Crimson Rosella Nest Box and Nesting Diary

Bill Leane, Lake Eucumbene Community Association (LECA)


crimson rosella, photo courtesy of Michael Dahlem
Crimson rosella, photo courtesy of M. Dahlem

The Nest Box Diary concept is derived from a Community Tourism Development Project proposal by LECA.

LECA's project provides:
1. new specialist nest boxes, and
2. interpretative material and activities to engage the interest and deeper involvement of visitors and residents.

The Adaminaby district is a major breeding ground for the Crimson Rosellas (Platycerus elega). Their presence is a source of satisfaction and pride in the area. Rosellas frequently nest within the villages' precincts, but the demand for sites exceeds supply.

The behavioural patterns of parrot nesting are known to bird enthusiasts and local residents, but are largely unknown by casual visitors and the wider public.

Residents, rental property owners and visitors are encouraged to take note of actual observed versus expected behaviour as the season progresses.

Experience with other nest box diaries demonstrates that observers become very involved in the activity and site, and enthusiasm and interest soon grows to consider other parrots and other species.

Crimson rosellas are an ideal bird to select for a diary-based project. They are accustomed to living closely with human presence, and readily populate artificial nests. They live for about 15 years; mate for life; and prefer to use the same nesting site at the same time, each year.

crimson rosella pair, photo courtesy of Michael Eaton
Photo by Michael Eaton, used by permission

You will find that keeping a nest box diary is a very satisfying, enjoyable pastime every summer season.

You will engage with the family life of our Rosella community and notice the behaviour and the seasonal migration of other parrots.

If you wish to participate in the LECA nesting box group, follow the nesting box experiences of others, share photos and stories, please contact me at LECA.

Keeping a Nest Box Diary

After many years of being fascinated by the beauty, behaviour and calls of our local crimson rosellas, I have decided to keep a diary of their comings and goings to a recently installed backyard nesting box.

Hopefully, I will develop a long-term relationship with our nesting avian partners, and people visiting my community will also observe the nesting experience and share a similar relationship.

I am also hopeful that the nest diary concept will be sustained well into the future and that locals and visitors can be encouraged to revisit the area to support, follow, and contribute to this important project.

My Nest Box Diary

Old Adaminaby, NSW, 2629

Elevation 1200m, Rainfall 729 mm pa

Local ecosystem: sub-alpine eucalypt woodland frost hollow

Typical vegetation: Snow Gum Eucalyptus pauciflora, Black Sallee Eucalyptus stellulata; sometimes Adaminaby Snow Gum Eucalyptus lacrimans

Day 1....

weeping snowgum

The Nest Box

rosella nesting boxMy nest box is a standard commercial nest box design which mimics a natural nesting site: 2m above ground level; NE facing; sized to attract a crimson rosella; constructed to deter predators (currawongs, cats) and unwanted competitors (possums, micro bats).

The crimson rosella nest box will also attract Eastern Rosellas; but this variety prefers to nest at a slightly lower altitude, below 1000m.

Commercial designs and "flat-pack" nest boxes are available via the Internet and by e-shopping. The most economical way to purchase nest boxes is to consolidate and order for several boxes (5 plus) and request a delivered price for the consignment order of nest boxes.

The Breeding Season

Prepare for the nest box to be occupied from September until early autumn, as up to 3 nesting pairs cycle through their breeding phase.

The nesting and breeding calendar of the crimson rosella begins in August - early spring, when nature urges females to prepare for the breeding season. She must find a nest, choose a mate, prepare for egg production and prepare to rear chicks to fledging stage. Once the chicks are fledged and capable of flight, they usually vacate the nest in 7 to 10 days.

Fortunately, it is relatively easy to track these breeding cycle stages by observing the behaviour of the pair at the nest.

Note: It can be difficult to distinguish between the sexes. A reasonable guide in distinguishing pairs is that the adult male is usually 10% bigger than the female.

Nest Site Selection

Choosing a nest site is a joint decision made by the prospective rosella pair. Site selection is an important bonding step in a relationship that will heavily rely on cooperation and the sharing of family responsibilities by the partners.

