From birds to butterflies: how widely can trends be applied?
Headlines about biodiversity declines abound, but the monitoring behind such stories is much more complete for some species groups than for others. How general then are the reported declines, and can trends be inferred in unmonitored taxa? BTO research has investigated these questions using data from bird and butterfly monitoring.
Is offshore wind farm risk to seabirds constant?
Offshore wind farms are being developed on an unprecedented scale, but their effect on wildlife is not yet well understood. BTO research shows how seabirds’ use of an area earmarked for wind farm development varies, with implications for the likelihood that individuals would be adversely affected by the presence of turbines.
Where in Britain are farmland and woodland birds declining most?
There is strong evidence that farmland, and to a lesser extent woodland, bird populations have declined in Britain. New analyses of Breeding Bird Survey data has shown the greatest losses have occurred in south-east Britain, identifying priority areas for further research and targeted conservation measures.
Understanding the effects of weather on bird populations
Analyses of national monitoring data show how resident and short-distance migrant populations tend to increase following warm winter and spring conditions. A more detailed field-based study of Long-tailed Tits has provided valuable insights about how such increases occur. Warmer temperatures in summer had a generally negative impact on populations, particularly if associated with drought, whilst long-distance migrants also appear to decline after a warm May.
Applying new statistical methods to garden bird data
Many biological datasets have a spike in the number of observations at zero – i.e. when a species wasn’t recorded – which can be difficult to analyse. A new statistical approach, developed using data from the BTO’s Garden Bird Feeding Survey, has neatly addressed this issue, and provided new insights into a complex problem.