Changes to the timing of spring events are some of the most obvious and highly documented responses to climate change. Differences in the response of timing between interacting groups, such as predators and prey, have the potential to leave some ‘mismatched’, meaning predators lack access to resources on which they rely.

The Curlew is Britain’s largest wader; it is also one of its most threatened. Previous BTO research has shown that this is largely due to the number of chicks fledged that are able to survive to reach breeding age. In this case, if we are to help improve the situation for the Curlew, then we need to understand the factors that influence their breeding success.

Good quality information on species’ population trends is essential for successful conservation action. In this paper, the dataset of the BTO/JNCC/RSPB Breeding Bird Survey (BBS) is made publicly available, along with details of how the data can be used to calculate bird population trends. This will help to further inform bird conservation in the UK and beyond. BBS data have been widely used in research over the past three decades, and they have always been available upon request. However, with this publication, over seven million records are made freely and openly available. In this, the BBS becomes one of few structured national recording schemes for birds anywhere in the world which makes the information collected by its volunteers wholly available to anyone who wishes to access it.

BTO research reveals that seabird population declines due to High Pathogenicity Avian Influenza (HPAI) can be detected using data collected by volunteer seawatchers.

In 2022 and 2023, the Welsh Ornithological Society (WOS) coordinated a countrywide colony survey of Rooks in Wales, to estimate population and distribution size and change.

One of the most obvious ways in which birds have responded to climate change is by shifting the timing of their breeding and migration. In spring, many long-distance migratory species are now arriving earlier than in the past, and most species are also nesting earlier than then used to, particularly in warmer years. But has this led to a mismatch in the timing of the breeding season and the peak availability of key food resources for breeding birds and their young, leading to a reduction in breeding success and eventual population declines?