Kaitorete Spit: An Overlooked Gem

Earlier this week, my daughter and I hiked onto the Banks Peninsula from Birdlings Flat. The walk afforded us gorgeous views of Kaitorete Spit.

Kaitorete Spit is only about 6000 years old, but is an important natural and cultural resource. Te Waihora / Lake Ellesmere, formed by the spit, is home to or visited by 166 species of birds and 43 species of fish which support commercial fisheries, recreational fishing and hunting, and traditional food gathering. In spite of its harsh, exposed environment, Kaitorete Spit is home to a remarkable number of threatened plants and animals, including pīngao (a native sand sedge prized for weaving), a flightless moth, and the katipo spider. A variety of lizards also flourish on the spit. The lake and spit have been important sources of food and fibre for Māori since they arrived in the area. Fragments of the oldest known Māori cloak were uncovered on the spit, dating to around 1500 AD, and many other signs of early Maori use of the spit have also been found there.

In pre-European times, Māori used the spit as a convenient highway as they travelled up and down the island. Unfortunately, the shifting gravel of the spit and the regular opening of the lake to the sea mean the spit isn’t passable in anything but the most capable of four-wheel drive vehicles. Today, travellers make the long trek all around the lake, so our home near the pointy end of the spit is a 40-minute drive from Birdlings Flat, just 25 km away on the fat end of the spit. But I’m happy to leave the spit to foot traffic—it helps protect the unique plants and animals that live there.

On a windy, wet day, Kaitorete Spit is a miserable, exposed place to be, but visit it on a warm sunny day, and you’ll see why it is an overlooked gem.

Nursery web spiders

The nursery web spider (Dolomedes minor) is one of New Zealand’s larger spiders, in spite of it’s species name. At this time of the year, it’s also one of the more visible spiders, or at least its webs are.

Nursery web spiders don’t use webs to catch food. Instead, they use their silk to create shelters for their eggs and newly-hatched young. These shelters are visible in late summer and autumn on the tips of shrubby plants, especially gorse.

The female spider can sometimes be seen hanging around the web during the day. In fact, if she’s nearby, its hard to miss her, with a body nearly two centimetres long, and a leg span reaching six centimetres.

The nursery web isn’t the only care the nursery web spider gives her young. Until the spiderlings are near to hatching, she carries the egg sac with her to protect it. The young hatch out inside the nursery web, staying within the web’s protection for about a week.

The spiderlings disperse by ballooning—they let out a strand of silk until the force of the wind blowing on it is greater than their own weight, and then they float away on the end of the thread to a new home.

Like other members of the genus Dolomedes, the nursery web spider is an ambush hunter, chasing down its prey on foot. But most other Dolomedes do this exclusively on or in water, whereas the nursery web spider hunts on land as well as water, eating a wide range of invertebrates.

Belated Poetry Day

I missed World Poetry Day last week, so here’s a belated poem in honour of the day, inspired by the little spider who has built its web over the kitchen window.

David and Goliath

Honeybee caught
In a spider web
Buzzes murder to
All eight-leggers,
Stinger stabbing at
Offending silk.

Alerted,
Out rushes
The tiny spider,
Dwarfed
By its angry prey.

Dart in,
Avoid the sting,
Dart out.
Throw silk with
Frantic hind legs.
Tangle wings, tangle legs.
Dart in.
Avoid the sting.
Bite.
Dart out.
More silk.
More silk.

Bee’s wings are stilled
Though she still buzzes
A warning,
As though through
Gritted teeth.

More silk.
More silk.
Dart in.
Bite again.
Dart out.

The bee’s movements slow.
Abdomen goes slack.
Legs twitch once.
Twice.

More silk.
More silk.

David slays Goliath.

Green Orb Weaver

This year has apparently been good for the green orbweb spider (Colaranea viriditas); I usually see them only rarely, but I’ve run across quite a few this summer.

These beauties are pale green with a kelly green leaf-shaped mark covering the abdomen.

As the name implies, these spiders make orb webs—the spiral-shaped webs everyone’s familiar with. Though they’re primarily nocturnal, I’ve regularly seen them hanging out in the middle of their webs during the daytime (often snacking on an insect). These sharp-looking spiders apparently like a tidy web; they rebuild their webs nightly, and the webs are always as attractive as their residents.

