CITY HAWKS

Things weren’t looking good for woodland hawks in the late 19th century and into the mid-20th century. The same old villains – habitat loss, hunting (killing), pesticides – were taking a heavy toll on hawk populations, as well as other birds of prey. In the 1960s and 70s state and federal legislation and regulation, such as the banning of DDT, the Endangered Species Act, and later the Migratory Bird Treaty Reform Acts of 1998 and 2004, began to turn things around. Woodland hawks and other birds of prey species population numbers began to rebound.

However, habitat loss and degradation continued to be a problem. This included acceleration of urbanization and suburban sprawl. The general thinking was hawks’ rebounding numbers would stall or perhaps even contract. But something interesting happened instead. Hawks moved into the cities and suburbs. They have stayed.

Evidence for this trend was compiled in an analysis of The Cornell Lab of Ornithology’s Project Feeder Watch data. In a 2017 retrospective study, Cornell found that Cooper’s Hawks presence at urban and suburban feeders had increased fourfold in two decades. The fact that the data was accumulated from feeder observations also provided insight for a reason for the increase in accipiter populations. An increase in feeders, an increase in prey. Feeders had become downtown buffets.

Similar trends for urban population increases for Red-shouldered and Red-tailed Hawks were found in eBird data. It seems that the buteos soaring over city parks and other green spaces discovered the small mammal populations, especially the rodents that co-habitate cities with us humans.

Red-tailed Hawk On Patrol Over Our Yard In Clear Blue Sky
Red-tailed Hawk On Patrol Over Our Yard

An early line of thinking was that the raptor population increase would concentrate in areas with less paving and more tree canopy, e.g., large city parks and suburbs. The reasoning was these species are ‘perch, scan, pounce’ hunters and need tree branches for the perches.

Juvenile Red-shouldered Hawk Urban Hunter Using Talons To Kill A Rat
Juvenile Red-shouldered Hawk Urban Hunter Using Talons To Kill A Rat

This perspective held true in the early study years, but in the last decade the increases have included highly paved and dense ‘concrete jungles’. The hawks and other birds of prey, especially owls, are proving to being very adaptable in the use of manmade infrastructure for hunting and eating perches. Utility lines and poles and street lampposts are working quite well for the hawks and owls.

The data are showing that these concentrations of hawks in heavily paved and concrete covered areas are a winter phenomena. The birds are not nesting. They are only interested in the high prey numbers as nutrition sources for survival for themselves during the hard times of winter. They are not moving into these areas to feed young. The birds move back into the ‘greener’ areas of parks and suburbs to breed and nest in the familiar and accommodating tree canopy. But, they have surprised us before.

This is all good news for urban wildlife photographers.

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