As many of you may know, we are celebrating 50 golden years of giving nature a home this year. We first became an RSPB nature reserve back in 1964 and have gone from strength to strength ever since. We are doing lots of things to mark this special occasion, one of which is a weekly blog, looking into one particular aspect of the site's 50 year history (apologies for this blog being a day late, I had some technical issues yesterday. It does mean though that you will be treated to two blogs this week).

This week has seen some truly glorious weather. On Tuesday, I went with Alasdair (one of our Assistant Wardens) and Kevin (our Membership Manager) to do a butterfly survey on Warton Crag. Through the spring and summer, this is something that the wardening team do every week to monitor how our butterfly populations are getting on. There are several places around the reserve where they carry out this work, and on Tuesday we headed to Warton Crag. It is a while since I have been up there in the sun and the visit served to make me remember just why I should do it more often - it is a truly spectacular place, so this week, I have chosen to focus on this special site for my 50th anniversary blog.

If you have never been to or even heard of Warton Crag, it lies approximately two miles away from the visitor centre at Leighton Moss. If you look into the Old English language, it gives you a clue as to the look of Warton Crag.  The name 'Warton' is derived from the Old English 'weard' meaning 'watch' or 'look-out' and 'tun' meaning 'farmstead'. The word 'crag' is from the Celtic 'crug' meaning 'hill' or 'mound'.  Warton Crag is most definitely a mound that you could watch or look out from.  It is a limestone hill, standing at 163 metres high, making it the highest point in the Arnside and Silverdale Area of Outstanding Natural Beauty.

The limestone rock has been eroded to form natural cliffs, scars and outcrops. Part of it was once quarried leaving a dramatic cliff face that now provides a nest site for ravens, jackdaws and peregrines.  There are also patches of woodland up there, which at this time of year are alive with the song of willow warblers and blackcaps. Because of the unique limestone habitat and the species it supports, Warton Crag has been designated a Site of Special Scientific Interest and is owned and managed by four organisations - us (the RSPB), the Lancashire Wildlife Trust, Lancaster City Council and Lancashire County Council. You can see which bits belong to who by clicking on the 'nature reserves' title here

The four organisations work together to make sure that the Crag is the best home for nature it can be. We bought the RSPB bit back in 1987, and it is around the size of 30 football pitches.  It was purchased primarily to manage if for some incredibly important butterflies. The limestone grassland supports a variety of plants such as rockrose, violets, and blue moor grass.  These plants are particularly required by the rare butterflies on the Crag, as their caterpillars rely on them as a food source.  There are several unusual butterflies on Warton Crag, such as the pearl-bordered fritillary, small pearl-bordered fritillary and the northern brown argus, with the rarest being the high brown fritillary.

 High brown fritillary by David Mower

 Pearl-bordered fritillary by David Mower

 Northern brown argus by David Mower

In order for butterflies to thrive, the Crag has to be actively managed to prevent the trees taking over too much. This is partly done by grazing cattle up there, but they don't eat much of the really woody stuff, so our wardening team go in to cut back the scrub (mainly blackthorn, hawthorn and bramble) in the Autumn.  If it was allowed to grow up too much, it would shade out the flowers that the butterflies rely on. Not all of the trees are removed, but some are in order to open up strips (known as rides) across the site where the light can get in and the flowers can flourish. It's tough work - check out the blogs from Alasdair about the work they do up there by clicking here and here.  

 Not a bad place to work by Alasdair Grubb

Whilst we were up there on Tuesday, as well as some butterflies, we also came across a slow worm warming itself in the sunshine. Warton Crag is a great place to spot these on sunny days. Now their name and appearance are a little mis-leading though. They are called a worm, they look like a snake, but they are actually a lizard. So if they are a lizard, where are their legs? Well they don't have any which is why they are often mistaken for snakes, but they have a number of features in common with lizards which snakes do not possess. The most important one is that they have eyelids that allow them to blink (which snakes do not have). They often also have visible ears (as do many lizards) which snakes don't. Finally, they shed their skin in patches like other lizards as opposed to all in one go like snakes do. Pretty interesting isn't it.

 Slow worm by Kevin Kelly

If you have never visited Warton Crag, I would highly recommend it, particularly at this time of year. There is a car park at the foot of the quarry from which you can watch the peregrines and ravens, then take a walk up to the top looking and listening for the important butterflies, plants, birds and reptiles that make it such a special place.