After decades of recovery thanks to environmental policies and conservation, the peregrine falcon is once again facing a threat: avian flu. This disease severely affected populations inhabiting coastal areas, reducing their numbers and emptying their nests.
The virus decimated the waterfowl that are part of their diet, facilitating its spread among species. The impact was more noticeable in regions like New Jersey, California, and Virginia, where these predators feed in high bird concentration ecosystems.
However, the outlook is not entirely discouraging. Some young birds are moving to recolonize territories, offering a glimmer of hope for recovery in affected coastal habitats.
Meanwhile, another part of the population has managed to adapt to concrete and glass: urban falcons show resilience against the viral outbreak.

### Cities that save lives
The falcons nesting in buildings, bridges, and urban structures largely escape the disease. Their diet, based on common birds like pigeons and sparrows, kept them away from virus-carrying birds.
Cities like New York have become unexpected refuges. With over 30 breeding pairs, the metropolis is estimated to host the highest urban density of this species worldwide.
From there, the peregrines inspire the community and scientists. Cameras installed in nests allow thousands of people to closely follow their life cycle, from incubation to the chicks’ first flight.
These birds not only survive but thrive. Their ability to adapt to extreme urban environments represents a story of ecological success and a sign that coexistence between humans and wildlife is still possible.

### What were the causes that led the peregrine falcon to this situation?
Throughout much of the 20th century, the peregrine falcon suffered a drastic population decline that brought it to the brink of extinction in several regions worldwide, especially in North America. The main cause was the extensive use of the pesticide DDT in agriculture, which entered the food chain.
This chemical accumulated in the tissues of birds and weakened the thickness of their eggshells, causing them to break before hatching. As a result, reproduction rates plummeted dramatically, affecting the species’ survival.
In addition to DDT, habitat loss and hunting also contributed to its decline. Nesting areas were altered or destroyed by human development, reducing safe sites to raise their chicks.
Global concern for their situation led to the ban of DDT in many countries and the promotion of conservation programs, captive breeding, and reintroduction, which allowed for a partial recovery of their populations.