When I go for walks in the Preservation Parks, I know what I can count on seeing: northern cardinals and other common birds, several species of squirrels and (often) white-tailed deer.

Depending on the park and the season, I watch for barred owls, groundhogs, dragonflies, migrating waterfowl and grasshoppers. And I know coyotes are here in Delaware County and sometimes make forays into the parks.

I don't see -- nor do I expect to see -- black bears, bobcats, black vultures and any hummingbird except for the ruby-throated variety. After all, these are not Delaware County species. Or are they? Or might they be in the future?

All the bird-identification books indicate the calliope hummingbird, a western species, will only occasionally show up east of the Great Plains, but mostly in the Gulf states. Yet one has taken up temporary residence in a Delaware County backyard. It went to a Liberty Township feeder in late October, and as of Nov. 8 it was still there. Naturalist Jim McCormac wrote a great blog about our little guest; visit jimmccormac.blog-spot.com and scroll down to the Nov. 1 entry.

The appearance of the calliope hummingbird in our county reminds me that nature is full of surprises, and that from now on, when I say the ruby-throated variety is the only Ohio hummingbird, I will add "except when it's not."

A few years ago, I received some phone calls about black vultures appearing in Char-Mar Ridge Park. At the time, that was a bit of a surprise, since all the bird books show its range ending south of Ohio. But the bird is gradually moving northward, and we'll likely see more and more of this guy.

Speaking of surprises, eastern Ohio residents periodically are startled by black bears, which are making a comeback in Ohio. Until the early 1800s, when westward expansion by European settlers led to a century of forest removal, most of the state was covered by forest -- 95 percent of the land, in fact. There is plenty of evidence that black bears roamed those forests, but the last Ohio black bear was reportedly killed in 1891. At that point, only about 10 percent of the state was forested, and the bear was considered extinct in Ohio. Many of us grew up "knowing" black bears were not part of our fauna.

Now, the bear population in Ohio is on the rise. Currently, an estimated 50 to 100 black bears live in the state, with most seen in the northeastern counties of Ashtabula, Lake and Geauga. But a Division of Wildlife map shows sprinklings of confirmed and unconfirmed sightings all over the place, including in neighboring Knox and Licking counties.

Bobcats are returning, too. Like black bears, they thrive in a forest habitat; when the forests disappeared, so did they. Bobcats were considered extinct in Ohio in 1850, but massive reforestation and other initiatives are fueling their comeback. Bobcats were taken off the Ohio endangered list in 2014, shortly after 200 verified, and more than 2,000 unverified, sightings the year before.

Most of the bobcats were seen in heavily forested southeastern Ohio, with dozens reported in Licking County -- right at Delaware County's doorstep. Wildlife experts expect further expansion of their range as habitat improves around the state and populations disperse.

I wonder if it is just a matter of time before a bear or a bobcat wanders into one of the Preservation Parks.

In some respects, it's an unsettling thought; these are wild animals, after all, and species we are not accustomed to dealing with.

But I look forward to the day when these mammals become part of our local natural world. It will speak to improved habitat, which has broader benefits -- not just to the animals, but to Delaware County residents, who will be living in a community that values nature and all it has to offer.

Sue Hagan is marketing and communications manager for Preservation Parks of Delaware County.