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Backyard Habitats – Lesson 6

Over the last six weeks we have explored several backyard habitats found in my yard – hopefully some of these you have.  This week I am turning the focus on habitats WE create – such as bird houses.  I am going to start with bluebird houses.

 

 

Bluebirds are beautiful, with that brilliant royal blue color – and they have a wide range across the eastern and middle portion of the United States – almost reaching the Rockie Mountains.  People love to see them in their yards and bluebird boxes have been popular for a long time.  But some have met this effort with success, others not so much.  It appears they are a bit picky about the box and the set up.

Adult bluebird on a nest within a bluebird box.
Photo: Molly O’Connor

Researchers have looked into this – why some work and others do not – and have come up with some clues.  Turns out the initial problem was, like so many other species, loss of habitat.  Bluebirds like nesting cavities (holes) in trees where they build their nests inside.  Holes the right size seem to be important to avoid predators – 1.5 inches in this case.  Many trees were cut down over time, leaving them with little habitat to raise young.  They became listed in many areas.

 

In more recent years, some of the cleared land is now reforested and cavities are becoming easier to find.  But we are also providing them cavities by building bluebird boxes to serve as their cavity.  The problem with both locations is that they bluebird must compete with other local birds for these cavities.  The researchers looked at the ones that were successful and compared to the ones that were not to help homeowners plan their new bluebird habitat.  Here is what they found.

The small eggs of a bluebird.
Photo: Molly O’Connor

The females build the nest, but it is the males who select the sites.  They chose sites they think the females will like – and they will like whatever is best for the babies.

 

Once the male selects a site he thinks will win her over, he sits near and sings.  If the female agrees, she will join him, and she will build a nest within of grass where they will lay the eggs.  Here are some key points to successful bluebird box site selection:

          Short, mowed grass.  Golf courses and cemeteries seem to be popular. 

          Open land, similar to a meadow, that can provide grasshoppers, and other insects, to feed. 

          Utility wires overhead for the birds to perch on and hunt.

          No nearby building that could harbor house sparrows which parasitize bluebirds and kill the babies. 

          Expanded front yards with gardens have worked. 

          Scattered knee-high bushes (such as those you would find in an open field) seem popular. 

          Grasses under the shade of 20-foot trees nearby are good. 

          Well established maturing trees nearby for perching. 

Measuring distance from a tree. Trying for 50-feet.

The reverse view to see what bluebirds would see from entrance hole.

Other resources have suggested fence post along large open fields.

Some say houses should be placed on metal poles to avoid ground dwelling predators (or competitors) from reaching; but wooden poles do work.

The 1.5-inch entry hole should not face directly face the sun.

Some suggest the hole should face east – though I have spoken with folks who have been successful facing it in other directions.

Within 50-feet of a tree and the hole facing the tree – this helps the fledglings when it is time to fly.

The bluebird box is in an open area, on a metal pole, under a power line, and there are nearby bushes and trees. We will see what happens.

The typical cycle is the male will arrive in the spring – females will choose and lay eggs by mid-spring – the young are flying by late summer.

 

We are trying this at our house (our first attempt at bluebirds).  Here is what we have planned.

          A bluebird box that is not painted (many are)

          On a metal pole in an open area of our yard where the grass is beneath and the garden nearby (saw lots of grasshoppers after the rain yesterday). 

          Facing northeast towards a pine tree about 40 feet away (no room to go further); the direct sun should not enter the opening. 

          A large boxwood bush is nearby that is currently the nesting home of several species, including a mockingbird.  We do not know if the house sparrow is there but will be on the lookout. 

Let’s see what happens.

 

ACTIVITY

          If you have the yard for it, try this!  See if YOU can get bluebirds to visit. 

          If you do not have the yard for this bird, maybe another.  There are lots of birds seeking shelter for egg laying.  One thing that has happened for us is hanging ferns on the front porch.  Almost every time mourning doves use them as a nest.  It eventually kills the fern, but it is cool to watch the birds from the window. 

          If not interested in a bird house, maybe a bird bath.  ESPECIALLY THIS SPRING, with such little rain, water is at a premium and bird baths are popular. 

HAVE FUN AND STAY SAFE.