Saturday, 28 March 2015

Long-billed Corella – strange behavior!

We made an early visit to the Twelve Apostles to avoid the crowds of tourists and look for Rufous Bristlebirds, which I had seen there on a trip many years ago. They are found in heathland along the coast from the Murray River mouth in SA to Jan Juc in Victoria. I was thinking that Bristlebirds at this location may be more approachable for photos given they are used to the presence of large numbers of people. As it turned out we did not hear or see any Bristlebirds at the Twelve Apostles or at any of the other areas where we looked for them that day.
But as we walked towards the various lookout points for the Apostles we heard a call that sounded like cockatoos, however it was not exactly familiar. Shortly after hearing the call and as we stood and took in the grandeur of the coastal cliffs and rock stacks (Apostles) the mystery of the strange call was solved. Two Long-billed Corellas were perched on the side of a large rock stack right in front of our lookout point!
One of the two pairs of Long-billed Corellas seen at the Twelve Apostles perched on a cliff edge.
One of the Apostles where we saw the first pair of Long-billed Corellas.
90 degrees from the above photo and looking west along the coast, a view many will recognise, which includes a number of sea stacks - some of the Twelve Apostles.
As we watched the two birds it became apparent that one was standing watch while the other was excavating a hole nearby in the soft rocky material of the stack. To me the bird looked like it was excavating a nest hollow, but it is possible the bird was seeking clayey material to ingest as some parrot species do this to rid their systems of toxins taken in with some foods such as fruits and seeds. We have seen this behavior in South America.
However in this case the bird was deep in a hole and given the whole rock stack seemed to consist of the same sand/clay material it did not make sense that the bird would obtain the soil to eat from within a hole.
The Corella on watch while its mate excavated a hole.
Long-billed Corella at the hole on a shear face of a sea stack
Note the soil on the end of the long bill.
Into the hole for another dig. When right in, only the tip of the tail was visible.
Long-billed and other species of Corella normally nest in tree hollows and Long-billed usually nest from July to November, so excavating a hollow in the soft clayey sand of one of the Apostles rock stacks in late March seemed very unusual indeed.
We left the two to their unusual behavior and moved to another lookout point some distance away where we found another pair of Long-billed Corellas. These two were perched in view on a cliff and were making flights to a section of cliff out of our sight and then returning again to the same perch. I am not sure what they were up to, however it is possible these two were also working on a nest hollow. I was pleased when they returned to the visible perch and I could capture some more photos.
The second pair of Long-billed Corellas we found at the Twelve Apostles.
Note the Starling at the top left of the photo.
One of the pair departs for a section of cliff where we could not observe them.
The other bird remains perched - but only for a few seconds.
The second bird departs to join its mate. The vertical plunge uses gravity to quickly pick up speed.
There were large numbers of Common Starlings perched on the cliffs and judging by the numerous holes and crevices it is likely that they roost and nest on the cliffs.
It would be interesting to hear if anyone has observed this behavior before or has an explanation or suggestion as to what the Corella was possibly doing in the hole.
As the saying goes, especially when birding, expect the unexpected.
I never would have expected to find Long-billed Corellas on a Southern Ocean sea cliff.

