The Peregrine falcon is the fastest living bid on earth. The species lives on almost every continent except Antarctica. Particularly, this species is endangered in Massachusetts. Explore this website to learn more about how this species is important to the ecosystem. These falcons used to be endangered because of the use of DDT in their system. The DDT pesticide makes the falcons eggs thinned and more likely to not survive. Since the mid-20th century(60's-80's), these birds have rebounded and regained their population. Learn more about this in population.