CONCORD, N.H. -- As someone who has studied bobcats for almost four decades, wildlife ecologist John Litvaitis remembers many times returning from the field without spotting a single one of these solitary and shy creatures that often hunt at dusk.

But bobcats are less elusive now as their numbers rise and they become more comfortable around humans. Joining the likes of foxes, coyotes and even mountain lions in rare cases, bobcats are making a home in small towns and suburbs -- and realizing there is plenty to eat in the cities.

They have turned up in recent years in such places as Manchester, New Hampshire's largest city; Waverly, Iowa; and outside Los Angeles. They have been spotted below backyard bird feeders, waltzing along streets in search of their next meal and, increasingly, as roadkill.

A website that Litvaitis set up to understand the bobcat rebound in New Hampshire features hundreds of amateur photographs -- of a cat lounging on someone's lawn, another stalking a chipmunk, a third sitting contentedly after gobbling up a guinea fowl and peacock.

"They are back in New England and at least as abundant as they were 100 years ago, if not more," said Litvaitis, who conducted much of his research while at the University of New Hampshire. "They are adapting to a landscape that has changed. You have roads and people everywhere, and they have figured out how to get along with most of that."

The resurgence of Lynx rufus comes during a shift over the past several decades from treating bobcats as vermin to be exterminated to being considered a top predator worthy of protection.

In contrast with the 1970s, when 40 states had no bobcat protections and bounties were common, most now put strict limits on hunting and trapping bobcats. As many as eight, including New Hampshire, completely outlaw both.

The naturally bobtailed cats -- as big as medium-sized dogs and known for brown or rust-colored fur with black and white spots on their bellies -- also are benefiting from warmer Northeast winters that allow for easier hunting, as well as expansion of public lands that increased prey, including white-tailed deer.

Bobcat numbers have almost tripled nationwide since the 1980s to as many as 3.6 million, according to a 2010 study in the Journal of Fish and Wildlife Management, the most recent national survey.

"Bobcats have been a real success story in wildlife conservation in the past several decades. They are at the point now that they are growing or stable across their range," according to Nathan Roberts, a wildlife research scientist at the Wisconsin Department of Natural Resources who co-authored the survey.

In New Hampshire, Litvaitis said, that is exactly what has happened.

He estimates bobcat numbers dropped to as low as 150 in the late 1980s, which prompted the state to ban hunting in 1989. Numbers have increased ever since. A University of New Hampshire/New Hampshire Fish and Game survey estimated their population in 2013 at 1,400.

The bobcat's success also reflects its ability to eat almost anything and thrive almost anywhere, from cornfields to swamps to suburban parks. With cottontail rabbits declining in New Hampshire, they shifted to preying on plentiful wild turkeys and squirrels.

"They are clever animals and creative animals," said Roberts, who has attached GPS collars to 60 bobcats in the past three years in Wisconsin. "We had one animal in particular in a small town that spent all of its time in town going from bird feeder to bird feeder."

Not everyone is rolling out the welcome mat.

In Massachusetts, police last month said they shot and killed a bobcat that had attacked two large dogs and was coming after officers. Farmers in New Hampshire have shot bobcats.

"Many people enjoy seeing them, but for others they are a nuisance," according to Patrick Tate, a wildlife biologist with New Hampshire Fish and Game Department. "Complaints about bobcats preying on domestic chickens have increased, requests from the public to trap and relocate bobcats have risen, and instances of road-killed bobcats have become common throughout the state."

Many states have considered reintroducing hunting and trapping to help regulate growing populations.

The New Hampshire proposal to offer 50 permits annually was withdrawn last year, over concerns that bobcat traps could ensnare Canada lynx, considered threatened under the Endangered Species Act.

In Illinois, however, hunting and trapping resumed last year.

"There has been a lot of conservation to get us back to this season," said Neal Graves, president of the Illinois Trappers Association. "It's something we haven't been able to do for 40 years."