Peregrine Falcons: Berkeley's Resident Falcons Greet Three New Chicks
The chicks beginning to hatch on April 17
For five years, two peregrine falcons named Annie and Grinnel have been living peacefully in the Campanile on Cal’s campus. Peregrine falcons usually mate for life, and this couple has had five successful breeding seasons on campus, resulting in thirteen chicks being born. On April 19th, triplets hatched and can be seen on the livestream.
Cal Falcons is a project dedicated to introducing Annie, Grinnel, and their baby chicks to a wide audience hoping to inspire and encourage interest in birds. Sean Peterson, a Berkeley Ph.D. student, and his wife, biologist Lynn Schofield, have created an Instagram, Facebook and Twitter with falcon content for all to enjoy.
The falcons’ nest is on the west-facing side of the second balcony, above the carillon bells in the Campanile. Though not visible from the ground, if you are lucky you might spot Annie or Grinnel on the base of the corner spires, or on the very top of the Campanile.
Peregrines have long primary feathers that give them a long-winged shape. They are about the size of a crow, though the male raptors are smaller than the females. These birds are blue-gray above with barred underparts and a dark head with thick sideburns.
Peregrine falcons are a remarkable species. Not only are these raptors the fastest animals on the planet--: they can dive at 200 miles per hour, but they were able to recover after a brush with extinction due to the use of organochlorine pesticides.
Dichloro-diphenyl-trichloroethane (DDT) was found to be an extremely effective insecticide in the 1940’s. DDT became widespread in the U. S. for commercial and agricultural use, due to its effectiveness, cost, versatility, and persistence. DDT worked its way through the food chain, and because these raptors are top predators, they absorbed large amounts of DDT from their prey. This is a process called bioaccumulation, which is the gradual accumulation of a substance inside an organism .
DDT is harmful to the falcons because it can poison adults and cause thinning of their egg shells, thus preventing the offspring from developing. This resulted in falcons being at risk of being extirpated (locally extinct) in the United States and Canada. Luckily, since DDT was banned in the 1970’s, falcons have steadily increased and worked their way off of the endangered species list.
It almost makes sense that such an impressive species like the peregrine falcons would choose an impressive and grand home like the Campanile. In 2016 when Annie and Grinnel first came to the Campanile, they created a makeshift nest on a sandbag, though this was replaced by researchers with a nest box filled with gravel in 2017. The Campanile is an effective and safe habitat as it protects the birds from predators and humans, while providing a safe space for chicks to learn to fly.
Peregrine falcons in natural areas tend to nest on cliffs. However, nowadays with massive urbanized cities covering the landscape, falcons substitute tall buildings for cliffs. Surprisingly, the creatures have adapted very well to city life; major cities including London, San Francisco, New York, Philadelphia, Birmingham one can expect that Peregrine falcons are living amongst the city dwellers in cathedrals, phone masts, power stations, and tall buildings.
Some go as far to say that peregrine falcons in the city are safer than they are in the countryside, as peregrines are often illegally shot or poisoned because they threaten the profitability of lucrative grouse shoots.
Aside from the great real estate, cities also provide falcons with lots of potential prey. Arguably this is the main reason why falcons have remained in the city-- the endless supply of pigeons, starlings, blackbirds, blue jays that they can feed on. The new nesting sites in tall buildings that provide greater protection from the elements and predators have resulted in urban birds breeding earlier in the year and producing more offspring than their rural counterparts. A study done in England, conducted by raptor biologist Nick Dixon, resulted in the finding that peregrines are better able to hunt and catch prey at night, due to the light pollution.
While the raptors seem to be succeeding in the new cityscape, the effect humans have had on the falcons’ lifestyles and adaptations seems more noticeable than in most species. From the DDT that practically caused the species to go extinct, to the city infrastructure that has changed their habitats, diets, and hunting methods, these birds have exhibited resilience with each obstacle that humans have created for them.
Next time you are on campus, keep an eye out for the bird of Kings, the peregrine falcons that live in our very own Campanile. Even in dense cities like Berkeley, nature is often hidden in plain sight-- so keep your eyes open!