Thursday, 26 March 2015

Waders at Lake Corangamite - Colac

Lake Corangamite is a large hypersaline lake located north west of Colac in the Lakes and Craters region of the Victorian Volcanic Plains. A number of the lakes in the region are important wader sites listed under the Ramsar Convention Ramsar-listed Western District Lakes. The last volcanic activity in the area was about 4,500 years ago, which for Australia is relatively recent. The lake was formed when larva flow blocked the local catchment drainage outlet.
Lake Corangamite is large with a shoreline length of about 150 kms and an area of 230 square kms (mean depth is about 5 m). Surprisingly for such a large lake there is only one public access point located a short distance from the small town of Alvie and the Red Rock scenic lookout, which provides an excellent view of the area including the lake. In hindsight it is a great shame that our forebears did not see any value in preserving some of the volcanic plains vegetation around Lake Corangamite.
We visited the lake to see if there were any waders present and were not disappointed as there were thousands of Red-necked Stints and good numbers of Curlew Sandpipers feeding together along the shoreline at the public access point. It was a moving scene to watch, knowing these small shorebirds were feeding actively to fuel up for their immanent migration flight to the arctic tundra to breed there during the short northern summer.
An added bonus was to see a few birds in breeding plumage as we mostly only see birds in their somber non-breeding plumage during their summer visit to Australia.
Curlew Sandpiper in breeding plumage.
Along the section of shoreline we visited I estimated there were around 500 Red-necked Stints over a distance of about 1km. Assuming this small area of public access was not, by some freak of nature and extremely long odds, the only shoreline favoured by the Stints then the numbers around the lake could be large. If two thirds of the shoreline, that is 100 kms, had Stints in the same numbers as the public access section then there could be 100 x 500 = 50,000 Red-necked Stints on Lake Corangamite. The total Australian summer population estimate is 270,000 birds so 50,000 may not be an unrealistic estimate.  
The Curlew Sandpipers were in much smaller numbers. My Shorebirds of Australia (Geering, Agnew and Harding) reprinted in 2008, put the Australian estimate for Curlew Sandpipers at 118,000.  Their numbers have crashed since 2008 due to the destruction of tidal flats for land reclamation in Korea, which was a critical refueling stop on their migration flyway.
Looking carefully through the birds near my observation point I could not see any other wader species. No doubt many other water birds and shorebirds (waders) use this lake at times. I have read that Banded Stilts once bred on the lake back when their breeding locations were a mystery.
Approaching the shoreline of Lake Corangamite where hundreds of waders were feeding.
It is impossible to capture the extent of birds feeding along the shore, this is just a very small section. There are 41 birds in the photo.
The Curlew Sandpipers and the much smaller Red-necked Stints fed together.
The Curlew Sandpiper is surrounded by Stints.
Curlew Sandpiper, non breeding, Stint behind.
Curlew Sandpiper with the start of some breeding plumage.
Curlew Sandpiper in breeding plumage.
Red-necked Stint non breeding plumage.
Two Red-necked Stints with bird on left showing some red on neck.
This bird has more red on neck making the common name for this species obvious.
If you are ever in the Colac area, especially during the summer migrant wader season, a visit to Lake Corangamite and Red Rock lookout is recommended (go to the Visitor Information Centre in Colac for directions if you are unsure how to find the public access point). 

Monday, 23 March 2015

Oh what large eyes!

Port Franklin is a small fishing village on a mangrove fringed tidal creek, which runs into Corner Inlet. On a walking trail here, one of the BirdLife East Gippsland Autumn camp members spotted a Southern Boobook owl roosting in a dense melaleuca thicket.
The Boobook, Ninox boobook race boobook,  (one of four races in Australia) sat quietly while we all had a very close look and some photos were taken.
My lens at 420mm was way too long for such a close shot and there was no position where a fully clear view could be obtained, so I settled for some partly obscured head and shoulder portraits.
I guess a Photoshop wizard could improve on the images given enough time on the computer. I thought some of the images were worth a post “warts and all”, they certainly capture the owl's beautiful large eyes and facial features.

The upper eye lid appears to have eye lashes but not the lower?
Even though it was an overcast day it still seemed quite bright so I am surprised how dilated the owl's pupils are!
The "wise owl" look!

Saturday, 21 March 2015

Ravens v’s Eagle

This week I participated in the BirdLife East Gippsland Autumn camp in the Yarram-Port Albert area where there is a great diversity of birding habitats. These range from the Corner Inlet mangrove fringed tidal flats, a great wader stronghold in Victoria, to the wet temperate rainforest in the Tarra-Bulga National Park on the Strzelecki Range, home of Lyrebirds, Pink Robins and Pilotbirds.
During our week in the area we were surprised to see Wedge-tailed Eagles every day in many locations.
On the road between Tarraville and Manns Beach we passed a Wedge-tailed Eagle perched on a fence post beside the road. A quick U turn and slow drive back for a photo opportunity saw the Eagle fly off but only up to the top most insulator of a power line pole on the opposite side of the road where it was joined by a pair of Australian Ravens.
The Eagle was a juvenile for two obvious reasons, one; an adult bird would have been far too wary to land in this location with a vehicle approaching and, two; the feather colours and markings were of a young bird.
The two Ravens were clearly not happy with the Eagle’s presence and at first expressed their displeasure vocally. Perhaps there was a dead animal in the adjoining paddock which would explain the Eagle’s presence low on the fence post and the Ravens’ objections as it was well past breeding time when the protection of a nest and young might be a concern. More likely, competition for food and an ingrained response to a top order predator was motivating the Ravens’ behavior.
Their objections soon ramped up a notch when one of the Ravens commenced an aerial attack while its partner perched on one of the power lines close to the Eagle and maintained eye contact and a vocal barrage.  After a number of close swoops the Eagle decided enough was enough and departed for a quieter perch with the pair of Ravens in pursuit.
These photos show some of the interaction.
A juvenile Wedge-tailed Eagle and Australian Raven eye one another off.
Their attention to one another is distracted.
The cause of the distraction swoops close by.
Another approach, not too close.
The Raven kept up its attacks, harrying the Eagle, but at no time making contact.
Eventually the young Eagle, which did not seem concerned by the attacks, had had enough
and prepared to depart.
The moment of lift off with the massive up-raised wings about to thrust down.
The Ravens in pursuit.
I could not resist cropping the Eagle from the above image to remove the distraction
of the pesky Ravens and show the magnificent Eagle in all its glory.

