Ant-ics

I am very ignorant about ants but have a “live and let live” policy, presuming them all to be indigenous creatures residing here long before I came along. Methinks there are at least three species here. The smallest kind, about 4mm long, collect seed for me (see post of 2^nd February 2011).

Then there are the medium-sized ones, 8 to 10mm long with a reddish head, which have a huge, inconvenient nest on the bare ground between my greenhouse and my potting shed. These nip any visitors not wearing shoes/boots (if I forget to give warnings), but their bite does not hurt much.This kind of ant have been busy over summer carrying Ruby Saltbush fruits (and are always very interested in my nail clippings when I clip them outside!)

Thirdly, scarily, there are the black Bull Ants which measure 20mm from front of face to pointed end of abdomen. I have been bitten by these on several occasions and each time the bite has hurt for days so I now avoid that part of the property.

Bull Ant antics, Newstead, 19th February 2012

This morning I noticed one of these Bull Ants on my verandah doing a strange kind of circling dance, with its hind legs up in the air. Was this a mating ritual? No, looking closer I figured out that the hind legs must be caught in a bit of spider’s web and the ant’s antics were merely attempts to escape. I was surprised that such a large insect, which could still move around a lot, could not release itself.

I couldn’t help thinking it looked quite exhausted, pathetic and desperate. I thought of the Robert Frost poem, A Considerable Speck (see ‘Reflections on Ecology’ section of this blog) and took pity on it. After taking these photos I got a ruler and chopped at the air above the tethered ant until it was set free from the invisible, super-sticky threads.

Bull Ant doing the 'Bamboo Dance' with a matchstick, 19th February 2012

According to the Australian Museum website there are 90 species of Bull Ants in Australia, all in the genus Myrmecia. If anyone can identify this one to species level, let me know!

Newstead Landcare Group will have a presentation on ants later in the year. Keep your eye on the ‘Events’ section of this blog.

A dam extravaganza

by Patrick Kavanagh

We’ve had a Little Pied Cormorant frequenting our dam recently and I thought I’d try to catch a photo of him. Birds were nowhere to be seen but as I sat by the dam I was able to see so much happening around me. There were myriad Blue Skimmer Orthetrum caledonicum dragonfly males, which from my reading on are the only ones of this species with the distinct powdery blue coating. Females are yellow and black, as are teneral males (having just emerged into adult form) but the latter are brighter yellow. The males were spending a lot of time chasing each other around the dam.

Male Blue Skimmer dragonfly.

The female Blue Skimmer.

Damselflies (which can be discerned from dragonflies because they fold their wings at rest) such as Eastern Billabongflies  Austroagrion watsoni and Aurora Bluetails were abundant amongst the water plants at one side of the dam.

An Eastern Billabongfly.

A male Aurora Bluetail.

Water Treaders (mesovelids) were skimming the surface of the dam and these mostly seemed coupled. Also more sedate in this area was a Scarlet Percher dragonfly and a Fishing Spider Dolomedes instabilis, which like the Water Treaders can skim across the surface of the water using surface tension to stay dry.

A pair of coupled Water Treaders.

A Fishing Spider on the floating pondweed.

In case I sound like I know what I’m talking about, I found Arachne.org and http://photos.rnr.id.au/ very helpful in identifying these species and can highly recommend a visit, as well as a visit to a dam near you.

Feasting on dragonflies

The Rainbow Bee-eaters along Cemetery Road are still feeding tunnel-bound nestlings, almost exclusively now on dragonflies. It must be a perilous life being a dragonfly – while these wonderful insects are themselves fierce predators they are easily caught by skilled hunters such as the Rainbowbird. This morning the birds seemed to be catching dragonflies at the rate of about one every five minutes or so!

Rainbow Bee-eaters with dragonfly prey, Cemetery Road Newstead, 31st December 2011.

According to one reference (Pywell, 1990) dragonflies may contribute up to 65% of the energy value captured by foraging bee-eaters – the insects seem to have become more important food as the young are close to fledging. Rainbow Bee-eaters are regarded as ‘sentinel-feeders’, sitting on a high perch and waiting for unlucky insects, such as dragonflies, bees, wasps and moths to pass within range. Generally they seem to be successful with at least 50% of their foraging attempts – a pretty good strike rate.

Returning to the perch after another successful feeding sally.

Another unlucky dragonfly!

Reference: Pywell, S.R. 1990. Unpublished. BSc (Hons) thesis, Monash University, Melbourne.

A question from Saide …

I received this email today from Sandon resident Saide Gray …

 

“My recent mystery is contained in the following photographs taken in the afternoon sun at Sandon in a patch of Heathy Dry Forest. While there is a hint on the Natural Newstead website as to the name of this creature, it appears to be slightly different to the one pictured.”

 

Imperial White, Sandon, November 2011. Photograph courtesy Saide Gray.

