Global warming has advanced the timing of biological events, potentially leading to disruption across trophic levels. The potential importance of phenological change as a driver of population trends has been suggested. To fully understand possible impacts, there is a need to quantify the scale of these changes spatially and according to habitat type. We studied the relationship between phenological trends, space and habitat type between 1965 to 2012 using an extensive UK dataset comprising 269 aphid, bird, butterfly and moth species. We modelled phenologies using generalized additive mixed models that included covariates for geographical (latitude, longitude, altitude), temporal (year, season) and habitat terms (woodland, scrub, grassland). Model selection showed that a baseline model with geographical and temporal components explained the variation in phenologies better than either a model in which space and time interacted or a habitat model without spatial terms. This baseline model showed strongly that phenologies shifted progressively earlier over time, that increasing altitude produced later phenologies and that a strong spatial component determined phenological timings, particularly latitude. The seasonal timing of a phenological event, in terms of whether it fell in the first or second half of the year, did not result in substantially different trends for butterflies. For moths, early season phenologies advanced more rapidly than those recorded later. Whilst temporal trends across all habitats resulted in earlier phenologies over time, agricultural habitats produced significantly later phenologies than most other habitats studied, probably because of non‐climatic drivers. A model with a significant habitat‐time interaction was the best‐fitting model for birds, moths and butterflies, emphasising that the rates of phenological advance also differ among habitats for these groups. Our results suggest the presence of strong spatial gradients in mean seasonal timing, and non‐linear trends towards earlier seasonal timing that varies in form and rate among habitat types.

Newly published research by BTO has shed light on the differing fortunes of two small wading bird species breeding in the UK. Little Ringed Plover first bred in the UK in Hertfordshire in 1938. Breeding numbers have increased steadily since, accompanied by a range expansion to the north and west. The species is Green-listed in the UK Birds of Conservation Concern. The Ringed Plover, by contrast, is on the UK Birds of Conservation Concern Red list. Both species were surveyed in 1984, and again in 2007. The new study estimated that the number of Little Ringed Plover breeding in the UK had risen by 71% between 1984 and 2007, to 1,239 pairs. The species’ core range remained in England, although breeding pairs have spread further into Wales, northern England and south and east Scotland. Gravel and sand pits were the favoured habitat for Little Ringed Plover, but its relative importance had declined compared to 1984. The species’ use of shingle habitat had grown, following range expansion into northern and western regions. Over the same time period, the breeding population of Ringed Plover in the UK was estimated to have fallen by 37%, to 5,438 pairs. The greatest declines were reported in England and Scotland, with numbers more stable in Wales, Northern Ireland and the Isle of Man. Decreases were marked in both coastal and inland areas, including at sites where Little Ringed Plover numbers had increased. The two species have similar inland habitat preferences, so the reasons underlying the different trends are not clear. Potential factors contributing to the decline in Ringed Plover at coastal sites include disturbance from human recreational activities as well as habitat change elsewhere. Although the UK populations of both species appear have stabilised recently, greater conservation and protection efforts are required at coastal sites to ensure local breeding numbers are prevented from dropping further.

Breeding wader populations have declined significantly in recent decades in the UK. During this time, areas of moorland managed for grouse shooting and adjacent areas of rough pasture have been identified as persisting strongholds. A contributory cause to wader population declines is afforestation, and in the Cairngorms National Park (CNP) there is likely to be significant woodland expansion (with associated conservation gains for woodland biodiversity) in areas currently holding breeding waders. Land management planning in the CNP requires a balance between these and other competing objectives. This project was carried out collaboratively with The East Cairngorms Moorland Partnership, which comprises six estates (Mar Lodge, Mar, Invercauld, Balmoral, Glenavon and Glenlivet) and the Cairngorms National Park Authority. The primary aim of the project was to investigate factors, including effects of woodland cover, affecting breeding productivity of wader species within the area covered by the East Cairngorms Moorland Partnership.