New Zealand

5 Simple Things You Can Do to Help Conserve Species

/ Robinne Weiss / Leave a comment

It’s Conservation Week here in New Zealand. Fittingly, one of the kōwhai trees we planted years ago has chosen this week to flower for the first time.

Conservation week is a good time to talk about backyard biodiversity. I’ve blogged more than once about biodiversity issues. It’s a topic near to my family’s heart, and something we strive to improve all the time.

Our yard is, unfortunately, home to a wide variety of non-native weeds, but it also sports native plantings (and even a fair number of native ‘weeds’). Here are just a few of the simple things we’ve done to improve the habitat value of our back yard for native organisms. You could do these, too.

  1. Plant natives instead of non-natives. Here in New Zealand this is especially important, but it’s a good rule of thumb wherever you live. Native vegetation will best support native wildlife, because they evolved together. Choose plants that provide food and shelter for local wildlife—shrubs with berries for birds and lizards to eat, dense grasses that provide hiding spots for invertebrates, and flowers that provide food for insects.
  2. Create lizard refuges. A pile of rocks or a stack of broken terracotta pot shards makes a nice refuge for lizards—the rocks and terracotta warm up in the sun, making a convenient basking spot for the lizards, and the little cracks between ensure a quick, safe get-away when predators appear.
  3. Just add water. Birds, insects, and other animals all need water to survive. Provide a bird bath, a small pond, or an attractive water feature, and you’ll find many more animals drawn to your yard.
  4. Kill non-native predators. Less important in some places, but here in New Zealand, protecting native birds and lizards requires controlling invasive predators. Trap out possums, stoats, and rats to give native birds a chance to nest successfully. Put a bell on your cat and keep it indoors around dusk and dawn when the birds are most vulnerable.
  5. Learn what you’ve got. No matter how small, your yard teems with species. Look closely, and you may be surprised at the diversity. Though our yard tends to be quite dry, we’ve discovered half a dozen species of moisture-loving slime moulds on the property. Once you know you an organism is present, you can tweak your planting and maintenance to protect and encourage it.

And that brings me back to the kōwhai tree, finally blooming. It’s not enough, yet, to attract bellbirds or tūī, across the vast stretches of agricultural land between us and the nearest populations, but someday, our kōwhai and flaxes, along with the neighbours’, may very well support a healthy population of native birds. All it takes is for each of us to care for our own backyards, and collectively we can improve the habitat for all our native species.

Sticky Feet! The Eucalyptus Tortoise Beetle

/ Robinne Weiss / Leave a comment

Hanging up the laundry this morning, I found this lovely beetle making its way along the washing line. It’s a eucalyptus tortoise beetle (Paropsis charybdis). I see them occasionally, but with only one eucalyptus tree in the yard, they’re not common.

I’m quite fond of tortoise beetles. This one isn’t much to look at, but many species are sparkling gold, and my first glimpse of them, as a kid, was a truly magical experience that I’ve never forgotten. What tortoise beetles have in common is their domed tortoise-like shape.

Their shape, combined with some pretty awesome feet is what keeps them safe.

Tortoise beetles have wide pads on their feet (this one obligingly sat on a clear surface and showed its feet under the microscope). The pads are covered densely in short hairs, like the bristles of a toothbrush. Each hair is moistened by oil, which helps it stick to the waxy surfaces of leaves in the same way two wet drinking glasses stick together if they’re nested. The oil bonds to both surfaces and acts as glue. When disturbed, the tortoise beetle presses its feet against the surface, employing as many as 60,000 sticky bristles (about 10 times more than other beetles have) to keep it attached. These sticky feet, combined with the dome-like shape make it difficult for predators to dislodge the beetle.

Entomologist Tom Eisner performed a series of elegant experiments with the palmetto tortoise beetle, attaching weights to the beetles to see how much force they could withstand before being pulled off a leaf. He found they could hold up to 240 times their body mass. Those are some seriously sticky feet!

So if their feet are so sticky, how do they walk? Eisner showed, by looking at palmetto beetle footprints on glass, that when they walk, they don’t let all the bristles on their feet touch the surface. Their full adhesive power is only deployed for defence.

I don’t think anyone has tested eucalyptus tortoise beetle grip strength, but it’s definitely impressive. I popped this one into a narrow jar, and it never hit the bottom—it reached out with one leg, like some movie superhero, and grabbed the smooth wall of the jar, arresting its fall. Then, when I tried to get it out of the jar, it stuck like glue to the side. I had to slide a stiff piece of paper under its feet, prying them up one by one. It was obliging for the photo shoot, but when I tried to let it go, it stuck itself to the paper. It took a few determined nudges, but eventually I got it to the edge of the paper and it dropped off.

