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Butterfly Update – Ray Collier – Wildlife in the North

Thursday, September 1st, 2016

peacock butterflyThis has been a very strange year as far as wildlife and the weather are concerned and this has been echoed by many readers who have E-mailed me with their comments.   For example some birds have not done very well and one has been the house  martin that failed to nest on some houses  where, in the past they have been common and brought  off more than one brood each year.  There have been reports of house martins visiting these sites for just an hour or so late in the season.  These would have been either birds that did  not  breed this year or nested elsewhere and were just looking at old sites  before migrating south.  To a certain extent swifts have been the same and one indication of this was that I saw very, very few wheeling over houses in Inverness this year.

All this non activity co-incided with a cold wet spring that seemed to go on and on and when we expected the first of the butterflies to appear there were none at all.   I can remember a   time when the small tortoiseshells that had hibernated as adults would be on the wing early and in some numbers.     For many years they were the only ones hibernating as adults this far  north but then after the famous invasion of September 2002 peacocks poured in from Scandinavia (see photograph).  Since then, in some years, they have been commoner than  the small tortoiseshells.   This year in my garden I only saw one small tortoiseshell and one peacock and many other gardens were the same in most parts in and around Inverness.

At least there would be late Summer and Autumn butterflies to look forward to but there were already  signs that this would not be the case.  To start with the weather did not improve and one or two days of sunshine and raised temperatures  were soon dashed as the rain and cold re-appeared.    Then there were the nectar sources in the garden such  as Buddleias and Sedums and they just stopped and would not come into flower.  Chives just about came into flower as  did the Scabious but apart from one small tortoiseshell  there were just no butterflies to be seen.   Readers reported a few small speckled woods in gardens which is a measure of the success, in recent years, of this butterfly.  It has been spreading north for some years and is now found in many parts of the Highlands and still increasing in range and numbers.   Perhaps they  managed to fly this year as it is essentially a woodland butterfly so  they are used to light and shade!   The caterpillars feed on a variety of grasses so they do not have to be too particular.

Now is the time for the roadside  verge butterflies to come into their own and I should be seeing  a range of them as I drive into Inverness.  Most of the days, however, have been dull and overcast or raining with comparitively low temperatures for this time of the year.   Meadow browns and Scotch argus should now be along the  verges but on the ones I have seen, even when the sun has been shining, there have been no butterflies apart from the occasional green veined white.   At the time of writing the  Sedums have not even come in bud and whilst the Buddleias have started to flower where are the butterflies?

Pine Marten – Ray Collier – Wildlife in the North

Friday, August 19th, 2016

pine martenOne of the mysteries of the animal world in the Highlands  is over the very mixed fortunes of the closely related pine marten and polecat.   For example in the last few decades the pine marten  has increased its range southwards from the Highlands  and increased  its numbers.   In direct contrast it is now believed  that the polecat is extinct in the Highlands and has been for decades.  One intriguing question is the reason for the extinction of the polecat.  It fluctuated in numbers in the same way as the pine marten but there must have been one other factor that the pine marten  could cope with but not the polecat.  One reason, often  mentioned, is that the polecat was more susceptible, for some unknown reason, to trapping with the  gin traps and that was the last straw.  Both the pine marten and polecat were very high on the  persecution list as the lists from various  estates show.  One local estate, Invergarry, for example, shows that between 1837 and 1840 they killed 246 pine martens and 106 polecats.  The list also includes 198 wildcats but, surprisingly only 11 foxes.  These figures were typical of many Highland estates.

There are still a few reports  of polecats and the “Atlas of Highland Land Mammals” 2011 gives a few records for Caithness.  However, if these are true polecats they are more likely to be from re-introductions than native to the site.      The latest valid records for the Highlands are for 1969.  As for re-introductions, I can never understand why people go to so much trouble over  such activities without formally registering what they have done to the various organisations.   There is also  the problem of mis-identification as ferrets can be mistaken as can polecat/ferrets often favoured because of their larger size.   The situation over many islands is confusing as many ferrets are deliberately  introduced to keep down the rabbit numbers because of the damage they do to crops.

