Researchers have long investigated the effects that climate change might have on species’ future ranges. However, for the first time, scientists at BTO have used abundance data to project the future distribution and abundance of more than one hundred breeding birds in Great Britain in order to assess how the whole bird community might change as a consequence of climate change. There have been numerous studies on species’ future distributions, where presence-absence or presence-only data were used to predict where species might occur in future in response to climate change. These studies are very useful to identify the most vulnerable species and habitats and therefore aid conservation prioritisation. However, significant population changes can occur without obvious changes in range. Such trends can only be identified using abundance data detailing how bird numbers vary in space and time. Scientists at BTO had previously tested future projections using abundance data for four selected species and in Special Protection Areas. In this latest study, we have produced future projections of distribution and abundance for 124 breeding bird species, including some which are not yet present in Great Britain, but could potentially colonise if they take advantage of higher temperatures. Data from the Breeding Bird Survey (BBS) and its French counterpart (the Suivi Temporel des Oiseaux Communs) were used in this research. French data were included to better quantify the species’ response to climate conditions found in France but yet to occur in Great Britain, and to consider potential colonists such as Melodious Warbler and Tawny Pipit. Future climate change was projected to result in significant population increases for 55 species and significant population declines for 11 species by 2080. This may apparently look like good news, but in reality 6 of the 11 species that are projected to decline are already red-listed in Britain for their recent population decreases (Grey Partridge, Curlew, Grasshopper Warbler, Ring Ouzel, Pied Flycatcher, and Yellowhammer), and 4 are already amber-listed (Red Grouse, Snipe, Willow Warbler, and Meadow Pipit). In contrast, 40 of the 55 species that are projected to increase are either currently green-listed or not yet breeding in Britain. This highlights how climate change will more seriously hit those species that are already of concern. As a consequence of these responses to climate change, different regions of Britain will see net gains and losses in species abundance. Our projections show that the largest gains in abundance will mostly be in northern and north-western Scotland and other smaller areas of western Britain. The south-east show apparent stability, but this is a result of large projected declines in red-listed species and compensating increases in green-listed species. Because of all these changes, community turnover will be high throughout Great Britain, but in particular in the west of Scotland, where changes in abundance of species that are already present will prevail. The analytical methods used provide an important framework to make projections of impacts of climate change on species abundance, rather than simply projected range changes. It has shown us significant changes in community composition that would have been invisible to us had we only used bird distributions. These projections will help conservation practitioners identify species that most urgently require mitigation and adaptation measures and target where those measures may best be adopted.

Small-scale fisheries provide an essential source of food and employment for coastal communities, yet the availability of detailed information on the spatiotemporal distribution of fishing effort to support resource management at a country level is scarce. Here, using a national-scale study in the Republic of Congo, we engaged with fishers from 23 of 28 small-scale fisheries landing sites along the coast to demonstrate how combining community engagement and relatively low cost Global Positioning System (GPS) trackers can rapidly provide fine-scale information on: (1) the behavioral dynamics of the fishers and fleets that operate within this sector; and (2) the location, size and attributes of important fishing grounds upon which communities are dependent. This multidisciplinary approach should be considered within a global context where uncertainty over the behavior of marine and terrestrial resource-users can lead to management decisions that potentially compromise local livelihoods, conservation, and resource sustainability goals. Small-scale fisheries provide an essential source of food and employment for coastal communities, yet the availability of detailed information on the spatiotemporal distribution of fishing effort to support resource management at a country level is scarce. Here, using a national-scale study in the Republic of Congo, we engaged with fishers from 23 of 28 small-scale fisheries landing sites along the coast to demonstrate how combining community engagement and relatively low cost Global Positioning System (GPS) trackers can rapidly provide fine-scale information on: (1) the behavioral dynamics of the fishers and fleets that operate within this sector; and (2) the location, size and attributes of important fishing grounds upon which communities are dependent. This multidisciplinary approach should be considered within a global context where uncertainty over the behavior of marine and terrestrial resource-users can lead to management decisions that potentially compromise local livelihoods, conservation, and resource sustainability goals.

Assessing the potential impact of additional mortality from anthropogenic causes on animal populations requires detailed demographic information. However, these data are frequently lacking, making simple algorithms, which require little data, appealing. Because of their simplicity, these algorithms often rely on implicit assumptions, some of which may be quite restrictive. Potential Biological Removal (PBR) is a simple harvest model that estimates the number of additional mortalities that a population can theoretically sustain without causing population extinction. However, PBR relies on a number of implicit assumptions, particularly around density dependence and population trajectory that limit its applicability in many situations. Among several uses, it has been widely employed in Europe in Environmental Impact Assessments (EIA), to examine the acceptability of potential effects of offshore wind farms on marine bird populations. As a case study, we use PBR to estimate the number of additional mortalities that a population with characteristics typical of a seabird population can theoretically sustain. We incorporated this level of additional mortality within Leslie matrix models to test assumptions within the PBR algorithm about density dependence and current population trajectory. Our analyses suggest that the PBR algorithm identifies levels of mortality which cause population declines for most population trajectories and forms of population regulation. Consequently, we recommend that practitioners do not use PBR in an EIA context for offshore wind energy developments. Rather than using simple algorithms that rely on potentially invalid implicit assumptions, we recommend use of Leslie matrix models for assessing the impact of additional mortality on a population, enabling the user to explicitly define assumptions and test their importance.

During December, January and February of the winter of 2015/16, BTO organised the third Non-estuarine Waterbird Survey (NEWS III), the fourth in a series of coordinated winter surveys of the non-estuarine coast of the UK. This report presents the findings of this survey.

This report investigates the habitat use of Lesser Black-backed Gulls Larus fuscus breeding within the Bowland Fells SPA.

Protected sites for birds are typically designated based on the site’s importance for the species that use it. For example, sites may be selected as Special Protection Areas (under the European Union Directive on the Conservation of Wild Birds) if they support more than 1% of a given national or international population of a species or an assemblage of over 20,000 waterbirds or seabirds. However, through the impacts of changing climates, habitat loss and invasive species, the way species use sites may change. As populations increase, abundance at existing sites may go up or new sites may be colonized. Similarly, as populations decrease, abundance at occupied sites may go down, or some sites may be abandoned. Determining how bird populations are spread across protected sites, and how changes in populations may affect this, is essential to making sure that they remain protected in the future. These findings come from a new study by Verónica Méndez and colleagues from the University of East Anglia working with BTO. Using Wetland Bird Survey (WeBS) data the study looked at changes in the population sizes and distributions of 19 waterbird species across Britain during a period of 26 years and their effect on local abundance and site occupancy. Some of these species saw steady increases in population size (up to 1,600%, Avocet), whereas other saw mild declines (-26%, Purple Sandpiper and Shelduck). The results showed that changes in total population size were predominantly reflected in changes in local abundance, rather than through the addition or loss of sites. This is possibly because waterbirds tend to be long-lived birds, with high site fidelity and new suitable sites may not always be available. Thus colonisation of new sites may typically occur when their existing sites approach their maximum capacity. As changes in populations are largely manifested by changes in local abundance – and as sites are often designated for many species – the numbers of sites qualifying for site designation are unlikely to be affected. Understanding the dynamic between population change and change in local abundance will be key to ensuring the efficiency of protected area management and ensuring that populations are adequately protected. Data from the Wetland Bird Survey and its predecessor schemes, which are celebrating 70 years of continuous monitoring of waterbirds this year, have been integral to both the designation of protected sites and monitoring of their condition. Continuation of this monitoring through future generations will ensure that the impacts to waterbird populations of future environmental changes may be understood.