Linda, the female peers round from her nightly perching spot with the Chicago skyline beyond.

It is amazing to think these birds were on the brink of extinction 30 years ago and now thrive in the centre of such a large city.

Peregrine falcons are highly proficient predators, built for killing prey with incredible eyesight, razor sharp talons and beaks.

Whilst humans went about their daily routine, peregrines went about theirs overhead.

Even after hatching the chicks are brooded for a few more weeks until they're large enough to cope on their own.

Whilst Steve, the tiercel, wasn't out hunting he'd never be far from the nest site. Ready to defend it from intruders.

Despite their appetite for killing, the adults transformed when at the nest, delicately plucking tiny bits of meat from their prey to feed the chicks.

Once large enough the chicks could group together to keep warm, instead of being constantly brooded.

As the sunset, Linda would guard the nest overnight.

Linda flies in to her waiting offspring.

The nest was a noisy spot, especially when food was involved as the chicks called for their meal.

The chicks would swamp Linda in search of food.

Once the confines of the flowerpot were too small some of the chicks leapt to the ground for a little more freedom.

Even after fledging the chicks were incessant in their pestering of their parents for food.

Growing up on a condo balcony led to little fear of people for the falcons.

Juvenile peregrines sport brown plumage compared to the adult's grey.

Being good flyers is essential to survival so for weeks the chicks would fly from building to building building their flight muscles.