The eucalyptus tortoise beetle is not native to New Zealand, and is considered a pest in the forest industry here. Still, I have to admire the beetles’ sheer tenacity, and am willing to share my eucalyptus tree with them for the opportunity to see those sticky feet in action.

Ice and Fire

/ Robinne Weiss / Leave a comment

One of the things I like best about springtime here is the juxtaposition of hot and cold, especially in the high country. The sunshine is warm, but winter lingers in the shade. I’ve gone hiking in shorts and t-shirt through 15 cm of snow in past years.

This weekend, we didn’t make it up to snow, but there was spectacular frost on our little Saturday jaunt. Hiking up the shaded side of a hill, we were treated to glistening plants as the first rays of the sun hit thick frost.

In addition to the frost, we crunched over a lot of needle ice. Needle ice can occur when the soil temperature is above freezing, but the air temperature is below freezing. Liquid water rises through the soil via capillary action and freezes on contact with the air. As more water is drawn upward, the ice needles grow in length. They’re common in the high country in springtime, when warm sun heats the ground during the day, but the temperature drops quickly after dark.

Ice needles are more than just a curiosity. They’re a significant factor in soil erosion, because they often push soil upward along with the ice. This loosens the top layer of soil, making it prone to erosion by wind and water.

The air was cold on Saturday morning, and as we started up the hill, we were well-bundled. But like all good tracks in New Zealand, this one started off by going straight up. Between the climb and the sun, we were soon stripped to our t-shirts, enjoying the crunch of ice underfoot and the warmth of the sun overhead.

Quake Cities

/ Robinne Weiss / Leave a comment

The old hall, post-quake.

It’s September 4. The daffodils are in full bloom, and I feel compelled to talk about earthquakes.

Eight years on from our M7.1 quake, the local hall is finally under re-construction. Its brick walls cracked and bowed in the quake, and it spent several years propped up by timber, then was razed completely. The site sat empty until about two months ago, when the walls began to rise again.

It’s a common refrain here. The damage done by the M7.1 on 4 September 2010 and the M6.3 on 22 February 2011, and the 15,000 or so lesser quakes in between and after is still visible. In the city, the Christchurch Cathedral still sits behind ‘temporary’ security fencing, it’s face crumbled away, weeds growing along the tops of jagged walls. A block of High Street remains closed, broken buildings frozen as they were when the shaking stopped. Throughout the region, churches remain truncated, their spires still gone. One church is still operating from a large tent. Houses are still undergoing repairs, and bare sections abound.

On a recent visit to Wellington, my son commented that Wellington seemed like such an older city than Christchurch, though they are nearly the same age. But Wellington hasn’t had a big quake since 1855. In that 1855 quake, many buildings were destroyed, and after that, most homes were rebuilt using timber, in the Victorian style popular at the time. Those Victorian houses give many Wellington neighbourhoods the quaint atmosphere they have, even today.

In Napier, the city-defining quake struck in 1931. The rebuild of that city followed the art-deco style popular at the time. The city retains the art-deco character today, and has become a popular tourist destination for its architecture.

Christchurch’s look has been affected by the 2010 and 2011 earthquakes, just as Wellington and Napier have been. Brick and stone have been replaced by wood, steel and glass. The new Christchurch includes more art, more open space (though some of those open spaces are slated to be filled with new buildings … eventually). Perhaps some day, visitors to Christchurch will view it as a product of the architectural styles of the 2010s.

Shining in the Dark

/ Robinne Weiss / 1 Comment

Not much to look at in the light, but spectacular in the dark.

I’m a morning person. I’m rarely in bed past six o’clock, and am often up long before that. But I will admit that even I get tired of getting up in the cold and dark at this time of year.

Of course, sometimes the most amazing things happen before the sun is up.

Yesterday morning, I stepped into the chicken paddock feed ‘the girls’. It was still dark, with just enough starlight to see my way. I bent to tip a scoop of feed into their dish and froze.

Something glowed on the ground—the eerie glow of bioluminescence.

I’ve seen bioluminescence while feeding the chickens before—a tiny sea creature whipped up and blown in with a violent snowstorm—but this was different.

I flicked my light on and saw something pink glistening on the ground. When I tried to pick it up, I discovered it was the head of an earthworm.

A brightly glowing earthworm.

