There was no continuous coverage this year and we restricted our site visits to less than one per week, only counting the Glow Worms present on each visit and not marking them as we have in previous years. The first female appeared earlier than expected on May 23rd and just four females had emerged by June 6th.

In other words, this has been a late season and with a very slow build up in numbers. A count of 41 females was recorded on June 22nd, but we may have missed a higher count on the nights preceding, or after this date. A recent visit on July 19th, produced just one female.

A week or so ago, we were predcting that the first female Glow Worm would appear at the end of the month and that the 2015 season would be quite a late one. More on the method of prediction we used follows and it turns out that we were wrong by about a week. The first female of 2015 appeared on May 23rd, in Section J of the survey area. This is the third earliest date we have recorded. Based on the lack of reports so far, this is probably the first Glow Worm to appear anywhere in the UK this year.

Predicting the date of when the first female Glow Worm will appear in 2015, is something we have been asked by a number of people during April and early May.

Its something we have actually tried to do at the start of each glowing season for the last few years, so we have recently spent a great deal of time trying to find a reliable method of prediction. We looked at the data for a number of potential factors (all of which were climatic) but which might provide a link to the appearance of the first female Glow Worms. Despite our efforts, the science of predicting an accurate date still seems down to guesswork, albeit based on a fair degree of knowledge and experience.

Even when we incorporated the average minimum temperature data for November and December, no difference was made to the results and it now seems clear to us that the emergence date of the first female Glow Worm, is more reliant on the average temperature during January to April than November to April.

So, following a cool late Winter and early Spring, we're predicting that the first female Glow Worm of 2015 will appear on May 31st (+/- 2days).

Part of our study since 2009, has been the counting and measuring the length of Glow Worm larvae found in four survey sections during the Spring. These surveys took place while still light, during the late afternoon and early evening periods. The gathering of larval size data had to come to an end in the middle of April 2015, but we believe that we had more than enough data, to suggest that the average larval size between March and May of each year, ultimately had no bearing on the emergence date of female Glow Worms a few weeks later.

The size data produced since 2010 has been remarkably consistant, showing a variation of just 1.40mm. Breaking the data down further, the average size variation in three of the years since (2011, 2013 and 2014) showed variation as little as 0.06mm. If we exclude the 2009 size data on the basis of being unusually large, then an average larval size at this site would be approximately 20.00mm.

The relative consistant larval sizes suggests to us that variations in rainfall and temperature between November and March in any year, actually had no influence on larval size.

Despite still being described by some authorities as common, evidence we have gathered through our own surveying and monitoring of Nottinghamshire's Glow Worm colonies since 2008, shows that the Glow Worm is clearly in a serious decline.

However, the decline is still denied by many and having no conservation status doesn't help matters, effectively meaning that site managers, owners and conservation organisations do not have to take any measures to protect Glow Worms on their sites. Yet many do, realising that the Glow Worm presents them with a great public relation, or engagement opportunity.

The total number of sites in Nottinghamshire where the Glow Worm survives, is currently down to just 19, effectively disappearing from most of its 49 known Nottinghamshire sites. Clumber Park, Sherwood Forest and Sherwood Pines, are now the best areas in the county to see Glow Worms, but they are decreasing at an alarming rate, even at particular sites within these strongholds.

Glow Worms in 2014

All in all, 2014 proved to be a good year in terms of Glow Worm numbers at Clipstone Old Quarter, but there continue to be worrying trends and prospects for Glow Worm populations in some of the more isolated sections of the study area.

We were able to show how damaging to small invertebrate populations, commercial forestry can be and will continue to be in 2015. The (hopefully) final phase of Pine removal was to take place this last Winter, but it seems will not be going ahead before the onset of this years glowing season.

It is the timber extraction process which has proved to be most destructive in previous years and some of the better Glow Worm areas at Clipstone Old Quarter will be affected by both this and track maintainance. Of course, we will monitor and report on this later this year.