Bird species in population decline have something in common with cancer. Learning about it is bad news. But, if you don't know, you can't seek a remedy.

In the case of 586 bird species worldwide that are listed as critically endangered or simply endangered, curing cancer is the better bet.

My pessimistic mood stems from review of a newly published book that looks hard at bird population problems. "The World's Rarest Birds" is a beautiful book, distressing subject aside. Hundreds of excellent photos display the glory and wonder of these birds. Photos of some species appear in print for the first time. The text that explains the problems is to the point.

This is a Princeton Press publication, so the excellence shown is not unexpected.

The heart of the book is a species-by-species account, region by region around the world, defining briefly why these birds are in trouble. Basically, as you'd suppose, it's us, one way or another.

BirdLife International, devoted to conservation, lists 10,064 bird species worldwide, 9,934 alive in vastly varying quantities and 130 gone extinct since 1500. The list contains 197 species designated critically endangered and 389 endangered. These are the most-threatened species. Many other species are "vulnerable."

Consider North America. The Eskimo Curlew, a bird once found in Minnesota, and Bachman's Warbler, resident in the southeastern U.S., are possibly/probably extinct. The curlew was last seen for certain in 1963, the warbler in 1988. Habitat change did them in.

Are they extinct or unseen? Impossible to say. And one is pretty much the same as the other. If you can't find it, it's good as gone.

In the past 50 years we've lost half of our Snow Buntings, an iconic winter bird here. They're vulnerable, one step below endangered, as are Sprague's Pipits and Rusty Blackbirds. All three species move through Minnesota. Habitat loss is the issue. Habitat is almost always the issue.

The population of Greater Scaup, a duck you can/might see here has declined 75 percent since 1960. Early thawing of its permafrost nesting grounds is one reason for lower numbers.

Look at an issue in the news almost every day: Canada's extraction of oil from tar sands. The drilling is being done after scraping away boreal forest. The forest is nursery to over 300 species of songbirds and waterbirds. Is this a problem? Sure. If it's a problem, is it an issue? Does anyone think they'll stop drilling because of some songbirds?

The Whooping Crane once nested in our state. Early European settlers shot it out, plowed its nesting ground. It is, however, one of the few success stories to be found. Cranes remain endangered, but numbers are growing slowly thanks to an introduction program headquartered just across the Wisconsin border.

This book's authors -- Erik Hirschfeld, Andy Swash, and Robert Still -- make clear our impact on birds. They don't have many success stories to share. We hit birds from so many directions.

We know that, don't we? We just don't know how to make the world work to the benefit of both humans and other living creatures.

For that reason, this book should be widely read. Take a look at what we're losing.