PORTLAND — At the top of Munjoy Hill on a weekday morning this month, residents of the neighborhood crisscrossed Congress Street carrying coffee cups and holding dog leashes.

Among them were an international student at Southern Maine Community College, a Washington Avenue restaurant owner originally from Massachusetts, a filmmaker who relocated from Michigan in 2019 and a Vermont native who moved here three years ago, maybe for good.

It’s well-known that people from other states (and, to a lesser extent, countries) have been coming to Maine in increasing numbers for decades, with the pace picking up during the pandemic. A new milestone revealed by the most recent census data starkly shows how that’s changed the makeup of Portland.

Only 40% of the city’s residents were born in Maine, according to the 2024 American Community Survey — a smaller chunk of inhabitants from in state than both New York City and, by a hair, Boston have (though not Burlington, Vermont, where the figure has fallen to 30%).

For some historic perspective, native Mainers made up 72% of Portland’s population in 1980 and 59% in 2000. The decline appears to have accelerated since the pandemic, dropping 8 percentage points since 2019, not accounting for margin of error.

Bringing diversity and new energy to a place are generally considered positive changes, fostering innovation and expanding everyone’s perspective. But is there a breaking point in the ratio of natives to newcomers at which the identity of a city starts to slip away?

There’s no magic number, said Loretta Lees, an urbanist and faculty director of the Initiative on Cities at Boston University. Places start drawing more transplants for various reasons, such as a favorable cost of living or job opportunities. The effect of those new residents depends on several factors, she said, including who they are and what they have in common with people who are already there, how well they’re accepted and whether they make an effort to integrate.

In Maine, Lees said, lifestyle is a major draw, and Portland has its own strong identity and reputation that is likely attracting new residents who want to keep it that way.

“The hope is that they would take part in that,” she said.

For Beth Tanenhaus Winsten, the filmmaker who moved from Michigan, finding somewhere that had respect for the arts was important when she was deciding where her “peripatetic life” would take her next. Portland checked a lot of other boxes, too.

“It had community and beauty and kind people,” she said, while waiting for a delivery outside her Munjoy Hill condo building.

As a climate haven on the coast, Lees said, Portland is well-positioned to benefit from an infusion of newcomers’ ideas and money, but the city also needs policies and practices that prevent the displacement of longtime residents.

Although I assumed the native Mainers would now be concentrated off the peninsula — hanging onto their single-family homes in neighborhoods like North Deering — I was surprised how many people I came across on Munjoy Hill that Wednesday morning who had grown up in Portland and the surrounding towns: Scarborough, Westbrook, Cumberland.

Clare Considine, who is originally from Falmouth, recently moved back to Maine after going to college in California and living in New York City for a few years. She always intended to return and realized she had no reason to keep putting it off.

“I love it here,” she said.

The amount of new people in the area is a frequent topic of conversation among her friends from home. Most of the people she’s met since she’s been back are from elsewhere.

Among her peers, being born in Maine feels like “kind of a novelty,” Considine said.

None of the Mainers living on Munjoy Hill whom I spoke to seemed bothered by the fact that they’re in the minority. They clearly still see a city they recognize and one where they want to live — probably for many of the same reasons others do.

If the population trend of the past five years continues at the same rate, there will be no Mainers living in Portland by 2050. I don’t think that’s likely to happen.

As long as enthusiastic new residents stay long enough to raise kids of their own here, in the eyes of the census, those are more Mainers getting added back to the mix.