Happy Cavity Nesting Families – Western Bluebird

Bird of Good Cheer and a Hopeful Spring

Throughout history, and within many cultures, bluebirds symbolize happiness, protection, and hope. People may have first taken notice of the birds because of their unusual coloring, or for their behavior; swooping through meadows and open spaces, cheerful song, or large family units raising young each spring.

When the bluebirds start building nests this spring (2021), it will signal a time when COVID quarantines and isolation may begin lifting. For those with creative inclinations, this cheer inspiring avian may, once again, be used to celebrate hope and authentic community freedom in song, writing, painting, filling in blocks of color on a coloring sheet, or building and distributing nest boxes.

Photo Credit: Julio Mulero

Secondary Housing Shortage

Bluebirds lack beak and skull adaptations to bore their own nesting cavities; therefore, they rely on second-hand holes of a certain circumference.

Like many animals highlighted on Following Deer Creek, human-caused environmental alterations – tree management practices and invasive species – have reduced their numbers.

Providing Bluebird nesting boxes (see Bluebird Nest Box Construction below) and replacing exotic plants with California native plants are two ways that individuals can contribute toward repairing California’s diverse natural ecosystems.

“Bluebird conservation is a shining example of a totally grassroots effort that has been tremendously successful. It illustrates the power of individuals and groups to make a difference.” – Elizabeth Zimmerman Smith 2020, Woodstock, CT at Sialas.org


Nevada County Western Bluebirds are year-round residents.

During spring and summer, bluebirds mostly feed on insects. Their hunting grounds are open grasslands where they perch on branches or fence posts to watch for bugs. When they spot prey, they’ll swoop in for the catch. In addition to insect hunting spaces, bluebirds also need reliable sources of fresh water.

Photo Credit: Becky Matsubara

In the winter, they feed on berries.


Females and juveniles have muted feather colors compared to mature males. Both males and females have straight beaks and rusty-colored chest feathers. Mature males have bright blue heads, wings, and tails.


Female left, male right | Photo Credit: Becky Matsubara

Social Behavior


Life Span

3-5 years

Life cycle

Reproduction & Family Chick Raising

Spring begins with nest building. Bluebirds choose existing cavities in which to nest.

Feb/March/April – males and females pair bond.

Females lay one egg a day for a clutch between 4 – 6 days.

After a fourteen-day incubation, with the male bringing her food and standing guard, all eggs hatch on the same day.

After hatching, both parents feed chicks for approximately two weeks.

Photo Credit: Shirley Binn

Once the young have fledged and begin traveling from the nest box to hearby branches, the female leaves to begin building a second nest while the male finishes caring for the first brood.

Bluebirds remain in family groups. First brood siblings may help raise the second brood. Inexperienced parents with failed nests may participate in helping raise their parents’ subsequent hatchlings.


Spring / Summer

  • grasshoppers
  • caterpillars
  • beetles
  • ants
  • butterflies

Fall / Winter

  • small fruit & berries
  • mistletoe
  • juniper berries
  • elderberry



domestic & wild cats




Nesting Box Chick Predators

  • bees
  • ants
  • earwigs
  • wasps

Undernourished chicks are also susceptible to parasitic infections.

Cavity Competitors

House Sparrows and Starlings are aggressive cavity-nesting competitors that were imported into New York between 1853 and 1890. The first to deal with inchworms and the second to introduce Shakespeare’s play birds into Central Park.

Other Birds that Compete for Cavity Nest Sites

  • Nuthatch
  • Chickadee
  • Swallow
  • House Wren


Detrimental Human Effects on Bluebird Populations

  • Introduction of competitive invasive species – House Sparrow & Starling
  • Tree & Forest Management practices
  • Herbicide & pesticide use
  • Wood fence post replacement with angle iron posts
  • Development of open spaces

The Bluebird Man – One Idaho Man’s Retiremet Conservation Legacy

Bluebird Restoration Project – Near Victoria, British Columbia

Bluebird Nesting Box Construction

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or view more Life on the Creek Art


click image to download FREE coloring sheet

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Audubon – How to Build a Bluebird Nest Box
Audubon – Western Bluebird
BBC – The birds of Shakspeare cause US trouble
Bear Yuba Land Trust – Bird Banding with Allison Nelson
California Bluebird Recovery Program
Cornell Lab of Ornithology – Educators Guide to Next Boxes
Cornell Lab of Ornithology – Nest Watch – national nest monitoring program
Cornell Lab of Ornithology – Western Bluebird
Ebird – Western Bluebird Identification & Call recording
Ebird – Western Bluebird Range Map
The Hatching Cat – 1853: The English House Sparrows Who Took Up House and Hotel in Manhattan
iNaturalist – About Western Bluebird
iNaturalist – Nevada County Western Bluebird Observations
North American Bluebird Society
North American Bluebird Society – Getting Started with Bluebirds PDF
San Diego Tribune – Bluebirds of Happiness keep local resident enchanted
Sailas.org – Bluebird Nest Box Style Pros & Cons
Wild Birds Unlimited (Grass Valley, CA)
Wikipedia – Bluebird of Happiness
Wikipedia – Western Bluebird

More Bluebird Videos:

Male Song

Eastern Bluebird – Brain Study – Male/Female Song Area

Making of Bluebirdman

Bluebirds in Popular Culture:

From Red Dead Redemption 2 to the Wizard of Oz, Sesame Street’s Big Bird, Niel Young, and Native American folklore the bluebird makes consistent appearances in American popular culture. It has also shown up in  as well as in ancient Chinese, Japanese, Native American and European folklore, the bluebird has symbolized hope, happiness, protection and change.
The symbol of a bluebird as the harbinger of happiness is found in many cultures and may date back thousands of years.


