The Pseudeos genus
In coloration, the single species in this genus is distinctive; in behavior it is reminiscent of Trichoglossus and Eos. But its chromosomes have revealed some surprises. Simon Joshua has studied the chromosomes of many parrot species, with special emphasis on lories (more than 30 species, from every genus except Oreopsittacus). He revealed that the karyotype of Pseudeos fuscata is of considerable scientific interest. "Perhaps most importantly, it is unique among other members of the Loriinae. Its relationship with species of Eos is therefore not as clearly defined as has been suggested. Clearly its evolutionary path has diverged considerably from other species in genera such as Eos or Chalcopsitta. It would appear that Pseudeos is in fact more closely related to Chalcopsitta than Eos (although the generic name suggests closer ties with Eos). Secondly, with 38 chromosomes, it has the lowest number of chromosomes which have been recorded for any bird" (Joshua 1994).
However, current impressions of karyotypes only tell part of the story. My own impression (after 20 years of keeping members of all three genera) is that Pseudeos has similarities and differences with both genera but is a species which is still evolving. The wide range of variation in plumage of young and adult birds suggests that this is so. I feel that the appearance of young chicks is of significance in trying to determine evolutionary relationships - and chicks of Pseudeos resemble Eos more than Chalcopsitta. I have recorded the juvenile food begging calls of all three genera on the same tape on the same day; to my ear, those of fuscata, insignis and bornea all differ slightly from each other.
If its chromosomal make-up is so different, can it hybridize with other lory species? The answer is yes, although there seem to be fewer records of hybrids, when one considers how freuently this species breeds in captivity and how readily other lories hybridize, even those of different genera. Many years ago, W. Sheffler in the U.S.A. bred a hybrid "white-rumped" (i.e., dusky) x Swainson's. (The inference is that the male was the dusky, as it is normal practice to name the male parent first.) The best evidence is that of A. Manning (1994/1995) who describes the breeding of an Obi (Eos squamata obiensis) x dusky lory. Photographs were taken depicting the parents and young one together, plus photographs of the young one which clearly show it's plumage. At first glance it could have been mistaken for a dusky. Although the author described the young one as inheriting the red Obi coloring "as a kind of frosting on the cheeks and down the front of the bird," dusky lories in immature plumage are so variable that this does not seem to be of great significance. Of interest, however, and not mentioned by the author, is the featherd area at the sides of the mandibles which is normally bare is Pseudeos.
At Taronga Zoo, Sydney, two hybrids between a male collared or solitary lory (Vini solitarius) and a female "white-rumped" were apparently reared in 1957 and another in 1958. Taking into consideration how much smaller is the collared, this seems a bizarre happening. Even stranger was their appearance. K. Muller (pers. comm. 1976) reported that "they resembled closely the Domicella lories, being predominantly red and blue pattern with a short tail, and resembled closely the Black-capped Lory." The hybrids were intermediate in size between the dusky and the solitary.
Another dusky hybrid is that recorded as P. fuscata x T.h.haematodus at Munich Zoo in 1978 (International Zoo Yearbook, vol 20).
Literature
- Low, R (1998): Hancock House Encyclopedia of the Lories. (232) Hancock House Publishers Ltd.