Distribution

Biak Island (previously called Mysore), Geelvink Bay, Irian Jaya.  Hubers (1994) states that it also occurs on the island of Korrido.  Because of its small range and the destruction of much primary lowland forest, it is considered to be a vulnerable form.

Plumage

An immediately recognizable subspecies, its head is like that of the nominate race, but even bluer, with no greenish streaks on the occiput.  There is a strong purple gloss on nape, throat, chin and chest bars.  Notable is the extremely heavy blue-black barring and the wide greenish yellow collar - much wider than in any other race - which extends down the mantle.  The primaries and secondaries lack yellow, which is replaced by red, and there is a corresponding extension of red down the sides and abdomen toward the tail.  Between the yellow collar and the nape is a narrow dull reddish band.  It's key identification features are its enormous greenish yellow collar and very heavy breast barring.

Aviculture

Rarely available.  P. H. Maxwell (1952) acquired a young one in the U.K. from the well-known collector Wilfrid Frost.  Maxwell had formerly kept another one that died at an old age, in the London Zoo Parrot House in 1943.  According to the International Zoo Yearbook (vol. 16), three Rosenberg's were bred at Barcelona Zoo, in Spain, in 1974; at least one of the parents was bred there.   Vogelpark Walsrode exhibited a pair in 1979.  In the late 1980s and early 1990s a few were imported into Europe.  Jos Hubers (1994), publisher of Lori Journaal Internationaal, could trace Rosenberg's with five breeders.  In 1990 he obtained seven females and three males, all young.  Through exchange and purchase, he was able to make up five true pairs.  The first pair started to breed at the end of 1991.  Two eggs were laid, the first of which hatched after 25 days, and the second on the following day.  At 12 days the chicks were ringed with 6 mm rings.  When feathers started to appear at about four weeks, the parents plucked them.  By the end of 1993 this pair had produced 10 young which were hand-reared or placed with foster parents.  Pair No. 2 started to breed in April, 1992; two infertile eggs were produced.  Two young were reared in the next two nests, but one died at five months.  From May, 1993, until near the end of 1994, nine young were reared from this pair.  When they plucked their young, the nestbox was placed on the floor with the lid open, and plucking ceased immediately.  One youngster had been reared from pair 3 and pair 4 had produced their first clutch which was infertile.  Hubers' birds were fed on Aves Lorinectar, with Loristart (higher protein content) when young were in the nest. 

Only a few Rosenberg's reached  the U.S.  In the U.K. there were several males only until 1996 when Trevor Buckell acquired a female and two young unrelated pairs from the Netherlands.  In that country, two eggs from a pair owned by G. van Dooren were laid on October 31 and November 4, 1994.  The first egg was infertile and the second hatched after 24 days.  The chick weighed 6 g on hatching, 10 g on day 2 and 15 g on day 4; it died on day 11.  In 1995 the female laid the first of two eggs on July 14.  They hatched on August 8 and 10.

Literature