MIMICRY

I don't know whether more Australian birds mimic than birds from other lands, but we certainly have a lot of mimics here. Everyone knows about lyrebirds imitating other birds and other sounds. We assume that this is the male endeavouring to impress any female within hearing distance. Why would she be impressed by his accurate impression of a car alarm? And lyrebirds are not the only birds to mimic. I'm told that many small passerines will mimic when they're in the hand. Are they frightened? Are they mimicking something big and scary to intimidate the person holding them? I'm told that Noisy Miners mimic. This is not at all surprising, given the large array of sounds they make. And my birding photographer friend, Ken Haines, tells me that a White-eared Honeyeater once responded to a Red-lored Whistler's call. Does that mean that the honeyeater would mimic the whistler? As far as we know, not many honeyeaters mimic, but we do know that Regent Honeyeaters mimic. Why should just one honeyeater be a proficiant mimic? Regents mimic wattlebirds and friarbirds (amongst others). In fact Little Wattlebirds are conned: they respond to the Regent's imitation. Australian Magpies mimic, although perhaps it is surprising that, for such a common bird, a bird I see every day, I've only ever been aware of them mimicking twice. The first time was some years ago at a park in Western Australia, when a bird imitated an entire race call, including the crowd reaction. I was spellbound. I'd never heard such a thing before - or since for that matter. I don't recall if the park was close to a raceway. The second time was quite recently, when a house was being built over the road from where I live and a magpie mimicked power tools. The clear conclusion is that not all magpies mimic. Just some individuals are that way inclined. What inspires them?

Other than this, I have two fascinating mimicking recollections. Well, I think that they're fascinating. The first was at Lake Gilles Conservation Park in South Australia when I was on a Peter Waanders tour and he was using callback tape to attract Copperback Quailthrush. A bird responded to the tape and we all believed it was a quailthrush. But not Peter. He said that it didn't sound quite right. We tracked the call down, and, of course, Peter was right. It was not a quailthrush. It was a Striated Pardalote mimicking a quailthrush! It certainly seemed to be calling in response to Peter's tape, but why would a bird do that? The second occasion was very recently when I was looking for Striated Grasswren at Yathong Nature Reserve in New South Wales. I thought I heard a grasswren, but it turned out to be an Inland Thornbill mimicking the grasswren's call. The thornbill called before I played the tape. I was excited and thought the thornbill must have learnt the call from grasswren. Therefore I must be close to my quarry. As far as I could tell, of the several Inland Thornbills present, just two individuals were mimicking grasswren calls. And, of course, I saw not a hint of any grasswren anywhere.

Inland Thornbills are well known mimics. This lovely photo is by Ken Haines. I am sure that if I had a better ear for bird calls, I'd recognize a lot more mimics. I suspect there are a lot of mimics out there. I'd love to know why birds mimic. I reckon there might just be as many reasons as there are birds mimicking. We will probably never know!

YATHONG NATURE RESERVE

Yathong Nature Reserve is in western New South Wales, an hour and a half's drive from Cobar. It is the only place to see the nominate race of the Striated Grasswren, called the Mukarrthippi Grasswren. Or not to see them as the case may be. I spent a few days trudging up and down in what I thought was suitable habitat and saw no hint of grasswren. The closest I came was a couple of Inland Thornbills mimicking the grasswren's call. The first time I heard this, my heart leapt and I thought I must be near the bird. Perhaps I was. But I saw no further evidence of it. I arrived on Saturday, spent Sunday and Monday looking for grasswren, took Tuesday off, partly to recover, but mainly to drive to Wilcannia and admire the race samueli of the Red-tailed Black Cockatoo, went back to Yathong again that afternoon, then again spent Wednesday looking for grasswren, before returning home on Thursday. I gave those grasswren every chance to show themselves. Of course I knew that these birds are critically endangered, that the tiny population is estimated to be 12 individuals, with a low possibility that there might be as many as 20 inidividuals. So, with that understanding, I really have no right to be disappointed in not seeing them. Yathong is a large reserve. It covers an area of 115,604 hectares. Hardly surprising that I didn't see a dozen tiny birds.

I saw new races of Grey-fronted and Brown-headed Honeyeaters, which was lovely, but the black cockies (race samueli) gave me a disproportionate amount of pleasure. I'd looked for them unsuccessfully in both Western Australia in June and the Northern Territory in July, so I was absolutely delighted to see them along the Darling River in Wilcannia, calling and taunting me, as if they'd always been there - why did I waste my time looking in other states?

These new subspecies were consolation prizes. All I really wanted was a Mukarrthippi Grasswren. The habitat was perfect and the weather was good. I thought August would be the right time of year, the birds would be getting ready to breed, and might be singing and more easily heard. But they simply refused to play ball. Here's what I thought was ideal habitat: spinifex, white mallee, some broom bush and red earth.

There were lots of lovely kangaroos (four species: Red, Eastern Grey, Western Grey and Euros) but far, far too many goats. An expensive predator-proof fence was under construction at the reserve and the park was about to be closed for a week for aerial bating for foxes. In my very limited time at Yathong, I didn't see any foxes. I saw several feral cats, a handful of pigs, and thousands and thousands of goats. There was a little evidence of rabbits, but not a great deal. And, of course, dozens of emus. The predator-proof fence will enclose an area of some 8000 hectares for soft release of captive bred endangered species, after all the exotic interlopers have been removed. It is clear that a lot of work and a lot of money has gone into this project.

Yathong Nature Reserve is a long way from everywhere. We stayed in Cobar, which, as I say, is an hour and a half's drive away. Cobar is a mining town. It calls itself 'Copper City' and is very proud of its open cut. There is a moving memorial to miners, and a museum, which I confess I did not enter. But under the eaves of the museum building, dozens of Fairy Martins had built their mud nests. I've often seen other birds occupying old Fairy Martins' nests, but on this occasion, I was surprised to see Red-rumped Parrots doing so. This is a most inferior photo (taken with my camera) but, if you squint and hold your tongue in the corner of your mouth, with a bit of imagination, you can just about see that there are parrots occupying a couple of nests.

Forgive me, I have to amuse myself somehow when the grasswren refuse to entertain me.