Nottinghamshire Glow Worms 2021 |
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The aim of the NGWS is to provide useful data on this decling species. Click the banner for information and how to contribute to the survey |
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Nottinghamshire Glow Worm records 2021 |
All those records contributed to the Nottinghamshire Glow Worm Survey 2021 will be published both here and on the NGWS page. |
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Contributors to the survey 2021:
Many thanks go to all of the following people who have sent in their survey results so far. Trevor Pendleton. |
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Surveyed | Site name | Grid ref | Site type/habitat | Qty | Notes | Recorder | ||||||
April 20th | Clipstone Old Quarter | SK608674 | Former Pine plantation and grass/scrub strip | 1 | A single 18mm larva found dead this evening | TP. | ||||||
April 18th | Clipstone Old Quarter | SK608674 | Former Pine plantation and grass/scrub strip | 0 | No larvae recorded | TP. | ||||||
April 4th | Clipstone Old Quarter | SK608674 | Former Pine plantation and grass/scrub strip | 1 | A single 20mm larva found this evening | TP. | ||||||
April 3rd | Clipstone Old Quarter | SK608674 | Former Pine plantation and grass/scrub strip | 1 | Cool conditions at present, so it was surprising to find a 19mm larva, which was extremely emaciated, so has been temporarily taken into care | TP. | ||||||
April 1st | Clipstone Old Quarter | SK608674 | Former Pine plantation and grass/scrub strip | 2 | Two (dead) 20mm larvae found this evening, including one unusually again in Section A. | TP. | ||||||
March 31st | Clipstone Old Quarter | SK608674 | Former Pine plantation and grass/scrub strip | 4 | Four larvae recorded with larval lengths of 18mm x2, 20mm and 22mm. | TP. | ||||||
March 30th | Clipstone Old Quarter | SK608674 | Former Pine plantation and grass/scrub strip | 7 | Seven larvae recorded in good conditions this evening, but unfortunately one was found freshly dead. Larval lengths included singles measuring 16mm, 17mm, 18mm and two at 14mm and two at 19mm | TP. | ||||||
March 29th | Clipstone Old Quarter | SK608674 | Former Pine plantation and grass/scrub strip | 1 | A single 19mm larva found this evening | TP. | ||||||
March 28th | Clipstone Old Quarter | SK608674 | Former Pine plantation and grass/scrub strip | 4 | A total of four larvae recorded this evening, with one unfortunately found dead measuring 18mm. The three live larva included lengths of 15mm, 18mm and 21mm | TP. | ||||||
March 26th | Clipstone Old Quarter | SK608674 | Former Pine plantation and grass/scrub strip | 1 | A single 22mm larva found fatally injured | TP. | ||||||
March 25th | Clipstone Old Quarter | SK608674 | Former Pine plantation and grass/scrub strip | 1 | A single 15mm larva found dead | TP. | ||||||
March 24th | Clipstone Old Quarter | SK608674 | Former Pine plantation and grass/scrub strip | 2 | Two larvae (14mm and 22mm) found in Sections B and D respectively this evening | TP. | ||||||
March 22nd | Clipstone Old Quarter | SK608674 | Former Pine plantation and grass/scrub strip | 2 | Two larvae found this evening, including a 15mm larva in Section A (unusually) and a 14mm larva in Section D | TP. | ||||||
