Natural History

The Meg

Often an object has a much wider story to tell than what can be seen at face value, as interesting as that can initially appear.  Part of the fun in researching it is uncovering the wider back story which helps to build up a bigger picture of where we stand at the present.

So with that in mind, how did a tooth from a megalodon end up in the riverbed near Whanganui?

2. Megalodon size

The Megalodon at the top, compared to a Great White Shark and a Human. Image sourced through Creative Commons.

The largest known shark, the Carcharodon megalodon lived from 16-2.5 million years ago. The megalodon was related to the Great White Shark of today but was huge. Fossil remains show the megalodon was an average size of 10.5 metres long but could grow up to 18 metres. An adult human could easily sand up in its jaws which measured over two metres wide.

The particular tooth in the Museum collection measures 13.5 centimetres high and 11.5 centimetres wide. It was found near Pīpīriki in a bank of sandstone estimated to be four to five million years old. Because of its marine past, Whanganui is a great place to find marine fossils, in particular fossilised shark teeth.

1. Megalodon tooth

The Megalodon tooth found near Pipiriki. WRM Ref: 1800.175

About 540 million years ago, New Zealand was being formed on the eastern edge of the supercontinent Gondwana. This continent included what we know today as Australia, Antarctica, India, Africa and South America.

Around 100 million years ago, hot rock began to accumulate underneath Gondwana and move towards the edges of the land, pulling it apart. This slowly made a giant rift which allowed the sea to flood in, and separated it from the mainland, thus creating the continent of Zealandia. After breaking away from Australia around 85 million years ago, Zealandia largely sank beneath the Pacific Ocean. What remains visible today is essentially the highlands of the continent, and the rift is now the Tasman Sea.

Zealandia sits across the edge of the Australian and Pacific tectonic plates and is slowly being broken up as they continue to move. The last 1.8 million years have shaped the land with tectonic movements, glaciers and volcanoes, altering the landscape. Whanganui, being on the coast of New Zealand and consisting of lifted sea beds, is more likely to reveal marine fossils.

The hinterland areas are fertile with volcanic ash at the core. The mountains in the north and west help to shelter the township and have created a wonderful climate, much warmer and drier compared to other coastal towns.

Before human settlement, this land was covered with forest: tōtara, matai, rimu, tawa and beech trees covered the landscape. The soft rock near the coast was easily worn down by water, and helped to create the Whanganui River, the longest navigable waterway in New Zealand, measuring 290 kilometres from its source at Mount Tongariro.

All this adds up to a beautiful place with fertile lands, fresh water, ocean access and a temperate climate, which made it perfect for settlement when Māori arrived.

 

Sandi Black is the archivist at Whanganui Regional Museum.

Butterflies and Moths

In New Zealand there are 22 species of butterfly and over 1,700 species of moth. Eleven of these 22 butterfly species are found only in New Zealand. Some of the others originally came from overseas and are now resident here. Others occasionally arrive here, usually from Australia, on wind currents. Towns on New Zealand’s west coast, such as Whanganui, are often host to these wind-blown species.

World-wide, there are about 17,500 species of butterfly and around 160,000 species of moth. They form a significant portion of world fauna. Butterflies and moths are from the insect order called Lepidoptera. The name comes from the Greek words lepido which means “scale” and pteron which means “wing”. The scales on Lepidoptera wings give them their colours and patterns.

2. Tiger moth

These moths have spots and stripes on their wings and are from the family Arctiidae. The caterpillars of tiger moths are often covered in tufts of hair and are known as woolly bears. WRM ref: TA.418

Like other insects, Lepidoptera have three body parts (the head, thorax and abdomen) and the adults have two pairs of wings (one pair of forewings and one pair of hindwings). They also have a pair of feelers (antennae) on their head and six legs joined to their thorax. We can tell species of Lepidoptera apart by the patterns on their wings, wing shape and leg shape.

There are several basic differences between moths and butterflies. Moth antennae are usually feathery or pointed and butterfly antennae are usually clubbed. Moths tend to fly at night and butterflies tend to fly during the day. Moths usually rest with their wings flat and butterflies rest with their wings closed upward. Moth abdomens are usually plump and butterfly abdomens are usually slender.

