Brushtail Possum

Brushtail Possum

By: Michael Fox

At night in Mt Gravatt Conservation Reserve you see the bush with new eyes … and eyes are what you see.

I knew the eyes of many animals seem to glow in the light of a torch so I was not surprised to find the orange glow of a pair of eyes, was a Brushtail Possum Trichosurus vulpecula, prowling around.

What has been really surprising though are the dozens of sparkling lights on the ground – Wolf spiders Lycosa species. In torch light the eyes of these spiders look like tiny diamonds the reflection is so sharp. When I first saw this the light seemed to flash like Fireflies but that effect was just caused by movement of my torch as I approached. When I held the torch steady the light from the spiders’ eyes was also steady.

Garden Orb Weaver web

Garden Orb Weaver web

Apparently Wolf spiders are one a small number of spider species that have a layer of light reflecting crystals, tapetum lucidum, right behind the retina of the eye. This reflective layer improves night vision for these nocturnal hunters by bouncing light back to the retina.

It is interesting to see the different shape, colour and intensity of the light reflected by the eyes of different species. The Wolf spiders have small crystal clear light, while the Brushtail’s eyes were larger, wide apart and the reflection was softer. Toads have similar reflecting eyes and I am getting good at spotting them at a distance, keeping them sitting still in the light, then scooping them up in a plastic bag ready for freezing. I have removed ten toads from the Reserve from my last couple of night walks.

Garden Orb Weaver spiders, Eriophora transmarina, are another night time creature making huge webs at night which are cleaned up in the morning before they retreat to spend the day in a leaf shelter. This particular spider likes to make a web across the fire trail in the Fox Gully Bushcare site. The web spans an amazing 5 to 6 metres to bridge the trail. A large bug or something has already flown straight through this web so I ducked under to avoid any more damage to this extraordinary construction.

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Tent spider webs covered in morning dew Photo: J. Fox

By: Michael Fox

I have spent thousands of hours walking and working in Mt Gravatt Conservation Reserve and I am still seeing things I have never noticed before. The misty mornings air this morning showed dozens of small tent spider webs in communities in the shrubs. The moisture on the webs this morning made for great photography. When I just checked this afternoon these webs are all but invisible.

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Dome Tent Spider - 29 March 2014

Dome Tent Spider web Photo: J. Fox

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I could not find any spiders to photograph however these webs are almost certainly made by Dome Tent Spiders Cyrtophora moluccensis which I have found in the Reserve. This larger web shows the amazing structure with a collection of something, possibly eggs, at the peak.

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Dome Tent Spider - close - 29 March 2014

Close up of Tent Spider Web Photo: J. Fox

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A close up photo shows the neat matrix of thread and the tension cables holding the shape just like a circus bigtop.

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Cyrtophora moluccensis - Jan10

Dome Tent Spider – Photo: M. Fox

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Dome Tent Spider I photographed at Mt Gravatt Campus in 2010.

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Garden Orb Weaver web - 29 March 2014

Garden Orb Weaver web Photo: J. Fox

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We also found this huge beautifully made web, of the Garden Orb Weaver Eriophora transmarina, stretched out between two trees. Another Garden Orb web had stretched right across the track earlier in the week but without the dew droplets it was virtually invisible and didn’t survive as I walked straight into it.

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Gardern Orb Weaver - 29 March 2014

Garden Orb Weaver Photo: M.Fox

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Garden Orb Weaver females build these huge webs as night and usually consume them again in the morning before hiding in a retreat of leaves and twigs. So it was a bit of a surprise to not only find the web still in place this afternoon but also find the owner sitting in the centre. The web had also caught dozens of flying ants during the day.

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Spider web - 29 March 2014

Mysterious web on ground Photo: M. Fox

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Another first for me is finding a large number of these webs on the ground which must be there everyday but only noticeable with the heavy dew. These webs are very fine with multiple layers which makes them look like very fine muslin fabric.

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Spider web - hole - 29 March 2014

Entry hole in web Photo: M. Fox

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I was not able to get a photo of the tiny spiders living in these webs as they quickly disappeared into the hole built into each web.

Any ideas on what spider species makes these fascinating webs?