Wednesday, 31 May 2017

Miscellaneous birds - Byron Bay 2

Five visits to the Byron Bay Integrated Water Management Reserve yielded 68 species of birds which is not bad for late autumn when many migrant species are absent. Also, following widespread rain after Cyclone Debbie, large areas of wet habitat for nomadic water birds have been created which means birds are distributed more widely and not concentrated in the more permanent wetlands.

The brochure “Birds of the Byron Wetlands, A Birdwatchers guide to Wetlands” prepared by members of Byron Bird Buddies, lists 227 species that have been recorded at the wetlands. Of the 227 species 112 (50%) are listed as common while 61 (27%) are uncommon, 54 (24%) are rare at the site and just 4 are introduced species.

The following photos are all from the Byron Bay Integrated Water Management Reserve.

Please click on photos to enlarge.

Azure Kingfisher – I crossed paths with Azures on a few occasions.

Forest Kingfisher fluffed up in the morning cool – looking for a frog breakfast.

           The bird moved to a new perch – shortly after it pounced and captured a small frog.

I saw two birds catch small frogs – unfortunately I was not able to photograph them with the frogs in their bills.

Intermediate Egret – the long body, legs and neck gives the bird a long reach when hunting.

Intermediate Egret in breeding plumage.

 Little Egrets were also hunting on the wetlands along with Intermediate and a few Great Egrets. 

Cattle Egrets roosted in the wetlands overnight, however I did not see them at the wetlands during the day – they were no doubt out feeding among cattle in adjoining paddocks.

Dozens of Australasian Grebes were diving for food among the water lilies.

There were also large numbers of Eurasian Coots feeding among the water lilies. 
A young White-bellied Sea-Eagle circled low over the wetlands obviously looking for prey (I think this bird is a “second immature” and therefore is about 3 years old).
The bird made a rather inelegant landing in melaleuca trees beside the wetland. A rather flimsy perch. 

Eventually the bird settled and then stayed for about 25 minutes overlooking the wetland.

I watched hoping to see the bird launch an attack on an unsuspecting water bird however the bird finally departed without making any such attempt.

Willie Wagtails and Restless Flycatchers hunted for insect prey around the margins and out over the wetlands.
There were good numbers of Pacific Black Duck on the wetlands. They often exploded from the water and flew off with indignant quacking.

I encountered several pairs of Tawny Grassbirds along the margins of the wetlands. 
Along with Little Grassbirds and Australian Reed-Warblers they rarely show themselves especially when a bird photographer is lurking nearby.

After spending some time trying to get a reasonable photo of this elusive bird, this and the photo above were about as good as I could achieve.

Female Variegated Fairy-wren – the male eluded me.
Double-barred Finch – there were also Red-browed Finches at the wetlands.
Large numbers of melaleuca were in flower in the Byron Bay area and around and in the wetlands so there were good numbers of honeyeaters present including the rather elusive White-cheeked Honeyeater.

If you are interested in visiting the Byron Bay Integrated Water Management Reserve, you must contact Byron Shire Council to arrange access – a copy of the brochure and a site map is provided on registration.

Tuesday, 23 May 2017

Comb-crested Jacana

The Byron Bay Integrated Management Reserve is a great place to see both terrestrial and water birds in the Byron Bay area. As access to the wastewater treatment wetlands is limited, it is one of the few places in the area accessible to birders that is not heavily impacted by human presence and activity.

Comb-crested Jacanas (Irediparra gallinacean) are common at the wetlands, especially on Cell H which has a large covering of water lilies. The local population when I visited included adults, sub-adults and juveniles, indicating successful breeding at the site over last summer’s breeding season.

The Jacana’s bright red comb or wattle, for which the bird is named, is conspicuous on the adults. The combs are large and bright red on mature adults, smaller and a dull flesh colour on sub-adults and almost non-existent on the juveniles.

It seems adult birds can change the colour of their combs. HANZAB states that colours can change rapidly, from yellow through to red, but ‘Causes of colour change are not properly known but to some extent are behavioural; yellow combs flush to red during or after territorial displays or fights. Yellow combs are often recorded on males incubating eggs.’ 

I observed adult birds for a while that seemed to have continuously red combs!

During the breeding season, males maintain their own territories, and females may range across territories of several males with which they mate.  The male does all the incubation but females may also contribute to care of chicks.  

HANZAB indicates that the sexes are only separable by size, not plumage or comb.  

There is no suggestion in HANZAB that flushing of the comb is associated with courtship rituals. It may be that flushing of the comb has more to do with maintaining feeding and nesting territories than mate selection per se.

Jacanas were observed and photographed from the bird hide on Cell H. The birds foraged alone and ranged far and wide across the pond so I had to sit patiently and wait for birds to come within range.

Please click on photos to enlarge.

Cell H with bird hide.
Juvenile Jacana – note there is very little comb development, head is rufous not black, no black breast bar or black tip to bill.

The young Jacanas even at hatching have large feet so they can be mobile on floating aquatic vegetation immediately.
This is a sub-adult bird – note the comb is not well developed and is a dull pink colour, the bill is brown with no black tip, however a black breast bar is developing and the crown feathers are turning black.
Another sub-adult bird.

Adult bird with fully developed red comb. 
Cropped version of the photo above showing the comb is translucent in the late afternoon light. 
The comb is red-orange on this adult bird.
A cropped version of the photo above shows blood vessels in the fleshy comb. 

The Jacanas were very active, constantly on the move, foraging across the lily leaves or moving through rushes so most photos had to be taken of the birds while they were moving.

This bird however paused and it soon became apparent it was settling down for a rest.

As with many birds it rested on one leg which involved tucking its very long feet up under its wing.

The tips of the three front toes are just protruding from the wing however the rear toe is mostly exposed.

In this photo the bird is looking sleepy!

All birds have evolved characteristics to exploit ecological niches with some able to generalise while others, such as Jacanas, are highly specialised. I find the development of extraordinarily large feet to enable exploitation of the floating world of aquatic plants particularly fascinating.