There are four stages in a Lepidoptera life cycle. Egg, caterpillar (larva), cocoon (pupa) and adult moth. Caterpillars look different to adult moths. While they eat and grow, they will shed their skin (moult) several times. Eventually, the caterpillar will build a cocoon around itself. While inside its cocoon the caterpillar will undergo metamorphosis and emerge from the cocoon as a moth or butterfly.

There are advantages in being a Lepidoptera. Larval insects which are different to the adults can occupy different niches from the adults. This avoids competition for resources between the young and adults of a species. In addition, winged insects can travel greater distances than similar insects which do not have wings. This allows them to access the resources of more distant areas and increases their feeding and breeding ranges.

Collecting insects, especially butterflies, was a popular hobby from the late eighteenth century to the mid twentieth century, and is still enjoyed by many people today. As we learn more about the relationships between living things, we are discovering the unique role each plant and animal plays in its ecosystem and the wider natural world. The removal of one species from the ecosystem will have an effect on the remaining species. Because of this, many naturalists now collect photographs of plants and animals, including butterflies and moths, rather than collecting actual specimens of a species.

1. Butterfly collection

These butterflies are part of a much larger collection of Lepidoptera gathered by a member of the Edwards family of Whanganui. WRM ref: 1948.29.11

Lepidoptera have a strong presence within cultural history and art, providing a wealth of colour, shape and activity to our surroundings. They have often been used to decorate both every-day and special objects. References to Lepidoptera in poetry, fables, fairy tales, dance and theatre abound. Butterflies often seem to be the the goodies while moths are sometimes depicted as baddies or just plain foolish.

Metamorphosis has always been the greatest symbol of change for poets and artists. Imagine that you could be a caterpillar one moment and a butterfly the next. Louie Schwartzberg, 2014.

Moth: I gave you my life.  Flame: I allowed you to kiss me.  Hazrat Inayat Khan (1882-1927).

 

Libby Sharpe is the senior curator at Whanganui Regional Museum.

Fossil Giant Crab

In 1990, a local Whanganui resident captured a giant crab in the Ahu Ahu Valley, inland from Whanganui. That’s a curious creature to find so many kilometres from the coast. It was, however, not a potential family feast. It was a large fossil embedded in a spherical boulder, known in geological terms as a concretion. A concretion is a hard rock that forms around an object such as a fossil, protecting it from damage. Concretions can often be found weathering out of soft mudstone. If a concretion is cut open very carefully, it may reveal an interesting fossil, well preserved within the boulder. Because mudstone is very soft, it can be generally be cleaned off the fossil using water and a stiff brush.

2003.42.1

Tumidocarcinus giganteus, giant fossil crab. WRM ref: 2003.42.1

This particular fossil crab was alive approximately 15 million years ago, during the middle of the Miocene period, when the Ahu Ahu Valley, along with the rest of the Whanganui region, was under the sea. It is an example of the extinct species Tumidocarcinus giganteus, a deep-water crab that lived along the seabed in warmer waters than we enjoy today, on the Whanganui coast. During the middle of the Miocene period, which lasted from 24 million years ago to 5 million years ago, temperatures are estimated to have been four to five degrees warmer over most of the planet than they are today, and the sea level was correspondingly much higher.

Large numbers of Tumidocarcinus giganteus fossils have been recovered from the soft papa rock that is characteristic of the hills between Taranaki and Whanganui. Papa is formed from thick muddy sediments accumulating in the ocean around the western coast of the North Island. The numbers of these crabs found indicates that they were a reasonably common species in New Zealand seas during the Miocene. An interesting feature of the Tumidocarcinus giganteus is that the right pincer is usually much larger than the left. On males, the right claw could grow up to twice the size of the left claw. It was probably used for fighting and perhaps for attracting female crabs, as well as feeding.

By discovering fossils, such as this giant crab a very long way from the ocean, we can get a much clearer picture of what the land-masses we now inhabit might be like if the earth’s climate became similar to the middle Miocene again. It is challenging for us to imagine what the planet might be like if temperatures throughout the world continue to rise at the current rate. It is clear, however, that seas will be significantly higher, and much of the New Zealand land mass, especially coastal regions, will probably be under water.

