SCOTTISH cities are providing an unexpected haven for an elusive bird of prey, according to new research.
Studies of sparrowhawks have revealed that not only are they colonising urban areas in increasing numbers, but city birds are also outperforming their country cousins.
Ongoing research suggests townies are rearing higher numbers of chicks, with youngsters developing at a greater rate than those hatched in rural settings.
Other birds of prey have survived successfully in urban areas, but sparrowhawks are a fairly recent arrival.
Sparrowhawks are widespread across the UK, but populations crashed in the 1950s and 1960s because of pesticide use and persecution. Numbers have been rising since the 1980s, after a ban on organochlorines in the UK in 1975.
Volunteers from Lothian and Borders Raptor Study Group have been monitoring sparrowhawks in the capital for the past five years.
It suggests cities are good for sparrowhawks to rear chicks
Ecologist Alan Leitch, who is responsible for tagging the birds, said: “In the 1960s kestrels were a common sight throughout the city. They nested in quarries and large trees, but also commonly on church steeples. Now kestrels have all but disappeared from the town, along with much of the surrounding countryside.
“However, sparrowhawks, previously rarely seen in the city, have colonised Edinburgh in a big way.”
The group has already recorded more than 100 sparrowhawk nests in the city, and observations of birds living in the Royal Botanic Gardens Edinburgh show city chicks enjoy far higher rates of feeding than in rural sites. Experts believe this is down to plentiful supplies of well-fed garden birds for them to eat.
Sparrowhawks prey almost exclusively on birds, though they have been known to eat small mammals on occasion.
As with most raptor species, female sparrowhawks are bigger than males – weighing in at around double the bulk of the smaller male, with males feeding on small birds such as finches, sparrows and blackbirds while females can take down a wood pigeon.
Results from the Edinburgh studies have been compared with earlier work in the Forest of Ae, in Dumfries-shire.
“When I started measuring the sparrowhawk chicks I was surprised at their weights, particularly the males. They appear much higher than expected at their stage of growth,” said Leitch.
“All the indications are that sparrowhawk chicks in Edinburgh are putting on weight significantly faster than their rural counterparts.
“All our chicks appear heavier than chicks from the Forest of Ae study. We can only surmise that this is due to plenty of songbirds to feed on, possibly at the numerous bird tables throughout the city.”
He says there is still work to be done on interpreting the latest research but it suggests cities are good places for sparrowhawks to rear chicks.
“This is completely contrary to the common perception that the countryside is a much better place for birds of prey than town,” he added.
“Important urban green spaces such as parks, gardens, golf courses and cemeteries now provide vital nesting and hunting areas for these charismatic birds of prey,” said study coordinator Mike Thornton.
New chicks are ringed to monitor their habits. The public is being asked to log sightings on the group’s website.