Session 1: Questions and Discussion Points
Q: What is the value of restocked conifer forest for black grouse?
- Probably a temporary boost only
- More research required; explore opportunities to use lek data from all NFE
- Need suitable moorland nearby as BG only use restocks seasonally: large restocks in Kielder were not used by BG because there was no suitable source moorland habitat nearby.
- Need to plan at a landscape scale for both species
Q: Were restock sites studied on areas with brash removed which might tell us about the suitability of bioenergy sites?
Some sites within Jenny Owen's study had whole tree cable crane extraction with very low brash cover and these had a longer period of good BG habitat.
Comment: May need disturbance in semi-natural forests to maintain habitat value, for example burning to rejuvenate the dwarf shrub layer and encourage regeneration. It's not just a matter of having large forest areas for capercaillie.
Q. What is the importance of ticks in adding to stress (e.g. for chicks in wet weather)
- Evidence on the effect of ticks on BG and Capercaillie is limited, although there was some evidence for red grouse suggesting improved survival if the tick burden was reduced.
- Research would be needed to assess the effects of ticks and it was not certain what could practically be done to prevent ticks: perhaps catch and treat hen birds.
- Suggestion that if deer were removed from an area then ticks may migrate to grouse.
Q. Any research on cumulative effects of bad weather together with tick burden, predation etc.?
Thought to be important but are not researched. Bad winters could tip the balance against survival at least for BG in some areas; capercaillie are able to cope better with severe winters.
Q. How can we get an overall picture of population of BG?
- At present the next national survey is scheduled for 2017 on a 12 year cycle following the 2005 report.
- The current review project funded by SNH, FCS and RSPB is examining monitoring effort and methods and identifying potential improvements.
Comment: The importance of extent and location of tree planting had emerged as a key factor for conservation of both species.
Q. How should we best focus predator control?
- Look at it in the context of habitat quality - target it at sites where cover is poor.
- On unkeepered Perthshire moors studied by GWCT breeding productivity of BG was good but winter survival was poorer. Main predators were raptors (protected) and foxes.
- For capercaillie, fox and crow control has been carried out for a number of years notably with LIFE project funding. Control had a possible effect in increasing capercaillie productivity temporarily during the project.
- However fox numbers are higher now than before control started, in Abernethy for example.
Q. In areas with just a few isolated black grouse, is it worth doing specific local management perhaps based on individual preferences of some birds for woodlands, ahead of longer term regional habitat improvements?
Probably better to focus on building metapopulation linkages.
Summary of Key Points from Session 1
Duncan Orr-Ewing, Head of Species and Land Management, RSPB
This session showed that 20 years work has increased knowledge greatly. This is a good time to take stock of whats needed and how to target future support efficiently as we approach the next SRDP.
Caper populations and habitat:
- Capercaillie numbers are around 1200 less than in the 1970s but population fairly stable between 1000 and 2000 birds since the early 1990s when formal national surveys began.
- Fragmentation and 75% of the national population being in one meta population decreases resilience.
- A minimum viable population is about 500 birds: need landscape scale planning seeking to maintain meta-populations.
- Caper don’t like large clear fells, or fences.
- There is a role for management of grazing to promote suitable habitat.
Black grouse populations and habitat:
- UK numbers have declined from 25k to 5k from the 1991 to 2005. Scotland now holds 80% of the UK population.
- There are varying regional trends including some increases; we need to pool data more effectively to monitor trends.
- Landscape-scale planning is needed to build suitable mosaics of moorland and woodland habitat: it is important to identify areas of good moorland habitat and avoid afforesting them.
The current review of the Calladine recommendations will provide a valuable tool for planning habitat management prescriptions.
- Valuable use of telemetry to study and model how individual black grouse use habitats
- In autumn and winter moorland areas are generally preferred by BG in the Tummel study area but individual variation is evident with some female birds showing a secondary preference for conifer forest areas
- Jenny Owen’s work showed the BG use of restocking areas in forests could be important as they increase in area through forest restructuring programmes.
- A longer fallow period before replanting trees could improve habitat suitability in terms of vegetation but also favour foxes.
- Leave some permanent openings within clearfells
- Clearfells are not as good as good quality moorland habitat because they lack valuable species like bog myrtle and cotton grass.
The trial management project ran for four years and is indicating some benefits of habitat management, but needs to be monitored for around 7 years as originally envisaged to confirm any treatment effects on BG populations.
- BG is seen as a meadow species in northern England, and it survives in moorland fringe areas which often have little or no woodland cover.
- Productivity is poor but survival generally better than in Scottish populations.
- The value of building metapopulation linkages to the fragmented Scottish Borders populations was highlighted.
Other factors affecting woodland grouse
Ron Summers (focused mainly on capercaillie):
- The planning and management of tracks and access to them is important, as caper avoid areas near tracks
- June rainfall is a critical factor and it has been increasing in recent decades.
- Blaeberry cover is important.
- Predation is important and shows an interaction with climate whereby predator control was only effective in increasing breeding success when spring rainfall was low.
- Pine marten predation rates on nests can be high.
- Both species need landscape scale planning to prevent habitat fragmentation and build metapopulation resilience and this needs to be factored in to SRDP mechanisms and forest expansion planning
- The relationship between use of moorlands and woodlands for BG is critical and needs to be better understood.
- There needs to be more focus for BG on improving habitat in south Scotland.