Feeders, water and birdhouses are three good ways to bring birds to your yard. The latter offers pleasures the former do not.

Birds that nest in houses or boxes are obligate cavity nesters: obligated by nature to nest only in a confined space of some kind. For millions of years that was holes in trees, but opportunities are seriously diminished these days. We trim trees, we cut them down, particularly trees beginning to show their age.

So, we have birdhouses.

In birdhouses in our yard, we have nesting house wrens, black-capped chickadees, great crested flycatchers, wood ducks and hooded mergansers, the latter two in houses adjacent to the pond in our backyard.

We get to watch the birds court, collect nesting material, feed hatchlings and, finally, see the fledged young birds. There is more to the story than feeders alone.

You can buy birdhouses or build them yourself. If buying is better for you, please watch a box construction video first (see below). It will acquaint you with the important elements a suitable birdhouse must have:

1. Size of house, varies by species.

2. Type of wood used (cedar is best).

3. Construction essentials (tight seams, secured with screws, no nails, no perch).

4. Size of entry hole (varies by species).

5. Mounting or placement.

"Woodworking for Wildlife," a Minnesota Department of Natural Resources book, is an excellent resource on birdhouses.

It's unfortunately out of print, but all of its birdhouse information is available on the website of the Tennessee Wildlife Resources Agency (tn.gov/twra/wildlife/woodworking-for-wildlife).

It is used there with permission of author Carrol Henderson, former chief of the Minnesota DNR nongame wildlife division.

There are diagrammed plans, dimensions, lumber choices — everything you need to know to build a proper, long-lasting nesting place for the songbirds that visit your yard.

For a simple way to mount a nest box see this video from the Cornell Lab of Ornithology: youtube.com/watch?v=3q8cH-9J58o.

Much information on bluebirds and nest boxes can be found at sialis.org. (Sialis sialis is the scientific name of the Eastern bluebird.)

Steve Gilbertson of Aitkin, Minn., has designed two of the best and most popular nest boxes for small songbirds. Find the illustrated story at nestboxbuilder.com/nestbox-article-gilwood.html

Lifelong birder Jim Williams can be reached at woodduck38@gmail.com.

Why are some nest boxes set in pairs?

Q: I see bluebird nest boxes along the road in pairs. Why two so close together?

A: The idea is one box for tree swallows, the second for bluebirds; both species are obligate (no choice) cavity nesters. The swallows are very territorial with other tree swallows, but not with bluebirds. No swallows are allowed to use the second box, thus kept available for bluebirds should they arrive. The two species both eat insects, but do not compete. Swallows specialize in flying insects, while bluebirds hunt on the ground.