Neotropic Cormorant or Olivaceous cormorant

Warmer winters, artificial water bodies, seasonal fish stocking, a selection of nesting trees and federal protection of the species has turned communities across metro Phoenix into an ideal long-term habitat for the cormorants.

Hundreds of these once migratory birds are now wintering in Arizona, setting off an environmental chain of dominoes on ecosystems across the region.

At southern Arizona, year-round hunting pressure from the birds has led to a dwindling fish population. With fewer fish in the lakes, algae has muddied the water, leading to more insects. An abundance of well-fed birds also means more droppings, which studies have shown can negatively alter soil chemistry.

Residents, have been asking homeowners associations and state agencies to intervene, but with federal protection, the cormorants are almost untouchable.

Almost.

Arizona is the only state in the country to have intentionally euthanized neotropic cormorants in more than a decade. Wildlife officials and conservationists continue to debate the legality of killing protected birds, which is made more complex with an impending change in presidential administrations.
https://www.azcentral.com/story/news/local/arizona-environment/2021/01/05/cormorants-settle-in-warmer-phoenix-climate-and-upset-local-ecosystem/4000112001/