I couldn’t get it out of the ground in order to bring it in and identify it yesterday, but I took the spading fork with me this morning when I went to feed the chickens, and I collected a little glowing earthworm from where I’d seen one yesterday.

I already knew that at least one of our native earthworms is bioluminescent—Octochaetus multiporus, which I’ve blogged about before. But O. multiporus grows to enormous size, and I’ve never found any worms in the garden that match its description. Doing a little research, I found that bioluminescence is quite widely employed by earthworms, presumably as a deterrent to predators.

Most earthworms produce light in much the same way that fireflies do, with a chemical known as luciferin that reacts with oxygen-containing compounds in the presence of luciferase to create light.

So, what species is my little glowing worm? There are about thirty New Zealand species within the genera where bioluminescence has been recorded. I’ve found record of only two of those species being bioluminescent: O. mulitporus and Microscolex phosphoreus, a small worm considered native here, but widely distributed around the globe. My best guess is that it’s M. phosphoreus, but data on that worm’s distribution in New Zealand is almost nonexistent (it’s been recorded from only one location), and data about any earthworm in New Zealand is scanty. Perhaps my worm is M. phosphoreus, but it might also be a worm in which bioluminescence hasn’t been recorded. After all, most people aren’t out in the garden at night to notice glowing worms.

Hopefully, I’ll be able to have the worm identified by an expert. If not, well, I still think it’s the coolest thing I’ve seen in a long while! And I won’t be grumbling about getting up in the dark and cold tomorrow.

Nifty Nematodes

/ Robinne Weiss / 2 Comments

Nematodes under the microscope. Image: CSIRO

A week or so ago, during a writing break, I spent some time peering through the microscope in my ongoing quest to find tardigrades in our yard. I had no luck on the tardigrades, but as usual I came across lots of fabulous little invertebrates.

Perhaps the most common creatures under the microscope were nematodes. No surprise, really. Nematodes are the most common multicellular organisms on earth; there are several million in every square metre of soil here in New Zealand. Most are tiny (less than 3 mm). But not all are so minuscule; the largest, a parasite of sperm whales, can grow to 8 to 9 metres in length.

Nematodes can be free-living or parasitic on animals and plants. In fact, most animals (vertebrate and invertebrate) and plants are host to at least one specialist nematode parasite. Free-living nematodes eat bacteria, fungi, or small invertebrates (including other nematodes).

As you can imagine, nematodes are of huge importance ecologically, economically, and from a human health perspective.

Humans are host to about 60 species of nematode. Diseases caused by nematode parasites in humans include: ascariasis (an intestinal infection that can cause growth retardation and a variety of intestinal and other problems), hookworm (causing anaemia and developmental problems),filariasis (a lymph infection, causing swelling in many body parts, including elephantiasis of the legs), trichinosis (an intestinal infection causing diarrhoea, fever, and other symptoms). Many nematode infections are asymptomatic, and it’s likely most of us play host to nematodes for most of our lives.

The control of nematodes is important in agricultural systems. Worldwide crop loss to nematodes is estimated to be 12.3 percent of production (US$157 billion). Livestock and domestic pets are also susceptible to nematode infection, and millions of dollars annually are spent to control nematode infections including lungworm, hookworm, trichinella, heartworm, and many others.

But nematodes aren’t just doom and gloom. They’re integral parts of natural ecosystems, and critical components in nutrient cycling (especially nitrogen) and food webs. They regulate the bacterial population in the soil, and provide food for many organisms (including some fungi, which catch nematodes with lassos, like tiny cowhands). They can be useful, too. Some insect parasitic species are bred to help control insect pests—a highly species-specific, organic control method.

And like the tardigrade, nematodes are tough. A culture of live nematodes aboard the Space Shuttle Columbia were the only organisms to survive the re-entry breakup of the shuttle, making them the only organism known to survive unprotected atmospheric descent.

Fabulous Flatworms

/ Robinne Weiss / 7 Comments

Australian flatworm

One of the common animals in my yard and garden is the flatworm. Strictly speaking, “the” flatworm here in New Zealand is actually multiple species—possibly up to a hundred—but they have been poorly studied, so it’s unclear just how many species there are.

Flatworms are some of the most impressive predators in the garden, able to consume prey up to 55 times their own size. That’s the equivalent of your house cat taking down a female elk. They eat snails, slugs, and earthworms, digesting them externally before sucking them up with one or more mouths located midway along their bodies.