The green orb weaver’s main predator is the native potter wasp, which paralyses the spiders with a sting and stuffs them into its nest for its larvae to feed on. However, the green orb weaver appears to be better at hiding from potter wasps than the non-native Australian orb weaver (at least on our property). Earlier this summer, the potter wasps decided that the screw holes in the bottom of the dining room table were perfect nest holes—every one of the dozens of orb weavers they crammed into the table was an Australian orb weaver.

I enjoy finding these little green gems in the garden. They’re as beautiful as they are helpful.

How To Eat a Whale

Melinda Mae took eighty-nine years to eat a whale, according to Shel Silverstein. How’d she do it? “…she started in right at the tail.” and “She took little bites and she chewed very slow, / Just like a good girl should…”

This morning I found this adult female white-tailed spider on my office deck. I don’t know what killed her—she’d dragged herself about 20 cm across the deck oozing hemolymph before succumbing to whatever it was—but by the time I saw her, the ants had found her.

At first, they swarmed over her body, biting at her legs, tugging at hairs. I looked closely with a hand lens—they’d made not a mark on her exoskeleton. Melinda Mae was lucky whales’ skeletons are on the inside.

Eventually, the ants stopped swarming, and I assumed they’d given up eating their ‘whale’.

But a few hours later, I checked again and noticed an ant slip underneath the spider’s body. Another photograph revealed the spider was shrivelling.

Some of the shrivelling would be from dehydration, for sure. But as I watched, I saw a steady stream of ants slipping in under the spider, then slipping out again. Something had punctured her, killing her. The ants had found the hole and were using it to access the soft bits inside.

I expect these ants will accomplish their task much more quickly than Melinda Mae did, but then, they’re working as a team.

So how do you eat a whale?

Well, if it’s got an exoskeleton, the answer is, from the inside out. And if you want to finish before you grow old, get some friends to help.

Playing with Spiders

If you’ve read my blog for any length of time, you’ll know I love jumping spiders. I’m not alone. In fact, I know people who, in general, can’t stand spiders, but who are nevertheless fond of jumping spiders.

I think part of the reason people like jumping spiders is that they are such visual animals. Like us, they navigate their world using visual cues. They turn to watch something pass by. They walk around objects placed in their path. They react to stimuli in a way we can understand.

The other day, a jumping spider on the computer screen began stalking the cursor as though it were a tasty fly. My husband began to play with the spider in much the same way we dangle a string for the cat. It was terribly cute. I know the cat understands it’s a game, but I doubt the spider did. I’m sure it ended up frustrated it couldn’t catch that little dancing arrow.

Orb Weavers

2016-10-24-13-39-42Weeding can be tedious, miserable work. Hard on the back, hard on the hands, and downright painful in much of my garden, where nettles and thistles grow exuberantly.

But there are some perks. Weeding brings you close to the vegetation, and gives you a chance to see things you might otherwise miss.

Today I was treated to two native orb weaver spiders—two of my favourite native spiders here.

The first was a bright green, round-bottomed Colaranea viriditas—the green orbweb spider. These little gems are supposedly quite common, but the bright green ‘leaf’ on their backs must do an excellent job of camouflaging them, because I count myself lucky when I see one. Unfortunately, my camera was nowhere close, and this one scurried away before I could catch it.

The second orb weaver I saw today is an expert at camouflage. You would be hard pressed to recognise it as a spider at all most of the time. This spider is in the family Tetragnatha—the big-jawed spiders. Tetragnathids have long thin bodies, and sit with their legs stretched out to the front and back, making the spider look like a small twig (I had to poke the one pictured here so it would stand up and look like a spider for the photo).

Tetragnathids are usually associated with wet areas, so I’m not sure what they’re doing in my dry yard, but they’re certainly common here. Though they’re hard to see, you can’t swing a sweep net in the tall grass without coming up with a few of them.

Both these spiders catch flying insects in webs shaped like the classic Halloween spider web—orb webs. Is it a coincidence that I saw them both today, a week before Halloween? Maybe they’re practicing for their big night.

Or maybe it was just my lucky day.