ALWAYS IN SEASON: Humans alter habitat, which affects birds

Birds are always in season because there are always some birds around -- though they are sometimes hard to find.

Of course, some places have more birds than other places.

The two most important factors are food and shelter. These are the minimum requirements in any habitat.

Nature provides food for most species, though feeding birds has become a popular human pastime, both winter and summer.

Nature also provides shelter -- but quite often humans take it away.

When people tell me they aren't seeing birds, I ask whether there's been any change in the environment, a hedge removed, for example, a grassy area mowed, a tree cut down.

Shelter is important for birds. It offers concealment.

Often when birds disappear from a neighborhood it is to escape predators. Increasingly in Grand Forks that means other birds. Cooper's hawks, especially, have become fairly common nesting birds here. The famous peregrine falcons are bird eaters, too. So are merlins, a smaller relative of the peregrine.

The presence of any of these birds in a neighborhood will have an impact on the number of smaller birds that occur there -- especially if the smaller birds don't have anywhere to hide.

Habitat, including shelter and sources of food, is the most important factor in bird populations.

Human activity plays an important role, since we humans are by far the most important manipulators of habitat on the planet.

Weather influences bird populations, too. A wet spring such as this one reduces nesting success for species that nest on the ground, including gray partridges and meadowlarks.

Partridge populations fluctuate quite a bit. This is probably a function of weather and, importantly, of the presence of predators. Skunks are egg lovers, and cats and coyotes take young birds.

Meadowlarks face a different challenge. They depend on fairly extensive areas of grassland. In relatively recent times, road ditches and field edges provided that kind of habitat, but modern farm equipment has reduced those areas.

So, the number of meadowlarks is down overall. In fact, the western meadowlark is a species of concern to bird lovers and conservationists.

Of course, the western meadowlark is a well-known and well-loved bird. It is the avian emblem of six Great Plains and western states, including North Dakota.

Only one other bird is honored by as many states. That is the American robin.

Yet meadowlarks remain common wherever habitat is available. There are at least two nesting pairs within a half mile of my place west of Gilby, N.D., which adjoins a fairly extensive meadow.

On a five-day canoeing trip in the Badlands of southwestern North Dakota last week, I was seldom out of hearing of meadowlarks. In fact, the meadowlark chorus woke me each morning.

The Badlands, of course, remain the state's largest expanse of grassland.

Prairie is disappearing rapidly -- and this time, it's not agriculture that's responsible. Indeed, areas that

couldn't be farmed because they were too rough or too rocky are now being disturbed by oil development.

All of these disturbances have an impact on bird life, and not just meadowlarks. Western North Dakota has a number of species that are rare elsewhere, especially Baird's sparrows and Sprague's pipits.

John James Audubon discovered the pipit in northwestern North Dakota and described it for science in the mid-1840s.

It relies exclusively on dry prairie -- precisely the habitat that's being disturbed by oil development.

The pipit is only one species that will likely be driven into areas that have already been set aside. For the pipit, the most important are probably Lostwood National Wildlife Refuge in northwestern North Dakota, and Grasslands National Park in southern Saskatchewan.

Probably nothing in human history has had a greater impact on the planet than the discovery and development of oil. We've become dependent on it -- and with our dependence comes risk for creatures that share the Earth.

That's true in North Dakota just as it is true in the Gulf of Mexico.

The ongoing catastrophe in the Gulf reminds us of how fragile the Earth really is and how devastating our activity can be.

Drilling in northwestern North Dakota doesn't pose a risk on the same scale as offshore drilling, but it would be a mistake to assume that it is without consequences for birds and other wildlife.

Mike Jacobs is editor and publisher of the Herald.