Returning birds are scoping out the areas for ideal nesting sites.
If you planted birdhouse gourds last year and have them drying somewhere, March (we are in zone 6)
is the time to clean them up and get them hung.
Birds that are cavity nesters are the types who are most likely to use gourds for their nesting sites. Swallows, wrens, chickadees, woodpeckers finches and bluebirds are all types who will take up residents.
Wrens, in particular, like a swaying birdhouse and most likely will check out several of these gourds before choosing one.
Gourds have many advantages over a typical box type bird house.
Being this type of gourd us usually 8 to 10 inches across, this provides a very roomy area for the young, avoiding any crowding.
There is more depth from the entrance hole to the bottom, so it is much safer from predators. Sparrows are known to invade the nesting areas of other birds, much to the aggravation of people trying to encourage Bluebirds and Purple Martins to take up residence. Sparrows can be a problem with Bluebird boxes but don't seem to like swinging gourds.
Metal Purple Martin houses are often made of metal. Though lightweight and easier to hoist up on the pole, metal is a poor insulator from heat and cold. Natural materials such as wood and gourds are much better at protecting the young from temperatures that could prove fatal, such as a cold snap in June or unusual heat.
Last, the natural color of gourds seems to be preferred by wild birds than those houses that are brightly decorated.
Wrens, Chickadees, Woodpeckers, House Sparrows, Bluebirds, and some Finches are all cavity nesters who will use a gourd house. (Don't be surprised if some birds use your gourd for a place to roost and not bother to build a nest in it.
- See more at: http://www.the-scoop-on-wild-birds-and-feeders.com/gourdhouses.html#sthash.qF3iepda.dpuf
They will be very light in weight, the seeds inside will rattle, and the outside appearance will look like dried, flaky mold spots.
Just take a wire brush or sandpaper and brush this off till it is nice and smooth.
With a serrated knife cut out a hole about midway from the bottom with a diameter hole size of about 3/4 - 1 inch. If you want to attract Purple Martins in particular, make the hole about 2 inches and in the shape of a crescent. This shape is easy for the Martins to get in and out, but deters Blackbirds and Starlings. Poke additional little holes or small slits into the bottom of the gourd for drainage.
Using an ice pick poke holes through the top near the stem so that you have two holes, one on each side. Now take a crochet hook and poke through both of these holes. Loop a length of about 12 inches of weatherproof cord rope around the hook and pull back through these holes. Now your cord rope is through the birdhouse and it is ready to hang.
Be sure to hang these bird house gourds at least five feet off of the ground to be out of the reach of nosy predators, such as cats. They can be hung in groups to attract the social types or spaced out around your area to attract those species who are more territorial.
It is difficult to clean these types of birdhouses after the season is over, so I don't even bother. Usually by winter's end, they either have fallen, have woodpecker holes in them, or they become a home to a mouse or a bees nest. I never cared since I try to have a fresh batch of gourds each spring.
Need to know how to grow birdhouse gourds?