The latest Breeding Bird Survey (published 29 August) shows kestrel numbers decreased by 65% in Scotland between 1995 and 2012. Louise Cullen met up with Senior Conservation Scientist Staffan Roos to find out why.
Scotland is a spectacular place for watching wildlife – especially birds. Whether it’s seabirds in summer or migratory geese in winter, there’s always something to look out for. Some of our resident bird species however, aren't doing so well.
Steve Round (rspb-images.com)
Kestrels used to be a common sight in Scotland, often spotted hovering above road verges looking for prey like voles, but between 1995 and 2012 we lost more than half of our kestrels; a whopping 65% decrease to be exact. That’s the largest drop of any monitored bird species in the whole country.
The figures came out at the end of August in the Breeding Bird Survey and it made me wonder what was sending these beautiful birds of prey into such steep decline. To help answer that question I went to Bridge of Allan, near Stirling, with Senior Conservation Scientist for RSPB Scotland, Staffan Roos.
We decided to take a mini road trip round the area to look at some kestrel habitat so Staffan could explain what might be going on. While on our way to the first spot he told me an unusual fact that stuck with me. Apparently kestrels can see in the ultraviolet light range, so when prey species like voles use urine to mark their territory kestrels can see it from the air, follow it, and bingo – a tasty snack! Interesting. It also made me appreciate the fact that I don’t have to employ a similar technique to find what I need in the supermarket.
Anyway, our first stop was an ideal location for kestrels and indeed there were a few nesting among a small clump of trees.
Staffan told me the key things kestrels need are an abundant food source, like voles and songbirds, and a good nest site. Kestrels are opportunistic birds and don’t actually build their own nests – they use the disused nests of other species like crows.
So all they need is food and somewhere to call home, sounds simple right? Wrong.
The second place we visited was a farmer’s field which had just recently been ploughed. When a field is ploughed it pushes all the left over seeds and grain down under the soil which means species like songbirds can’t access the food when they need it most – in winter. And if there’s less food for prey, there’s less food for predators like kestrels too.
Early research by the RSPB Centre for Conservation Science suggests the intensification of agriculture could be the main reason for the significant drop in kestrel numbers. Specifically, preliminary results suggest that kestrel numbers have fallen at times when there has been a change from spring-sown barley to autumn-sown wheat and oil seed rape.
Our final stop was an abandoned farm in Bridge of Allan. The reason? Staffan told me the increasing use of second generation rat poisons could possibly be playing a part in the decline of the kestrel. If an effected rat is eaten by a kestrel, the poison is passed on to the bird as well. They’re often used in buildings for storing grain and food, to keep out rodents.
There are several other possible contributing factors that are being investigated too, including competition for nest sites and climate change. RSPB conservationists are currently carrying out this vital research to identify what is causing the decline, so solutions can be created and put in place to hopefully increase populations of kestrel in Scotland once again.
Kestrel chick ringing
Brookfield Drinks, the owners of Kestrel Lager, is supporting the RSPB in those efforts. The money they provide is used to fund the research programme set up to help save the kestrel, as well as increased monitoring of kestrels in Scotland through the Scottish Raptor Monitoring Scheme and to advise landowners, land managers, crofters and farmers on wildlife friendly practices that will benefit these beautiful birds.