The Whanganui region probably won’t be so great for humans, but giant crabs and other enormous sea creatures might be plentiful again.

Margie Beautrais is the Educator at Whanganui Regional Museum

Henry, Son of Drew

Henry George Drew was born in 1875, the son of Catherine (nee Beatson) and Samuel Drew. His father Samuel is still a well-known figure in Whanganui, not just as the founder of the Whanganui Regional Museum, but as a scholar, a musician, a philanthropist, a creative jeweller and a successful businessman.

2. Henry Drew

Portrait of Henry Drew.  Source: Public Domain.

Henry is somewhat overshadowed by his father’s reputation, but never-the-less deserves recognition for his own substantial contribution, both to the family jewellery business and to the world of museums.

He attended Wanganui Collegiate School from 1885-1887 and then moved to Wellington to train as a jeweller, and returned to Whanganui to join his father in the family jewellery business. He was renowned as a creative and adept craftsman. The Drew premises still stands on the south side of the Bridge Block at 19 Victoria Avenue. Henry was responsible for rebuilding this shop in 1909, the previous shop being pulled down to accommodate the new. He later moved his business premises further up Victoria Avenue to Perrett’s Buildings, where it remained until the 1950s.

1. Tankard engraved by H Drew

 Engraved by jeweller Henry Drew, this silver tankard has dates, place names and descriptive images of battlefields of North Africa and Italy in World War II where New Zealand contingents fought. Ref: 2003.54.2

Like his father, Henry had a passion for natural history. Samuel Drew maintained contacts with world-renowned naturalists such as the Austrian collector and taxidermist, Andreas Reischek who, on two visits in 1886 and 1888, helped to classify his collections. At the age of 11 young Henry received lessons in taxidermy from Reischek and developed into a highly skilled taxidermist and a recognised collector of New Zealand birds, butterflies and moths.

In 1901, after the death of his father, Henry Drew was appointed Honorary Curator of the Museum. Following the appointment of a paid Curator, George Marriner in 1908, Henry was elected as a trustee and served from 1908 to 1912. In 1916 he was again appointed Honorary Curator, a position he held for three years.

In a 1916 letter to Amy Castle, an entomologist at the Dominion Museum (now Te Papa), he commented, “I have just been appointed Curator of Wang. Public Museum, and therefore my private collection must be reluctantly placed on one side. My duties at the Museum will take up all my spare time.”

Henry has been described as the best taxidermist produced by New Zealand. He mounted exhibits for many different museums around the country. He was especially noted for his ability to mount bird specimens in a natural way. A case of native birds, titled Morepork Under Siege, was mounted by him while Honorary Curator and was on display at the Museum for many years. It depicts a sleepy Ruru, or Morepork (Ninox novaeseelandiae), being besieged during the day by small birds that include Riroriro (Grey warbler), Tauhou (Silvereye), Miromiro (North Island Tomtit) and Piwaiwaka (Fantail). Still in the Museum collection, the diorama demonstrates the sort of natural poses that Drew was attempting to perfect.

20181005_151756_Richtone(HDR)

A close-up view of Henry Drew’s Morepork Under Siege, showing the birds in natural poses. Ref: 1916.66

In 1924 he produced a collection of 350 birds for display at the Wembley Exhibition in England. This included eleven blue penguins which were kept at his home for a few weeks by his two children before being killed and mounted for display. He also mounted a large brown bear that came to Whanganui in a travelling circus.

Henry Drew retired from the family jewellery business in 1949, leaving his son Frank in charge.

 

Libby Sharpe is the Senior Curator at Whanganui Regional Museum

King Penguin: a Royal Line in Trouble

New Zealand was once home to a gigantic species of penguin, as tall as an adult male human. Like many megafauna species of the planet, this species is now extinct and exists only as fossil remains held in museums.

Two other very large penguins, the Emperor penguin and the King penguin, live in huge colonies around the southern seas. They were so numerous that it appeared there was no risk of them following New Zealand’s fossil Giant penguin into extinction. This, however, may no longer be true of the King penguin. The once numerous bird may be already be an endangered species. The end of the current century, according to scientific research, might signal the end of this royal branch of penguins through the effects of climate change on ocean currents and sub-Antarctic habitats.