As for the pine martens there are now more  in Scotland, including the Highlands, than  ever before and for conservationists and organisations it is a success story.  The leading such authority is the Vincent Wildlife Trust who have pioneered the design and erection of pine marten den boxes.   The occupation rate and breeding rate has been high including areas in southern Scotland.  The Trust is now in the process of taking pine martens from the Highlands into Wales and the latest I hear is that the programme is going well with breeding already having taken place.   There are plans for more pine martens being taken there as it has been so successful.

One interesting aspect of the pine marten concerns their  inter-reaction with the red squirrel as many people just say that they prey on red squirrels. Fortunately there seems to be no proof that there is direct predation and I know of no record of a pine marten taking  an adult live red squirrel.  No doubt young – called kits – are taken but the adult red squirrels are more likely to be in the form an injured red squirrel, such as from a road casualty.   There is much more evidence of pine marten predating grey squirrels.  However, there is  now the problems of pine martens taking over nest boxes designed for birds such as owls,  goldeneye and mandarin ducks.   Fortunately these can be modified.   With the increase in pine martens there is also the problem  of them attacking domestic hens and ducks and the answer is to make sure the birds are put away in a  shed each night.

Butterflies – Ray Colliers Wildlife in the North

Sunday, June 26th, 2016

scotch argusRoadside verges are not the places we readily think of a far as butterflies are concerned.  However, in the next few weeks there are a number of butterflies that can be found there, especially if the verges  border woodland or grassland.   One of these is the Scotch argus and one of the delights of the summer sunshine is to see these large butterflies flitting along the verges as they are such a rich brown  colour and stand out.  The photograph of the  Scotch argus was taken on a roadside verge near Inverness.   The food plants of the caterpillars are grasses so the adult butterflies have no need to look  for special foodplants.    Indeed the Scotch argus has the remarkable habit of actually laying  eggs as it flies over  a verge as it knows there will be grasses underneath.  The butterfly has a unusual  distribution as apart from a few colonies in the Lake District in England it is confined to Scotland where it can occur in very large colonies indeed.

In contrast to some butterflies the Scotch argus is unusual in that it is confined to well defined colonies from which they seldom stray.   The rich dusky wings are adorned with a series of intense white spots hence the  name of “Argus” after the giant of Greek mythology that possessed a hundred eyes.   In places in the Highlands it can be the commonest butterfly but it has a strange distribution.  It does not occur north of Laxford bridge on the west coast and not north of the  Dornoch Firth on the east coast.  According to the “Atlas of Highland Butterflies” they fly from the  first week in July to the end of September depending on the weather.    It hibernates for the winter as a caterpillar.

In contrast one of the success stories of butterfly  conservation in recent years has been the spread of the speckled wood.   Perhaps one of the reasons for this is  that at one time  it was only found, as the name suggests, in woodland whereas these days it can be seen flying along roadside verges even sometimes with the Scotch argus.    Speckled woods must have the longest flight period of any of the butterflies as the adults can be seen on the wing any time from late February until early November.  However, that bland statement  is from the colonies down south as further north in the Highlands a more likely season is early May to late September.    The chocolate brown and cream uppersides of the wings are unmistakable and the males are particularly  conspicuous as they sit in woodland glades and defend territories against other males and attract females.

The remarkable spread of the  speckled wood is dramatically shown on maps in the Highland Butterfly Atlas.    Three maps cover 1980-1988, 1980-1992 and 1980 – 1996.   The most dramatic spread is around Inverness with an apparent   spread along the west coast right up in the last map to north west Sutherland.    This does not include  a very isolated and odd record I made with late Bill Henderson so many years ago for  a speckled wood in scattered woodland well north of Ullapool.    Could this be simply a lack of coverage of observers in those early days?    Speckled woods in Britain are remarkable and unique in that they  can over winter as caterpillars or chrysalises.   One can only hope that this year will produce more butterflies than in previous years,  although the  cold spring this year, and for that matter a cold start to June, has not helped.