In Our Backyard: Peregrine Falcon

A dark brown peregrine falcon in flight.

The peregrine falcon (Falco peregrinus) holds the title of fastest bird on the planet, and some argue it’s even the fastest animal on the planet using gravity to reach speeds of up to 320km/hr. During the summer these incredibly fast birds call the Thompson Watershed home.

Populations of peregrine falcons are dependent on their prey populations, which mainly include coastal shorebird colonies, waterfowl populations, and other small-bodied birds like crows, robins, and swallows. Their prey populations are becoming increasingly at risk due to habitat loss and degradation which adversely affects peregrine falcon populations. 

Peregrine falcons are one of the most widely distributed birds on the planet, inhabiting every continent except Antarctica. Two subspecies are found in North America, the pealei subspecies and anatum/tundrius, both of which inhabit BC.  

The pealei subspecies of peregrine falcons, known as Peale’s peregrine falcons, mainly reside on BC’s coastline and interior, and were designated by COSEWIC as a species of special concern in 2007 and was re-designated as such in 2017 due to its small population size. The small numbers of this population make them highly susceptible to environmental disturbance and the detrimental effects of changes in prey populations. 

The anatum/tundrius subspecies, also referred to as the American peregrine falcon, experienced significant population declines across North America in the 1960s and 1970s due to intensive use of the pesticide DDT, which birds ingested via the food web, resulting in the thinning of egg shells and subsequent reduced hatchling success. Following the ban of this pesticide and re-introduction of this species, the population has since recovered and today this subspecies is not at-risk. 

The rugged terrain of BC’s dry interior provides critical habitat for peregrine falcon nest sites as they typically form their nests on cliffs, especially near rivers and wetlands. The availability of these nest sites and the success of their hatchlings is critical to maintaining populations of these falcons since adults only lay one clutch of 3-4 eggs per year.

The ongoing recovery of the peregrine falcon is, in part, thanks to extensive, focused stewardship efforts including a major captive-breeding program. For this impressive raptor to survive into the future, it is essential that its breeding sites and prey remain in sufficient quantities to support current and future populations – and that the peregrine falcon doesn’t fall foul to another pesticide similar to DDT. As the American peregrine falcon breeds wherever there are sufficient concentrations of prey along rivers and wetlands, protecting these critical habitats in the Thompson Watershed is key to helping the peregrine falcon thrive.