Memorandum to:         The Director of Birds Australia

 

From:                          Birds Australia Rarities Committee (BARC)

 

Date:                            9th October 2007

 

Voting Members:         Tony Palliser                 Andrew Silcocks

                                    David Bishop                 Glenn Holmes

                                    Paul Andrew                  Jamie Matthew

                                    John Hatch                    Danny Rogers

                       

Cc.                               Ron Johnstone              

 

 

 

Submission No 509: Asian Brown Flycatcher Muscicapa dauurica West Island, Ashmore Reef, WA, 29th October 2005. Submitted by: Rohan Clarke, Mike Carter & George Swann.

 

 

Verdict: Accepted

 

 

This case involves the occurrence of an Asian Brown Flycatcher Muscicapa dauurica on West Island, Ashmore Reef, on 29 October 2005.  The bird was found in a dense stand of Octopus bush on the island and was seen by eight birdwatchers taking part in an expedition to Ashmore Reef.

 

Photographic evidence and a very thorough submission have been provided to the committee of a bird that was in view for more than an hour. The bird was clearly one of the grey Muscicapidae flycatchers and given the locality was (understandably) considered to be one of the migratory species from Asia. 

 

Species most in need of  consideration in order to reach a positive identification were Asian Brown M. dauurica, Grey-streaked M. griseisticta and Dark-sided (also known as Siberian) Flycatchers M. sibirica. All three winter regularly in the Greater Sundas (MacKinnon & Phillipps 1993), the first two also in Wallacea (White & Bruce 1986; Coates et al. 1997) and Grey-streaked also in New Guinea (Coates 1990). Another possibility was Sumba Brown Flycatcher Muscicapa (dauurica) segregate a resident species / race from Sumba.

 

The submission properly analysed the possibilities and concluded that this bird was an Asian Brown Flycatcher (M. dauurica) for the following reasons (to quote direct from the submission):

 

·         Asian Brown Flycatchers have a distinctly shorter primary projection than either Dark-sided or Grey-streaked Flycatchers. In the Asian Brown Flycatcher, the primary projection is shorter than the tertials. Alstrom and Hirschfeld (1991) estimated that this was usually 80-90% of exposed tertials. Whereas the other two species display a primary projection equal to or distinctly greater than that of the tertial projection (typically c15-20% longer) (Alstrom and Hirschfeld 1991). In the Ashmore bird relative proportions provide a value of 72% for primary projection compared with tertial projection.

 

·         Asian Brown Flycatchers have a proportionally larger bill than either Dark-sided or Grey-streaked Flycatcher. Photographs in Alstrom and Hirschfeld (1991) demonstrate the exposed bill length is significantly less than the distance between the base of the exposed bill and the eye for both Dark-sided and Grey-streaked Flycatcher, whereas for the Asian Brown Flycatcher it is similar.  Estimates taken from these images are ~110% for Asian Brown Flycatcher (Plate 5 in Alstrom and Hirshfeld 1991), ~60% for Dark-sided Flycatcher (Plate 1 in Alstrom and Hirshfeld 1991) and ~65% Grey-streaked Flycatcher (Plate 7 in Alstrom and Hirshfeld 1991). Measurements taken from photographs of the Ashmore bird show the exposed bill length (to base of frons) is equal to the distance between that point and the front edge of the eye in the Ashmore bird (~100%).

 

·         The base of the lower mandible is palest in Asian Brown Flycatcher. Only in this species does the pale base of the lower mandible reach forward of a point level with the nostrils (Alstrom and Hirschfeld 1991). This was noted in the field and is well illustrated in the photographs.

 

·         As in this bird, the lores in Asian Brown Flycatcher are conspicuously pale and unmarked whereas both Dark-sided and Grey-streaked display less prominent lores that are often washed brown and frequently dark along their lower edge, such that a small dark wedge is present between the eye and the bill (Alstrom and Hirschfeld 1991).

 

·         Asian Brown Flycatchers show unmarked, white undertail coverts, as do Grey-streaked Flycatchers. In contrast, Dark-sided Flycatchers show dark centres to the undertail coverts (Alstrom and Hirschfeld 1991). Excellent views and the photographs confirm the undertail coverts were white and unmarked.

 

·         Asian Brown and Grey-streaked Flycatchers show pale fringes to the tertials and greater coverts that are ‘cold’ off-white to pale cream whereas these same pale fringes are typically a rich warm buff tone in Dark-sided Flycatchers (Alstrom and Hirschfeld 1991).

