birding-aus
Phil, John and others.
There are three disjunct populations of "sooty owl", tenebricosa in SE
aust., multipunctata in the Wet Tropics and arfaki in highland New Guinea.
The lesser sooty owl was named as a subspecies of Sooty Owl (T.
tennebricosa multipunctata) by Gregor Mathews. It was split from Sooty T.
tennibricosa by Schodde & Mason (1981). They found that the isolated wet
tropics form was smaller, showed less sexual dimorphism, had more gracile
feet, paler plumage and so on. They considered that the New Guinea form, of
which only a few specimens were available was conspecific with the SE Aust.
form (or at least, found no good evidence for spearating it as a separate
species. They suggest a biogeographic explanation for this anomolous
distribution (two widely spearated populations of one species with an
isolated population of another in between). nevertheless, thats all
speculative.
An earlier review by Mees (1967) had treated them as three subspecies of T.
tenebricosa. Schodde & Mason's taxonomy was accepted by the BA checklist
(Christidis & Boles 1994) and by the Zoological Catalogue of Australia
(Schodde & Mason 1997). (Hmmm, hardly surprising)
I wrote the HANZAB texts on plumages and related matters (including
geographical variation) for this group in about April 1997. apparently they
are due out in March. In general, from the study of museum specimens and
literature I could only confirm the findings of Schodde & Mason. the New
Guinea arfaki is very similar to tenebricosa and both are quite different
to multipunctata. (My field observations of tenebricosa and multipunctata
also suggest to me that these two are morphologically and ecologically
distinct).
The situation is quite complicated, and hence world-wide checklists have
come to grief trying to deal with it. More work is needed, but for the
meantime the best model is that which Schodde & Mason proposed in 1981: T.
tenebricosa tenebricosa in SE. Aust.(Eungella to Bass Strait), T.
tenebricosa arfaki in New Guinea, and T. multipunctata in NE Aust.
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
This is the last draft I saw of the Geographical Variation text for Sooty
Owl from HANZAB 4 (in press).
Two very similar subspecies: nominate tenebricosa of humid forests in se.
Aust., and subspecies arfaki of montane rainforests in New Guinea.
Subspecies arfaki appears to differ only in: smaller size (Bergmann's Rule;
see Measurements); possibly generally darker (sootier) on facial disk and
underparts; legs have denser brown barring; and upperparts have finer white
spots (Schodde & Mason; four skins, AM, ANWC; photo in Strahan). Subspecies
arfaki differs from Lesser Sooty Owl in same way as nominate tenebricosa
does, apart from size (see Recognition). In se. Aust., nominate tenebricosa
shows only very slight geographical variation: birds south of Clarence R.,
NSW, average slightly longer in wing (and possibly weight) (Bergmann's
rule) but not bill and legs (Allen's Rule; see Measurements). The slight
geographical difference in size is not sufficient for recognition of
additional subspecies, and Mathews (1912) name magna from Vic. is not
accepted (also see Mees 1964; Schodde & Mason; Schodde & Mason 1997).
Lesser Sooty Owl of ne. Qld (Wet Tropics) treated here as separate species,
following Schodde & Mason, Christidis & Boles (1994) and Schodde & Mason
(1997). This arrangement supported by analysis of plumages, measurements
and structure (see Recognition), and by preliminary molecular studies (J.
Norman & L. Christidis.). The biogeographical implications of this
arrangement are anomalous (but with parallels in other species-pairs): two
widely allopatric subspecies of Sooty Owl with an allopatric species,
Lesser Sooty Owl, between. This led Sibley & Monroe (1990) to treat
tenebricosa as a s. monotypic species and arfaki and Lesser Sooty Owl as
subspecies of a n. polytypic species. Mees (1964, 1982) favoured the
recognition of only one species, observing that treating these three taxa
as two species obscures their close relationships. Relationships in this
complex require more study.
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>.
References
Schodde, R. & I. Mason. 1981. Nocturnal birds of Australia. Lansdowne,
Melbourne..
Schodde, R. & I. Mason. 1997. Zoological Catalogue of Australia 37.2 AVES
(Columbidae to Coraciidae). CSIRO, Canberra.
Mees, G. 1964. A revision of Austrlaian owls. Zool. Verh. 65: 1-62.
Christidis, L & Boles, WE. 19994. The taxonomy and species of birds of
Austraia and its territories. RAOU Monograph 2, RAOU, Melb.
At 14:53 7/02/99 +1000, Phil Gregory wrote:
>Whilst working on a list of New Guinea endemics, the taxonomy of Sooty
>and Lesser Sooty owl has caused me some confusion. The PNG guides show
>the species as Sooty Owl T. tenebricosa, of the subspecies arfaki
>according to Brian Coates. However, looking at the National Photographic
>Index volume on Cuckoos, Nightbirds and Kingfishers indicates that it is
>T. multipunctata in New Guinea ( then listed as a subspecies of Sooty
>Owl)
>I checked in Monroe and Sibley World Checklist of Birds, which gives it
>as Sooty Owl T. tenebricosa there, yet Clements (1991 edition) gives it
>as Lesser Sooty. Curiouser and curiouser!
>The Handbook of Birds of the World hasn't covered Owls yet, so no joy
>from that source, ditto HANZAB. The birds there certainly look large
>enough to be Sooty Owl, but I'd like to know for sure whether Lesser
>Sooty is an Aus endemic or not.
>Advice and comments please. Thanks.
>Phil Gregory
>
>To unsubscribe from this list, please send a message to
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David James
PO BOX 5225
Townsville Mail Centre 4810
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