The Psitteuteles Lorikeets

Varied lorikeet Psitteuteles versicolor, copyright Joshua Robertson.

Few groups of birds have been the object of human interest as much as parrots, with their striking coloration and intelligence inviting comment at least as far back as ancient Greek times. This interest has continued into recent times and scientific research into all aspects of parrot life has been extensive. Nevertheless, the classification of parrots has long been problematic. As a group, parrots combine a high degree of superficial disparity in features such as colour pattern with an underlying overall morphological conservatism (a not uncommon issue with birds). As such, though recognition of distinct species may be fairly straightforward, establishing the relationships between those species may be less so. Prior to the advent of molecular studies, few higher groups of parrots could be considered widely accepted. One such group was the lories, found in Australasia and the Pacific Islands (smaller members of this group are known as 'lorikeets' but, as with 'parrots' vs 'parakeets', the difference between the two is a question of size and shape rather than affinities). Members of this group evolved a long, narrow, brush-tipped tongue that allowed them to pursue a diet of nectar and pollen (Schweizer et al. 2015). About a dozen genera of lories are currently recognised: one such genus, Psitteuteles, is the subject of the current post.

Goldie's lorikeets Psitteuteles goldiei, copyright Ltshears.

Psitteuteles is commonly recognised to include three species of smaller lory: the varied lorikeet P. versicolor, the iris lorikeet P. iris and Goldie's lorikeet P. goldiei. In general, these are primarily green species with a red forehead and with varying amounts of blue across the back of the head and/or behind the eyes. The plumage is longitudinally streaked in the varied lorikeet and Goldie's lorikeet. Goldie's lorikeet has mauve cheeks whereas those of the varied lorikeet are partially yellow. The varied lorikeet is also mauve across the upper breast whereas the other two species are more evenly green. All three species are separated geographically: the varied lorikeet is widespread in northern Australia, Goldie's lorikeet is found in New Guinea and the iris lorikeet is found on the islands of Timor and Wetar in Indonesia. The varied lorikeet is particularly common in association with paperbarks and eucalypts around streams and waterholes, migrating as required to find trees in flower. Similar wandering habits are characteristic of Goldie's lorikeet which is mostly found in montane forest. The more sedentary iris lorikeet is mostly found in lowland monsoon forest. The varied and Goldie's lorikeets are not currently regarded as being of conservation concern but the iris lorikeet is more threatened by habitat loss and collection for the pet trade.

Iris lorikeet Psitteuteles iris, copyright Dick Daniels.

Not all authors have recognised Psitteuteles as a distinct group: some have included its species in the related genus Trichoglossus with the rainbow and scaly-breasted lorikeets. Recent phylogenetic studies suggest that suspicion of Psitteuteles' status may not be unwarranted. Molecular studies by Schweizer et al. (2015) and Provost et al. (2018) both fail to identify the three Psitteuteles species as forming a single clade. Instead, P. iris is placed close to Trichoglossus species whereas P. versicolor and P. goldiei are both placed outside a clade including Trichoglossus and related genera such as Eos, the red lories, and the musk lorikeet Glossopsitta concinna. A case could probably be made for restricting Psitteuteles to the varied lorikeet as type species while including the iris lorikeet in Trichoglossus. The fate of P. goldiei is more uncertain: though neither of the aforementioned studies identified P. versicolor and P. goldiei as sister species, it might be too early to exclude the possibility. Alternatively, should P. goldiei prove too phylogenetically isolated to include in any pre-existing genus, I am not aware of any available genus name for it. As seems to be one of my standard sign-offs on this site, further study is required.

REFERENCES

Provost, K. L., L. Joseph & B. T. Smith. 2018. Resolving a phylogenetic hypothesis for parrots: implications from systematics to conservation. Emu 118 (1): 7–21.

Schweizer, M., T. F. Wright, J. V. Peñalba, E. E. Schirtzinger & L. Joseph. 2015. Molecular phylogenetics suggests a New Guinean origin and frequent episodes of founder-event speciation in the nectarivorous lories and lorikeets (Aves: Psittaciformes). Molecular Phylogenetics and Evolution 90: 34–48.