Another wonderful bird encounter!
I wondered later, was the more aggressive Raven doing the swooping a male or a female?
PS.   The two Ravens may well be Little Ravens and not Australian, I am not sure?

Saturday, 7 March 2015

Brown Thornbill

In East Gippsland the Brown Thornbill is easily our most common thornbill in a wide range of habitats. However it avoids open habitats such as grasslands where Yellow-rumped Thornbills tend to be the most common of the thornbills.
Browns perhaps seem more common because they occupy understory where we are more likely to see them compared with Striated and Yellow Thornbills which often operate higher up in the canopy where they are harder to see. Also we are more likely to notice the Browns because they have a large repertoire of calls, with many distinctive calls and some quite melodic and loud, compared with the more limited range of calls and quieter voices of other thornbills. That said, I am fairly sure Browns are more numerous and widespread than other species of thornbill in East Gippsland.
Browns are relatively easy to identify with buff scallops on the forehead, a dark red eye and blackish streaks on a grey throat and breast. 
Right click with mouse on photo to enlarge and use wheel to scroll through images.
Close up of Brown Thornbill showing the buff scalloped forehead, dark red eye and dark streaks on grey throat and breast.
They actively forage in dense understory for insects and other small prey either alone, in pairs or small family groups. In the non breeding season they can often be found in mixed species flocks of thornbills and other small insectivores such as robins, scrub-wrens and so on.
The following sequence of photos show a Brown Thornbill foraging in Hazel Pomaderris (aspera) under tall Mountain Ash (E regnans) near the top of Mt Elizabeth, a long extinct volcano which is now a Flora Reserve where rare plants are protected.

Following a morning of rain and overcast conditions for most of the day the Thornbills seemed to be enjoying the late afternoon sunny breaks when light beamed down through the Mountain Ash canopy to the understory far below.
I was there to check out road conditions to this magic place for a BirdLife East Gippsland Monday outing the following day.

Friday, 6 March 2015

Red-capped Plover chick

On the Gippsland Lakes late in February, heading south in the channel between Fraser and Rigby Islands, we noticed a lone very young shorebird (wader) chick on the shoreline of Fraser Island. We did not have to ponder which species it was for long, a female Red-capped Plover soon joined the young bird.
Red-capped Plover, mother and chick, Fraser Island, Gippsland Lakes.

Male Red-capped Plover, not the chick's parent, photo taken elsewhere on a clear blue sky day, included to show a male which has a red head or cap.
 Even though the chick was not long hatched, in fact still a camouflaged ball of fluff, it was highly mobile on long legs, darting forward and stopping abruptly as it searched for food along the shoreline. We only saw the female parent, though both parents usually tend the young, which can vary in number from one to three. 
The presence of our boat just off shore aroused the protective instinct in the mother bird; she followed the chick closely, and it seemed to be oblivious to us, as it darted here and there along the shore looking for food. I think the chicks find their own food, they are not fed by the parents (?). 
Capturing images of the small stop/start bird was tricky in the overcast conditions with dull and flat light, an extreme test for the auto-focus system.

The start of a tiny wing is just visible.

The chick has found a small food item by the water's edge.
Mother continues to keep a close eye on the chick and us. The chick continues to forage, it has to grow up fast.

The young bird was very cute and very vulnerable. With no wings or feathers developed yet to fly, the young bird must rely on its long legs, camouflage and its mother for protection from predators.