March 21st | Clipstone Old Quarter | SK608674 | Former Pine plantation and grass/scrub strip | 0 | No larvae recorded | TP. | ||||||
March 20th | Clipstone Old Quarter | SK608674 | Former Pine plantation and grass/scrub strip | 0 | No larvae recorded | TP. | ||||||
March 18th | Clipstone Old Quarter | SK608674 | Former Pine plantation and grass/scrub strip | 3 | Three larva recorded today, with a 15mm larva, a 24mm larva (both alive) and a dead larva measuring 19mm | TP. | ||||||
March 17th | Clipstone Old Quarter | SK608674 | Former Pine plantation and grass/scrub strip | 1 | A single 13mm larva found dead this afternoon | TP. | ||||||
March 16th | Clipstone Old Quarter | SK608674 | Former Pine plantation and grass/scrub strip | 1 | A single 14mm larva found dead this afternoon | TP. | ||||||
March 13th | Clipstone Old Quarter | SK608674 | Former Pine plantation and grass/scrub strip | 0 | No larvae recorded | TP. | ||||||
March 9th | Clipstone Old Quarter | SK608674 | Former Pine plantation and grass/scrub strip | 1 | A single 21mm larva found active mid-afternoon | TP. | ||||||
February 23rd | Clipstone Old Quarter | SK608674 | Former Pine plantation and grass/scrub strip | 0 | No larvae recorded | TP. | ||||||
........................... | . | .................................................... | . | . | . | ............................................. | . | . | . | .......................................................................................... | . | .......................... |
Fig 01. ... Diurnal Glow Worm larval size ranges found during March 2021 Data correct as of 31/03/21 | |||||||||||||||||||||||
.. | |||||||||||||||||||||||
9mm-15mm larval size range | Intermediate | 19mm-28mm larval size range | |||||||||||||||||||||
Section | 9mm | 10mm | 11mm | 12mm | 13mm | 14mm | 15mm | 16mm | 17mm | 18mm | 19mm | 20mm | 21mm | 22mm | 23mm | 24mm | 25mm | 26mm | 27mm | 28mm | |||
A | .. | 1 | 0 | 0 | 1 | 0 | 0 | 1 | .. | 0 | 0 | 0 | .. | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
B | .. | 0 | 0 | 0 | 0 | 0 | 1 | 1 | .. | 1 | 0 | 2 | .. | 2 | 0 | 0 | 1 | 0 | 1 | 0 | 0 | 0 | 0 |
C | .. | 0 | 0 | 0 | 0 | 0 | 1 | 0 | .. | 0 | 0 | 0 | .. | 0 | 0 | 0 | 1 | 0 | 0 | 0 | 0 | 0 | 0 |
D | .. | 0 | 0 | 0 | 0 | 1 | 3 | 2 | .. | 0 | 1 | 3 | .. | 2 | 1 | 2 | 1 | 0 | 0 | 1 | 0 | 0 | 0 |
.. | |||||||||||||||||||||||
9mm-15mm larval size range 35.70% | Intermediate 25.00% | 19mm-28mm larval size range 39.30% | |||||||||||||||||||||
Total % | .. | 0.00 | 0.00 | 0.00 | 0.00 | 3.57 | 17.85 | 14.28 | ... | 3.57 | 3.57 | 17.85 | ... | 14.28 | 3.57 | 7.14 | 10.71 | 0.00 | 3.57 | 0.00 | 0.00 | 0.00 | 0.00 |
Fig 02. ... Diurnal Glow Worm larval size ranges found during April 2021 Data correct as of 20/04/21 | |||||||||||||||||||||||
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9mm-15mm larval size range | Intermediate | 19mm-28mm larval size range | |||||||||||||||||||||
Section | 9mm | 10mm | 11mm | 12mm | 13mm | 14mm | 15mm | 16mm | 17mm | 18mm | 19mm | 20mm | 21mm | 22mm | 23mm | 24mm | 25mm | 26mm | 27mm | 28mm | |||
A | .. | 1 | 0 | 0 | 1 | 0 | 0 | 1 | .. | 0 | 0 | 0 | .. | 0 | 1 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