1. King penguin with egg

Taxidermied King penguin with egg. Ref: 1802.1688

King penguins live and breed between latitudes of 45 and 55 degrees south, on sub-Antarctic islands and northern parts of Antarctica. The most numerous colony, with about half of the global population of King penguins, has historically been the Crozet Islands in the Southern Indian Ocean. In 1982 the King penguin population of these islands was estimated, through aerial survey, to be around two million individuals. Recent analysis of satellite images taken over the last thirty-five years indicates that the population has plummeted by 90% to around 200,000 birds, with just 60,000 breeding pairs. While this is still a very large number, such a rapid decline is concerning. So what has changed?

Researchers suggest the causes may be overcrowding and the resultant competition for resources; disease such as avian cholera; or the possible arrival of invasive pest species. A non-migratory species, such as the King penguin, relies on the continued health of its sub-Antarctic habitat for survival. King penguins leave their young and swim south to forage for fish and squid along the polar front, where cold, deep water meets more temperate sea.

2. King penguin egg

King penguin egg. Ref: 1802.5822

The research team suspects that climate change could be contributing to the decline, as it has with colonies of penguins in parts of Antarctica. In 1997, a strong El Niño weather event warmed the southern Indian Ocean and temporarily pushed fish and squid, normally eaten by King penguins, further south, beyond their foraging range. The result was population decline for all King penguin colonies in that region. Although El Niño events are cyclical, they can be amplified by global warming. The researchers have concluded that based on current climate change predictions the Crozet Islands, once home to half the world’s population of King penguins will become uninhabitable for these penguins by the mid-century.

With nowhere else to go, the Crozet Islands population of King penguins will be in serious trouble. It would be such a shame if one of the world’s most iconic and loved penguins exists only as taxidermied specimens in natural history museums.

 

Margie Beautrais is the Educator at Whanganui Regional Museum.

Green Sea Turtle

Beautiful Soup, so rich and green,

Waiting in a hot tureen!

Who for such dainties would not stoop?

Soup of the evening, beautiful Soup!

[From Alice’s Adventures in Wonderland by Lewis Carroll, 1865]

 

One turtle not protected by its briny environment was a Green Sea Turtle, Chelonia mydas, also known as the Green Turtle, Black Turtle, or Pacific Green Turtle, whose shell is in the Whanganui Regional Museum collection, donated by Tom Shout in 1954.

1. Green Sea Turtle carapace

The shell of the Green Sea Turtle that ended up as soup at Bellamy’s. Ref: 1954.103

The turtle shell had been given to Tom Shout’s father in around 1910 by the New Zealand Prime Minister, Sir Joseph Ward. Ward had been presented with a live turtle on a return voyage from London, possibly in Sierra Leone, West Africa. Still alive when it arrived in Wellington, Sir Joseph donated it to the kitchen in the parliamentary restaurant, Bellamy’s, to be turned into soup. Shout’s father was the chef at Bellamy’s at the time.

Green Sea Turtles are named for the green color of the fat under their carapace or shell, a vital ingredient for making turtle soup. Turtle soup was a fashionable and popular repast for Edwardian gentlemen, and very suitable fare for Bellamy’s, New Zealand’s premier restaurant at the time.

2. Green Sea Turtle skull & jawbone

Skull and jawbone of a Green Sea Turtle. Some skin scales still adhere to the bone. Ref: 1802.3523

Green Turtle soup was not, however, limited to diners at Bellamy’s. It was, for decades tinned and sold throughout the world. One of the most famous brands was the American product by Campbell, launched in the 1920s and lasting in popularity into the 1950s when it began a slide into obscurity and was discontinued in the 1960s.

 

A passion for Green Turtle soup had emerged in England in the mid-18th century. Considered a great delicacy, it needed to be made from freshly slaughtered turtles that had to be shipped from warmer climes in great tubs of water. It became, inevitably, more and more expensive, so a substitute was invented to address popular demand. Mock turtle soup often incorporated meats such as brains or calf’s head to mimic the texture of true turtle meat. Many consumers thought that these animal body parts also tasted very like turtle. Tinned mock turtle soup sustained many a British subject throughout World War II when rationing was at its most severe.

