Lek Report for 2002 and 2003

Lek Report for 2002 and 2003

Sandra Maclean,

Black Grouse Recovery Project Officer

9 Achnamara

Lochgilphead

Argyll

PA31 8PU

The Project is funded by a partnership of Scottish Natural Heritage, Forestry Commission, RSPB Scotland, Scottish Power and an award from the Esmée Fairbairn Foundation.

Survey Coverage and Methodology

2002

When the Project began on 1 April 2002, baseline information on the current status and distribution of the Argyll and Bute population was not available. The Project aims to provide this information through full survey coverage of Argyll and Bute. In 2002, Kintyre, Knapdale and Mid Argyll were targeted for survey. These areas provided the initial target as their populations have historically been strong, sightings of black grouse are still relatively common and the Project had good contacts on the ground to direct survey work. Landowners, gamekeepers, forestry workers, and birders were contacted to request information on sightings. Newspaper articles were placed in the local press asking members of the public to pass sightings on to the Project Officer.

A workshop was held for West Argyll Forest District rangers at the start of the season to explain the survey methodology. Survey work was conducted by the West Argyll Forest District rangers within their own beats whilst the Project Officer’s survey work was mainly conducted on private ground. Several members of the Project’s steering and working group also undertook survey work.

By the end of the 2002 survey season, Kintyre and Knapdale had been fully surveyed and Mid Argyll north of the Crinan Canal had received partial survey coverage. Out with the target survey area two leks in Glen Orchy were surveyed and a farmer on Kerrera passed on information of a single male seen displaying on the island.

The methodology used was taken from instructions for the 1995-96 national sample survey (Hancock, M. et al 1999). The maximum number of males attending a lek was recorded between the period of an hour before and an hour after dawn. Males displaying more than 200m apart were recorded as separate leks. Where time allowed repeat visits were made to each lek site. All survey records in 2002 were collected between 25 March –17 May similar to the 1995-96 national sample survey (Hancock, M. et al 1999). Though it did not strictly accord with the above methodology, one recurrent record during the main survey period was included, because its isolated location meant there was no risk of it being a duplicate record.

2003

All leks surveyed in 2002, with the exception of three, were resurveyed in 2003. Increased survey coverage of Mid Argyll was achieved. North Bute, the Roseneath peninsula, the Helensburgh area as far north as Glen Douglas and Cowal, south of Strachur were also surveyed. Cowal, north of Strachur was partially surveyed. Three leks were also reported from Lorne.

Re-survey of most of the 2002 leks was achieved with the help of West Argyll Forest District rangers, members of the Project’s steering and working group, and volunteer surveyors. Volunteer surveyors were given survey instructions based on those used by the 1995-96 national sample survey (Hancock, M. et al 1999). In Kintyre, Knapdale and Mid Argyll most volunteers were asked to re-survey leks, which held birds in 2002. More experienced surveyors were given new areas to cold search for additional leks.

In 2003 the Project Officer’s main survey area was Cowal south of Strachur. The northern boundary of the target area was drawn from Strachur to near Carrick Castle on the east coast of Cowal. This survey work was directed in part at the study area surveyed in 1996-98 by Sue Haysom. Her study, funded chiefly by the Martin Wills Fund, in the Cowal peninsular surveyed for lekking males over 3 years. In 1996 the eastern half of Cowal was surveyed and in 1997 the western half was surveyed. In 1998 all lek sites, except two surveyed in the preceding two years, were re-surveyed. The 1995-96 national sample survey methodology (Hancock, M. et al 1999) was used in all years. The locations of leks from Haysom’s study on Forest Enterprise ground were passed onto the Cowal and Trossachs Forest District rangers who surveyed their own beats in this project. Information made available to the Project from leks on private ground was restricted to respect the confidences and rights of landowners. Haysom identified the tetrads, which held active leks during her study, the number of leks in each tetrad and the number of males recorded at each lek in each year. In 2003 each tetrad which held active leks on private ground in 1996, ‘97 or ‘98, was searched for lekking males by the Project Officer. Rangers from the Loch Lomond and Trossachs National Park assisted with searches of three of these tetrads.

Gamekeepers, farmers, forestry workers, and local birders were contacted for black grouse information and recent sightings. Potential new black grouse habitat, for example young forestry plantations, within the target survey area was also surveyed. All leks holding more than one male in Cowal in 2003 were visited a minimum of twice during the survey period. In Cowal, volunteer surveyors were given six figure grid references of leks to survey, as they became available from local sources or the Project Officer’s survey work.

John Simpson of the MOD police surveyed the Roseneath peninsula and the Helensburgh area as far north as Glen Douglas. Ian Hopkins surveyed north Bute.

Where it was possible in Argyll, several surveyors visited a tetrad or area, which held several lek sites on the same morning to eliminate the possibility of double counting. In practice a single surveyor made most visits.

The Project Officer continued surveying and searching for additional lek sites until 31 May. Two leks each holding a single male were recorded in the second half of May, after the main survey period. These are included in the figures below. It is intended that these sites will be revisited in 2004. Two additional records from out with the main survey period were also included. These were sightings, one in early March and another in late May (Forest Enterprise staff) that provided the highest count for those leks and are not thought to duplicate any other data. Three records of single males made during the main survey period, but not according to the above methodology, were also included. These were regular sightings and were not considered to be duplicate records.