Bat – a Colonial Insectivore

Bats are the only flying mammals. Wing membranes are attached to their fingers. After rodents, they are the largest order of Earth animals. 

Microbats live in California. they are insectivores and can eat their weight in insects daily. (Large bats, such as the Fruit Bat, also known as a Flying Fox, live in tropical climates.)


Roosts, which can contain up to thirty generations of family members, are used for protection, warmth, grooming, eating, resting, and mating. Roosting sites include caves, mines, bridges, buildings, crevices, and tree hollows. Bats are nocturnal. They leave their roosts at dusk to hunt and drink water at night.

Since roosts are where large numbers of bats congregate, it’s a system that provides fertile conditions for the spread of diseases such as, rabies, histoplasmosis, and other viruses. Roosts are where White-nose syndrome is spreading (see below).

The Mexican free-tailed bat or Brazilian free-tailed bat (Tadarida brasiliensis) is a migrating bat native to the Americas. Since it roosts in large numbers in few locations, it’s vulnerable to habitat destruction. This bat is considered a species of special concern in California because of declining populations.

Environmental Obstacles:

A keystone species, bats keep ecosystems healthy by controlling insect populations, but they’ve got obstacles. Habitat loss and destruction of roosting sites, wind farms on migratory pathways, and drought are a few.  White-nose syndrome, a muzzle and wing flesh-eating fungus, has decimated bat populations across North America.

Some good news for California bats may be forest lands opened up by wildfires.  UC Berkeley postdoctoral researcher Zachary Steel found that certain bat populations have increased in burned forests. The causes are still under study but causes may be increased food sources, roosting locations in dead trees, and/or more space for flight maneuverability 

Special Adaptations:

Bats hunt with echolocation, sounds out of human hearing range that help locate prey.

While bats can use their mouths to catch prey, most bugs are caught in their wing membranes and either eaten in the air or carried to a roosting spot.

Bats have bendy bones which makes them ultra maneuverable. Some say bats have the fastest horizontal flying speed of any animal, close to 99 miles per hour!

Among roosting bats that create large quantities of urine and guano, they’ve developed respiratory mucous Ph buffer. 

Torpor is an important adaptation for microbats. It can range from a partial state of heterothermic arousal to full hibernation. Lowing body temperature reduces the need for food and fat storage.

A new study by University of California, Berkeley, researchers shows that bats’ brain activity is literally in sync when bats engage in social behaviors like grooming, fighting or sniffing each other.

Using scent markers and sound, mothers can locate their own babies out of thousands.

Life Span

10-20 years


  • mosquitos
  • moths
  • beetles
  • dragonflies
  • flies
  • wasps
  • ants
  • grasshoppers
  • termites


Photo Credit: Mnolf

Females can breed after 9 months of age, they congregate in maternity roosts.
Males become sexually mature at two years.
Gestation is about three months.
Generally, one pup is born per year. 
Young suckle for between four to seven weeks.
Mother’s must eat their body weight in insects to keep up with nursing demands.


  • owls
  • hawks
  • falcons

Roosts may come under predation from:

  • climbing animals
  • cats
  • coyote
  • raccoon
  • some species of snakes

Bat Species in Nevada County

  • California Myotis, MYOTIS CALIFORNICUS
  • Fringed Myotis, MYOTIS THYSANODES
  • Little Brown Myotis, MYOTIS LUCIFUGUS
  • L0ng-eared Myotis, MYOTIS EVOTIS
  • Long-legged Myotis, MYOTIS VOLANS
  • Mexican Free-tail, TADARIDA BRASILIENSIS (migratory)

White-Nose Syndrome

“WNS is considered one of the deadliest wildlife diseases, having killed over six million North American bats since it was discovered,” said CDFW Wildlife Veterinarian and Epidemiologist Dr. Deana Clifford. “WNS doesn’t affect human health or pets, but the ecological impacts of bat die-offs may indirectly impact agricultural systems through loss of the natural pesticide effect and nutrient cycling of bats.”

As of spring 2019, the California Department of Fish and Wildlife detected white-nose syndrome in bats in Chester, Plumas County.

Californians Can Help By:

Cavers/Spelunkers Can:

Click image to see more Life on the Creek art. Five dollars from every sale goes toward supporting the documentary project.


California Department of  Fish and Wildlife – Deadly Bat Fungus Detected in California

Corkys Pest –Bat Identification 

Northern California Bats – Education, Lectures, Rescue & Resources

Sierra Club – A Song of Bats and Fire

Smithsonian Magazine – What is Killing the Bats?

UC, Berkeley – Bats Brains Sync when they Socialize

USGS – What is White-nose Syndrome?

Washington Post – The batty history of bats in the military and why this new idea just might work

White Nose Syndrom Response Team

Wikipedia – Bat

Wikipedia – Maternity colony

Wikipedia – Mexican Free-tail bat


AUSTIN, TX (May 8, 2019) – Bat Conservation International (BCI) announced today that early signs of the fungus Pseudogymnoascus destructans (Pd) have been detected at one of the world’s premier bat conservation sites, Bracken Cave Preserve.

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