The preferred site is a hollow bole in a large tree, 2 metres plus above ground level, NE facing, and with protection from the prevailing wind at that time (usually SE). Suitable nest sites are not abundant and there will be competition for suitable sites, especially where abundant feed is at hand.

Pairs can be seen visiting and revisiting prospective sites, until a site is confirmed as vacant and available for occupancy.

Observed behaviour: Pairing, visiting nest sites, hollow or bole inspection, revisiting prospective sites, staying at the site for several successive days to affirm occupancy.


crimson rosella male feeding female, photo by Michael Dahlem
Male rosella feeding female, photo courtesy of M Dahlem
Once the decision is made to occupy the site, the female will stay at the nest and will prepare a dust base of shredded bark for the coming eggs and rarely leave the nest.

During this 10 day confinement, the male will forage widely and bring food to feed the female. This is also a bonding behaviour to confirm the ability of the male to care for a brood and raise offspring.

The female may terminate nesting behaviour if the male is delinquent (fails to return to the nest) or if the food supply is insufficient to sustain a successful brood.

Occupied sites will be defended fiercely by the female while the male feeds and brings food and bark pieces to dress the nest.

Observed behaviour: Male feeding female, pair defending nest, male collecting small bark pieces for female to chew to dust.

Brooding Eggs and Incubation

Crimson Rosellas lay between 4 and 6 eggs over a period of 7-10 days and incubate these for 20 days to hatching. During this time, the female is fed almost entirely by the male, with only very occasional excursions from the nest.

Observed behaviour: female predominantly fed by male at the entrance to the nest, frequent foraging behaviour by the male.

Growth and Fledging

Once hatched, the task of feeding at the entry of the nest falls both to males and females.

The hatchlings or 'naked' chicks rapidly gain weight and develop fluffy down feathers for warmth and protection. After about 15 days, the nestling's tail and flight feathers will over-grow the thin down undercoat, and the bones and muscles develop in wings and body to allow crawling and hopping, and later flight.

At the nestling stage, chicks are most vulnerable to predation by currawongs, other hunting birds, and feral cats. Nest box design is important in preventing predators reaching deep into the nest to steal chicks.

Newly green-feathered juveniles will emerge from the nest to feed at the entrance, exercise flight muscles and gain experience of the canopy and environment. First experimental flight is tested shortly after emerging from the nest, after hops and scaling branches and retreating to the nest.

Fledglings will accompany their parents and siblings on foraging flights to learn food sources and social etiquette and parrot behaviour. After the fledged chicks are about 35 days old, the parent pair prepare to release their near-adult charges to life out of the nest as subordinate society members of a mixed flock.

A pair will usually have only one clutch of 4-6 white eggs per year, occasionally two; and will usually attempt to return to the same nest in the following year.

Observed behaviour: adults feeding chicks at the nest entry, regular emergence of chicks, flight training, socialisation, presence of threats from Currawongs and other bird species.

Adult Life

After the fledglings leave the nest, they stay with their parents for about a month and join a local foraging group or flight. The immature birds gradually lose their green plumage, which is replaced by the mature colours (crimson and blue feathers) by about 8 months of age. Females achieve sexual maturity at 18 months, but males take up to 2 to 3 years. Birds pair for life and remain in close contact throughout the year.

Keeping Your Diary

crimson rosella
Crimson rosella: image by Auzz33 from Pixabay

The easiest way to maintain a nest box diary is to purchase an inexpensive calendar or short, hardcover paper diary and keep this exclusively for information regarding activities at the nesting box. A paper diary can readily generate content for an interesting online diary or blog.

Observe the nesting box and write a short description of what you observe and note the dates.

The birds will keep generally to the above cycle, but times and durations may vary. It is not common for birds to abandon a nest during nesting, but trespass and perceived threats or danger will cause the females to abandon eggs or to evict hatchling chicks.

Your diary will be repeated once the nest is vacated and new occupants commence their cycle.