A tree of cultural significance

A couple of weeks ago I made a very short trip to Sydney to visit Prue, whom I had met on the subtropical rainforest ecology course in Maleny last year. She was about to embark on a camping trip in Tasmania, and I wanted to catch up before she left. I squeezed the trip in between two jobs – sorry to other Sydney friends whom I didn’t have time to visit. This time of year is always busy for me with textbooks, so I might get down again in winter when work slows down.

Prue lives in the Blue Mountains, west of Sydney, and is a keen bushwalker and botanist. It was great to go on some short walks with her off the Bell’s Line of Road side of the Grose Valley. I’d done a fair bit of bushwalking from the Katoomba side when I lived in Sydney because it was easy to catch a train up and walk from the various railway stations to the walks.

Grose Valley

One of our walks was the Waterfalls Walk at Mt Wilson. Sharp-eyed Prue spotted this tree (Eucalyptus cypellocarpa), and we immediately grasped its possible significance.

Aboriginal carved tree

I did some research on the interwebs and there were three possibilities: (1) a natural scar; (2) a marker tree made by Europeans back in the day (or later); or (3) an Aboriginal carved tree. There are a lot of sites of Aboriginal heritage in the Blue Mountains (see Assessment of Aboriginal Cultural Heritage Values) so I wondered whether this tree had been recorded. There have been a lot of surveys up there, so I thought it highly likely.

First port of call was friend Betty, a retired botanist and former education officer at the Royal Botanic Gardens in Sydney. She thought the shape was too regular to be a natural scar, and suggested it could be a mark made by early explorers tracking their path, or maybe an old land division or fence line. The remains of a famous “explorers’ tree” at Blackheath (also in the Blue Mountains) have been documented in detail here.

So I got on the research trail (which I enjoy). First was an email to the Australian Museum in Sydney. I figured they might have someone who knew about that tree. Turns out not, but they suggested I try the Royal Botanic Gardens. Turns out not, but they suggested I try the National Parks and Wildlife Service in Blackheath. The trail got warmer then, because they have an Aboriginal Heritage Conservation Officer. But she was on leave. (Ain’t research fun!) When she got back from leave, she replied that it appeared to be a tree of Aboriginal cultural significance – eureka! But she had to check earlier surveys and would get back to me when she found out. That’s where we are at the moment, and I will update when I find out. If Pure and I saw that tree, surely someone else would have documented it. It’s not exactly hidden.

Another place of Aboriginal cultural significance is the Emu Cave. It is not marked on the road and I am not saying where it is, but it was an impressive place to see. I would never have found it on my own, so thanks, Prue. The walls are covered with carved emu footprints. Sometimes I look at this photo and it seems like the footprints are raised, but they are actually carved into the rock. Other times I look at it and they look engraved. Weird!

Emu footprint carvings, Emu Cave

According to Attenbrow’s 2010 book, Sydney’s Aboriginal Past : Investigating the Archaeological and Historical Records:

a radiocarbon date was obtained from a mineral crust formed over an engraved bird track, one of 172 recorded engraved figures in the [Emu Cave] rockshelter. This crust provided a minimum age of 1790 years old for the engraving, though the authors [of an unpublished report in 2003 = Taçon et al.] contend they may have been made hundreds or thousands of years earlier.

I do like finding archaeology but being in places of significance to an ancient but living culture is different to digging up your average field in, say, Britain, where the culture of the artefact makers has long gone. ‘Aretfact’ seems an inappropriate term to describe these footprints. Much more respect is involved and you feel a connection to the people who made the thing you are looking at because they are, in a sense, still around. At least I do.

Prue’s house is on 9 acres, which she is successfully restoring to rainforest. On a short walk around one day, we were privileged to see Australia’s largest owl, the powerful owl (Ninox strenua). Ours didn’t have a possum in tow, like the one below. Yum!

Photo by Moonlight0551, Wikimedia Commons

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

We also saw the eyeshine of what Prue assured me was two greater gliders, Australia’s largest gliding possum. They certainly didn’t move like common brushtails. They were too far away up a very tall eucalypt to see properly. Here’s one she saw earlier at her place.

Greater glider (Petauroides volans); photo by Prue Gargano

They are listed as vulnerable. I list them as cute and furry, too.

From Prue’s balcony on a clear day, you can see the Sydney skyline.

Sydney at a distance

It’s a completely different vista to when I lived in the very centre of that city. Thanks to Prue for her hospitality.

Meanwhile in Cape Town … the spider invasion

Friend Jane says there’s been an influx of Nephila fenestrata, the black-legged golden orbweaver, into suburban Cape Town. Where she lives, the strong webs of these spiders are being strung across walking paths as well as gardens. Luckily, it’s easy to gently reposition them manually, and the spiders aren’t disturbed.

