Late emerging females
Late emerging females
Virtually all the Meadow Browns I am seeing now (late August) are females. It is thought they generally mate on the first day of emergence but where are the males? Do they mate at times when we don't usually see them, in the early morning or late evening and/or are the males hiding in deep vegetation?
It is a complete mystery to me why adult females and not males are seen so late in the year unless perhaps as a means of dispersal.
ATB
Peter
It is a complete mystery to me why adult females and not males are seen so late in the year unless perhaps as a means of dispersal.
ATB
Peter
My website: http://www.stevenagebutterflies.co.uk
Re: Late emerging females
This is interesting...
In hot Mediterranean climates (eg Portugal) and some parts of Greece, the females actually aestivate during the high heat of mid-summer, before reawakening to lay eggs later in the year. I wonder if this occurs to a lesser degree in this country also - it may be that this year's heatwave has made this more noticeable in the UK this year. Presumably the females pair up before entering aestivation, although that would suggest very long term viability of the male meadow brown semen, unless they are able to fertilize eggs and the female can then arrest their development.
I am sure someone on here will have more knowledge on their biology!
In hot Mediterranean climates (eg Portugal) and some parts of Greece, the females actually aestivate during the high heat of mid-summer, before reawakening to lay eggs later in the year. I wonder if this occurs to a lesser degree in this country also - it may be that this year's heatwave has made this more noticeable in the UK this year. Presumably the females pair up before entering aestivation, although that would suggest very long term viability of the male meadow brown semen, unless they are able to fertilize eggs and the female can then arrest their development.
I am sure someone on here will have more knowledge on their biology!
Re: Late emerging females
Yesterday, about 12:30, I disturbed a pair of coupled Meadow Brown. They were in a thick clump of marram grass and fluttered away still joined. I was preoccupied and didn’t give it a second thought, but this post has made me realise that I don’t recall seeing Meadow Brown mating before.
- Essex Bertie
- Posts: 247
- Joined: Sat Jul 24, 2010 6:16 pm
- Location: Brentwood, Essex
Re: Late emerging females
I mainly see females at this time of year, often in egglaying mode in cut grassland. But there is still the odd male about. Some people talk as if this is a partial second brood, as they tend to only see fresh-looking individuals. But transect graphs show this is not the case and it is just the last of the summer's protracted emergence. It's as if the proportion of fresh to worn individuals changes towards the end of the season
Re: Late emerging females
The aestivation theory could well have some value. I've noticed reports of fresh looking Meadow Browns in the south of England well after the last in south Wales have disappeared.
Of course, temperatures are consistently 4 or 5c warmer in the south and SE of England than in Wales, so maybe there's a 'tipping point' which encourages certain butterflies to take a temporary 'sabbatical'?
That tipping point is clearly not normally reached in my part of the world, as Meadow Browns are generally spent completely by the end of August.
Of course, temperatures are consistently 4 or 5c warmer in the south and SE of England than in Wales, so maybe there's a 'tipping point' which encourages certain butterflies to take a temporary 'sabbatical'?
That tipping point is clearly not normally reached in my part of the world, as Meadow Browns are generally spent completely by the end of August.
Re: Late emerging females
Thanks Pete. I suspect you are right that females might aestivate to some extent in hot weather in the UK. I have read that females can live for some months in the warmer climes in Europe and egg-laying can be delayed by up to 2-3 months. See http://journals.plos.org/plosone/articl ... ne.0111955 . Do females expend less energy than males in locating mates, for example, which may prolong their lives?
Thanks Wolfson. I regularly see mating pairs, perhaps 2 or 3 a year, in the middle of the day.
Thanks Bertie. The protracted emergence of females seems to be the consensus but do the latest emerging females find any males?
Thanks David. It would not surprise me if there is a tipping point in temperatures above which females may decide to aestivate, which may be more evident this year in the UK because of the recent heatwave.
ATB
Peter
Thanks Wolfson. I regularly see mating pairs, perhaps 2 or 3 a year, in the middle of the day.
Thanks Bertie. The protracted emergence of females seems to be the consensus but do the latest emerging females find any males?
Thanks David. It would not surprise me if there is a tipping point in temperatures above which females may decide to aestivate, which may be more evident this year in the UK because of the recent heatwave.