3. Turtle illustration by John Tenniel

The gryphon and the mock turtle, an illustration by John Tenniel in Alice’s Adventures in Wonderland.  Sourced under Creative Commons.

The Green Sea Turtle’s range extends throughout tropical and subtropical seas around the world, with two different populations in the Atlantic and Pacific Oceans. Adults can grow up to 91 cm in length and weigh up to 180 kg. They migrate long distances, sometimes thousands of kilometres from their feeding sites, to breed on the beaches where they hatched. They can lay more than 100 eggs in every nest.

Today many species of sea turtle are endangered, with surreptitious culinary demand possibly contributing to their population decrease, as well as markets in turtle skins, tanned to make leather bags and wallets. While it is illegal to hunt sea turtles in most countries, they continue to be caught worldwide.

Since 2004 the Green Sea Turtle has been listed as Endangered (facing a very high risk of extinction in the wild in the near future) by the International Union for Conservation of Nature and Natural Resources. Conservation initiatives centre on nesting sites and include eco-tourism and environmental action plans.

 

Libby Sharpe is the senior curator at Whanganui Regional Museum.

Taxidermy

The word taxidermy is derived from the ancient Greek roots táksis (arrangement) and derma (skin), and loosely translates to “arrangement of skin”. It refers to the art of preparing, stuffing and mounting the skins of dead animals for exhibition in a lifelike state. Taxidermy takes on a number of forms and purposes, including hunting trophies and natural history museum displays, and sometimes to memorialise loved pets. It is used as a method of preserving specimens for research and recording, and for display, including those that are extinct and threatened, in the form of study skins and life-size mounts. It is practiced primarily on vertebrates (mammals, birds, fish and reptiles) but can also be applied to larger insects and arachnids (spiders).

The earliest known taxidermists were the ancient Egyptians who developed a form of animal preservation through the use of injections, spices, oils, and other embalming tools and methods. The modern form of taxidermy greatly differs from the taxidermy of antiquity, as taxidermists now produce lifelike mounts by accurately modelling the anatomy of animal specimens as they might appear in their natural habitat.

2. Drew's museum

 Drew’s taxidermied specimens in the Wanganui Public Museum that opened in 1895 and was situated in Drews Avenue.  Photograph by AD Willis. Ref: 1802.3375

In the Victorian era, taxidermy became very popular and fashionable, with many seeking curiosities for their cabinets in an exciting age of discovery. With the surge of international exploration, there was a growing community of natural history observers, or naturalists, who became intent on discovering fascinating new species abroad.

When new species of mammals, fowl and fish were still being discovered, naturalists looked for ways of preserving them for classification. Famed British explorer Captain James Cook was one of the early supporters of taxidermy for his newly discovered species. Charles Darwin was another early practitioner of taxidermy. He had some specimens from the Galapagos Islands taxidermied in situ; they later helped support his scientific theory of evolution.

In the early 20th century taxidermy came into its own and became a respected art form. Wealthy aristocrats would fill their homes with mounted animals from all over the world. As big game hunting became more popular, so did the practice of displaying wild animals. Early taxidermy mounts were stuffed with sawdust and rags without regard for actual anatomy, so the models were often disfigured. In fact, some mounts from those days skewed how people imagined such creatures for years. The long-extinct dodo is a prime example of creative taxidermy misleading actuality. Over time, taxidermists developed techniques to more accurately represent anatomy.

The Whanganui Regional Museum collection houses many taxidermied specimens, including rare and now extinct species such as huia, koreke (New Zealand quail) and whēkau (laughing owl). There are many trophy heads and even an extinct Tasmanian tiger.