Results 2002 and 2003

The general trend for the total number of lekking males recorded between 2002 and 2003 was downward (Tables 1 and 2). Maps 1 and 2 show the general distribution of leks in the two survey years but the numbers of lekking males for each lek have been omitted in order to protect the confidences and rights of private landowners. Three leks, holding a total of 9 birds from the 2002 survey were not resurveyed in 2003. Information from the leks surveyed in both years indicated a 15% decline between the two years. The largest leks in Argyll in both years held 7 males. The average lek size in both years remained below 2 males.

In the area studied by Haysom in Cowal south of Strachur, numbers fell from 1998-2003 by 73% (Table 3). Losses from leks on Forest Enterprise ground appeared to be greater than on private ground. The average lek size for this study area fell from 2.4 to 1.3 between 1998 and 2003.

Table 1. Totals of lekking males recorded in Argyll in 2002 and 2003

(Forest Enterprise and private ground)

2002 / 2003
Kintyre / 36 / 26
Knapdale / 25 / 19
Mid Argyll (north of Crinan) / 13 / 11
Lorne / 9 / 7+1*

Total for 2002 survey area

/

83

/ 63 +1*
North Bute / 4
Helensburgh north to Glen Douglas / 9
Roseneath peninsula / 8
Cowal north of Strachur / 4
Cowal south of Strachur / 29

Total for 2003 survey area

/

118

* One additional lek with a single male not surveyed in 2002

Table 2. Totals of lekking males recorded on Forest Enterprise ground 2002 and 2003

Summary / 2002 / 2003
Kintyre / 13 / 8
Knapdale / 15 / 11
Mid Argyll, north of Crinan / 9 / 4
West Argyll Forest District Total / 37 / 23
Lorne Forest District / * / 0
Cowal & Trossachs Forest District / * / 5
Total / 28

* No counts available

Table 3. Comparison of numbers of lekking males in Cowal study area 1998

(from Haysom 2001) and 2003 (this study)

1998 / 2003
Total number of lekking males in
study area / 106 / 29
Total number of lekking males on FE ground in study area / 29 / 5
Males at largest lek / 8 / 3
Average lek size / 2.4 / 1.3

Map 1 Black Grouse 2002: Lek Distribution

Map 2 Black Grouse 2003: Lek Distribution

Summary

Survey work in Argyll 2002 and 2003 provides further evidence of the serious and continuing decline in the British black grouse population. The Argyll black grouse population has reduced to a serious level, which requires urgent conservation action and adequate funding to carry out this work.

Whilst a full analysis of habitat preferences is still to be carried out, the majority of leks in Argyll appear to be associated with forestry habitats.

The Argyll Population in Context

On the basis of current survey knowledge the populations of black grouse to the north of the Argyll boundary, in Morvern and south Lochaber, are modest and unlikely to be a source for immigration to supplement numbers on mainland Argyll. A partial survey in south Morvern in 2003 recorded a total of 10 lekking males at 5 leks. In the west, on the Argyll Islands, black grouse are currently reported only from Islay and Jura. Both populations appear to be at very low levels and it is unlikely that either island holds more than a few males. To the east of Argyll reasonable populations of lekking males were recorded in 2003 within a few kilometres of Loch Lomond. An exchange of birds between Central Scotland and the Argyll population seems feasible given the distance between lek sites.

Future Survey Work

Survey work will be undertaken in October 2003 to identify lek sites in preparation for the spring 2004 survey season. North Cowal, Lorne, north Mid Argyll and Jura will comprise the main focus for the 2004 survey season. It is hoped that a re-survey of most of the leks identified in 2002 and 2003 will be possible through a combination of Forest Enterprise rangers, steering and working group members and volunteer surveyors.

Acknowledgements

The Project would like to thank Susan Haysom for providing data from her study area on the Cowal peninsular.

The following people are also thanked for their contribution to survey work: Gordon Bishop, Roger Broad, Tom Callan, Rhona Campbell, Winston Churchill, Marina & Geoff Cowham, Ross Firth, Donald Macgregor, John Halliday, Saya Harvey, Colin Hodge, Malcolm Holder, Ian Hopkins, Paul Kent, Anton Locket, Stuart Marshall, Jane Mitchell, Pam Johnson, Ross Preston, Katie Penreigh, Ian Potts, Ju & Liz Randall, Nigel Scriven, John Simpson, Peter Staley, Dave Walker, Roger Wright, Fergus Younger, West Argyll Forest District Rangers, Cowal & Trossachs Forest District Rangers, Lorne Forest District Rangers, Loch Lomond and the Trossachs National Park Rangers.

The Project was initiated following the establishment of the Argyll & Bute Biodiversity Partnership and the launch of the Argyll Local Biodiversity Action Plan to address the plight of Black Grouse in Argyll. It is funded by a partnership of Scottish Natural Heritage, Forestry Commission, RSPB Scotland, Scottish Power and an award from the Esmée Fairbairn Foundation.

References

Hancock, M. Baines, D. Gibbons, D. Etheridge, B. & Shepherd, M. (1999) Status of male black grouse (Tetrao tetrix) in Britain 1995-96. Bird Study, 46, 1-15

Haysom, S. (2001) Aspects of the Ecology of black grouse (Tetrao tetrix) in plantation forests in Scotland. Unpublished PhD Thesis, University of Stirling

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