|Written by Jeff Clarke|
|Friday, 11 March 2011 20:23|
All images unless otherwise stated © Jeff Clarke 2011
The title refers to the 'birders' short-hand name for Sparrowhawk Accipiter nisus. Yesterday I watched a young female Sparrowhawk dismantle a Collared Dove in my garden. She was a very impressive creature and with some careful maneuvering I managed to get a few decent shots. Two days earlier I'd been visited by an adult male Sparrowhawk, one of many over the years.
Sparrowhawks are incredible predators which specifically target birds. Everything about them is geared for their capture. The feet have long toes and talons, the long legs end with shins that are aerodynamically shaped to reduce drag during the strike. A long tail for fast twists and turns, short rounded wings provide easy maneuverability in tight spaces, combined with phenomenal eyesight and genuine cleverness all align to make this an exceptionally agile predator.
Sexual dimorphism is considerable in this species, females being significantly larger than males. Whilst incubating and brooding females stay close, defending the nest and young. The males job is to supply food. Males mostly take birds up to the size of a Blackbird. Once the young a well grown the female starts hunting and her greater size makes her an efficient provider of larger prey items, up to the size of a Woodpigeon. A few years ago whilst visiting the Solway area I was lucky enough to take a picture of a female Sparrowhawk that had captured and killed a Carrion Crow; gamekeepers take note!
Sparrowhawks do not have it all their own way. Most attacks fail, and they are successful only about 1 in 10 times. Their intended prey are equally well adapted to escape. Many young Sparrowhawks die before they reach breeding age, either through starvation, or misadventure. In areas with Goshawks Accipiter gentilis, Sparrowhawks exist at a lower density, primarily because the Goshawks actively target them as a potential competitor.
After the organochlorine poisoning in the 50s and 60's which devastated raptor populations sparrowhawks slowly recovered their numbers and reached their peak around the turn of the 21st century. Though a wholly unscientific assessment my impression is that in the last few years Sparrowhawks in the UK have undergone a slight decline in numbers. One thing is for sure, a Sparrowhawk cannot out-eat its food supply, no matter what false propaganda pro-predator control groups such as Songbird Survival pump out, it is the prey levels that control the Sparrowhawk population, not the other way around. Furthermore predators are good for the prey population as a whole, though the individuals killed and eaten may not feel the benefit. It would be a damning indictment of our society if we once again allow misconceptions, bad science and outright prejudice to enable control of raptors to take place in this country once again. Sparrowhawks are magnificent birds, we should cherish and respect them, not persecute them!