The Uplands team are pleased to deliver some new research. Please see below abstracts from two of our published papers from this year. Get in touch if you would like a full copy of the paper by emailing email@example.com.
Fletcher, K., & Baines, D. (2020). Observations of breeding and dispersal by Capercaillie in Strathspey. Scottish Birds.
Capercaillie in Scotland have undergone a considerable decline in numbers and range contraction since the 1970s. The latest national survey in 2015/16 concluded that they remain at a critically low level of around 1,000 birds, with previous studies highlighting low breeding success as the proximate cause of decline. This study used radio-tagged females to assess the likely causes of poor breeding. Of the 12 possible breeding attempts followed, clutches were found for nine, six of which hatched, but only two (17%) successfully fledged young, giving an overall rate of 0.25 chicks reared per potential breeding attempt. Low productivity occurred due to 60% of first-year females not nesting and low chick survival, estimated at 8%. Over the same years, surveys in four local forests found 0.49 chicks per female (210 females found of which 24% were found with well-grown broods). Dispersal distances of six juvenile females ranged from 3.5 to 16.3km highlighting the importance of conservation action across neighbouring forests at a landscape scale.
Warren, P., Land, C., Hesford, N., & Baines, D. (2020). Conserving Black Grouse Lyrurus tetrix in southern Scotland: evidence for the need to retain large contiguous moorland habitat within a forest-moorland landscape. Bird Study, 1-9.doi:10.1080/00063657.2020.1726875.
Capsule: Black grouse in southern Scotland are in severe decline, with remaining birds associated with large contiguous patches of moorland.
Aims: To inform black grouse conservation programmes in southern Scotland we quantified recent trends in numbers, assessed habitat composition within lek ranges, and evaluated the size of suitable habitat patches.
Methods: We explored trends in numbers of males at 121 leks surveyed between 1989 and 2018 in southwest and southeast Scotland. Wider surveys of males attending leks between 2006-12 were used to measure habitat composition within lek ranges and to compare with that in the study areas. Numbers of males at leks were considered in relation to habitat types and moorland management categories. Occupancy of moorland habitat patches was explored in relation to their size, connectivity and gamekeeping activity.
Results: Abundance at a sample of 121 leks surveyed between 1989-99 and 2017-18 fell from 70 males to zero in the southwest and from 340 to 44 in the southeast, with 82% of leks no longer occupied. Retained leks had more acid and rough grassland (53%) and less conifer cover (6%) within a 1 km radius than extinct leks (32% and 29%) and declines were similar across gamekeeping activity levels. Wider surveys in 2006-12 found acid and rough grassland, and dwarf shrub heath and bog the two preferred habitats within lek ranges. Leks were attended by twice as many males where driven red grouse (Lagopus lagopus scotica) shooting was practised. Occupied moorland habitat patches were 26 times larger than unoccupied patches.
Conclusion: Black grouse in southern Scotland are declining across all habitats. Moorland provides important habitat for remaining birds. With government targets to plant more woodland, remaining moorland habitat patches are likely to become more fragmented making them less able to support sustainable connected populations, which may exacerbate declines and enhance risk of regional extinction.