Bird-watching, it turns out, is a hobby well-suited to film actors, who go to far-flung locations and have time to kill between shooting.While on set for Sunshine State, on Florida’s Amelia Island, actress Jane Alexander swore she heard a breeding heron. “They make these strange, barking grunts,” said Alexander, who made, as gracefully as possible, her best approximation of them.So she followed the sound through a palm meadow and a swamp, only to find that the creature making it was, in fact, an alligator.“I backed off very slowly,” she said with a laugh, “because she did not look happy.”She usually meets with more success. Alexander, who is on the board of the National Audubon Society, has traveled across the country, and to many parts of the globe, to hear the songs and see the flight of all kinds of birds.From her home in Nova Scotia, she recently talked about her favorite spots for birding. Following are edited excerpts. Where’s the best bird-watching in the United States?If you chose one county that has more bird species than any other in the United States, it’s L.A. County. That’s saying a lot, because Texas is the birding state, along the coast and Big Bend. But it’s huge. L.A. County, you tool around to the beach, to the Santa Monica Mountains, to the interior where you get farmland — you have a remarkable range of species because of that diversity. And in the world?You can’t not be overwhelmed with the diversity of wildlife in the tropics. The good news is that the tropics has more birds than you’ll ever hear in your life. The bad news is that you’ll hear them and you won’t see them. The tropics are dense, you know, but that’s what makes them so exciting. Can you suggest any tours?If you went to any birding magazine or site like the National Audubon Society or the Cornell Lab of Ornithology, you’ll see a lot of things advertised for reputable companies. Or if you’re headed somewhere, check with that city’s local Audubon chapter — we have about 460 of them in the U.S. — and join them in a local outing. You’ve been bird-watching for decades now. What has changed?There are a lot fewer birds. When I was first in Putnam County, N.Y., in the 1970s, we had quite a lot of rose-breasted grosbeaks. That is an absolutely gorgeous songbird, and there are a lot fewer of them around today. Climate change is bringing a lot of birds north to breed. The Carolina wren now is all over the Northeast. In Nova Scotia, we never had turkey vultures, but it’s now breeding here. Has birding gone digital?Oh my God, yes. There are many, many apps. I use iBird Pro. The National Audubon app. And David Sibley’s app is good, too. When you think of what I used to take into the field — a field guide, an actual book; tapes that had the bird songs so I could recognize them — now all that’s on your iPhone. It’s very exciting.