The Rosy Birds

Violet-necked lories Eos squamata, copyright Niels Poul Dreyer.

In taxonomic days of yore, it was a not uncommon practice for new genera to be baptised under the names of classical figures: gods, heroes, emperors, even the occasional prophet (the practice only died down once the barrel of available names became largely empty). In many cases, the connection drawn between the organism in question and its awarded namesake was tenuous at best. In others, it was simply non-existent. But in a favoured few cases, the association fit perfectly.

Eos is a small genus (recent authors have recognised six species) of lories found on islands in eastern Indonesia. They are named, of course, after the Ἠώς ῥοδοδάκτυλος, the 'rosy-fingered dawn', of the ancient Greeks. It takes no great insight to realise why they were so-called: all members of the genus are predominantly coloured in a vibrant red, together with varying extents of blue, purple and/or black. Green is usually absent from their plumage (with some noteworthy exceptions that I'll have cause to mention again), distinguishing them from most closely related parrots such as the rainbow lorikeets in the genus Trichoglossus. Charles Lucien Bonaparte (nephew to the other Bonaparte, and a prominent nineteenth-century ornithologist) stated in 1850 that Eos could be recognised by its "elegant form, small stature, compact, red plumage with more or less blue; compressed, moderate, red bill, with the cere apparent... and longish, not very broad, wedged tail".

Blue-streaked lories Eos reticulata, copyright Doug Janson.

For the most part, Eos species are found on islands between Sulawesi and New Guinea. The black-winged lory Eos cyanogenia is found on islands in Geelvink Bay, in the north-west part of West Papua, but not on the mainland of New Guinea itself. For the most part, no island is home to more than one species of Eos. The island of Seram is an exception, with the endemic blue-eared lory Eos semilarvata found in the central highlands, and the red lory Eos whatchumacallit (see below) closer to the coast (this species is also found on other islands in the South Moluccas). The blue-streaked lory Eos reticulata is found in the Tanimbar group east of Timor. The violet-necked lory Eos squamata lays claim to the North Moluccas, and the red-and-blue lory Eos histrio is found on Talaud and other islands to the north-west of Sulawesi (Juniper & Parr 1998).

Black-winged lory Eos cyanogenia, copyright Lip Kee Yap.

While the taxonomy of the group has been mostly stable in recent years, it was not always so. Bonaparte (1850) snidely commented that some species of Eos had been described "too many times". Hume & Walters (2012) referred to five described species of Eos, all based on isolated specimens since lost, whose identity has been contested. While it is possible that some may represent species now extinct, it is equally possible that they represented unusual individuals of living species. In the absence of examinable type specimens, the identity of most is of academic interest only. The exception is the 'red-and-green lory' Eos bornea, which was originally named Psittacus borneus by old Carolus Linnaeus himself on the basis of a description and plate of a lory supposedly from Borneo published in 1751 by George Edwards (Walters 1998). Edwards' bird, which he had bought as a stuffed specimen from a toyshop in London, was described as dark pink, with a yellow bill, and green patches on the wings and tail. However, no species quite matching Edwards' description is known from Borneo or anywhere else, and it was subsequently suggested that he may had an unusual or a faded specimen of the Moluccan red lory, with the Bornean locality being an error. As such, the name Eos bornea came into use for the red lory, replacing the later-published name 'Eos rubra'. However, Walters (1998) subsequently disputed this identification, recommending the continued use of E. rubra. At present, 'Eos bornea' still seems to be the more commonly used name, and my own sympathies would be more with maintaining the familiar usage than with insisting on strict adherence to the original concept.

Red lories, Eos... let's just say bornea, shall we? Copyright Arnaud Delberghe.

Because of their striking appearance, Eos species have been heavily collected for the pet trade. The have also been widely affected by habitat degradation with the clearing of primary forests. While populations of most species are still regarded as reasonably robust, the IUCN regards all except E. squamata as on the decline. Eos histrio is regarded as actively endangered, having all but disappeared from some of its home islands. In 1999, it was estimated that 1000 to 2000 red-and-blue lories were being captured and exported for the pet trade each year—despite the total population of this species probably being not much more than 20,000 individuals!

