During a hike along a creek in Baltimore County last week, we found in the thick mud of its sloping banks the huge tracks of the great blue heron. They were unmistakable because of their size, between six and eight inches long, with four toes — three forward, one aft — planted in the muck like fossils on a Jurassic beach.

The tracks were bigger than any others in sight — enormous next to the raccoon prints, far bigger than what the deer had left behind, much bigger than the paws of the dog that had come through the woods and crossed the creek. This heron had walked along the banks, fishing for a meal. Judging the bird’s weight from the depth of its tracks, it had found and consumed plenty of protein from the creek.

My son and I looked around but did not see the heron. She might have heard us coming, or she might have found bigger fish to swallow in the nearby Gunpowder River. It didn’t matter. I find as much fascination in their tracks as in their astonishing presence. It is April, and the herring and shad will be migrating up the Susquehanna River into Deer Creek, creating a feast for heron. They will be there in big numbers.

The heron have out-fished me on several occasions. So have osprey. On a summer day when the trout of the Gunpowder had baffled me — anglers call it “gettin’ skunked” — an osprey provided the final insult, flying 30 feet overhead, right above the spot where I was wading, and there was a fat, wriggling brown trout in its talons. The bird was so precise in its flight, I am certain its intent was to show off and show me up.

If you go out into the woods, or along streams, or hike through meadows on the edge of forests, or visit one of Maryland’s great state parks, or if you just sit in your backyard, birds are almost always with you — if not in direct appearance, then off in the sing-song distance, especially in spring. There are hundreds of species around us, some, like the heron and osprey, far more obvious than others.

For me, those that are not so obvious — the flickering small birds that need to be appreciated with binoculars or through the lens of a camera — hold the most mystery and fascination. And if you’ve never been able to fully appreciate the red poll, phoebe, towhee or great crested flycatcher, you might derive hours of pleasure from a new book from Johns Hopkins University Press, “Birds of Maryland, Delaware and the District of Columbia.”

It’s the size of a coffee table book and looks at first like one, heavily dependent on photographs. But it’s far more than that. Part field guide, part birding atlas, part conservationist pleading, it is nearly 500 pages of photos by Middleton Evans and prose by ornithologist Bruce Beehler. It comes with charts, checklists and maps of birding hot spots. The foreword is by the late conservationist Chandler Robbins, author of “Birds of Maryland and the District of Columbia,” a guide that was published in 1958 with only one illustration. The new book is smartly designed and organized, with hundreds of color images by Evans and numerous nature photographers listed in the acknowledgements.

I can’t imagine a more complete record of the birds of our region. It’s an inspiration for anyone who has thought about — but never got around to — becoming a birder.

And the experienced birder might appreciate it as a kind of album of old friends.

Evans’ work is truly remarkable, with photographs that capture the splashes of color and feathery details that are hard to appreciate from a distance. He found birds everywhere, from Baltimore to the Delaware shore, from tidal creeks to suburban gardens. He recorded common birds and rare birds, including the pair of brown boobies that visited Baltimore’s harbor for a month in 2015. Evans’ work along marshes and coastal areas has been particularly productive, bringing into stunning focus avocets, sandpipers, sanderlings and oystercatchers.

Though the index contains no reference to climate change or global warming, Beehler devotes some words to the subject. Climate change is expected to move the range of birds of our region further north, making it harder to spot certain species, including the Baltimore oriole, Maryland’s state bird. The changing climate has also diminished seasonal food sources for migrant birds. Beehler describes other threats, including sea-level rise related to climate change, the use of pesticides, loss of habitat and, for birds that live on the bay or ocean, competition with humans for fish. That is why the Beehler-Evans book is timely and important. It’s an impressive accounting of what we have and what we could lose if we don’t do more — and fast — to counter the effects of human behavior.

As if his parting words, Robbins, who died in 2017 at 98, implores readers in the book’s introduction to find one special place in the outdoors, a woodlands or wetlands, and embrace it and care about it. If everyone did that, one piece of Earth at a time, we could save the planet for future generations of people and birds — those that leave big prints in the sand and those in the sing-song distance.

drodricks@baltsun.com

twitter.com/DanRodricks