Butterfly Diary
- field notes by Adrian Hoskins
my earliest
sightings of each brood are highlighted in bold type
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Sightings
policy - details of certain sites where visitor pressure
or trampling may pose a threat to butterflies or alienate
landowners are excluded from these pages.
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2009
Jan
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Feb
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Mar
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Apr
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May
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Jun
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Jly
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Aug
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Sep
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Oct
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Nov
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Dec
March
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Sunday 29th March
Cool, breezy and generally cloudy weather resulted in a
virtually butterfly-free day at West Wood near Winchester.
The only species seen was a Peacock which had been roosting
among fallen branches until my dog charged through the
drifts of fallen leaves and frightened the butterfly into
the stratosphere !
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Saturday 28th March
I spent about 2 hours in Stansted Forest early this
afternoon, but the cold breeze was enough to deter even the
hardier butterflies from flying. However as I drove home a
female Brimstone flew across the road at Havant. Moth
species reported this week include Early Thorn in Berkshire;
Blossom Underwing, Pale Pinion and Red Chestnut in
Oxfordshire; also Brindled Pug and Powdered Quaker in Bucks.
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Sunday 22nd March
I headed west today, first visiting a Marsh Fritillary site
in west Hampshire. The caterpillars have now dispersed from
their webs and are feeding solitarily. Numbers were very low
- just 5 found after an hour of searching, whereas the same
site produced several hundred last year. Parasitism levels
in 2008 however were very high, reducing the population of
adult butterflies considerably. Breeding and egg-laying
success was also reduced as a result of cool weather during
the 2008 flight season. There is some good news however -
the cold nights and sunny days we are currently experiencing
should be beneficial to the species, allowing the larvae to
develop quickly, but delaying the emergence of the
Apanteles
parasitoids. My guess is that this will result in lower than
average levels of parasitism in the current generation of
larvae, hopefully enabling the populations to rebuild.
Later in the day I visited Ballard Down, a site where most
butterfly species appear very early due to the site's warm
and sunny coastal location. I saw a male Brimstone, 9
Peacocks and 4 Commas - one of which, unusually, was
nectaring at daisies. I also added 2 personal 2009 firsts -
a Speckled Wood seen flying in the shade of trees at
the bottom of the hill, and 3 Small Whites. The
latter were seen flying in off the sea despite the wind
blowing from the north. I failed to find any Small
Tortoiseshells, but a friend tells me that he saw no less
than 4 today near Dorchester, providing further evidence
that the cold winter has been beneficial, allowing the small
numbers that emerged last autumn to make it through to the
spring successfully. We can only hope that we get good
spring weather that will allow the butterfly to recover from
it's current precarious position in southern England.
Additional sightings for 21st March have now been reported,
including a male Orange tip at Farlington Marshes.
Far more exciting however is the news that 3 people reported
seeing Large Tortoiseshells on the Isle of Wight.
Photos indicate that at least 2 recognisably different
butterflies were present.
By about 1990 the butterfly was considered to be either
extinct or on the verge of extinction in the UK but it now
seems more likely that it maintained its presence as a
breeding resident along the south coast, but that numbers
were so low as to be unobservable.
Sporadic sightings over the last
4 years strongly suggest that it is now
re-establishing itself as a breeding species on the
Isle of Wight and possibly also along
the Dorset / Hants / Sussex coast, although it has not been
established for certain whether these colonies originated from wild,
bred or migrant stock.
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Saturday 21st March
Following a week of warm sunny days I had expected to see
good numbers of Brimstones today but a mid-morning visit to
Noar Hill produced just a solitary Comma. Later, at around
midday I visited the
Butterfly Conservation reserve at
Magdalen Hill Down but again there was very little activity
- just a single Peacock and another Comma. I had better
luck in the afternoon at Stansted Forest where I saw 2
Peacocks and at least 5 Commas along a 200m stretch of
footpath, but again no Brimstones. Earlier in the week when
temperatures were a degree or two higher there were reports
of a Small White in
London, and the
first Large White, Small Copper and
Green-veined White of the year were seen along the
Hampshire coast. On 18th March a Holly Blue was
recorded in East Sussex. On the same day there were encouraging
reports of Small Tortoiseshells from Hampshire, Dorset,
Bucks, Surrey and West Sussex. Moth "2009 firsts" reported
this week included Early Tooth-striped, Brindled Beauty,
Engrailed and Orange Underwing from West Sussex; Dotted
Chestnut and Light Orange Underwing in Bucks; and Water
Carpet in Berkshire.
