Mike Thornton, SNH Operations Officer in the Forth Area and active member of the Lothian and Borders Raptor Study Group, talks about the colonisation of birds of prey into our towns and cities – and why we should celebrate these charismatic urban predators.
I walk slowly through the wood, feeling watched – the intense, penetrating stare of the hawk entering my very soul. Noise from cars, sirens and voices punctuate the tranquility of the wood. I search for the sparrowhawk’s nest in an avian crime scene – songbird pluckings littering the forest floor. How are the sparrowhawks faring this year, have they survived, are they breeding successfully in the city and why should we care?
Over the last four decades, many birds of prey in Scotland have recovered, principally due to the banning of harmful agricultural pesticides and a decrease in human persecution in much of the lowlands.
As rural populations have expanded, these birds of prey started to colonise towns and cities, with the sparrowhawk one of the first species to colonise in the early 1980s. The colonisation of Edinburgh occurred after 1980, and within five years, there were probably more than 20 pairs breeding within the city limits. Many of their breeding sites have been monitored since the late eighties, and a recent scientific study has shown that over a four-year period, breeding success in Edinburgh was significantly higher than a rural population in Ayrshire. The residential gardens, parks, small woodlands and hedges in Edinburgh provide both suitable nest sites, as well as an abundant songbird prey supply. Sparrowhawks have also been reported breeding in other Scottish cities, including Glasgow, Inverness and Aberdeen.
Another urban coloniser is the peregrine falcon, with an increasing number breeding on man-made structures, such as buildings, bridges, steeples and industrial cooling towers, as well as quarries. Although there were only a handful of pairs breeding on man-made structures in the early 20th century, such as the Tay Bridge, Dundee and Sinclair Castle in Caithness, it wasn’t until the late 20th century when they started breeding in our cities.
We now have these charismatic predators breeding on buildings in Edinburgh, Glasgow and Dundee. The results of the most recent National Peregrine survey revealed that almost 25% of all pairs monitored in Scotland were breeding on man-made structures or in quarries, with 45% in England. This newly acquired habit of tolerating human presence has allowed the species to spread into much of lowland Britain. Furthermore, some urban peregrines have been observed hunting nocturnal bird migrants using the light from street lamps, a true testament to their adaptability to breeding in these new environments. These urban breeders are doing well, and studies from England suggest that breeding success in urban populations is higher than in many rural areas.
Once confined to the western half of the UK, the expansion of the buzzard population has arguably been one of the biggest changes in British birds during the last three decades. There has been more than a doubling of its range in the UK since the 1990s, and this species has also recently colonised our urban environments. A thriving population is currently being studied in Cumbernauld, and Edinburgh now supports at least six breeding pairs, all within close proximity of the city center.
Although the kestrel was once a more common sight over our towns and cities, breeding on buildings and hunting over rough grassland in parks and roadside verges, this species has become less common in urban environments. This reflects a national decline, with a greater than 60% decline in Scotland since 1995. Research is underway by RSPB Scotland to identify the causes of this decline. Let’s hope that in the future we see kestrels returning to grace the skies over our towns and cities.
The red kite was also once a common bird of prey in towns and cities. In medieval times, it was common in London, scavenging on human waste and Shakespeare refers to London as “The city of kites and crows”. However, like many other birds of prey, it was heavily persecuted in the 19th century to protect game birds, and was eventually driven to extinction in Scotland and England by the late 19th century. However, thanks to an RSPB/SNH red kite reintroduction programme, the species has reclaimed some of its former haunts and is now commonly seen over cities like Aberdeen and Inverness. If the growth of the red kite population continues, it may not be long before this species fully returns to exploit opportunities in the urban environment.
The colonisation of our towns and cities by birds of prey is a good news story, one that we should celebrate. These spectacular predators depend on urban green space, as do many of us. They bring a sense of wilderness to our highly civilized societies, injecting a sense of wonder to our lives. However, their future, as well as the future of our wider urban biodiversity, will depend on how we plan our towns and cities, and manage our urban green space for generations to come.
I eventually find the sparrowhawk’s nest in an old beech tree next to a busy footpath. People walk by, oblivious to the breeding activities of these urban hawks. The female is calmly incubating her clutch – I wonder whether they will successfully raise young again this year.
For more information on raptors in Edinburgh see http://www.edinburghhawkwatch.org.uk/