There are thought to be as many as 7 million pigeons in the city, among an estimated 400 million worldwide. Their numbers reflect the rise of urbanization: As New York’s population grows, so does that of pigeons, who live largely on seeds, bread crumbs, popcorn and our other leftovers. Cities are ideal for pigeons because window ledges, rooftops and bridges are perfect substitutes for the cliffside ledges they use for roosting and nesting in the wild. As long as there are people leaving food behind in cities, pigeons will keep coming. Most don’t live past 15 years and many die sooner, thanks to a wide array of predators—including red-tailed hawks, falcons, owls and feral cats. When they feel the flutter of the Grim Reaper, they’ll often retreat to attics or ventilation shafts to die alone, out of view. Pigeons breed prolifically between March and July.
Source:
https://www.crainsnewyork.com/article/20160915/EXPERT/160919937/why-do-pigeons-reign-in-new-york-city-in-5-steps
"SARS-CoV-2, the newly identified human coronavirus causing severe pneumonia pandemic, was probably originated from Chinese horseshoe bats. However, direct transmission of the virus from bats to humans is unlikely due to lack of direct contact, implying the existence of unknown intermediate hosts. Angiotensin converting enzyme 2 (ACE2) is the receptor of SARS-CoV-2, but only ACE2s of certain species can be utilized by SARS-CoV-2. Here, we evaluated and ranked the receptor-utilizing capability of ACE2s from various species by phylogenetic clustering and sequence alignment with the currently known ACE2s utilized by SARS-CoV-2. As a result, we predicted that SARS-CoV-2 tends to utilize ACE2s of various mammals, except murines, and some birds, such as pigeon. This prediction may help to screen the intermediate hosts of SARS-CoV-2."
Source: Microbes and Infection
https://www.sciencedirect.com/science/article/pii/S1286457920300496
