Despite a year of unpredictable weather, 2023 saw positive trends for breeding Barn owls across the UK. Nesting occupancy increased by an impressive 22% on average, signaling a healthy resurgence for these iconic birds. While this increase wasn’t quite as dramatic as the 37% jump seen in 2022, it still points to a hopeful future for Barn owls. Let’s dive into the data to understand what drove this increase and the challenges that remain.
Regional Highlights
Several regions experienced significant gains in nesting occupancy, with the West Midlands leading the pack. Cheshire reported an 82% increase, Shropshire a stunning 129% increase, and Staffordshire a solid 56% increase. In Ulster, there was a notable 130% increase, with the number of occupied sites rising from 5 to 8. These figures suggest that Barn owls are adapting and finding more suitable nesting sites across these regions.
However, not all areas shared this upward trend. Four regions saw declines of 10% or more: Gloucestershire (-25%), Jersey (-36%), Oxfordshire (-56%), and Wiltshire (-11%). While these numbers may be concerning, the overall picture for Barn owls remains positive, with the majority of regions showing growth in nesting occupancy.
The Impact on Brood Size
Despite the increase in nesting occupancy, the mean brood size showed only a marginal improvement, with a 2.7% positive change. This suggests that while more Barn owls found nesting sites, the number of chicks per nest did not increase significantly. Only a few regions recorded substantial gains in mean brood size, with Galloway leading with a 21% increase, Leicestershire at 31%, and Derbyshire, Powys, and Somerset each reporting around a 19% increase.
In contrast, Warwickshire, Wiltshire, and Yorkshire faced noticeable declines in brood size, with decreases of 37%, 24%, and 34% respectively. These regional variations in brood size highlight the complex relationship between weather patterns, food availability, and Barn owl breeding success.
Weather’s Role in Breeding Success
The weather in 2023 played a significant role in Barn owl breeding outcomes. The winter of 2022/2023 was relatively dry and mild, which likely contributed to the increase in nesting occupancy. However, the breeding period itself was marked by extreme weather fluctuations. A wet March was followed by heatwaves in June and September, with several named storms disrupting the summer. This weather variability impacted vole populations and limited hunting opportunities for Barn owls, affecting brood size.
Interestingly, many groups reported that Barn owls nesting later in the season had better success, likely because the weather had settled by then. This suggests that timing can be crucial for successful breeding, especially in a year with such variable weather.
The Future of Barn Owls in a Changing Climate
As global warming continues to drive extreme weather events, Barn owls and other wildlife face increasing challenges. The recent report indicating that global warming has exceeded 1.5 degrees Celsius for an entire year (compared to pre-industrial levels) raises concerns about the ongoing impact of climate change. The uncertain weather patterns seen in 2023 may become more common, posing a threat to Barn owl populations and their food sources, like field voles.
To ensure the continued success of Barn owls, conservation efforts must adapt to these changing conditions. This may include creating more nesting sites, supporting habitat restoration, and monitoring food availability. By understanding the factors that contribute to Barn owl breeding success, we can better support these magnificent birds in the face of an uncertain climate.
The full report can be downloaded here.
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