Nephila fenestrata female, ventral view; photo by Jon Richfield, Wikimedia Commons

Female, dorsal view; photo by Jon Richfield, Wikimedia Commons

She says:

It’s only recently that they’ve decided to go suburban but they seem to be in many gardens now, although not in quite such rampant numbers as mine – people are beginning to come and take pictures.

These spiders are native to southern and eastern Africa. You can see a photo of the large and strong web at Biodiversity Explorer, which says:

Nephila fenestrata, the black-legged nephila, occurs over most of South Africa, excluding the arid central and western regions, and is the only species of Nephila to occur in the Western Cape. Since 2002 this species has crossed over the Hottentots Holland mountain range and is now the most commonly seen orb-web spider on the Cape Peninsula. It can be seen from January till the end of June or even to the end of August, usually in forested areas or near areas with trees allowing for suspension of their large orb-webs. In Kirstenbosch and Newlands Forest one can easily see 30 or more of these spiders on a walk.

Wikipedia says of Nephila in general:

The webs of most Nephila spiders are complex, with a fine-meshed orb suspended in a maze of non-sticky barrier webs. As with many weavers of sticky spirals, the orb is renewed regularly if not daily, apparently because the stickiness of the orb declines with age. When weather is good (and no rain has damaged the orb web), subadult and adult Nephila often rebuild only a portion of the web. The spider will remove and consume the portion to be replaced, build new radial elements, then spin the new spirals. This partial orb renewal is distinct from other orb-weaving spiders that usually replace the entire orb web. In 2011 it was discovered that the web of Nephila antipodiana contains ant-repellent chemicals to protect the web.

Typically, the golden orb-weaver first weaves a non-sticky spiral with space for two to twenty more spirals in between (the density of sticky spiral strands decreases with increasing spider size). When she has completed the coarse weaving, she returns and fills in the gaps. Whereas most orb-weaving spiders remove the non-sticky spiral when spinning the sticky spiral, Nephila leave it. …

The circular-orb portion of a mature [US] N. clavipes web can be more than 1 metre across, with support strands extending perhaps many more feet away. In relation to the ground, the webs of adults may be woven anywhere from eye-level upwards high into the tree canopy. The orb web is usually truncated by a top horizontal support strand, giving it an incomplete look.

Adjacent to one face of the main orb there may be a rather extensive and haphazard-looking network of guard-strands suspended a few inches distant across a free-space. This network is often decorated with a lumpy string or two of plant detritus and insect carcasses clumped with silk. This ‘barrier web’ may function as a kind of early-warning system for incoming prey or against spider-hunting predators, or as a shield against windblown leaves; it may also be remnants of the owner’s previous web. At least one reference explains the suspended debris-chain as a cue for birds to avoid blundering into and destroying the web.

Indeed, some webs have captured small birds, but no one’s found that the spiders actually eat the birds.

I’m particularly fond of the species name for this spider as it is a Latin version of my surname 🙂

Jane says it’s on for young and old in a small patch in her garden:

I would never have thought 4 square metres could have held such variety. I was out in front chatting to my neighbour about how one of the nephila orbs had caught a gecko lizard and sucked out all its juices, leaving the dehydrated corpse in the web, which she’s still fiercely guarding. ‘Look,’ says Louise, and lo and behold behind that orbweaver a praying mantis is stalking a white butterfly – such drama – but the butterfly did escape.  Some butterflies have flown smack into the orbweaver’s curtain, but a surprising number manage to avoid it. A gorgeous black bumble bee managed to duck and dive, as do most of the damsel flies. Mind you, a little white eye bird (a tiny passerine) nearly copped it, but seemed to have rebounded off the web and got stuck in one of my sheets, which was hanging out to dry. I come indoors from the dazzling display to make a cup of tea and a triumphant jumping spider staggers across the kitchen counter with its trophy, a fly bigger than itself. Go spider! I’m having to move strands of orb nearly every morning or I’d be trapped in the house – great colonisers, these ladies.

Dwarf sea hare at Woody Head

Thanks to Peter Scharf for the photo of this dwarf sea hare, Aplysia parvula, taken while he was snorkelling off the reef at Woody Head in early January 2017.

Dwarf  sea hare, Aplysia parvula; photo by Peter Scharf

The Sea Slug Forum gives information about this species, plus a photo of a juvenile with the shell visible. The mantle grows over the shell as the animal matures. These sea hares, vegetarians all, are small, up to 6 cm (just over 2 inches) in length.

Another goody at Woody!