It is important for birds to maintain their plumage in good condition, something that is facilitated by the periodic moulting of their feathers. However, moulting feathers is energetically costly and can also compromise an individual’s ability to forage and avoid predators. Because of this, the timing of feather moult needs to be balanced against the demands imposed by other key events, such as breeding and migration.

Habitat loss and climate change are two major threats to global biodiversity. How these two threats interact to drive biodiversity changes is less well understood. In this study, the authors examined changes in bird, butterfly, moth and plant distributions across the UK over the past 75 years to investigate how species respond to these combined threats.

In an effort to cut carbon emissions, many countries (including the UK) are constructing ever more offshore wind farms. Seabirds are at risk of colliding with the blades of offshore wind turbines, posing the potential for injury or death. However, the extent of this risk depends on several factors including how high the seabirds fly in relation to the area swept by turbine blades, the seabirds’ flight speeds, and any avoidance behaviour they undertake in response to either individual turbines or entire wind farms. Accurate understanding of these behavioural aspects of seabirds is important when assessing the potential population impact an offshore wind farm will have through so-called Collision Risk Models (CRMs). As previous BTO research has shown, bird-borne tracking devices are essential for shedding light on seabird flight behaviour. Different methods for gathering flight height information within tracking devices can influence the altitudes they produce, with implications for the collision estimates ultimately produced. This study compared the flight height altitudes produced from GPS and barometric altimeter data from tagged Lesser Black-backed Gulls to investigate this matter. Novel methods for calibrating GPS and altimeters were trialled to reduce error within the altitudes calculated by these methods as much as possible. The data were collected by attaching tracking devices to adult Lesser Black-backed Gulls captured while they were incubating their eggs at two breeding colonies (the Isle of May in Scotland and Havergate Island in England) in 2019 and 2020. Tags contained both GPS, which estimates a bird’s position using a network of satellites, and altimeters, which use air pressure measurements to estimate flight height. These two systems enabled flight heights obtained from either method to be compared. The results showed that altimeter data, when combined across years and colonies, produced higher flight heights than GPS data, and that this difference was more marked at higher sampling frequencies (e.g. one data point every 10 seconds) than at lower ones (e.g. one data point every five minutes). This in turn led to a greater number of collisions being predicted by CRMs for altimeter data than for GPS data. However, when GPS-altimeter data was split by sampling rate, year, and colony, flight heights from altimeters were not consistently higher, indicating local environmental conditions play a role influencing the accuracy of altitudes recorded. Tracking devices can provide information on flight height across a range of behaviours and environmental conditions. Improvement of calibration steps to account for the influence of the environment on tracking devices will help improve the accuracy of flight height information collected in future. This will increase confidence in the use of tracking devices in future assessments of collision risk and help to better predict mortality associated with wind farms. Forming a better understanding of the impacts of wind farms on seabirds will help ensure their appropriate development in future throughout the North Atlantic.

Models of future land-use scenarios show that it is possible to reduce greenhouse gas emissions from the land sector to zero, and increase habitat availability for most birds, including many species of conservation concern. However, some farmland-associated species may lose habitat, and the resulting decrease in food production will require reforms of the food system. Reducing greenhouse gas (GHG) emissions is one of the greatest challenges humankind is currently facing. A growing coalition of countries are now pledging to achieve net zero emissions, which means that any emissions of GHG will need to be balanced by carbon removal in the same year. The United Kingdom has committed to reach net zero by 2050.The land use and food production systems have a key role in addressing this challenge and are the only sector realistically capable of offering a net sink in terms of carbon sequestration at a significant scale. Fortunately, some land-based actions can produce multiple positive outcomes at the same time: for example, protecting and restoring natural ecosystems can support both biodiversity conservation and carbon sequestration. However, some trade-offs are unavoidable: for example, if farmed land is reduced, the remaining land will either deliver less food, or will need to deliver higher yields. However, the latter is usually associated with more intensive farming, and ensuing wildlife declines. This collaborative study led by the RSPB has developed mathematical models to explore nine different scenarios of future land use for the whole of the UK. These scenarios apply different levels of several climate change mitigation measures, such as, for example, creation of intertidal habitats, creation of hedges, or organic farming. All scenarios except one (the baseline scenario) are aimed at reducing, and possibly eliminating, net GHG emissions by 2050. Results show that the four best-performing scenarios in terms of brining down net GHG emissions are the nature-based ones, which are particularly focused on creating habitats such as intertidal areas, woodland, and hedges, but also favouring low-carbon farming measures. The nature-based scenarios also perform well in terms of providing habitats for birds and are associated with projected increases in the abundance of Red- and Amber-listed species between 16% and 19% by 2050. However, farmland species are projected to decline between 17% and 21% over this period, so conservation interventions will be needed to prevent this loss without affecting yield at the same time. Food production will be the big challenge, with a predicted decline under the nature-based scenarios between 26% and 29%. This reduction will require intervention on the demand side, particularly in terms of large-scale dietary changes and waste reduction. The study shows the potential of nature-based scenarios to deliver both climate change mitigation and biodiversity conservation in the UK, but interventions will also be needed both on the food system, to compensate for diminished food production, and the management of remaining farmland, to make sure that we don’t lose farmland birds.