Friday, 13 May 2016

Bell Miner

When we first moved to our rural property in East Gippsland in 1976 there were no Bell Birds. We now have a colony that has been here for about 15 years. A long-time local told me that there used to be Bell Birds on the river for many years however they were either wiped out or moved during the disastrous 1965 fires. It took 35 years for a new colony to establish after the fires. The new colony has increased in size over the past 15 years and while the area they occupy has expanded, the location has not changed even though there is plenty of suitable habitat along the river.

The colony is located on the Nicholson River in a tall stand of dominant Manna Gums (E viminalis) and a smaller number of closely associated River Red Gum (E tereticornis), Apple Box (E bridgesiana) and Coast Grey Box (E bosistoana).

The Bell Miner (Manorina melannophrys) is a honeyeater. The Manorina genus includes three other species, the Noisy, Yellow-throated and Black-eared Miners. Like their cousins Bell Miners are colonial birds and aggressively defend territory however the Bell Miner is unique in that each colony occupies a relatively small well defined area where it feeds more or less exclusively on sugar produced by sap sucking insects called psyllids. The white crystalline structures produced by the psyllids are known as lerp.

Bell Miner, adult males and females look the same, the red triangle behind the eye is olive in juveniles.  
Tall Manna Gums near the centre of the Bell Bird colony’s area.

Bell Miners are well known birds in southeast Australia from Melbourne in the south to around Gympie in SE Queensland in the north. They are generally confined to the east side of the Dividing Range. Their loud bell like calls are distinctive and easily recognised however seeing the birds, even with binoculars, can be difficult even when there are large numbers calling close by. Their olive-green-yellow plumage blends in well with the eucalypt canopies they occupy.

Much has been written about Bell Miners so I will not include more details in this post but instead refer you the the following excellent blog posts:

The Following photos were taken during three sessions over the past couple of days.

Bell Miner eyeing off lerp – small white dots on eucalypt leaves.
I managed to catch this bird as it made its way along a branch to feed on lerp.
This photo managed to catch the bird with its tongue out.
Looking for lerp.
Still looking.
In this shot you can just see a lerp in the bird’s bill.
A lucky flight shot captured just as the perching bird flew.
A juvenile bird clumsily flew in to perch beside an adult.
The juvenile begged briefly. Was this just a ritual bonding behaviour or did the young bird expect to be fed?
No food was forthcoming so the juvenile departed leaving the adult to watch it go.

The chorus of bell calls generated by a large Bell Miner colony can be hard on the ears at times - a good thing this colony is some distance from our house.

Sunday, 1 May 2016

Satin Bowerbirds

We have been fortunate to have a resident male Satin Bowerbird (Ptilonorhynchus(1) violaceus violaceus), including a bower, the male’s courtship display arena, continuously in our garden for about 10 years now.

Mature male Satin Bowerbird at bower.
Over the 10 years there have been at least six bowers that we know of, each constructed and decorated in a separate location with only one bower in the garden at a time. So it seems only one dominant male at a time is in charge of our garden.

As the males only reach the fully blue mature stage at age 7 and probably only live on average to about age 10 or 11 years, we have no doubt had a number of dominant blue males over the 10 years.

Each bower is dismantled as the new bower is constructed and the precious blue objects are moved to the new location.

Male bower birds are great thieves so the blue objects are continually changing at a bower as some items are stolen and new ones turn up - some of these stolen and some newly found. The objects include blue plastics of various origins, however blue bottle tops and straws are common and Crimson Rosella blue tail feathers are also common. A few yellow objects are included, often flowers, but sometimes we have found Sulphur-crested Cockatoo crest feathers at bowers in our garden.

This is the last bower before the one featured in this post. It has now been completely removed including blue objects.

The number of blue objects at the new bower is less than are seen in the photo above of the old bower so I am assuming some have been taken/stolen by other males.

The blue objects match the colour of the mature male’s plumage, though, depending on the amount and angle of the light, the plumage can vary from blue to black. The blue objects also match the vivid blue eyes of the females and immature males. The mature fully blue males have lilac coloured eyes (see photos).