What Saide discovered is an Imperial White (also known as the Imperial Jezebel) Delias harpalyce. This butterfly is closely related to another local, the Wood White Delias aganippe. It’s a fascinating shot – the recently emerged adult is surrounded by empty pupal cases from which other adults have left. This species uses a number of mistletoe species as a host plant. Congratulations to Saide on such a great find!

 

A group of Imperial Whites amongst a cluster of spent pupal cases, Sandon, November 2011. Photograph courtesy Saide Gray.

 

The “Abundant Brown”

Some warm weather has produced an explosion in numbers of one of our familiar butterflies, the Common Brown Heteronympha merope. While this species is certainly abundant it seems a little harsh to christen it ‘common’ as it’s a very handsome addition to forest and woodland habitat! The Common Brown uses native tussock grasses such as a food plant. Recent research published in the journal Biology Letters suggests … “The mean emergence date for H. merope has shifted −1.6 days per decade over a 65-year period with a concurrent increase in local air temperatures of approximately 0.14°C per decade. We used a physiologically based model of climatic influences on development, together with statistical analyses of climate data and global climate model projections, to attribute the response of H. merope to anthropogenic warming.”

Female Common Brown, Muckleford State Forest, 23rd November 2011.

The male Common Brown has quite a different appearance.

The cascading effects of climate change on ecosystems are impossible to predict and the complex relationships between plants and animals such as the Common Brown Butterfly are just one example of a myriad of changes in our environment that we are witnessing.

Nice breeding record

The White-bellied Cuckoo-shrike Coracina papuensis is a typical bird of the box-ironbark country and our local area is one of its strongholds. Earlier this Spring I found a pair making a nest along Mia Mia Track, but subsequent efforts to find the nest were fruitless. I was pleased then this morning on a visit to the Rise and Shine to find a youngster being fed by one of its parents. The juvenile bird made a conspicuous begging pose with its neck craned forward and wings spread, enticing the adult to part with what looked like a caterpillar.

Juvenile White-bellied Cuckoo-shrike in begging pose, Rise and Shine, 31st October 2011.

Down the hatch!

Enjoying another morsel.

The return of Vanessa

Over the past few weeks I’ve started to see a few butterflies, some early emergents from last years bountiful breeding season. One species to make an appearance is the Australian Painted Lady Vanessa kershawi. I spotted this one enjoying some late afternoon sunshine on Gough’s Range.

Australian Painted Lady, Gough's Range, 5th September 2011

A view of the underwing pattern of the Australian Painted Lady

Nodding Greenhoods … easily overlooked

I have been noticing the profusion of orchid leaves for more than a month now, but with gloomy winter days walks in the local bush have been short and brisk and its easy to overlook the changes taking place. Nodding Greenhoods Pterostylis nutans are now starting to flower and they look fantastic!

Nodding Greenhoods, Muckleford State Forest, 4th July 2011

They will keep flowering for perhaps two months now so its well worth keeping an eye out for colonies – they tend to occur in groups, sometimes in the hundreds. Apparently this orchid is pollinated by fungus gnats and mosquitos, both belonging to the order Diptera.

Another view of the Nodding Greenhood colony

Thornbills and galls

I found this amazing gall infestation today in the Rise and Shine, on the leaves of a Long-leaved Box Eucalyptus goniocalyx. There are a variety of causes for these strange growths including insects such as parasitic wasps, fungi, bacteria and viruses. If you look closely most eucalypts are infected by galls and you can often find multiple types on the same tree. Wasp galls are particularly common, the adult wasp depositing the eggs inside the leaf where the gall forms around the developing larva. Remarkably, sometimes these larvae are themselves parasitised by other species of wasps!

Leaf gall infestation on Long-leaved Box, Rise and Shine, 29th May 2011

No doubt these gall forming wasps form an important part of the food web in the box-ironbark ecosystem, especially for birds such as the Striated Thornbill (pictured below). I spotted this one today moving as part of a mixed feeding flock that included a Scarlet Robin, Buff-rumped Thornbills and a White-eared Honeyeater. Striated Thornbills Acanthiza lineata can be identified from their close relatives by a number of features , especially the streaking on their rufous crown and ear coverts.

Striated Thornbill, Rise and Shine, 29th May 2011

Pin-cushion pollinators

Many native plants depend upon birds and insects for pollination. This leads to some interesting relationships that benefit both plants and animals. One native shrub flowering at this time of year is the Pin-cushion Hakea Hakea laurina. This species is indigenous, not to Newstead but south-western WA. Nevertheless it is an excellent source of nectar and pollen for native birds and insects, including another exotic, the European Honeybee. Late this afternoon a couple of New Holland Honeyeaters were feeding on the Pin-cushion Hakeas at Newstead Primary School, stoutly defending the flowers from their much larger relatives – Red Wattlebirds. Despite the size difference the smaller honeyeaters were pretty successful in driving off the wattlebirds whenever they intruded on the feasting.

New Holland Honeyeater and Honeybee feeding on Pin-cushion Hakea, Newstead, 17th April 2011

Enjoying the sugary feast!