B | .. | 0 | 0 | 0 | 0 | 0 | 1 | 1 | .. | 1 | 0 | 1 | .. | 2 | 1 | 0 | 0 | 0 | 1 | 0 | 0 | 0 | 0 |
C | .. | 0 | 0 | 0 | 0 | 0 | 1 | 0 | .. | 0 | 0 | 0 | .. | 0 | 0 | 0 | 1 | 0 | 0 | 0 | 0 | 0 | 0 |
D | .. | 0 | 0 | 0 | 0 | 1 | 3 | 2 | .. | 0 | 1 | 1 | .. | 1 | 1 | 2 | 1 | 0 | 0 | 1 | 0 | 0 | 0 |
.. | |||||||||||||||||||||||
9mm-15mm larval size range 00.00% | Intermediate 20.00% | 19mm-28mm larval size range 60.00% | |||||||||||||||||||||
Total % | .. | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | ... | 0.00 | 0.00 | 20.00 | ... | 20.00 | 60.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 |
We found
that the average larval size from Spring 2009 to 2014 was 20.32mm, based on
the data gathered from a total
of 771 larvae. It also showed that larvae were
considerably larger on average in 2009 (22.21mm) than in
any of the following years, equating to 1.89mm larger
than the average produced between 2010 and 2015. This has continued to
be the case and the average length of larvae in 2016 was found to be
just 17.99mm, showing a decrease of 4.22mm. The data in the table provided in Fig 03, is presented as 17.00mm/tL6 for example. An explanation of this would be 17.00mm (the average larval length) / tL6 (taken from a total of six larvae) but this obviously changes daily after each survey. The Spring average follows the same principle, but the average is obviously taken from the total larvae found that particular Spring. |
Fig 03. ... Glow Worm larval averages during Spring 2009-2021 Data correct as of 20/04/21 | |||||||||||
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Week/period | . | 2009 | 2010 | 2011 | 2012 | 2013 | 2014 | 2015 | 2016 | 2020 | 2021 |
March 22-31 | . | ..... | ..... | 18.03mm/tL27 | 21.16mm/tL6. | ..... | 17.90mm/tL13 | . | 18.44mm/tL90 | 17.63mm/tL28 | |
April 1-7 | . | 23.33mm/tL3. | 21.27mm/tL13 | 18.64mm/tL70 | 19.00mm/tL5. | .... | 18.65mm/tL24 | 18.16mm/tL6. | 16.46mm/tL13 | 19.75mm/tL4 | |
April 8-14 | . | 21.14mm/tL14 | 19.58mm/tL17 | 19.19mm/tL31 | 19.66mm/tL9. | 17.11mm/tL9. | 18.27mm/tL59 | 19.11mm/tL16 | 15.00mm/tL3 | ||
April 15-21 | . | 20.45mm/tL10 | 20.78mm/tL18 | 19.78mm/tL53 | 23.20mm/tL5. | 18.34mm/tL34 | 18.62mm/tL22 | 20.66mm/tL8. | 18.26mm/tL20 | ||
April 22-29 | . | 23.32mm/tL25 | 18.74mm/tL53 | 19.97mm/tL39 | 18.77mm/tL9. | 18.61mm/tL25 | 20.20mm/tL36 | . | 18.83mm/tL6* | 18.00mm/tL1 | |
April 30-May 6 | 22.95mm/tL20 | 23.20mm/tL5. | 21.87mm/tL8. | 20.95mm/tL22 | 19.85mm/tL16 | 21.87mm/tL21 | . | 17.66mm/tL15 | . | ||
May 7-14 | . | 22.08mm/tL17 | 23.25mm/tL4. | ..... | 22.30mm/tL10 | 21.62mm/tL21 | 21.25mm/tL4. | . | 18.22mm/tL22 | ||
May 15-22 | . | . | 19.66mm/tL60 | . | . | 21.71mmtL/8 | . | . | 19.97mm/tL34 | ||
May 23-30 | . | . | . | . | . | . | . | . | 19.11mm/tL90 | ||
. | |||||||||||
Spring avg | 22.21mm/tL89 | 20.92mm/tL116 | 19.58mm/tL228 | 20.45mm/tL66 | 19.52mm/tL103 | 19.53mm/tL169 | N/A | 17.99mm/tL83 | N/A | N/A |
The size data produced since 2010 has been remarkably consistant, showing a variation of just 1.40mm. 2021 data is not included in this. 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. |
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