New Neighbors

This is the second article in a series related to attracting bluebirds to your yard and properly caring for them.

Click here if you would like to comment on this article.

May 25, 2007

  New bluebird neighbors moving into Gilbertson style nest box.

---

This morning a bluebird couple claimed a Gilbertson style bluebird nest box located about 20 feet across the driveway from our back door.  The process was filled with a number of small challenges that are often associated with bluebird nest site selection and nest building.

---

Challenge #1

The young female bluebird began to attack her reflection in our kitchen window.  I closed the curtains and that helped for a few minutes.  Then she started visiting our cars parked in the driveway and attacked her reflection in the windshield and side view mirrors.  I relocated both cars some distance from the driveway. She then joined her mate in sitting on top of the Gilbertson nest box.

Note:  Bluebirds become quite territorial during nesting season.

Challenge #2

Birds feeding on a feeder array near the Gilbertson distracted the bluebirds from building their nest.  I relocated the feeder array to another part of the yard some distance from the Gilbertson nest box.  The bluebirds settled down and started going in and out of the nest box.

Note: Feeders located too close to the nest box may disturb bluebirds and distract them from the nesting process.

Challenge #3

The young female bluebird apparently had never built a nest before and did not know how to begin.  She repeatedly went into and out of the nest.  She landed beside her mate on top of the nest box and they engaged in animated conservation.  The male flew into the yard and picked up a piece of pine straw in his beak and deposited it inside the nest box.  He then landed on the roof beside her and they had another conversation of sorts.  She flew into the nest box, stayed a couple of minutes, and then returned to the top of the nest box.  The male repeated the process of placing one piece of pine straw in the nest box.  This time the female must have understood because she flew into the yard and returned with a big wad of pine straw in her beak and entered the nest box with it.

Note:  Put several small handfuls of pine straw or clumps of dried grass in the general vicinity of the nest box to facilitate nest building.

---

Bluebird Nesting Basics

Bluebirds are secondary cavity nesters.  That is to say, they use available cavities or nest boxes in which to build nests and raise their young.  They do not excavate their own cavities as do some species of woodpeckers.

Nest Selection & Building

The male bluebird identifies and assesses potential nesting sites.  He then tries to persuade his mate that one of the nesting sites is ideal for their needs.  The male will often sit on top of a nest box and sing to attract the female’s attention to the box.  The male may even go so far as to leave a piece of pine straw protruding from the entrance hole to entice her to enter the nest box.

The female bluebird makes the final decision on which nesting site to use and she builds the nest in preparation for the egg-laying step. 

Note:  Nest selection & building can occur in 1 day or take several weeks to complete. 

Egg laying

The female lays one egg per day usually first thing in the morning until all the eggs in the clutch have been laid.  The typical clutch size for Eastern bluebirds is 3–5 eggs.  The range is between 2–7 eggs per clutch.  Clutch sizes larger than 7 eggs have been reported but are thought to be the result of additional eggs deposited by another female bluebird experiencing problems with her own nest.  The process of depositing eggs in other nests is referred to as “egg dumping.”

Note: The egg-laying step takes one day per egg until the entire clutch of eggs has been laid.  Five days will be required for a clutch size of 5 eggs. Bluebird eggs are oval shaped and blue in color.  In rare cases, bluebird eggs may be white in color and hatch normally.

Incubation

The female bluebird incubates or regulates the temperature of the eggs as needed depending upon the ambient temperature.  She develops a “brood patch” on her stomach. The brood patch is an area where the down covering thins and blood vessels near the surface or the skin enlarge to allow her to better transfer body heat to the eggs. The incubation period is 11–19 days (13–14 days is typical) but can vary due to temperature and weather conditions.

Egg Hatching

Hatching is the next step in the nesting cycle.  The eggs hatch usually all on the same day in the order they were laid.   Just hatched baby bluebirds are referred to as “hatchlings.”

Nestling Stage

For the remainder of their time in the nest, baby bluebirds are referred to as “nestlings.”  During this stage, the nestlings develop and mature in preparation for leaving the nest.  The nestling stage has a range of 16–21 days. The typical nestling stage is 17–18 days in duration.

Fledgling Stage

One by one the nestlings leave the nest on their solo flights and become fledglings.  Once out of the nests, fledglings do not return to the nest on their own.  For the next two weeks after they have fledged, the new bluebirds are taught how to fend for themselves by their parents.

Extended Family

An extended family of bluebirds may be observed later in the the nesting season.  This happens when the offspring of earlier cycles remain with their parents throughout the remainder of the nesting season.  They can be seen accompanying the parents and even helping to feed the nestlings of a later cycle.  The extended family dissolves before the next nesting season as the bluebirds select their own mates and search for suitable nesting sites.

---

Click here to comment on this article.

Technorati Tags: bluebirds, nesting, nest boxes