar 12, 2025 2:19 pm
by David Lazarus

- 2025 Large Tortoiseshell recorded sightings
Source: iRecord
Re: Large Tortoiseshell.
Posted: Wed Mar 12, 2025 2:35 pm
by Lawts
That's great David.
Thanks.
Re: Large Tortoiseshell.
Posted: Wed Mar 12, 2025 5:52 pm
by Lawts
bugboy wrote: ↑Wed Mar 12, 2025 12:25 pm
essexbutterflyer wrote: ↑Wed Mar 12, 2025 12:10 pm
David M wrote: ↑Wed Mar 12, 2025 11:31 am
They ought to be, Zayed. March is a very active month for them with the males holding territory.
Thanks David. Just waiting for the weather to improve now... may have to wait a while
The weekends looking promising, particularly Saturday (at least on the apps on my phone!)
The BBC is saying only 6 degrees for Saturday, feeling like 2. I know those are shade temperatures though. I also know I underestimate conditions when butterflies will actually be active. See what happens. It doesn't look particularly favourable through to the end of March

.
Re: Large Tortoiseshell.
Posted: Wed Mar 12, 2025 5:57 pm
by John W
Hi David,
What do the blue squares on the iRecord map represent?
Cheers
John W
Re: Large Tortoiseshell.
Posted: Wed Mar 12, 2025 8:07 pm
by millerd
John W wrote: ↑Wed Mar 12, 2025 5:57 pm
What do the blue squares on the iRecord map represent?
Cheers
John W
I can nip in and answer this - they correspond to the sightings listed below the map. The size of the squares just indicate the precision of the map reference given, so the bigger squares are just less refined grid references (the six figure ones), and the small ones the more precise grid refs (the eight figure ones).
Cheers,
Dave
Re: Large Tortoiseshell.
Posted: Wed Mar 12, 2025 8:12 pm
by David Lazarus
John W wrote: ↑Wed Mar 12, 2025 5:57 pm
What do the blue squares on the iRecord map represent?
Hi John,
The blue dots and squares are locations differing in accuracy based on a 6-figure or 8-figure national grid reference. The squares represent a location within a 100 metre square and therefore is less accurate. They are used for transect sections. I prefer the more accurate 8-figure reference which locates a butterfly within a 10 metre square. This is more than sufficient for our purposes, and can be used, for instance, to locate a congregation tree when searching for Purple Emperor. A 10-figure grid reference will locate a butterfly within a 1 metre square and is not commonly used for recording butterfly sightings.
You can see on the list above that two of the references TQ980348 & TQ981345 are 6-figures - these are the two squares. The others are 8-figure grid references. I hope that is what you wanted. Sorry if the full explanation was not required - it might help others if you already knew it.
Happy hunting everyone if you get a sunny one.
edit - Ah, thanks Dave, you beat me to it while I was writing my essay.

Re: Large Tortoiseshell.
Posted: Thu Mar 13, 2025 9:55 am
by Lawts
One on Monday at St. Margaret's apparently. Hardy!