Peregrine Falcon - Ecology and Behavior

Ecology and Behavior

The Peregrine Falcon lives mostly along mountain ranges, river valleys, coastlines, and increasingly in cities. In mild-winter regions, it is usually a permanent resident, and some individuals, especially adult males, will remain on the breeding territory. Only populations that breed in Arctic climes typically migrate great distances during the northern winter.

The Peregrine Falcon reaches faster speeds than any other animal on the planet when performing the stoop, which involves soaring to a great height and then diving steeply at speeds of over 320 km/h (200 mph), hitting one wing of its prey so as not to harm itself on impact. The air pressure from a 200 mph (320 km/h) dive could possibly damage a bird's lungs, but small bony tubercles on a falcon's nostrils guide the powerful airflow away from the nostrils, enabling the bird to breathe more easily while diving by reducing the change in air pressure. To protect their eyes, the falcons use their nictitating membranes (third eyelids) to spread tears and clear debris from their eyes while maintaining vision. A study testing the flight physics of an "ideal falcon" found a theoretical speed limit at 400 km/h (250 mph) for low altitude flight and 625 km/h (390 mph) for high altitude flight. In 2005, Ken Franklin recorded a falcon stooping at a top speed of 389 km/h (242 mph). A video of one of the dives can be seen in this link.

The life span of Peregrine Falcons in the wild is up to 15.5 years. Mortality in the first year is 59–70%, declining to 25–32% annually in adults. Apart from such anthropogenic threats as collision with human-made objects, the Peregrine may be killed by eagles or large owls.

The Peregrine Falcon is host to a range of parasites and pathogens. It is a vector for Avipoxvirus, Newcastle disease virus, Falconid herpesvirus 1 (and possibly other Herpesviridae), and some mycoses and bacterial infections. Endoparasites include Plasmodium relictum (usually not causing malaria in the Peregrine Falcon), Strigeidae trematodes, Serratospiculum amaculata (nematode), and tapeworms. Known Peregrine Falcon ectoparasites are chewing lice, Ceratophyllus garei (a flea), and Hippoboscidae flies (Icosta nigra, Ornithoctona erythrocephala).