1. Tasmanian tiger

Taxidermied and mounted specimen of the extinct Tasmanian tiger, Thylacinus cynocephalus, first acquired by Samuel Drew for a private museum at his home. Ref: 1805.61

The taxidermy collection started with an avid local naturalist and collector, Samuel Drew. He collected and classified many natural history specimens, certainly enough to establish a small museum at his home in 1880. He was a significant collector of molluscs, birds, and beetles, and maintained contacts with world-renowned naturalists. He exchanged specimens with Julius von Haast, a German geologist, later director of the Canterbury Museum. He met with and corresponded with taxidermist Andreas Reischek, who helped him classify some of his specimens. Reischek also trained Drew’s son, Henry, in taxidermy. Drew’s private collection eventually became too large for his family home and became the foundation of the Whanganui Regional Museum collection that we all enjoy today.

 

Rachael Garland is the Events Coordinator at Whanganui Regional Museum.

Cave Crabs of Bali

As a museum curator, I’ve done field work in lots of places, but this was the first time I’d had to wear a purple sash.

The sash and sarong were hired for 5,000 rupiah (about 50c) from a shop by the main road on the island of Nusa Penida, near Bali, Indonesia. I was about to venture into a cave to look for endangered crabs, but because the cave is also a popular Hindu temple you have to be properly attired.

1. Entrance Giri Putri

 You are warned when entering Giri Putri cave that it is a sacred place.

The Giri Putri temple used to be just a smallish hole on a hillside; you have to crouch, clamber, and shuffle to enter it, before the ceiling rises and you’re in one of several large caves. Today, there are steps, buildings, white-clad priests praying, and a visitor’s book.

Back in 1993 Australian biologist Tony Whitten explored Giri Putri, and was struck by the number of crabs scuttling about on the cave floor. He collected some, and they turned out to be not one, but two new species, dubbed Karstarma emdi and K. balicum. Freshwater crabs like these can be found in several cave systems in south-east Asia. They have long legs for feeling their way about in total darkness. Isolation and time leads to speciation, and the two species in Giri Putri seem to be found nowhere else but this small cave.

4. Hindu Temple at Giri Putri

Giri Putri is a working Hindu temple, with worshippers present at all hours, leaving food offerings and coexisting with insects and bats.

Unfortunately, they’re under threat. Giri Putri is now a busy temple with artificial lighting everywhere, large fans to keep the air moving, lots of concrete and tiled floor and rows of benches and altars. Whitten noted that in every visit he made there were fewer crabs, and in the hour I spent searching with a headlamp in the dark corners of the cave I didn’t see any at all. I asked one priest if the crabs were there. He told me “sometimes”. The International Union for Conservation of Nature is pushing for better monitoring of the crab population, and the temple authorities seem keen to work to minimise human impact, so here’s hoping.

There’s plenty of other life in Giri Putri, though. I kept disturbing bats which zipped here in there in silence, sometimes an inch from my face, reminding me that I didn’t get a rabies vaccination before coming to Bali. The walls of the cave were crawling with invertebrates, including large Periplaneta cockroaches, camel crickets that looked just like the cave wētā back in New Zealand and good-sized whipscorpions.

2. Cockroach

The cave was full of large winged cockroaches in the genus Periplaneta.

Back home, I uploaded the photos I’d taken with my phone to NatureWatch, and asked Mark Harvey at the Western Australian Museum what he thought. Mark identified them as tailless whipscorpions in the family Phrynidae, probably the genus Phrynus. This was interesting, because almost all species of Phrynus are found in the New World, through Mexico and Central America. The sole exception is a species Mark himself named and described, Phrynus exsul from the island of Flores, Indonesia, thousands of kilometres away from its closest relatives.

3. Whipscorpion

Whipscorpions are also known as whipspiders. They are arachnids, but are neither scorpions nor spiders.

Only one problem: Bali is 400 km away from Flores. So either these whipscorpions are Phrynus exsul and a new record far west of where they were first observed, or they’re an undescribed species of Phrynus.

Whipscorpions are not especially inconspicuous. Giri Putri is right by the main road, and a popular tourist destination. Nusa Penida is a short ferry ride from Bali, which has millions of tourists a year. And it seems that in over 20 years nobody has thought to collect one of these critters, take it to an expert, and find out if it’s an undescribed species or not. This is the plight of the tropics in miniature: stuffed full of biodiversity which is disappearing faster than we can discover and put names to.