REFERENCES

Bonaparte, C. L. 1850. On the trichoglossine genus of parrots, Eos, with the description of two new species. Proceedings of the Zoological Society of London 18 (1): 26-29.

Hume, J. P., & M. Walters. 2012. Extinct Birds. T. & A. D. Poyser.

Juniper, T., & M. Parr. 1998. Parrots: A guide to the parrots of the world. Christopher Helm Publishers.

Walters, M. 1998. What is Psittacus borneus Linnaeus? Forktail 13: 124-125.

A King among Parrots

Moluccan King parrot Alisterus amboinensis, photographed by Helsinki***.

For today's post, I'm looking at the King parrots of the genus Alisterus. There are three recognised species in this genus: the Australian King parrot Alisterus scapularis of eastern Australia, the green-winged or Papuan King parrot A. chloropterus of central and eastern New Guinea, and the Amboina or Moluccan King parrot A. amboinensis of eastern Indonesia and western Papua. However, each species is divided into subspecies, and some subspecies are quite distinct from each other. For instance, Alisterus scapularis shows distinct sexual dimorphism: the male has a bright red head and breast while the female has a green head and breast. In A. amboinensis, both sexes have red heads. In A. chloropterus, the nominate subspecies has a green-headed female like that of A. scapularis, but the northwesternmost subspecies A. chloropterus moszkowskii has a red-headed female like that of A. amboinensis (Forshaw & Knight 2010). In relation to other parrots, Alisterus belongs to the tribe Psittaculini that extends into eastern and southern Asia and the Mascarenes, among which it forms a clade with the other Australian genera Aprosmictus and Polytelis (Mayr 2010) (and hybrids have even been recorded between A. scapularis and species of these two genera—Rutgers & Norris 1972).

Female (left) and male Australian King parrot Alisterus scapularis, photographed by Peter Firminger.

You might be wondering why, among an entire order of particularly regal birds, it is this particular genus that is honoured with the title of 'King' (I know I certainly did). As it turns out, the reason appears to be that Alisterus is not, properly speaking, the 'king of parrots', but 'King's parrot', named after Philip Gidley King, governor of New South Wales from 1800 to 1806 ('Stentoreus' 2004; I might as well also point out for the benefit of those not familiar with Australian history that the original 'New South Wales' was considerably larger than the current state by that name, taking in the entire eastern seaboard of Australia).

Papuan King parrot Alisterus chloropterus, photographed by Mehd Halaouate.

King parrots are generalist feeders on fruit and seeds, which has not always endeared them to horticulturalists. They nest in deep holes in hollow trees: while the entrance to an Alisterus scapularis nest may be more than nine metres high, the actual nest may be nearly at ground level (Rutgers & Norris 1972). They lay 3-6 eggs between October and December.

REFERENCES

Forshaw, J. M., & F. Knight. 2010. Parrots of the World. Princeton University Press.

Mayr, G. 2010. Parrot interrelationships—morphology and the new molecular phylogenies. Emu 110: 348-357.

Rutgers, A., & K. A. Norris. 1972. Encyclopaedia of Aviculture vol. 2. Blandford Press: London.

Reference Review: Parrots in the Early Days of Molecular Analysis

Ovenden, J. R., A. G. Mackinlay & R. H. Crozier. 1987. Systematics and mitochondrial genome evolution of Australian rosellas (Aves: Platycercidae). Molecular Biology and Evolution 4 (5): 526-543.

Rosellas (Platycercus) are a genus of five or more species of smallish parakeet found in more coastal areas of Australia, particularly the eastern states. Significant differences in opinion exist about just how many species there are in the genus - a number of subspecies are recognised that may be raised as separate species depending on author (I'm going to take a neutral position and treat all taxa as if they were species - see Wikipedia for a more detailed taxonomy). At least one taxon in the genus, the variable Platycercus adelaidae (the Adelaide rosella), is claimed by some to be a hybrid swarm derived from cross-breeding between two other subspecies and therefore not a valid taxon at all*. Rosellas are also possibly the most familiar parrot in New Zealand, at least in the north, due to abundant populations of introduced Platycercus eximius (the eastern rosella, shown at the top of the page in a photo from Wikipedia).