I love to find flatworms around the yard. They come in striking colours, and some have lovely brown stripes—the orange Australian flatworm (Australoplana sanguinea) is most common in my garden, followed by the relatively nondescript brown New Zealand flatworm (Arthurdendyus triangulatus). Like the slugs they eat, they prefer damp places, and they protect themselves with a layer of mucous. Flatworm mucus is stickier than slug mucous, and they use it to attach themselves to their prey during feeding.

New Zealand is full of non-native invasive organisms, but New Zealand flatworms are one of the few organisms that have turned the tables and become pests overseas. They are easily transported in potted plants, and have successfully invaded Ireland and Scotland. Though there was widespread panic at first about their potential to threaten the local ecology, they appear to have caused little damage to earthworm populations in the UK. Like most cold-blooded animals, their appetites are small. Far from being a devouring hoard, each flatworm can manage, on average, just one earthworm per week. And if they don’t manage to find an earthworm every week, it’s not a problem—they can go a year without eating.

Smells Like Spring

/ Robinne Weiss / Leave a comment

I know, technically it’s still winter. We’re still likely to have icky, cold, wet weather. There will be ice on the water troughs, and frost on the grass in the mornings. There are still plenty of weeks left in the skiing season. And I won’t even think about planting anything out in the garden for at least six weeks.

But yesterday smelled like spring.

That heady combination of lanolin, damp soil, and cut grass.

It sounded like spring, too, with magpies warbling in the trees, swallows chittering overhead, and lambs bawling in the paddocks.

It is not spring. Not yet. But the days are lengthening and the first daffodils are beginning to bloom. It’s time to finish all those indoor winter projects. Spring is on its way.

Still Life with Insects

/ Robinne Weiss / Leave a comment

I’ve written and discarded half a dozen blog posts over the past week. Nothing seems to be quite right. Out of ideas, I resorted to the book of 500 writing prompts I created for my daughter. A random stab at the non-fiction section of the book brought me to the question: What objects tell the story of your life?

I tried to encapsulate everything in four objects:

The fiddle: made by a neighbour in Panama, given to me for my birthday by my husband. The fiddle not only tells the story of our years living and working among the incredible, resourceful people of Panama, but also tells the story of my lifelong interest in learning to play the violin…an interest which always ended up being pushed aside for other interests. Because I’m interested in learning so many things, there simply aren’t enough hours in the day.

The beetle puppet represents my insatiable curiosity about arthropods, and how that curiosity has bled into my other interests. Peanut butter jars full of bugs on my dresser when I was a kid led to the entomology degree, which led to teaching about insects at Penn State University, and then starting the Bugmobile. And the puppet is only one of many insect-themed and inspired artistic projects I’ve done over the years, as art and science mingle in my brain.

The gardening gloves speak of my weeding addiction and my love of growing food. The gloves are never more than a month or two old, because I wear through them in that time. I think that says it all about gardening for me.

The rock represents adventure, the natural world, and the wild places I have visited and lived in. Like me, the rock has traveled far and has been changed by the stresses it has experienced along the way.

Happy New (Garden) Year!

/ Robinne Weiss / Leave a comment

I love the month of July; it’s the beginning of the garden year in my mind, because it’s the month I plan the garden and order my seeds. It’s been a few years since I blogged about my garden year, so I figured it was time to do it again. I unearthed this little graphic my husband helped me create a few years back, showing my annual planting and harvesting schedule. It has changed a little since then, and I notice some crops, like garlic, are missing from it, but it’s still a fairly good indication of my year in the garden.

I struggled the first few years here. Coming from the Northern Hemisphere, I had no idea when I should plant things. And the idea of growing vegetables over winter was foreign to me, too.; gardening in Minnesota and Pennsylvania is sharply seasonal. It’s seasonal here, too, but much less dramatically so.

Instead of growing a ton of spinach over the summer and freezing it for winter, I learned to simply plant small quantities regularly throughout the year, for a perpetual supply of fresh greens. Same with lettuce, chard, broccoli, cabbage, and cauliflower.

Today my garden year ebbs and flows, but there is never a down time in the garden. There is always something to plant, weed or pick. The end of last year overlaps with the beginning of this year, so while I plan my seed order, I’m harvesting the lettuces, broccoli, leeks and other late crops planted in the autumn, and I’m weeding the garlic and broad beans that will be harvested in the coming spring and summer.

Sometimes I miss the complete downtime of gardening in Minnesota—the winter lull when there’s no need to go out and weed in the cold. But only sometimes. The never-ending garden year here has its perks in garden-fresh vegetables year-round.