Dear Jim,
In reaction to your request about the Gaviidae I first need to
stress my concern about your usage of the term "sp. nov."
(species nova: new species). As far as I am concerned, this
should only be used (to prevent confusion) in the original
scientific description first mentioning the name to which the
term "sp. nov." is added, and NOT for denoting a (recent)
split of two (or more) already described forms! The diver you
queried about is currently known as follows:
1. Gavia (a.) pacifica (Lawrence) 1858
2. Gavia a. arctica (Linnaeus) 1758
2a. Gavia a. suschkini (Sarudny) 1912 (synonym of arctica)
3. Gavia a. viridigularis Dwight 1918
Having said this, I have to add that I do not have a direct
answer to your question ("the paper resulting in the split of
arctica and pacifica"), unless one of the references listed
below may be it (especially perhaps 10 or 18):
1. Appleby, R.H., S.C. Madge & K. Mullarney (1986)
Identification of divers [Gavia] in immature and winter
plumage. British Birds 79 (8): 365-391
2. Barthel, Peter H. (1991) R=E4tselvogel 26 [Prachttaucher
Gavia arctica]. Limicola 5 (6): 306-307
3. Barthel, Peter H. & Killian Mullarney. (1988). Die
Bestimmung der Seetaucher Gaviidae [Gavia] im Winter.
Limicola 2 (2): 45-69
4. Birch, Andrew & Cin-Ty Lee (1995). Identification of
Pacific Diver [Gavia pacifica] - a potential vagrant to
Europe. Birding World 8 (12): 458-466
5. Dierschke, Jochen & Lars Jonsson. (1991). Die Bestimmung
von Seetauchern Gaviidae im Flug [Gavia]. Limicola 5 (5):
233-247
6. Dunker, H. (1975) Habitat selection and territory size of
the Black-throated diver, Gavia arctica (L.). Norwegian
Journ. Zool., vol. 23, pp. 149-164
7. Dwight, J.A. (1918) A new species of loon (Gavia
viridigularis) from [Gichega,] northeastern Siberia. Auk
35 (2): 196-199 [198]
8. Hunter, E.N. & R.H. Dennis (1972) Hybrid Great Northern
Diver [Gavia immer] x Black-throated Diver [Gavia arctica]
in Wester Ross. Scottish Birds 7: 89-91
9. Jonsson, Lars (1996) Stillahavslom [Gavia pacifica]
f=F6rekomst och f=E4ltbest=E4mning. V=E5r F=E5gelv=E4rld 55 (2): 8-14
10. Kistchinski, A.A. & V.E. Flint (1983) Taxonomix relations
within the group of the black-throated divers [in
Russian]. Ornithologiya 18: 112-123
11. Lehtonen, L. (1970) Zur biologie des Prachttauchers, Gavia
a. arctica (L.). Ann. Zool. Fennici, vol. 7, pp. 25-60
12. Littlewood, Nick (1996) Letters: Black-throated Divers
[Gavia arctica] and throat straps. Birding World 9 (8):
321
13. McIntyre, A.E. & J.W. McIntyre (1974) Spots before the
eyes, an aid to identifying wintering loons [Gavia]. Auk
91: 413-415
14. Moores, Nial (1996) Letters: Pacific Divers [Gavia
pacifica] in Japan. Birding World 9 (8): 320
15. Pycraft, W.P. (1909) On the pterylosis of the Black-
throated Diver [Gavia arctica]. British Birds 1: 93-98
16. Robertson, I. & M. Fraker (1974) Apparent hybridization
between a Common Loon [Gavia immer] and an Arctic Loon
[Gavia arctica]. Can. field-Nat. 88: 367
17. Schenk, Chris (1997) [Front cover photograph: Gavia
pacifica]. Dutch Birding 19 (3)
18. Storer, Robert W. (1978) Systematic notes on the loons
(Gavidae: Aves). Breviora no. 448: 1-8
Finally, the following chronological overview might perhaps be
of interest too:
In the early 1900's Buturlin and Bianki recognized two
distinct species until Jonathan Dwight described the east
Siberian form as a distinct species in 1918, although S.A.
Buturlin and L.A. Portenko still [or again?] treated arctica
and pacifica as distinct species in the 1930's (mainly based
on external characters and distribution), as did Bailey in
1948.
Ernst Hartert however (V=F6g. pal. Fauna), treated all forms as
subspecies of arctica, which treatment was followed by most
subsequent authors (e.g. Kozlova in 1947, Dement'ev & Gladkov
in 1951, AOU-Checklist in 1957, Palmer in 1962, Ivanov &
Stegman in 1964, Portenko in 1972, Voous in 1977, Cheng in
1987 and del Hoyo et al. in 1992).
Nevertheless, a slight tendency to treat both forms as
separate species arose (Vaurie 1965, Stepanjan 1975, Ivanov
1976, Kistchinski 1978), resulting in the current treatment
(Kistchinski 1980, Kiscinski & Flint 1983) as two distinct
species (Il'icev & Flint 1985, Sibley & Monroe 1990, Beaman
1994).
References for the hronological overview:
1. Beaman, M. (1994) Palearctic Birds: 17 & 63
2. Il'icev & Flint (1985) Handbuch der V=F6gel der Sowjetunion
3. Ivanov (1976) Katalog ptic SSSR. Leningrad: 215-228
4. Kiscinskij, A.A. (1978) Pp. 27-37 in Il'icev [Migration of
Birds in Eastern Europe and Northern Asia] (in Russian).
Moscow
5. Kiscinskij, A.A. (1980) [Birds of the Koryak Higlands] (in
Russian), pp. 24-27
6. Kiscinskij, A.A. & V.E. Flint (1983) [Taxonomy of Black-
throated and Pacific Diver] (in Russian). Ornitologija 18:
112-123
7. Sibley & Monroe (1990) Distribution and Taxonomy of Birds
of the World. New Haven: 320
8. Stepanjan, L.S. (1975) [A distributional check-list of
birds of the U.S.S.R.] (in Russian). Moscow: 9
9. Vaurie, Ch. (1965) The Birds of the Palearctic Fauna: 4-7
I certainly hope this helps...
Regards,
Oscar.vanRootselaar@FA.SLM.WAU.NL