*The ICZN (in contrast to the ICBN) does not permit the recognition of taxa based on hybrids. This rule works fine when dealing with singleton hybrid specimens, which were doubtless what the ICZN had in mind when they drafted it, but is somewhat problematic when dealing with populations that have a hybrid origin, some of which may become established as new species.

The species of Platycercus can be readily divided into two groups, referred to as the "P. elegans" and "P. eximius" groups (though the latter should probably be called the P. adscitus group as that species has priority). Platycercus elegans and P. caledonicus are the blue-cheeked rosellas (P. elegans, the crimson rosella, is shown at left from Wikipedia). Platycercus adscitus, P. eximius and P. venustus are the white-cheeked rosellas. The geographically isolated P. icterotis (the western rosella) from the south-west of Western Australia has white or yellow cheeks and was once included in the P. eximius group, but is now generally excluded from either group.

At the time today's paper was published, molecular phylogenetics were still very much in their infancy. PCR, the technique that revolutionised molecular studies, was not to appear until the following year (Saiki et al., 1998). Before the advent of PCR, most molecular techniques were expensive, time-consuming, delicate and often unreliable (after the advent of PCR, they became expensive, delicate, often unreliable, and able to be done much more readily*). As such, most molecular studies in the 1980s used methods that by modern standards appear decidedly rough and ready. In the case of the one I'm looking at today, the method of choice was mitochondrial restriction fragment polymorphisms.

*It's a bit like the joke about the soldiers in the desert camp being to told by their general that there was bad news and good news. The bad news was that supplies had run so low that all they had left to eat was horseshit. The good news was that there was plenty of it.

Restriction endonucleases are enzymes that cut DNA into bits. There are a huge number of endonucleases in use at the present, and each one works by attaching to a specific sequence of bases in a DNA strand and dividing it at that point. Depending on need, there are enzymes that require relatively long sequences of bases and so would cut a given DNA strand rarely if at all, or there are enzymes that only require short sequences and so would be expected to cut strands far more readily. Probably the most familiar use of endonucleases to the general public is in DNA fingerprinting, where the resulting fragments from the endonuclease treatment of DNA samples are compared to see whether or not the samples contain the same fragment. The use of RFLPs (restriction fragment length polymorphisms) in phylogenetics is essentially a distance method - it proceeds by the assumption that samples that are most similar to each other in the resulting restriction fragment pattern are the most closely related phylogenetically. As for the use of mitochondrial DNA, there were a number of reasons why mitochondrial DNA was preferred to nuclear DNA for molecular studies at the time, but not least of them was that there is usually a lot more of it about and it is much easier to extract from a specimen than nuclear DNA. It should not be forgotten that prior to PCR, researchers only had as much sample to work with as they could directly draw out of the specimen.

There are a great many reasons why the use of RFLP for phylogenetics should not work. The assumption that genetic distance is equivalent to phylogenetic distance is simply not reliable, because evolution does not always occur at the same rate in separate lineages. Add to that the fact that in an ideal phylogenetic data set changes in one character state should not affect the state of other characters - a requirement blatantly violated by RFLP data, as the loss of a restriction site causes the resulting data set to "lose" two fragments and gain a whole "new" fragment. Fortunately for this case, the results actually make a certain degree of sense. Ovenden et al. recovered the same two species groups that had already been identified on the basis of morphological data. The only exception was that Platycercus icterotis, rather than clustering with the P. eximius group, came out as the most divergent species of all. However, this, too, had already been suggested on morphological grounds.

Unfortunately, the phylogeny of Platycercus does not appear to have been re-examined since the advent of more reliable analytical methods. There are no obvious reasons not to believe Ovenden et al.'s results, but considering the methodology they can hardly be said to not be worth a further look.

REFERENCES

Saiki, R. K., D. H. Gelfand, S. Stoffel, S. J. Scharf, R. Higuchi, G. T. Horm, K. B. Mullis & H. A. Ehrlich. 1988. Primer-directed enzymatic amplification of DNA with a thermostable DNA polymerase. Science 239: 487-491.