Walsh Point

I would not have complained about the endless rain if I’d known if was going to be replaced by constant gale-force winds off the snowfields. It’s colder now than it was in the middle of winter.

The river’s edge at Walsh Pint was covered with thick black smelly oil for as far as I walked. Hope it is contained/cleaned up before reaching the shore bird areas just upstream. Dusty of course ran through it before I noticed it, so I’m engaged in my own oil clean up.

It was almost impossible to hold the camera steady, but I stalked this Brown Falcon and managed a couple of shots before leaving him to his windy perch.

 

Soldiers Point

Headed to Soldiers Point on the outgoing tide to see if the Double-banded Plovers had coloured up prior to leaving for New Zealand, and if any of the Northern Hemisphere waders had arrived in their breeding plumage.

We were lucky on both counts with around twenty plovers showing their coloured bands, Pacific Golden Plovers in bright gold plumage and Grey-tailed Tattlers wearing their breeding chevrons.

There was also a Sooty Oystercatcher, a White-faced Heron, two Bar-tailed Godwit, and a group of Red-Necked Stints.

     

The Double-banded Plover breeds only in New Zealand, where it is widespread. In the non-breeding season, part of the population remains in New Zealand, while the remainder migrates to Australia. It is the only species of land bird that migrates from Australia to New Zealand and is unique among waders in that much of the population undertakes an east-west migration.

It is not unusual to find them on exposed reefs and rock platforms with shallow rock pools such as on Soldiers Point. Little is known about the foraging of this species although some general observations of diets of young and adult birds have been made on a population of Double-banded Plovers that are known to forage at night alongside Sydney Airport runways.

Interestingly, the biggest threat to Double-banded Plovers wintering in Australia is the cessation of grazing and the return of grazing land to woodland.

Walsh Point

Given that the wind was still blowing this evening, I took the dogs to Walsh Point on Kooragang Island, hoping to catch gulls and terns held up by the wind as they travelled upstream. Only Silver Gulls, Welcome Swallows, Crested Terns and Little Black Cormorants, and this Brahminy Kite that flew past just eight to ten feet above the ground.

Hunter Wetlands Centre

I wandered across to the Hunter Wetlands Centre with my sandwich today. The conditions weren’t ideal for either picnicing or photography, with 30kmph north westerlies, but at least the sun was out.

Lots of springtime activity with birds collecting nesting material, and chasing each other through the shrubs, and many of the flowering plants in full bud.

Bird List:

Superb Fairywren

Freckled Duck

Black Swan

Australian Wood Duck

Pacific Black Duck

Chestnut Teal

Hardhead

Australasian Grebe

Australian White Ibis

Straw necked Ibis

Peregrine Falcon

Little Black Cormorant

Australian Pelican

White faced Heron

Great Egret

Crested Pigeon

Rainbow Lorikeet

Eastern Rosella

Laughing Kookaburra

Spotted Pardalote

White browed Scrubwren

Yellow-rumped Thornbill

Little Wattlebird

Noisy Miner

Yellow faced Honeyeater

Golden Whistler

Magpie-lark

Grey Fantail

Willie Wagtail

Black faced Cuckoo shrike

Pied Butcherbird

Australian Magpie

Pied Currawong

Australian Raven

House Sparrow

Red browed Finch

Welcome Swallow

Silvereye

Olive backed Oriole

Striped Honeyeater

A Weed and a Pest

Many years ago, about 6 or 7 species of coral trees were promoted by the nursery industry as a beautiful and easily grown ornamental tree. They were right on both counts. Coral trees have bright red flowers from mid winter to mid spring, and are very easy to grow - in fact, far too easy. They were known as instant trees - in fact it was well known that you could break off a large branch and just stick it in the ground and watch it grow! Two of the species became problem weeds.

The first is the Indian Coral or Cockspur Coral Tree (Erythrina crista-galli). This species spreads by seeds and vegetatively. The seed are known as ‘sea beans’ because of their ability to float with the currents. They have become a weed in many areas of Australia, choking creek banks.

The second is the Common Coral Tree (Erythrina x sykesii) seen predominantly along many of our creeks, and also in public parks. It is a hybrid so thankfully does not produce seeds, but spreads readily vegetatively. Logs, branches and even twigs readily regrow. The species also coppices and suckers. The wood is very weak, breaking easily, thereby spreading. Thankfully Newcastle lost many of these in the major storms of recent years, however those that fell over and remained on the ground have now formed huge coppices. They have nasty thorns, a prick from which quickly becomes infected if not treated.

Noisy Miners are one of the few native birds to have become serious pests in their own country. They force other native birds from areas they have taken over including suburban gardens and Eucalyptus woodland habitat. In doing so they damage and potentially destroy it by upsetting the balance between flora, insects and other fauna. To compound the damage, some birds like the Grey-crowned Babbler and Regent Honeyeater whose habitat Noisy Miners have usurped, are rare or endangered.

Another concern is that the Noisy Miners may not be eating the range or numbers of insects previously consumed by the displaced birds. This has the potential to lead eventually to the death of trees from insect damage, and the loss of whole woodland communities of plants and animals.

Hot wind and wrong names

I enjoyed this post from the Two-Fisted Birdwatcher, as he says “When the wind is blowing out of hell, you get pissed about little things.”

Newcastle, in August, is the time of the cold wind. Icy south-westerlies that bring with them a chill straight from Antarctica. Walking is difficult, holding a telephoto lens still, an impossibility.

You can get pissed about little things when the wind is blowing from the south pole, too.

Tarro Off-leash Area

After two months of almost daily rain all of the parks are waterlogged, not so great for dog walking (or at least for the dog-walker, the dogs enjoy the chance to get muddy) but the ibis and egret are taking advantage of the new food source.

The lone white ibis amongst the flock in flight did have a good number of companions on the ground, however I concentrated my photographic efforts on trying to catch the straw-necked ibis just as the sun picked up the iridescence in their feathers. A slight shift in angle and the birds were a uniform dull black.

Iridescent colours are found in a broad range of species from tiny marine animals to insects and birds. The flashing gorgets of the hummingbirds I was trying to capture in Orange County, and the brilliant sheen of the hibiscus beetles that fascinate me when they arrive each year en masse, are examples of iridescence.

Iridescence appears to play an important role in communication between animals of the same species, especially in sexual selection. A growing number of studies suggest that iridescence plays an important role in mate choice. But iridescent colours may also help animals avoid predation, providing camouflage by breaking up the bodies outline, or producing bright flashes of colour that might briefly startle a potential predator. Iridescent colours may also serve to warn predators of the unpalatability of potential prey items. Iridescence may also have non-communicative functions such as enhancing vision, repelling water or strengthening tissue connections.

With the exception of bioluminescence, all animal colours are produced by one of two primary mechanisms, or by a combination of these mechanisms: (i) pigmentary coloration and (ii) structural coloration. Pigmentary colours are, as you might guess, produced by pigments that absorb certain wavelengths of light. Structural colours are produced by the physical interaction between light and the variations in the tissues of some animals, which lead to light being refracted in different ways. Structural colouration can be produced by interference, diffraction or scattering of the light.

Iridescent colours are by definition highly directional. Changes in viewing position can dramatically alter the appearance of iridescent colours, producing considerable changes in hue, intensity or both.

Iridescence: a functional perspective Stéphanie M Doucet1, and Melissa G Meadows J. R. Soc. Interface 6 April 2009 vol. 6 no. Suppl 2 S115-S132