Mangrove and Varied Honeyeater

To: david james <>, birding-aus threads <>
Subject: Mangrove and Varied Honeyeater
From: martin cachard <>
Date: Thu, 14 Feb 2013 22:07:29 +1100
Hi David & Ivor,

This is a very interesting analysis David that makes plenty of good sense to me 
- thanks for sharing this with us up here in the Wet Tropics & southwards... 

All I wanted to add here is that I can confiirm the "hybrid" birds in the 
Halifax-Lucinda area that Kath had reported...
In the very late 90's the birds I always saw at Dungeness looked like apparent 
hybrids to me - this locality is at the mouth of the Herbert River at the very 
southern end of Hinchinbrook Channel, just to the west of Lucinda. I never saw 
any birds there that appeared either pure Varied or Mangrove... However, I 
didn't check the birds either side of the Dungeness locality, so I therefore 
have no idea from personal observations of what occurs outside the immediate 
area of Dungeness. 
Sorry but that's about all I can add.


Martin Cachard

> Date: Thu, 14 Feb 2013 00:05:41 -0800
> From: 
> To: 
> Subject: Re: [Birding-Aus] Mangrove and Varied Honeyeater
> Hi Ivor,
> I looked into Mangrove and Varied Honeyeaters a bit during
> the 90s and early 00s when I was living in Townsville. To answer your 
> question is more complicated
> than you might think. My methods were very simple; I looked at them at as many
> locations as I could in NQ, and recorded some plumage details particularly on 
> the
> underparts, throat and head. NO captures, no DNA, not even any photos, just 
> plumage
> notes. 
> In summary, I found almost exclusively pure Mangrove
> Honeyeaters from the mouth of the Ross River (south side of Townsville) 
> southwards
> to Gladstone at many locations. I found almost exclusively pure Varied 
> Honeyeaters
> from Rowes Bay (north side of Townsville) north to Cape York and PNG. The
> furthest north I ever found a Mangrove Honeyeater was in the small 
> recolonising
> areas of mangroves at South Townsville, near the port. This is about 5 km in a
> straight line from Rowes Bay where Varied were resident, and there is no
> suitable habitat in between, so they effectively abutted at Townsville. 
> The exceptions were interesting: 
> 1). Julian Ford collected 2 hybrids at “Cleveland Bay” in
> the 1980s. Both Ross River and Rowes Bay are in the huge Cleveland Bay but
> Andrea Griffin was with Julian and she told me they were at the mouth of the
> Ross River. I never saw a single hybrid or anything that made me suspicious,
> anywhere in Cleveland Bay, though of course I might have just missed them. 
> 2). 40 km or so South of Townsville at Cape Cleveland and
> Cungulla, there were only Mangrove Honeyeaters, except on a couple of 
> occasions I
> saw a single Varied with the Mangroves somewhere in the township of Cungulla. 
> I
> suspect it was just the one bird that I saw repeatedly. This was the only
> location where I ever saw the 2 species together. 
> 3). In 1989 or 1990 at either Lucinda or Halifax (about 100
> km n of Ross River) Kath Shurcliffe showed me a population of hybrids. Later
> when I was looking into it I couldn’t find this locality again, and only got 
> insufficient
> views of honeyeaters in this area, so I was never able to verify the earlier 
> sighting for myself. 
> My data set doesn’t prove anything, but here is my wild and
> reckless hypothesised explanation:
> Mangrove and Varied Honeyeaters are closely related (sister
> taxa). They evolved from a common answer relatively recently when some 
> historical barrier split the
> ancestor’s range into 2. They are now in ‘secondary contact’ after the barrier
> broke down. Since they both have linear distributions tied to coastal 
> mangroves
> this is a rare example where the secondary contact effectively occurs at a 
> single
> location, rather than across a broad front. They can and do hybridise, but
> mostly they do not. Varied Honeyeater is expanding southwards and displacing
> Mangrove as it goes. The individual Varied I saw at Cungulla living with
> Mangroves was, at that time, leading the charge, an unwitting scout. The 2
> hybrids collected at Ross River were love children of the battle front at that
> time. Varied had not one that battle and had retreated slightly, at least 
> temporarily. The hybrid swarms at Lucinda or Hallifax (if they exist) are 
> isolated historical
> remnants from a time when Varied swept southwards through there displacing 
> Mangrove
> as it went. 
> That speculation aside, if someone looked at the genetics I
> wouldn’t be surprised to find either: a) a complex mix of secret hybrids
> throughout, even though they look like one species or the other; or b) there 
> is no
> difference between them genetically. My ‘explanation’ would likely prove too
> simple.
> So I would expect that birds north of Townsville are still
> Varied. Your yellow washed birds at Ross River might also be Varied, 
> advancing south once more, or they might be hybrids or they might
> even be juvenile Mangroves. Get some photos if you can.
> Thanks Mike Carter for bringing this to my attention. 
> Cheers,
> David James
> Sydney
> ________________________________

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