· To date 16 volunteers have returned their survey results.
· Returns have been received from 7 different counties.
· 10 returns were from Suffolk, 2 from Hampshire, and one from each of Essex, Kent, Surrey and North Yorkshire.
· Returns were all from stag beetle hotspots, with the exception of North Yorkshire.
· A total of 133 stag beetles or their remains were observed on the roads.
· Of these, 90 were the victims of road traffic.
· The remainder (43) were live beetles observed crawling on the road.
· The average number of times a road transect was walked was 22.
· Excluding beetle remains, where the sex could not be determined, female beetles killed on the road outnumbered males in a ratio of 2.4: 1. This compares favourably with previous findings.
· One Suffolk respondent cycled his hotspot route on 52 separate days (which in previous years revealed a number of stag beetle road-kills) but no stag beetles were observed. The colonies along this route may no longer be present.
· Surveys carried out throughout the ‘adult season’ gave the best results.
· Surveys carried out several times a week gave better results than those carried out once a week.
· Surveying throughout the ‘adult season’ is essential if this method is to be used to calculate the sex ratio. The sex ratio changes as the season progresses. Males are more abundant early in the season, emerging approximately one week before the females. As the season moves on females become more abundant than the males, the latter dying and declining in number before the females.
· Surveying throughout the ‘adult season’ is essential if this method is to be used to calculate an annual index of abundance.
· Four surveyors submitted the stag beetle corpses and remains that they had collected along their road transect. The dead beetle remains were useful in (a) confirming the species (b) confirming the sex (c) attempting to determine the sex where this had presented difficulty for the surveyor.
Road-kill surveys are belt transects which are designed to give an indication of trends in abundance. The method used has proved reliable both in local and national trials, is easily repeatable and can be carried out quickly. It can also be carried out in daylight. The method is not suitable for calculating population size, but (a) is a good indicator of stag beetle presence or absence (b) requires no special equipment or chemicals and (c) can be used along footpaths, pavements, tracks and roads of all types. It is not intended that the method should replace trapping to monitor numbers, but be used as a complement to it.
Trapping in Suffolk was limited to the use of pitfall traps at two known stag beetle emergence sites in Bentley*. Traps were baited with a variety of lures, but no stag beetles were caught during the 36 days (31/05/03 – 05/07/03) of the trial. Trapping in other counties, carried out by volunteers, was more successful. Plans are already in place to trial a different range of lures in 2004.
* Trapping was limited to that which the surveyor could manage while recovering from surgery.
Experimental, laboratory based work to examine the beetle’s behavioural response to various environmental factors was severely limited due to the low number of live beetles available. No conclusions could be drawn from the few results obtained.
Dead beetles and remains of beetles (from Suffolk, other counties, and from Europe) were sent to Deborah Harvey at Royal Holloway, University of London, where they have been used to examine the range of size in different populations of the insect. Sufficient analysis has been completed to draw conclusions and a paper has been written for publication in 2004.
Suffolk Biodiversity Action Plan
The County Biodiversity Action Plan has recently been revised and brought up to date by the Suffolk Lead Partner for this species.
In Bentley, the ‘adult season’ started with the warm weather at the end of May, males appearing first, as expected. Frequent, cool, windy evenings, which began early in June and continued until the 10 July curtailed beetle activity. Conditions for flight improved from mid-July, but few beetles were seen.
The earliest siting, a male was recorded 27 May, flying at 21.15, Rushmere Road, Ipswich (D. Harper). The earliest female (a dead beetle) recorded was on 29 May, Capel Road, Bentley (A. Hockley). The first live female record came from Grove Road, Bentley at 16.00, on 12 June (C. Hawes).
A confirmed record from Falkenham (P.Ling) adds another parish to the list of Suffolk sites for the beetle. An unconfirmed record was received from Parham (G.Woodard), a parish from which there is only one previous record.
Since June 2003, larvae have been recorded in Buddleia (Buddlja sp.) roots (Holbrook), Lilac (Syringa sp.)roots (Ipswich), Snowberry (Symphoricarpos albus) roots (Bentley), Sycamore (Acer pseudoplatanus) logs (Bentley), the bottom of a compost heap (Bentley) and in the bottom of a rotting heap of horse manure (Tattingstone). Snowberry and Sycamore are new larval food/habitat records for Suffolk. Snowberry is a new larval food/habitat record for Britain. Captive larvae, kept in rotting elm compost, pupated inside their earthen cocoons in mid-October. These pupae have since metamorphosed and are now adult beetles, which will remain torpid in their cocoons until the end of May, when the temperature is suitable for emergence.
Please continue to send me annual records of stag beetle sightings, even if you have sent records from the same site in previous years. Where possible, please give: the sex of the insect, the name of the place where it was seen, e.g. Woodbridge, in garden of No. 15 Birkett Road (a grid reference and postcode is helpful) and the day, month and year of the sighting. If you have recorded stag beetles and have not yet sent your records to me or to the SBRC, we would be pleased to receive them. Historical records are also very useful.
Acknowledgements
Acknowledgements for the support received appeared in White Admiral 55. Once again I am indebted to all the volunteers who have contributed their records of stag beetle sightings either directly to me or to the SBRC. I am especially grateful to the volunteers who took part in the road-kill survey, itrequires dedication to walk/cycle the same route throughout the stag beetle season.
Colin Hawes
Suffolk Lead Partner for the Stag Beetle Biodiversity Action Plan
People’s Trust for Endangered Species Stag Beetle Steering Group
© 2003 Suffolk Naturalists' Society