New butterfly for Australia!
April 8, 2012 — April 10, 2012
Within 15 minutes of the heart of Darwin city, we discovered a new butterfly for Australia!
As we pushed around the back of the ponds, the stars of the day started appearing. First we had a flock of martins buzzing around us, which is sometimes a herald for an unusual swallow or two making an appearance. True to form, an immature Barn Swallow joined them and flew around us. Young Barn Swallows can be difficult to separate from Welcome Swallow, though the latter would be far more unusual in Darwin. Thanks to some photographs we took we were able to make out a darker band around the breast (red, not blue, but still darker), and a generally more white tone to the breast.
Next in line was a flock of ducks. Mostly Radjah Shelduck, they had been joined a few weeks back by a southerly cousin, the Australian Shelduck. This lovely female was still there, though looking a bit ragged as she is moulting right now. We felt quite fortunate to be one of what must be a small number of people to have seen both of Australia's shelduck species together in the wild. With the ducks were a number of very well coloured up migratory shorebirds - Sharp-tailed Sandpiper, Common Sandpipper, Wood Sandpiper and Marsh Sandpiper. A single Curlew Sandpiper was keeping them company, though it was lagging behind its companions in terms of breeding colours.
Our final highlight of the day was a single Eastern Yellow Wagtail that put on a great show for us, allowing an unusually close approach by the car for us to take some photos. In all the time I worked in Broome I probably saw over 200 Yellow Wagtails, and none at any stage allowed us to reach anything close to the distance we were from this bird! To add icing to that cake, it was in resplendant breeding colour too.
So at the end of the trip we had quite a swag of great birds, some nice photos, and an all round excellent time.Read more.
We had just walked down to the nearby beach, a great way to spend the morning in the area. On our way back I noticed an orange butterfly fluttering very strangely. As a child I collected butterflies, and while I gave that up a long time ago, I kept my interest in them. When I took up photography it was only natural to get back into "collecting" butterflies, but this time without harming them in the process! So when I saw this butterfly, I realised straight away something was odd. At first I thought it could be a moth, however on closer inspection the body was spotted like a Monarch or Common Crow (Danaus or Euploea). At this point I realised two things: that it was a butterfly, and that is wasn't in the butterfly book I own. When I finally managed to see one settled on a flower I snapped a few quick shots, and realised I was looking at something a lot like our Glasswing, a fairly common butterfly, but clear, white and black in colour. This one was bright orange with white and black markings. A quick google search turned up Tawny Coster (Acraea terpsicore) as a likely candidate. At this stage we had only seen three individuals, so it could still be an odd coincidence, a few butterflies blown in from Indonesia by the last cyclone.
This theory lasted until mid-morning, when we checked out several more sites in the area. Every site we stopped had at least a few Tawny Costers. In the end we recorded around twenty individuals from three completely separate sites, evidence of a thriving population. I have no doubt had we spent more time looking, we would have continued to find many more Tawny Costers in the area.
The Tawny Coster is found from India and Sri Lanka all the way to Sumatra in Indonesia. I tried to find information on the butterflies of Timor, to see if the species was known from there, and it turns out there was a recent record from the island. The butterflies are the classic shape of an Acraea butterfly, with elongated upper wings and short round lower wings. The outer surface of the wings has complex orange, black and white patterns, most notably with strong white and black scalloping on the bottom border of the lower wing. The inner wings are a solid orange with black spots, and have an almost waxy sheen in strong light, as can be seen in some of the photos in this trip report. Male butterflies are much brighter than the females in this species.
Behavior-wise, the butterfly has a slow flight, almost erratic in pattern, but with very fast wingbeats. They flew an unpredictable pattern, mostly low to the ground over short grassy areas, but occasionally higher into the low canopy of nearby trees. Every few minutes they would settle, usually on a flower for feeding. While at rest they would open and close their wings almost constantly, though they never settled in one place for long. The flowers that were being fed on were mostly forb species in the grass, however on one occasion the butterfly fed on the flowers of a nearby Acacia tree. On a few occasions butterflies were seen to rest on bare stony ground, where they kept their wings folded tight together, and flushed readily if approached.
I have been helping butterfly expert Dr Michael Braby learn more about these butterflies, and we have an article in the latest edition of Myrmecia, the journal of the Australian Entomological Society.
So there you have it. I am amazed to have been lucky enough to stumble across a special butterfly like this, and even moreso to be the first person to realise they were something new, particularly so close to one of Australia's major centres. It was a wonderful moment that I'll never forget.Read more.
With only a morning to spend before leaving Darwin, we decided to try for Rainbow Pitta at East Point. This site is good for the species through summer, but April turned out to be a bit to late for the species. We did hear one call, once, but not close enough to help us find it. We were compensated for our efforts with some other great sightings though. Bird highlights included great views of Northern Fantail, Green-backed Gerygone, Broad-billed Flycatcher and Red-headed Honeyeater. We also were fortunate enough to come across some great reptiles, with a beautiful red-morph Australian Bockadam being the best, but a beautiful Ctenotus essingtoni skink was also a nice way to end the trip.Read more.