ATB
Peter
My website: http://www.stevenagebutterflies.co.uk
- Neil Freeman
- Posts: 4465
- Joined: Fri Jul 23, 2010 6:25 pm
- Location: Solihull, West Midlands
Re: Late emerging females
This has come up before. I see good numbers of fresh Meadow Browns during my visits to the Dorset coast in late August / early September, long after they have finished for the year back home in the midlands, although I have seen the odd individual locally in September.
Jeremy Thomas states in 'The Butterflies of Britain & Ireland' that the emergence of Meadow Browns is greatly prolonged on warm southern chalk downs where they continue to emerge throughout September and it is not unusual to see fresh females in mid-October.
He also states that there is no evidence that individuals aestivate...they simple emerge gradually over a longer period on English Chalk.
Cheers,
Neil.
Jeremy Thomas states in 'The Butterflies of Britain & Ireland' that the emergence of Meadow Browns is greatly prolonged on warm southern chalk downs where they continue to emerge throughout September and it is not unusual to see fresh females in mid-October.
He also states that there is no evidence that individuals aestivate...they simple emerge gradually over a longer period on English Chalk.
Cheers,
Neil.
- Essex Bertie
- Posts: 247
- Joined: Sat Jul 24, 2010 6:16 pm
- Location: Brentwood, Essex
Re: Late emerging females
I saw 6 Meadow Browns on my Brentwood transect yesterday and at least 2 were males. As Neil has researched, Meadow Brown larvae develop slowly and the emergence is protracted.
Re: Late emerging females
Thanks Neil.Neil Freeman wrote:This has come up before. I see good numbers of fresh Meadow Browns during my visits to the Dorset coast in late August / early September, long after they have finished for the year back home in the midlands, although I have seen the odd individual locally in September.
Jeremy Thomas states in 'The Butterflies of Britain & Ireland' that the emergence of Meadow Browns is greatly prolonged on warm southern chalk downs where they continue to emerge throughout September and it is not unusual to see fresh females in mid-October.
He also states that there is no evidence that individuals aestivate...they simple emerge gradually over a longer period on English Chalk.
Cheers,
Neil.
I have a copy of the book and read Jeremy Thomas' account of the species before I responded
![Smile :)](./images/smilies/icon_smile.gif)
ATB
Peter
Last edited by peterc on Mon Aug 27, 2018 3:08 pm, edited 1 time in total.
My website: http://www.stevenagebutterflies.co.uk
Re: Late emerging females
Thanks for that reminder, Neil. Clearly, if males are being seen in numbers alongside females then the idea the latter aestivate holds less value.Neil Freeman wrote:This has come up before. I see good numbers of fresh Meadow Browns during my visits to the Dorset coast in late August / early September, long after they have finished for the year back home in the midlands, although I have seen the odd individual locally in September.
Jeremy Thomas states in 'The Butterflies of Britain & Ireland' that the emergence of Meadow Browns is greatly prolonged on warm southern chalk downs where they continue to emerge throughout September and it is not unusual to see fresh females in mid-October.
He also states that there is no evidence that individuals aestivate...they simple emerge gradually over a longer period on English Chalk.
Re: Late emerging females
Thanks Bertie. We'll see how the season progressesEssex Bertie wrote:I saw 6 Meadow Browns on my Brentwood transect yesterday and at least 2 were males. As Neil has researched, Meadow Brown larvae develop slowly and the emergence is protracted.
![Smile :)](./images/smilies/icon_smile.gif)
ATB
Peter
My website: http://www.stevenagebutterflies.co.uk
Re: Late emerging females
Read this discussion with interest, as I've been doing Adonis Blue surveys in Dorset this month, and have seen 5 mating pairs of Meadow Brown since August 14th. I don't encounter these that often even in peak season, so was quite surprised by this, and have been wondering if this was a sign of delayed emergence caused by aestivation. To add a bit of weight to this, on Monday (27/08), I found a freshly emerged female at White Horse Hill (Nr Osmington), she was still drying her wings, with the pupal case underneath in a tussock underneath.
I'll post some pictures in the next couple of days when I get time.
Cheers,
Will
I'll post some pictures in the next couple of days when I get time.
Cheers,
Will