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Comma
Polygonia c-album, male,
Stansted Forest, West Sussex |
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Sunday 15th March
I awoke this morning to be greeted by a beautiful sunny day which held the promise of butterflies, and within 5
minutes of setting off in the car I spotted a female
Brimstone in flight. I headed for Stockbridge Down, and
along the route saw several male Brimstones flying along the
roadsides. On arrival at Stockbridge the first butterfly I
saw was a Peacock - my first of the year. There were
also several Brimstones and at least 5 Commas in the valley, including 2 pairs of
territorial males seen engaging in aerial sorties. One of the
Commas decided to give chase to a male Brimstone which had
entered his territory, and quickly saw it off. Battles with
other male Commas tended to last for about a minute, with
the pair spiralling up to a height of about 15m, at
which point the intruding male flew off, and the "owner" of
the territory returned to reclaim his original perching
place.
On the way home I dropped in to spend half an hour at Crab
Wood. By the time I arrived the sun was getting hazy,
temperatures had dropped, and the butterflies were
beginning to go to roost. Nevertheless I was able to add 2
more Brimstones, 3 more Commas and another Peacock to the
day's sightings.
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Saturday 14th March
Sallow catkins, blackthorn blossom, coltsfoot, primroses,
dandelions, daisies and even a few early violets are now in
flower, but despite mild conditions and the odd sunny spell,
I failed to find any butterflies on my walk around Stansted
Forest today. There were several bees flying however, and
plenty of evidence of Stigmella
aurella leaf mines - the larva of this micro moth
burrows into bramble leaves and spends its entire life
living and feeding between the upper and lower membranes,
leaving a characteristic trail as it weaves its way about
between the membranes. When fully grown the larva emerges to
pupate on the surface of the leaf.
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Friday 6th March
Last nights frost was
followed by
a day of gorgeous sunshine, so I visited Crab Wood this
afternoon hoping to see a few butterflies. Unfortunately
with patches of snow still lying on the ground there was
nothing flying, but the trip was made worthwhile by the
appearance of a friendly muntjac deer which casually walked
out from a forest clearing and began munching at foliage
less than 3 metres in front of me. Unfortunately my
camera was still packed in my rucksack so I missed what
would have been a magical shot.
Although I failed
personally to see any butterflies, I received a report from
a friend at Leatherhead in Surrey of a Small Tortoiseshell
nectaring at heather in his
garden this morning.
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Monday 2nd March
The Small Tortoiseshell has declined dramatically in recent
years, to the point where this formerly abundant and
ubiquitous species is now considered a great rarity in
southern England ( although it is still fairly common in
parts of northern England and Scotland ).
The cause of the decline is unknown,
although there is speculation that it may be linked to the
arrival in Britain of a parasitoid Tachinid fly
Sturmia bella.
This fly however does not lay its eggs directly on the
caterpillar. Instead it lays them on nettle
leaves which are then ingested by caterpillars. The
parasitoid grubs later hatch in
the caterpillar's gut, and slowly devour it from within.
If the eggs are ingested by Small Tortoiseshell
caterpillars, they must also be ingested by other
nettle-feeding species including Comma, Red Admiral,
Peacock, Small Magpie and Mother of Pearl. This raises the question - why has
the Small Tortoiseshell suffered so badly while the other
nettle-feeding butterflies and moths have
maintained or even increased their levels of abundance ?
While it is far too early to start celebrating, there do
seem to be signs that the Small Tortoiseshell may be making
a minor comeback. There were several reports of the
butterfly appearing in one's and two's last autumn, and
hibernated adults seem to have survived the winter quite
well - several records of singletons were received from
Somerset, Hertfordshire, Buckinghamshire, East Sussex and
West Sussex last week.
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