Climbers and Raptors on Cliffs
A very obvious, spectacular bird that rock climbers encounter in Tasmania is the Peregrine Falcon Falco peregrinus, found in Australia as an endemic subspecies F.p. macropus (essentially meaning “traveller with big feet” – the traveller bit being relevant to the early description of northern hemisphere peregrines many of which, unlike ours, migrate). This, almost worldwide species, arguably the fastest self-powered organism on earth, has nested in Tasmania for at least 19,600 years, a date established by carbon 14 dating carcases found in debris stratified under an old nest. It’s pretty well another world record. Peregrines are famous for their tenacious fidelity to nest sites, even particular nest ledges or potholes. In Tasmania they nest almost solely on cliffs. It’s amazing to think that thousands of successive generations of falcons layed maybe 50,000 eggs, hatching 40,000 fledglings eating 100,000 kgs of prey, in exactly the same place.
Peregrines are very widespread in Tasmania and its islands. Inland, one can run into a nest almost anywhere there is a cliff more than 5m high, especially if it faces away from prevailing winds, although coastal cliffs need to be 20m or more. Often a nest ledge is marked by generations of guano but peregrine roosts (resting and/or hunting perches) can also be ‘whitewashed’, as can roosts of other species that use cliffs such as Australian (Nankeen) Kestrels, Masked Owls and seabirds. So, just as climbers would check a route, then so the possible neighbours should also be checked.
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