Results of the third Non-Estuarine Waterbird Survey, including Population Estimates for Key Waterbird Species
During December, January and February of the winter of 2015/16 the BTO organised the third Non-estuarine Waterbird Survey (NEWS III), the fourth in a series of coordinated winter surveys of the non
Protected sites are assigned based on population statistics for vulnerable and endangered species. This new study using WeBS data shows that changes in population size can affect local abundance, and thus influence whether or not key targets are met for site protection.
Bird and bat species' global vulnerability to collision mortality with wind farms revealed through a trait-based assessment.
Wind farms and biodiversity: a collision course?
The development of green energy is more important than ever. One of the most well-developed and cheaply available options is wind power, but there is evidence that wind farms can also have a negative impact on biodiversity.
Environmental correlates of breeding abundance and population change of Eurasian Curlew Numenius arquata in Britain
The decline of the Curlew
Wader populations are declining worldwide, and here in the UK we have seen dramatic declines of Curlew populations. This study by the BTO in cooperation with the RSPB looks at which threats are influencing our Curlew.
British birds more likely to go extinct
The UK has lost seven species of breeding birds in the last 200 years. Conservation efforts to prevent this from happening to other species, both in the UK and around the world, are guided by species’ priorities lists, which are often informed by data on range, population size and the degree of decline or increase in numbers. This paper presents the first analysis of British birds using the IUCN Red List criteria.
By pairing artists, storytellers and photojournalists with the researchers and volunteers studying our summer migrants, we are able to tell the stories of our migrant birds, and the work being done
The Bird Photographer of the Year competition celebrates the artistry of bird photography, and this large-format book is lavishly illustrated to reflect this.
Identifying why Whinchats are declining
Populations of Afro-Palearctic migrant birds, which breed in Europe but winter in Africa, have shown severe declines in recent decades. To identify the causes of these declines, accurate measures of demographic rates (e.g. the number of fledglings per season, estimated survival from year to year, and immigration from other populations) are needed to allow effected targeting of conservation and research activities. A new study involving the BTO has examined these measures in Whinchats.
A national-scale assessment of climate change impacts on species: assessing the balance of risks and opportunities for multiple taxa.
Low and annually variable migratory connectivity in a long-distance migrant: Whinchats Saxicola rubetra may show a bet-hedging strategy
The spatial scale of non-breeding areas used by long-distance migrant animals can vary from specific, relatively small non-breeding areas for each independent breeding population (high connectivity) to a distribution over a large non-breeding area with mixing of breeding populations (low connectivity). Measuring variation in the degree of connectivity and how it arises is crucial to predict how migratory animals can respond to global habitat and climate change because low connectivity is likely to be an adaptation to environmental uncertainty. Here, we assess whether use of non-breeding areas in a long distance migrant may be stochastic by measuring the degree of connectivity, and whether it is annually variable. Twenty-nine wintering Whinchats tagged with geolocators over two years within 40 km2 in central Nigeria were found to be breeding over 2.55 million km2 (26% of the land area of Europe), without an asymptote being approached in the relationship between area and sample size. Ranges differed in size between years by 1.51 million km2 and only 15% of the total breeding range across both years overlapped (8% overlap between years when only first-year birds were considered), well above the range size difference and below the proportion of overlap that would be predicted from two equivalent groups breeding at random locations within the observed range. Mean distance between breeding locations (i.e. migratory spread) differed significantly between years (2013, 604 ± 18 km; 2014, 869 ± 33 km). The results showed very low and variable connectivity that was reasonably robust to the errors and assumptions inherent in the use of geolocators, but with the caveat of having only two years’ ranges to compare, and the sensitivity of range to the breeding locations of a small number of individuals. However, if representative, the results suggest the scope for between-year variation (cohort effects) to determine migrant distribution on a large scale. Furthermore, for species with similarly low connectivity, we would predict breeding population trends to reflect average conditions across large non-breeding areas: thus, as large areas of Africa become subject to habitat loss, migrant populations throughout Europe will decline.
Stand structure and breeding birds in managed Scots pine forests: Some likely long-term implications for continuous cover forestry
Continuous cover forestry (CCF) systems are increasingly advocated for stand management, with biodiversity among the ecosystem services perceived to benefit.
Exploring the lives of Goshawks in the Brecks: identifying patterns in nest behaviour, habitat use and movements within and beyond the Brecks
A New Approach to Modelling the Relationship Between Annual Population Abundance Indices and Weather Data
Weather has often been associated with fluctuations in population sizes of species; however, it can be difficult to estimate the effects satisfactorily because population size is naturally measured by
Context: Connectivity is fundamental to understanding how landscape form influences ecological function. However, uncertainties persist due to the difficulty and expense of gathering empirical data to drive or to validate connectivity models, especially in urban areas, where relationships are multifaceted and the habitat matrix cannot be considered to be binary. Objectives: This research used circuit theory to model urban bird flows (i.e. ‘current’), and compared results to observed abundance. The aims were to explore the ability of this approach to predict wildlife flows and to test relationships between modelled connectivity and variation in abundance. Methods: Circuitscape was used to model functional connectivity in Bedford, Luton/Dunstable, and Milton Keynes, UK, for great tits (Parus major) and blue tits (Cyanistes caeruleus), drawing parameters from published studies of woodland bird flows in urban environments. Model performance was then tested against observed abundance data. Results: Modelled current showed a weak yet positive agreement with combined abundance for P. major and C. caeruleus. Weaker correlations were found for other woodland species, suggesting the approach may be expandable if re-parameterised. Conclusions: Trees provide suitable habitat for urban woodland bird species, but their location in large, contiguous patches and corridors along barriers also facilitates connectivity networks throughout the urban matrix. Urban connectivity studies are well-served by the advantages of circuit theory approaches, and benefit from the empirical study of wildlife flows in these landscapes to parameterise this type of modelling more explicitly. Such results can prove informative and beneficial in designing urban green space and new developments.
Winter bird ID and WeBS (Residential, Flatford Mill, Suffolk)
Improve your winter bird ID skills and learn all about the Wetland Bird Survey (WeBS) on this weekend residential course for relative beginners and improvers. With a focus on waterfowl and waders, discover more about...
Unlocking the science to reveal the state of nature
David Noble takes a sober look at the latest State of Nature Report.