The Sumba Brown Flycatcher Muscicapa (dauurica) segregata represents an isolated resident population of the Asian Brown Flycatcher that has recently been afforded full species status by some authors (e.g. Howard and Moore 2003). This form is restricted to the Lesser Sunda island of Sumba, which is some 375 km from West Island, Ashmore Reef.  It is distinguished by having a longer bill (16.4 vs. 14.7 mm), a shorter wing (63-67 vs. 67-74 mm) and a different wingdifferent wing -formula (White & Bruce 1986; Coates et al. 1997).  Consequently, the longer wing tip and extent of visible tertials and comparatively shorter bill eliminated this species.

 

A study of the photographs and the description shows that the Ashmore bird meets the criteria for the migrant form (nominate dauurica) and committee members voted unanimously in favour of acceptance.

 

and extent of visible tertials and comparatively shorter bill eliminated this species.

A study of the photographs and the description shows that the Ashmore bird meets the criteria for the migrant form (nominate dauurica) and committee members voted unanimously in favour of acceptance.

Asian Brown Flycatchers are a seasonally fairly common and widespread migrant in the Greater Sundas east to Bali (MacKinnon & Phillipps 1993; Strange 2001), but is rare in the Lesser Sundas with just one record (White 1977, White & Bruce 1986; Coates et al. 1997). There are no previous claims of Asian Brown Flycatcher from Australia.

 

References

·         Alstrom, P. & Hirschfeld E. (1991), ‘Field identification of Brown, Dark-sided and Grey-streaked Flycatcher’, Birding World 4, 271-278.

·         Coates, B.J. (1990), The Birds of Papua New Guinea, Vol. 2, Passerines, Dove, Alderley, Queensland.

·         Coates, B.J., Bishop, K.D. & Gardner, D. (1997), A Guide to the Birds of Wallacea, Dove, Alderley, Queensland.

·         Cramp, S. & Perrins, C.M., (Eds.) (1993), The Birds of the Western Palearctic, Vol. VII, Flycatchers to Shrikes, Oxford University Press, Oxford.

·         Harvey, P. (1992), ‘The Brown Flycatcher on Fair Isle – a new British bird’, Birding World 7, 252-255.

·         Higgins, P.J., Peter, J.M. & Cowling, S.J. (Eds) (2006), Handbook of Australian, New Zealand and Antarctic Birds, Volume 7: Part B, Dunnock to Starlings, Oxford University Press, Melbourne.

·         Howard, and Moore, (2003), The Howard and Moore Complete Checklist of the Birds of the World, Princeton University Press, Princeton.

·         Iozawa, H., Yamagata, N. & Yoshino, T. (2000), Japanese Bird 550: Landbirds, Bunichi General Publisher, Tokyo (in Japanese).

·         Johnstone, R.E. & Storr, G.M. (2004), Handbook of Western Australian Birds, Vol. 2, Passerines, Western Australian Museum, Perth.

·         Kanouchi, T., Abe, N. & Ueda, H. (1998), Wild Birds of Japan, Yama-Kei, Tokyo (in Japanese).

·         MacKinnon, J. & Phillipps, K. (1993), A Field Guide to the Birds of Borneo, Sumatra, Java and Bali, Oxford University Press, Oxford.

·         Mullarney, K., Svensson, L., Zetterstrom, D. & Grant, P.J. (2001), Collins Bird Guide,

·         Harper Collins, London.

·         Strange, M. (2000), A Photographic Guide to the Birds of Southeast Asia, Periplus Editions, Hong Kong.

·         Strange, M. (2001), A Photographic Guide to the Birds of Indonesia, Periplus Editions, Hong Kong.

·         Viney, C. & Phillipps, K. (1989), Birds of Hong Kong, Government Publications, Hong Kong.

·         Wells, D.R. (1999), The Birds of the Thai-Malay Peninsula, Academic Press, London.

·         White, C.M.N (1977), ‘Migration of palaearctic passerine birds in Wallacea’, Emu 77, 37-38.

·         White, C.M.N. & Bruce, M.D. (1986), The Birds of Wallacea (Sulawesi, The Moluccas and Lesser HERE TOOSunda Islands , Indonesia). British Ornithological Union Checklist 7, 1-524.  

 

 

 

 

Tony Palliser

Chairman, Birds Australia Rarities Committee