Sunday, March 22, 2015

Some Bothersome Browns

The R J Chambers Flora and Fauna Reserve is located at Pakenham Upper, just south of Emerald, just east of Cardinia Reservoir and just north of another of my favourite locations – Officeworks at Pakenham!

The reserve consists of several forest communities that contain a wide range of trees, shrubs, grasses and herbs.  For my first visit recently I did a simple reconnoiter and quickly made a mental note to put the place on my list of sites to visit in the spring.

With a stiff breeze blowing under a dull sky, I was pleasantly surprised to discover quite a number of butterflies flitting about across the tracks, often taking advantage of the tiny patches of sunshine that occasionally struggled through the cloud cover and tree canopy.

The Southern Browns and Southern Xenicas always pose an identification problem for me and I admire people in the field who can spot the difference between some of these species with the naked eye. I hope I’ve got these right?

Common Brown

The females of this very common butterfly are capable of delaying their egg laying until conditions are just right - for periods as long as several months. Apparently there is a causal link between the early emergence of the Common Brown Butterfly and global warming, (ABCScience ext link).

Painted Lady

Apparently this species can perform mass migrations. It was reported in 1889 that a Painted Lady migration blackened the sky and caused trains to lose traction when they tried passing over them while they rested on the rails!

Banks’ Brown

This is a late summer to early autumn species that can be locally abundant. In Victoria it occurs mostly in the ranges and foothills of the central and eastern regions of the state.

Ringed Xenica

I find this butterfly one of the few of the ‘browns’ that appears to be more striking with its wings closed rather than the usual open-winged position. With wings open it is easy to confuse this butterfly with the Common Brown. Supposedly the Ringed Xenicas like cooler wetter gullies but on this occasion I was finding them dry hilltops as well.


Wednesday, March 18, 2015

Bell Miners and Dieback

A favourite nearby short walk takes me through a small patch of bush that is occupied by Bellbirds or Bell Miners.

Bell Miners are an aggressive native honeyeater and are closely related to that other aggressive species, the Noisy Miner. Both birds spend an inordinate amount of time chasing away other species of insectivorous birds – in fact I have seen Noisy Miners chasing herons!?

Bell Miner in mid-call, see link below.

The Bell Miner feeds on the lerps on the leaves of eucalypts. Lerps are the crystallized structure of honeydew produced by sap sucking insects called psyllids.

Sugary secretions or lerps.
A tiny psyllid is just visible.

Much work is being done on the dieback effect in some areas produced by the loss of canopy foliage due to psyllid attack. One theory directly connects the Bell Miner. The birds chase away the insectivorous species to protect their ‘lerp zones’, so allowing the psyllid numbers to increase beyond normal proportions. The resultant loss of canopy foliage puts the trees under stress and may eventually cause them to die.

Of course, as the trees die in one area the psyllid population is reduced and the Bell Miner numbers will reduce by attrition or by migration. Studies are underway in many places to determine if the trees might recover naturally and so the whole thing becomes cyclical.

Bell Miner Associated Dieback WorkingGroup.
Australian Museum, The Bell Miner.
Birds In Backyards, The Bell Miner call


Tuesday, March 17, 2015

Nangara Note - March 2015

Old Man’s Beard, Goatsbeard, Mountain Clematis, Austral Clematis and Traveller’s Joy are a few of the common names for Clematis aristata that I’ve come across. All seem pretty appropriate. 

There are two significant climbers in Nangara Reserve, Old Man’s Beard and Wonga Vine. Clematis aristata is a common and widespread climber found in wet and dry forest situations and is an Australian endemic. The creamy-white star-shaped flowers are eye catching against the dull green-grey backdrop of eucalypt and other foliage.

At the end of flowering, the fertile flower-heads of the female plants produce the silver fluffy seed-heads that give rise to the ‘beard’ description of the plant, (arista is Latin for bristle), and this is when the plant really lights up the bush.

It isn’t hard to see the principle of seed distribution in this case. In fact just as I finished getting this next shot a breath of wind took these seeds and they floated off to fresh fields and pastures new!

Hard Water-fern
The Hard Water-fern, (Blechnum wattsii), can be very abundant and vigorous in its growth. Hard Water-ferns mostly grow in the ground but sometimes can be found, like this one below, climbing the trunks of Soft Tree-ferns. Some references state it can grow in extensive colonies, others suggest its habit is more as an individual plant.

The new fronds of the Hard Water-fern are bronze coloured and the fertile pinnae are distinctly narrower. The bottom pair of pinnae are barely shorter than the rest and the stipes can have dark scales at their base.