The Peregrine Falcon (Falco peregrinus)
The Peregrine Falcon has been a symbol of speed and power for centuries. A favourite of the ancient Egyptians and Chinese who practised falconry as long ago as 2000 BC it is one of the swiftest and deadliest of the birds of prey. Known for swooping on its prey at speeds of up to 300 km/h, its mere appearance causes panic amongst potential victims. Found throughout the world, the Peregrine Falcon occurs in all parts of Australia.
Yet its biological strengths have not protected it from the threat of extinction. The Peregrine Falcon, like other birds of prey, are relatively long lived, with low reproductive rates and low population density. These factors combined with the fact that they are at the top of the food chain and limited by their prey makes them particularly vulnerable to human impact.
No impact has been greater on the Peregrine Falcon than the widespread use of DDT, which saw their decline and extinction from vast areas of the world during the 1960s and 1970s. Pesticides build up in concentration as they spread through the environment, eventually reaching peak concentrations in the tissues of the predators at the top, namely human beings and birds of prey such as the Peregrine Falcon.
The impact of DDT on the species went unnoticed for a long time. This was due to the long lived adults continuing to inhabit the nesting sites for many years thus masking the low numbers of young birds and corresponding reduction in the breeding population. When the devastating effects of DDT and similar pesticides did come to light, as documented in Rachel Carson's landmark book Silent Spring, the Peregrine Falcon became a worldwide symbol for the environment movement. The decline of this species, found on all continents except Antarctica, alerted the world to the characteristics of these agricultural chemicals.
The drastic thinning of eggshells caused by DDT affected Australian populations of Peregrine Falcons to some extent, but losses were not as severe as those in the Northern Hemisphere before restrictions on pesticide use were introduced.
Today populations in Australia are now generally higher than elsewhere in the world. There are no natural predators here and unlike other endangered species it is not confined to a specific habitat. Found everywhere from woodlands to open grasslands and coastal cliffs – though less frequently in desert regions – it feeds almost entirely on other birds. It also eats rabbits and other moderate sized mammals, bats and reptiles. The Peregrine Falcon is very territorial during breeding season, the male courting the female with an impressive display of aerobatics.
Since 1971 all Australian raptors have been protected by legislation. Care still must be taken to ensure their conservation, particularly as Peregrine Falcons are excitable birds and easily disturbed. They nest on spectacular cliffs that are also the preferred sites used by rock climbers, nature lovers and sightseers. The risk of disturbance to some Falcon pairs has also led to closure of some cliffs to the public during breeding season and nature trails and lookouts have also been moved to where they cause least disturbance.
As with all bird species, habitat loss is a major threat, in particular, loss of woodland trees where the Peregrine Falcon nest in areas where there are no cliffs. Other threats include accidental poisoning from baits left for dingoes and agricultural chemicals.
Due to their high profile and historic proof of their vulnerability, consideration is ensured wherever the Peregrine Falcon is now encountered – even if it is as unlikely a site as the 33rd floor of a Melbourne skyscraper.
Palaeontological evidence shows that one cliff site in Tasmania had been occupied by Peregrines for some 20,000 years until it recently fell away. Due to the success of intensive management programs this species of falcon should be with us for years to come.
For more information of this species, contact Dr Penny Olsen at the Australian National University on (02) 6249 2536.
For general information about threatened species, or to ask about obtaining a Hard Copy of the Bird Action Plan contact the Department of the Environment and Heritage's Community Information Unit on 1800 803 772 or email firstname.lastname@example.org