When people think about bird surveys, they almost always think about the breeding season. April to July, dawn chorus, nesting birds – that’s the image most people have. And yes, breeding bird surveys are important and often required. But they’re not the whole picture, and for many projects, they’re not even the most relevant survey.
Winter bird surveys are required far more often than people realise, and overlooking them can cause real problems for a project further down the line.
Why Winter?
Scotland’s birdlife doesn’t switch off when summer ends. In fact, for many species, winter is when the action happens. Large flocks of waders and wildfowl move onto lowland fields and wetlands. Raptors like hen harriers and short-eared owls hunt over open moorland and grassland. Pink-footed geese arrive in their tens of thousands. Some of our most significant and legally protected bird activity happens between October and March.
If your project site supports any of these species during winter, you need to know about it before work starts – not after.
When Are Winter Surveys Required?
The short answer is: whenever the project site might support significant numbers of wintering birds, or when the project could disturb or affect habitats that wintering birds depend on.
This is particularly relevant for infrastructure projects – overhead lines, wind energy, solar farms, cable routes, and drainage schemes – where large areas of land are involved. It’s also relevant for any development near wetlands, estuaries, or open farmland.
Planning authorities and environmental regulators like NatureScot will often require winter bird data as part of an Environmental Impact Assessment or Habitat Regulations Appraisal. If you don’t have it, you may find yourself with a data gap that delays consent or requires another full winter of survey work.
Timing Matters
This is where people sometimes get caught out. Winter bird surveys need to be done in winter – which might sound obvious, but the implications aren’t always appreciated during the planning stages of a project. If your project is going through planning in spring and you haven’t commissioned winter surveys, you may already be a year behind.
The survey season for wintering birds typically runs from October through to February or March, depending on the species and methodology required. That means decisions about whether surveys are needed should ideally be made the previous summer at the latest.
What Do Winter Bird Surveys Involve?
Methods vary depending on what’s required, but typically involve repeated visits to the site during the winter months to record all bird species present, their numbers, and how they’re using the site. This builds up a picture of the site’s importance for wintering birds and identifies any potential sensitivities that need to be factored into the project design.
Getting It Right Early
The best approach is to think about bird survey requirements – both breeding and wintering – at the very start of a project, before survey seasons are missed. A short scoping conversation with an ecologist early on can save significant time and expense later.
If you’re not sure whether your project might need winter bird surveys, it’s worth finding out sooner rather than later.