Hi,
I was talking offline with a list member, about the sightings of affinis gullbills, and wondering why there don’t seem to be any reports of sightings across the Top End, when they seem to appear regularly during the summer in the North-west (Broome) and the North-east (Cairns). Or have I missed reports of them? Do they appear in between west and east during the summer period when they are present? Can anyone enlighten us? (The New Atlas doesn’t differentiate between subspecies.)
Cheers,
Jill
Hi Jill, I started looking into the origin of these things in 1991, after the Newcastle sighting and before I joined the HANZAB team for Vol 2. By the time we were ready to write Gull-billed Tern for Vol 3 I was busy in NZ with large skuas, gulls, southern ocean terns etc. Paul Scofield had stepped in to take a few species off Danny and I as were behind schedule (as usual). I begrudgingly handed Gull-billed to Paul. I gave him my data and historical literature (mostly breeding records for Asia) and tried my best to influence him completely, but naturally he drew his own conclusions. I guess he saw my point but couldn’t confirm it. Danny was working on other species at the time, but developed an interest a few years later when banding significant numbers in Broome. His findings were therefore based on an entirely different set of data. I can’t remember why he stuck with affinis either, but I seem to recall classifying it as “plausible but not compelling”. This compares with my own conclusion of nilotica which might also be “plausible but not compelling”. As you say, we are all agreed they are not macrotarsa.
Many thanks to David and Denise for enlightenment. I had already gleaned from hanzab that there had been the odd earlier NT record, but found it odd that birders don’t seem to report them nowadays. Clearly they ARE there, and I wasn’t reading the right literature. And David, back in 1996 when hanzab V3 was published, there was doubt even then about it being affinis, or the nominate nilotica. It seems that in recent times the term affinis has become more widely accepted. Can’t recall on what basis, but I guess in the coming years we will learn more. This is really tricky stuff. From memory, I think Danny Rogers’ paper favoured affinis.
The point is that they certainly aren’t macrotarsa, and thanks for taking the time to communicate.
Cheers,
Jill
Jill Dening Sunshine Coast, Queensland, Australia
26° 51′ 41″S 152° 56′ 00″E
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Hi David and Jill In Annotated Birds of the Top End (Thompson and Goodfellow, 1990), several sightings of S.n. addenda (as we knew it) are reported from Leanyer Sewage Ponds, Fogg Dam and Kakadu by John McKean and others. These birds visit Darwin during the Wet Season.
A specimen from the sewage ponds was found in December 1989, and I assume this in the the NT Museum collection, if anyone is interested.
Hi Jill, The earliest Australian records of affinis were two collected at the estuaries of the North and South Alligator Rivers in Feb 73 and October 84 respectively (See Schodde 1991: Bull. B.O.C. 111(4): 216-6). John MacKean (1981: Australasian Seabird Group Newsl. 15: 11-15) reported small numbers of affinis in the Darwin area between Sept and April, and implied that they were regular. I haven’t spent much time in the top end at all, but I saw a few affinis types on a bank in the Adelaide River at the mouth of Leaders Ck on 9/10/00. I’d be surprised if there weren’t many more records, because they are certainly there. I didn’t find them in NQ during 9 yrs there between 1993 and 2002, though I didn’t look very often. I checked my notes and the first Gull-billed’s from SEQ were found by Chris Corben and David Stewart in early December 1990. These were an adult and a 1st yr bird. When I went to look at them with Dave on 20/12/90 only the first year was there. I guess the ones at Wynum that Paul Wallbridge referred to were a different lot? Dion Hobcroft and I saw one at Stockton Sandspit, (Hunter River) on 22/2/91. I’m not aware of any other NSW records, and had assumed this to be the southern most record in Australia until we learnt about the Murray Bridge record on B-A the other day. For the sake of completeness I have also seen a single affinis on Christmas Island, (where macrotarsa is possible but less likely) and in large numbers at Derby, WA. Actually, I have doubts that the correct name of these birds is affinis. There is a only the slightest cline between affinis and nominate nilotica. The type locality of affinis is Java where the species does not breed. Some years ago I tried to find out where it might breed, and concluded that it must be north-eastern Asia. This means that affinis appears to be incorrectly used for eastern populations of nilotica migrating through southern Asia and the birds we see are probably nilotica. Mathews named the breeding birds in China as addenda, which makes things a little more complicated.