While the activity at the bower is at a peak during the breeding season the bower is maintained throughout the year. The bower in this post was moved to this location over the past couple of weeks and is still being refined with new sticks added and sticks in place adjusted and painted. Even though it is autumn and the breeding season is over there is still plenty of display activity at the bower as the photos in this post show.

I was surprised to observe an immature male at the bower busily adding and adjusting sticks and painting the inside of the bower. The immature male also displayed and danced around the bower with blue objects held in its bill while another immature male looked on. The mature blue male was not present.

Immature male Satin Bowerbird. Note the green throat and breast with fine white spots and streaks. Also note the dark grey bill is just starting to turn a light colour at the tip indicating this male is about 3 to 4 years old.
The immature male spent 15 minutes or so adding and adjusting sticks at the bower.
This stick looks to be too short and crooked for the bower walls?
The bird was busy moving in and out of the bower.
A brief pause from bower work for a scratch.
The green birds are very attractive. This photo has not been cropped - I was very close, concealed in a chair hide using only a 300mm focal length lens.
The immature male took a break from bower work to put on a performance with a piece of blue plastic.

The display involves jumps and wing and tail movements while making various calls and buzzing sounds. Another immature male watched on.
The under tail feathers are very attractive – I am not sure what purpose such attractive feathers in this location serve given the females selecting mates are looking at all blue males?
A little later the blue plastic was discarded and a dry brown faecal pellet, or perhaps it is an insect larva case, was taken up and the display continued.
The display included a variety of moves including hops, side jumps and sudden wing movements.
The display continued.

In an observation session a couple of hours later when the adult blue male was present, two immature males were also at the bower. One of the immature males stood motionless inside the bower, as a female would, while the mature male commanded the display area and put on a performance with dance, a variety of calls and blue objects held in its bill.

The magnificent mature blue male arrived at the bower and the immature males adopted a subservient stance.
Note the lilac coloured eyes of the mature male, the creamy white bill and bill feathers.
This immature male appeared to adopt the role of a female at the bower in the mature male’s presence?
The immature male stood in the bower while the mature male moved about the display arena.
The mature male appeared larger than the immature males?

It would seem that young males practise bower construction at a mature male’s bower and also learn to display in preparation for the day when they reach maturity and build their own bower. The mature male in command of the bower, the owner, seemed to tolerate the presence of the immature males. I suspect this may not be the case during the breeding season when receptive females are visiting bowers.

(1)  From Fraser and Gray, Australian Bird Names - A Complete Guide.
Ptilonorhynchus from Greek means feather-bill.

The Satin Bowerbird and other species of this genus have a small patch of feathers extending from the forehead down over the root of the bill which gives the head and bill when viewed from some angles a rather unique shape – see photos.

Australia is fortunate to have 8 species of bowerbirds with 5 species in the Ptilonorhynchus genus. This list of Bowerbird species is copied from the BirdLife Australia working list:

Tooth-billed Bowerbird
Scenopoeetes dentirostris
Golden Bowerbird
Amblyornis newtonianus
Regent Bowerbird
Sericulus chrysocephalus
Satin Bowerbird
Ptilonorhynchus violaceus
Wet Tropics Satin Bowerbird
Ptilonorhynchus violaceus minor
Southern Satin Bowerbird
Ptilonorhynchus violaceus violaceus
Spotted Bowerbird
Ptilonorhynchus maculatus
Western Bowerbird
Ptilonorhynchus guttatus
North-west Cape Western Bowerbird
Ptilonorhynchus guttatus carteri
Inland Western Bowerbird
Ptilonorhynchus guttatus guttata
Great Bowerbird
Ptilonorhynchus nuchalis
Western Great Bowerbird
Ptilonorhynchus nuchalis nuchalis
Eastern Great Bowerbird
Ptilonorhynchus nuchalis orientalis
Fawn-breasted Bowerbird
Ptilonorhynchus cerviniventris

A post featuring the Western Bowerbird can be found here:

For more information about Satin Bowerbirds the following sites are well worth a look: