New research involving the BTO has revealed important information about the migration routes and wintering grounds of Nightjar, a species of conservation concern in the UK. Up until very recently our knowledge of Nightjar wintering areas in Africa was almost entirely based on visual observations and just two recoveries from all European ringing activities. Our knowledge of migration was slightly better thanks to the moderate number of ringing recoveries, but these only cover within Europe and a few sites in North Africa. New tracking technology is now vastly improving our understanding of Nightjars' movements, with implications for this species' conservation. The advent of geolocators allowed Nightjars to be tracked for the first time in 2009. These give daily locations accurate to around 100 km, meaning they are more than appropriate for tracking migration routes and wintering area at the continental scale. More recently, GPS devices have become sufficiently small to use, and these provide high precision locations but only once every 10 to 20 days. Using a combination of geolocators and GPS tags, researchers from Hasselt University, Biotrack, and the University of Sorbonne worked with Greg Conway and Ian Henderson from the BTO to examine the migration routes and wintering areas of 11 adult Nightjars marked at breeding sites in the UK, France and Belgium between 2009 and 2015. The results show that the main wintering area is located in the Savannah and scrub forests, to the south of the central African tropical Rainforests, mainly in the southern region of the Democratic Republic of Congo (similar to that favoured by our satellite-tagged Cuckoos). This area has not previously been identified as a wintering area for this species, but now appears to be a very important for Nightjars breeding in western Europe. The study also identified key stopover sites for the first time, on the boundaries of major ecological barriers including the Mediterranean Sea, Sahara Desert and Central African Tropical Rainforest, avoidance of the latter being somewhat surprising given the high insect resource potentially available in such habitat. Major differences in spring and autumn migration were noted, with autumn passage being on a broad front involving a fairly direct crossing of the central Saharan region, while birds in spring took a substantially longer western route back to their breeding grounds, involving a detour via West Africa of around 2000 km. Further work is underway to investigate migration routes and wintering area used by other breeding populations throughout Europe. In the UK, the Nightjar has recently been moved from the Birds of Conservation Concern Red List to the Amber List. By identifying key migration routes and wintering grounds, this study provides important information that will further aid monitoring and conservation efforts of this charismatic species.

One of the great strengths of the BTO is its volunteer networks, and the organisation’s expertise in working with and supporting volunteers delivers valuable monitoring outputs across a broad range of taxa, from deer and butterflies through to bats and bush-crickets. Many of those interested in birds and birdwatching are also interested in other wildlife, and the BTO recognises the contribution that its volunteers can make to our knowledge of habitats and wildlife. This note outlines recent BTO research, monitoring and partnership working involving other taxa.

This report explores means by which a standardised trend analysis of data from the Wetland Bird Survey (WeBS) can aid rapid assessment of condition for non-breeding waterbird SPAs in England. For supporting material please contact Natural England.

Bush-crickets are a little-known group of insects that inhabit our marshes, grasslands, woods, parks and gardens. Some may be seen in the summer when they are attracted to artificial lights, but as most produce noises that are on the edge of human hearing, we know little about their status. There are suggestions that some bush-crickets may be benefiting from climate change, while others may be affected by habitat changes. But how to survey something that is difficult to see and almost impossible to hear? Advances in autonomous recording devices are transforming our understanding of bats, but the large-scale deployment of such devices has the potential to improve our understanding of other species groups that produce loud and characteristic sounds too. The original objective of BTO's Norfolk Bat Survey, led by Stuart Newson, was to trial the recording of bat activity using passive real-time detectors, to gauge the willingness of members of the public to engage in bat monitoring at a large scale, and to determine the suitability of automated identification routines for processing large volumes of citizen-science collected bat recordings. However, it soon became clear that bush-crickets were also being recorded in large numbers. Working with the Museum of Natural History in Paris and Natural England, BTO staff developed a computer algorithm to identify the sounds made by different species of bush-crickets. After carefully validating these state-of-the-art methods using field recordings in Norfolk, the daily activity patterns of different species of bush-cricket was examined to determine where different species live. The Speckled Bush-cricket, for example, would normally be easy to overlook because it occurs in vegetation and stridulates at a frequency too high for humans to hear. With over 260,000 recordings of this species collected through the Norfolk Bat Survey, this study found this species to be common and widespread, with a distribution that extends into the city of Norwich. At the other extreme, Great Green Bush-cricket, previously known from only a few locations in Norfolk, was recorded at two locations, of which one was a new site for this species. This research demonstrates the huge potential to take advantage of established large-scale bat monitoring to also collect high-quality monitoring data for bush-crickets. It is likely that large volumes of information on bush-crickets are already being collected incidentally by bat workers using static detectors, but this information is at best noticed and ignored. This work also marks an important step towards the development of automated sensor networks, which are likely to play growing role in the future biodiversity surveying, and the whole approach enables members of the public to become actively engaged in wildlife monitoring, with important conservation implications.

