Story By Norma Wall
Photos by Vic Prislipsky
Eastern Bluebirds were endangered in the mid-20th century.
Bluebirds are cavity nesters who can’t build their own cavities. They must compete with larger, more aggressive species for nest sites and food.
But thanks to the efforts of volunteers who erected hundreds of thousands of bluebird nesting boxes, that decline has been reversed.
HSV Audubon started their bluebird recovery effort in 1974 with 20 nest boxes on one golf course. They now have over 300 boxes on nine golf courses, supporting up to 2000 eggs annually; 40 volunteers monitor the boxes weekly from April through August.
More about becoming a bluebird monitor
Eastern Bluebirds are a small thrush with a rounded head, large eyes, plump body, long wings, and fairly short tail and legs. The bill is short and straight. They are enthusiastic insect eaters.
The males are deep blue above with a rusty throat and breast, white under belly. Females are grayish above with bluish wings and tail, and a subdued orange breast.
Eastern Bluebirds perch erect on low branches are easily observed in open areas as they forage for insects. In the winter they eat berries and seeds and will eagerly dine at your suet feeder or accept your offering of mealworms year round.
Often thought of as gentle birds, they will aggressively defend their nest. Both male and female protect and maintain their territory, patrolling boundaries and launching an aggressive defense against potential intruders.
This may also explain the “pecking” behavior on your windows.
The bluebirds may see their own reflection as a threat.
Take a peak inside the nest box
- Pairs usually raise two or three broods per year
- The female lays 4-5 pale blue to white color eggs
- Young birds hatch after 11-19 days of incubation
- Leave the nest about 19 days after hatching.
- Stay nearby for 7-10 days
- Remain in family groups for as long as 3 weeks
Clean out old nests as soon as a brood fledges so that it can be used for a second nest attempt.
Anatomy of a Bluebird Nest Box
HSV Audubon builds and maintains bluebird nest boxes, designed to help protect the nesting birds from predators and the elements. They are built using quality materials and superior construction details. These are available to the public for a base price of only $28. What a bargain!
- Extended overhang roof to help protect the entrance from the elements.
- Upward swing front opening for full view of the interior, easier to clean and monitor.
- Cedar floor with drainage holes for longer wear.
- Exterior grade 5/8" plywood with solid hardwood trim.
- Entry Block 2" thick to help keep birds safe from the long arm of raccoons etc.
- Plexiglas on the exterior of entry block to prevent woodpeckers and squirrels from enlarging the opening.
- Mechanical closure to keep predators from opening the box.
- Openings for ventilation and natural light on both sides and above the entry.
- Stainless steel screws; hot dip coated nails
- Glued for extra strength to last longer
- Metal brackets to brace the roof.
Special thanks to our volunteer craftsman, Adolph Juarez, for this superior handcrafted bluebird home. Questions? Call Adolph 501-915-0201
Position the nest box about 4-6 feet above ground
entrance hole facing east, toward an open area
The birds prefer meadows and open areas surrounded by trees
use minimum spacing of 300' between boxes to reduce competition between bluebirds for territory
use predator guards to discourage snakes, racoons
from HSV Audubon Bluebird Monitor data:
March 11 Male bluebird locates a nesting site.
March 15 - 17 Male tries to induce the female bluebird to accept his chosen nesting site (natural cavity or nesting box).
March 17 Female accepts the site, and in so doing accepts the male as her mate.
March 17 - April 8 “Honeymoon” period: The bluebird pair remains in the vicinity of the nesting site, frequently examines it, and attempts to drive away other possible occupants.
April 9 - 13 Female bluebird builds a nest, with encouragement from her mate.
April 14 - 18 Pair remains in the general vicinity of the nest.
April 18 - 22 Egg laying takes place (usually one egg a day for five days) 4 to 8.
April 22 - May 6 Incubation period: The female incubates the eggs for 14 days, while the male remains close by, often bringing food to the female. He guards the nest while the female is out for food and exercise.
May 6 Eggs hatch and the female bird carries away the shells and fecal matter.
May 6 - 11 Both adults work tirelessly from dawn to dusk to feed the nestlings. The female broods the young for shorter and shorter periods as they grow.
May 23 Young bluebirds leave the nest, generally flying directly to a tree, shrub or fence nearby on their first flight.
May 24 - 30 Both parents continue to devote full time to the feeding and protection of the young.
June 8 - 11 Egg laying for the second brood (typically one egg each day for four days).
June 11 - 24 Incubation period: The incubation of the second brood ordinarily lasts 13 days. Young of the first brood have now become independent but stay nearby.
June 24 - July 11 After hatching the young of the second brood remain in the nest and are constantly fed. (Sometimes young of the first brood assist in the feeding).
July 11 Nestlings of the second brood leave the nest. (The nesting season may end here, or a third brood may be raised as described above.)