Wednesday, May 29, 2013

Togetherness.....Banded Stilt

     Driving back from South Arm a couple of weeks back, I noticed a group of predominentlyy white birds a hundred or more metres away which I couldn't readily recognise. I stopped and investigated and found six Banded Stilt feeding in the shallow water of Ralph's Bay. I was already late for an appointment, and reluctantly drove on, persuading myself that trying to photograph these birds on a wide and open beach would be difficult if not impossible anyway--that was to prove false. I made a note to return on a full tide and try when they were roosting.
     An email from Eric Woehler (Chair Birdlife Tasmania) a few days later, telling me that Mark Holdsworth and Sue Robinson had also reported them, "fired" me up, and high tide or not, I'd try my luck.
      There have been several recent reports of sighting around the state, from Moulting Lagoon, Bruny Island, and not forgetting the "few thousand" seen at Logan's Lagoon on Flinders Island. Given the number of sightings/birds involved, you might be wondering why the excitement. Well Banded Stilts are usually described as "rare", "casual" or "vagrant" visitors to Tasmania, and the last time I saw them in Tasmania's south-east, was back in the '80s, and prior to that, my only record was a solitary bird at Lauderdale in 1976/8.
       On a bright, clear morning, with the thermometer hovering in the low single figures, I donned gum boots and wandered off with hope, but little expectation, of getting somewhere close enough to 'meaningfully' photograph this group of stilts feeding avidly in a few inches of water out in the centre of the bay. A few distant "record" shots and a slow approach worked well and I closed to within 15 metres or so. By sitting on my haunches and being very patient, they closed on me until they seemed to suddenly 'notice' me and scurried past to resume feeding a little farther on.
       As you can see in the accompanying photographs, they fed together, walking line abreast, picking up unseen prey from the shallow water. Subsequent viewing of images, showed the prey was almost entirely of small snails (salinator fragilis has been suggested, a very common snail here). They were very jumpy, and even an alarm call of a distant Noisy Miner obviously "worried" them, although they took my presence in their stride. At one point they all stood upright and milled about in all directions, so I turned and walked away from them fearing I was causing them some distress. On turning round they had gone! I soon found them a few hundred metres away, and the 'cause'--a passing Swamp Harrier high overhead. They had formed a flock with Pied Oystercatchers and White-faced Herons, but within a few minutes they were back feeding.
         Banded Stilt, an Australian endemic species, breed in the salt lakes of inland Australia, primarily in Western Australia, but also in northern South Australia. Their chief food there are the numerous brine shrimps and I'm assuming that the habit of feeding in line abreast is a very effective method of maximising their 'catch'. 'Old habits' obviously die hard, as the local snails are not known for their fast getaway!
        It's very hard to determine how many snails the stilts were consuming, but a quick estimate was that they caught (all 6) between 20 and 30 a minute, possibly more, which seems a lot! But I suppose the actual amount of meat, as opposed to shell, is quite small in this snail. After about 30 minutes of photography and just watching them, they stopped, preened and roosted no more than 20 metres away, quite remarkable.
           The first recorded sighting of Banded Stilt in Tasmania was also in Ralph's Bay, back in June 1854, when seven were shot! I assume they were considered "fair game' back then and eaten. Which reminds me, if you're considering photographing them, do it with consideration. If you are causing them to continually change the direction that they are feeding, you are too close. Stay your distance and be patient.

Thursday, May 09, 2013

Suburban Cattle Egret

    A recurring back "issue" has limited my birding opportunities, so the following event was gratefully received.
      I was returning from watching granddaughter Caitlyn play soccer, and driving up Gordon's Hill Rd., a suburban 'link' road between Bellerive and Lindisfarne, two of the Hobart's largest Eastern Shore suburbs, when something white and moving on the roadside caught my eye. As I passed I realised it was an egret and  possibly a photo opportunity, but I was in a stream of traffic and stopping was just not on. "I'll take the next right and come back up the hill" and then proceeded to get lost in the labyrinth of back roads and I was beginning to get both frustrated and agitated as time ticked by. Finally, I got back onto to the main road, by now fully expecting that the 'bird had flown'. But I was in luck and stopped briefly to take a few shots from the car, only for the bird to be disturbed by a jogger, fortuitously flying up a side street, I followed and took the accompanying images.
     The 'egret" is in fact a Cattle Egret and as its' name implies, is more at home in the paddocks catching insects disturbed by stock than feeding in suburban front gardens. It had obviously found an untapped food resource, catching insects, probably grasshoppers, as it made its' way from one garden to the next, and there seemed to be no lack of available food. At one point it crouched and stalked an unseen prey, much in the way cats do, and after a swift jab, came up with a hapless skink, dispatching it in a trice.
       Cattle Egrets are mainly winter visitors to Tasmania, and are occasionally seen in flocks numbering in the hundreds, especially so in the North West of the state and on King Island. Here in southern Tasmania the flocks are usually modest in size, often a dozen or less. Although their name implies an association with cattle, they are also found in association with both sheep and horses, or indeed just feeding in grasslands or around lagoons.

     About 30 years ago, it was confidently assumed that they would soon start breeding here in Tasmania, particularly on King Island and along the Northeast coast, but this hasn't yet occurred. If you look at the way this species has colonised Australia in the past 70 years, beginning in the 1940s in the Northern Territory, I think I can confidently predict that it will eventually become a breeding resident of this state.