Experiences of nature provide many mental-health benefits, particularly for people living in urban areas. The natural characteristics of city residents’ neighborhoods are likely to be crucial determinants of the daily nature dose that they receive; however, which characteristics are important remains unclear. One possibility is that the greatest benefits are provided by characteristics that are most visible during the day and so most likely to be experienced by people. We demonstrate that of five neighborhood nature characteristics tested, vegetation cover and afternoon bird abundances were positively associated with a lower prevalence of depression, anxiety, and stress. Furthermore, dose–response modeling shows a threshold response at which the population prevalence of mental-health issues is significantly lower beyond minimum limits of neighborhood vegetation cover (depression more than 20% cover, anxiety more than 30% cover, stress more than 20% cover). Our findings demonstrate quantifiable associations of mental health with the characteristics of nearby nature that people actually experience.

Fifty years ago, volunteers began annual breeding bird surveys in woodlands as part of the Common Bird Census. Few probably would have anticipated the enormous changes the bird communities in those woodlands have shown, but their data have been a gold-mine for understanding how the many guises of environmental change are impacting birds. In our latest study we worked with colleagues at the University of Reading, Centre for Ecology and Hydrology, Butterfly Conservation and Natural England to assess how climate change and habitat interact to affect bird and butterfly populations. As climate warms, we expect species that are tolerant of warm climates to be least affected, or indeed to benefit in areas that were formerly too cold for them. Conversely, species that prefer cold climates are expected to fare poorly, perhaps by declining or retreating from warming areas. Following previous studies, we used the Species Temperature Index (STI), which corresponds to the average temperature across the European range of each species, to rank bird and butterfly species from cold-associated (e.g. Meadow Pipit, Willow Warbler, Chequered Skipper, Northern Brown Argus) to warm-associated (e.g. Cetti’s Warbler, Stonechat, Lulworth Skipper, Gatekeeper). Several studies have combined these STI values with the species’ population trends at individual sites to produce a composite “Community Temperature Index” (CTI). Most studies find this CTI is increasing, which is usually taken to mean that the community is increasingly dominated by species that prefer warm conditions. We took this further by looking separately at how the different species in the communities are faring. Although the bird community CTIs had increased, changes for constituent species weren’t as predicted. For example, the top 25% of birds as ranked by warmth-association had not increased as predicted but had declined on average. The overall increase in bird CTI was driven by a large decline in the abundance of the most cold-associated species and an increase for moderately warm-associated species. Importantly, the extent of the declines of the most cold- and warm-associated species was related to the amount of intensively managed land surrounding the monitored woodlands. This suggests that the lack of natural habitat in the surroundings makes it harder for cold-associated birds to find cool corners of sites, or to disperse away from warming regions. Butterfly results were subtly different but with similar conclusions about the role of intensively managed land. This provides a clear recommendation to land managers and conservation agencies – creating larger natural areas in strategic places will help species to cope with the changing climate.