Colonies show a marked preference for the west and south-west of the region, especially around Honister, the Langdales and Wrynose where numbers have traditionally been highest and are holding up well. Colonies to the east, around Ullswater, Haweswater and Kirkstone, are fewer in number, generally smaller and more isolated. The Red Screes colony, where the species was first discovered in Britain in the early 1800's, now appears to be very small.

The species appears in the Lake District earlier than many books suggest. Numbers peak very quickly, often around the last week of June, followed by a fairly long tail. Data held at Tullie House, Carlisle, covering the whole of the last century provide the following analysis:

Hot weather during the flight period may restrict its flight to no more than a fortnight, whereas cool cloudy weather makes for a longer tail but little opportunity for flight and observation. Predation by birds is also heavy during sunny periods, perhaps also contributing to a shorter tail to the flight period. The lower altitude colonies tend to emerge a little earlier.

One feature of the species that experienced watchers have noted is that the peak flight period does seem to vary backwards and forwards from year to year. This is a complex behaviour that is not simply linked to spring temperatures. For example, early emergence has been known following a cold wet spring and in a cold wet summer. It might be that this is a consequence of the weather in previous years. From September to April the half-grown caterpillars hibernate deep in tussocks, often covered with a protective blanket of snow. It is believed that adverse weather in spring (or perhaps even in late summer of the previous year) may delay development so much that the larval stage lasts two years. In that event, development would be advanced in the second year leading to early pupation and emergence of adults, even if the current season's weather is unfavourable.

In short, this is a frustrating species for the casual observer to plan to see and why records over the years are relatively sparse, despite the increasing popularity of fell-walking!!!

Colonies are normally found above 550 metres, although several are well below this and one very productive site is known at a mere 250 metres:

In spite of its preference for altitude the species does avoid the summit tops, as it is nearly always found in sheltered nooks and crannies or flushes at the base of crags. One recent piece of research has suggested that British colonies have moved 150 metres (500 feet) higher on average in recent years, but this is improbable for the Lake District as it would place most colonies on the mountain summits, which are too exposed.

Where the species does occur, it can be very abundant and numbers can be very high. One researcher, having camped out at a site, estimated a total emergence over 12 days at 9000 individuals. The casual observer will see nothing like this quantity however. Females fly very little and, except in periods of prolonged hot sunshine, males can spend much of their time in the vegetation. The database of all known records for 1990-2006 (which was used to compile the distribution maps below) contains only three records where more than 100 individuals were present!

Known sites are found only on certain of the Borrowdale Volcanic rocks - the Skiddaw and Silurian Slates have no colonies. It may be that the areas avoided, being more acidic, are mineral deficient (especially in calcium). Matt Grass is so lacking in mineral nutrition that even the sheep leave it alone!

Plants on which the Mountain Ringlet nectars, such as wild thyme, tormentil and meadow buttercup, tend to be found at the base of crags and gullies, where mineral enrichment occurs. They would also be absent on the summit tops, making this another reason why the species is unlikely to move higher in the Lakes.

There have been no records ever from some fells (although well walked) such as Great Gable, Bowfell and the Band, The Fairfield Horseshoe, Skiddaw and Matterdale Common, despite the abundance of Matt Grass throughout. The species has many strong colonies just to the north of the Wrynose Pass, but curiously has never crossed the road to the Coniston range! There appears to be a very strong geological link to its habitat requirements (see map below). If you are walking in the Lake District in June or July please look carefully and report any sightings via this website.

 

1990 - 2006 Mountain Ringlet colonies (red dots) and ALTITUDE. Records of less than three are omitted.	Mountain Ringlet colonies and GEOLOGY (green dots) - pink and lilac are the Borrowdale volcanic rocks, red is granite.
N.B. AN ENLARGED DISTRIBUTION MAP CAN BE SEEN BY CLICKING ON THE ALTITUDE MAP

The colonies in the west of the Lake District could all be considered to be one super-colony as they are all inter-connected by the ridges that radiate out from the central dome of the Scafells (very noticeable on the altitude map above). A little interchange probably occurs here between "colonies", leading to genetic mixing and stronger individuals. It may be the case that colonies in the east will continue to decline through lack of genetic mixing caused by their greater isolation from each other.

Within a colony there are genetic differences of size, brightness and number of spots. English specimens differ slightly from those of Scotland, which differ again from European specimens. Perhaps genetic differences between the west and east Lake District colonies may have occurred as these have become increasingly polarised, even if there are no visible differences?

There has been much speculation and warnings about the potential loss of an alpine species like the Mountain Ringlet as global warming occurs. It is just that, speculation, as so little is known about the habitat requirements and ecology of this species. One of the strongest colonies in the Lakes is the one found at lowest altitude (250m) and on the milder west coast, where it enjoys the benefits of warm Gulf Steam air and higher humidity - just the sort of conditions Global warming is supposed to bring. This colony has been observed for over 60 years, with little apparent change in strength. On the other hand, a colder, drier climate is found on the Eastern fells and should in theory favour an alpine species, but these colonies have declined dramatically in the last 60 years, although I suspect this is not in fact weather related.

The trends predicted from Global warming of warmer wetter weather may be much less significant than other requirements for the survival of the species. Could it be that the amount of snow cover becomes critical? At low altitudes this protective cover is not present and appears not to be needed. At high altitude it may be beneficial, in which case the species may well need to move to higher ground, as appears to be the case in Scotland but this is not possible in the Lake District.

All in all, the Lake District Mountain Ringlets are a fascinating and unsolved enigma! If you have any comments on the above theories please get in touch.