“Have these coyotes been deliberately imported to that area?”
No, it’s wolves the government enviro-nuts want to reestablish everywhere. Coyotes have a lifestyle that’s ideally suited to survive in suburban areas. They’re nocturnal so people often don’t see them even if they’re living in bushes on your property. They eat trash, which is available in copious amounts. They also love to snack on cats and little dogs. People often leave food out for their pets, which feeds them well.
Coyotes will go into urban areas at night too. One of the drive time DJs on WEEI Radio in Boston lives in Seaport area of the city. This is just on the south side of Faniel Hall area(Downtown Boston) right on the harbor. A coyote had been seen in this area about a month ago at night. They made a big joke about it that he was lucky to survive.