Spiders at Skyrail

Skyrail Nature Diary: September 2014

First time visitors to Skyrail and the Wet Tropics may be puzzled by a seeming absence of animal life. Most mammals in this region are nocturnal. Although there is an abundance of bird life, these creatures are difficult to observe in the soaring darkness of the rainforest. One fascinating order of organisms Skyrail guests may encounter are spiders. 

When we consider the top killers in the animal kingdom, creatures such as lions, tigers, great white sharks and killer whales immediately spring to mind. Although these apex predators are at the top of the food chain in a particular habitat, through sheer weight of numbers, spiders surpass these high-profile carnivores. There are few places where spiders are not found. In the house and garden of an average suburban house there may be many hundreds even thousands of spiders from different species; all of them use different methods to subdue and kill other creatures for their food. Spiders have mastered every imaginable habitat, ranging from the ocean, underground depths to deserts and, of course, tropical rainforests.

For those who turn squeamish at the mere mention of spiders there is no need to be concerned. By sticking to designated paths at the various Skyrail stations these incredible creatures may be observed safely. Humans are of no interest to a spider. Spiders are harmless if they are left untouched.

Three spectacular spiders that warrant the attention of those many nature lovers and eager photographers who travel on Skyrail are the St. Andrew’s Cross Spider, the Golden Orb Weaver Spider and the Jewel Spider.   

St. Andrew’s Cross Spider

These spiders are most often seen from October through to May. During this period they take advantage of building infrastructure to support their webs. Whilst on the platform at Red Peak, guests should take time to look at the station’s ceiling, walls or balustrades. A white cross resembling that of its namesake on the flag of Scotland will alert guests to the presence of this spider. The spider itself, usually found in the middle of the ‘cross’ is unmistakable. Its eight legs are grouped into four diametrically opposed pairs. The spider’s abdomen is marked by a ‘rugby guernsey’ of horizontal stripes of alternating colours. 

Upon closer examination of the web, guests will notice that behind the X-shape, which is comprised of denser fluffy strands of web, lies a nearly invisible web constructed of extremely fine strands of silk: this serves to capture unwary insects. The highly visible cross that visually dissects the web serves to reflect UV light. The latter, whilst invisible to humans, attracts insects. As the spider is almost always located within this cross, the UV light it reflects may also confuse potential predators. 

Golden Orb Weaver Spider

 From December through to May, those who stretch their legs at Red Peak Mid-Station can hardly fail to notice the imposing bulk of the Golden Orb Weaver Spider. These showpiece spiders may also be seen at other cableway locations. Golden Orb spiders are conspicuous for their size. Their legs, which are black with golden bands, grow to ten centimeters, ensuring that the spider may reach a length of about 20 centimetres. A further give away as to the presence of the Golden Orb is its colossal web (sometimes spanning several meters) with its numerous strands of gold (these are at their most resplendent during sunny conditions).

Although their diet consists almost entirely of insects, Golden Orbs are opportunistic feeders. Small birds such as Silvereyes and finches will not escape the incredibly strong web of this species. In the event of a bird or even a young snake becoming ensnared, the Golden Orb subdues its prey by injecting venom. 

If you are close to the web, look out for a small red spider. This is the male of the species who is roughly one fiftieth of his spouse’s size. Also look out for other small spiders that resemble the male Golden Orb, but are not quite the real thing. These are likely to be female Dewdrop Spiders who are impersonating male Golden Orb Spiders in order to feed on scraps. The female tolerates these imposters as they serve as charwomen to safeguard web hygiene.

Jewel Spider

Whilst strolling along the boardwalk at Skyrail’s Red Peak Mid-Station, rich rewards come to those who take time to pause and carefully observe their surroundings. The exquisite Jewel Spider is always present in this area. However, due to its petite proportions (just under a centimetre in length) these aptly named spiders are often overlooked. Their gossamer webs may typically be seen at chest height near the edge of the boardwalk.

Those with capable zoom lenses are in for a treat! These diminutive arachnids are vividly coloured; varied patterns of yellow, red, black and white being typical. Jewel Spiders possess unique body shapes. Also known as Christmas Spiders or Spiny Spiders, Jewel Spiders have hard upper bodies, similar to a beetle’s carapace. Some are covered with protrusions that resemble spikes, others have slightly curved bodies resembling shields.

What is the purpose of these extravagant designs? These bright colours and unusual patterns serve to startle and deter predators.

These three spiders are a mere sampling of the rich abundance of spiders present in the rainforest of tropical Far North Queensland.

By Paul Elliott, Skyrail Ranger