 

Mike Dickison was the Curator of Natural History at the Whanganui Regional Museum.

Bees, harvestmen, wētā and more take the stage at the Entomology Conference

Recently the War Memorial Centre hosted the annual New Zealand Entomological Society conference, and researchers from all over the country congregated to share their discoveries and find out what was happening in the world of bugs.

2. Australian resin bee

An Australian resin bee Megachile ustulata. Photo: MPI, PHEL, Milen Marinov

One of the talks was very relevant to Whanganui residents. In January, a Springvale couple discovered an odd-looking bee when it stung one of them. Realising it was unusual they forwarded the corpse to the Ministry for Primary Industries. James Haw of MPI explained it was identified as a species of Australian resin bee, Megachile ustulata, never before recorded in New Zealand. MPI searched the neighbourhood for more bees but came up empty-handed. In Australia Megachile ustulata is a solitary insect that makes its home in cracks and burrows. It especially likes the hollow ends of bamboo garden stakes. It is not clear if this was a one-off incursion, or if these bees have taken up residence in Whanganui. If you’re a keen amateur naturalist, keep your eyes open for resin bees when spring arrives. Feel free to bring possible specimens to the Museum (in sealed containers, please).

4. Tree weta Brodifacoum

Tree weta feeding on Brodifacoum

One of the more intriguing talks was by Adele Parli, a Masters student at the University of Otago, working on Wellington tree wētā (Hemideina crassidens). The Wellington species is the more aggressive of the two tree wētā we get in the Whanganui area. Adele was quantifying their aggressiveness with a measure known as the “poke test”; how many times do you need to poke the wētā before it flips its lid and begins to thrash and bite? The answer for the Wellington tree wētā was generally “once”. Adele was poking wētā to test whether their behaviour changes after feeding on the poison brodifacoum. Brodificoum is commonly used for rat and mouse control in the bush and around buildings, and is the rat poison anyone can buy at the supermarket without a permit. (It’s much less humane than 1080 and takes longer to break down in the environment, but you don’t see people protesting brodifacoum outside supermarkets.) Wētā love to eat brodifacoum bait pellets, and it doesn’t kill them, but Adele suspects it may be changing their behaviour, such as how often they emerge to feed, how far they travel, and how aggressive they are.

3. Daddy long legs

A common household daddy-long-legs Pholcus phalangoides. Photo: Olaf Leillinger CC-BY-SA

As well as talks on insects, there were presentations on spiders, which are more or less an honorary insect at these events. Anne Wignall at Massey University Albany had been studying a common house spider, the daddy-long-legs Pholcus phalangoides. These are territorial, staking out one corner of a ceiling and repelling intruders. Anne was curious about whether these spiders could recognize each other; something called the “dear enemy” effect in vertebrates, where animals are more aggressive to complete strangers than rivals they’ve already encountered. Sure enough, when spiders were allowed to become familiar with each other, their territorial battles, while no less frequent, became less violent. It’s remarkable to think that a creature with such a tiny brain can remember its opponents and assess the risk of fighting.

The conference finished with Bugs in the Pub in Frank eatery. Three entomologists gave short talks on beetles, insect weaponry, and whether we should eat more bugs, and invited questions from the audience. Afterwards, beers in hand, pubgoers chatted with the scientists and looked at a selection of live insects they’d brought along – a fitting end to a grand three-day conversation on the wonders of the insect world.

 

Dr Mike Dickison is Curator of Natural History at the Whanganui Regional Museum.

Stick Insects

Stick insects are often overlooked, and that’s the way they like it.

New Zealand is home to a wide variety of stick insects, from the horrid stick insect (Argosarchus horridus) with a body as long as your hand, to spiky creatures smaller than your little finger. Most species of stick insects are found in the tropics, so it’s peculiar for a cool-temperate country like us to have so many, even a mountain stick insect (Mimarchus tarsatus) that lives in South Island tussock that’s covered by snow all winter.

1. prickly stick insect

Prickly stick insect (Acanthoxyla prasina).  Photograph: Alan Gilchrist.

Although they’re relatively common, stick insects excel in hiding. Our New Zealand species are flightless and defenceless. If discovered, they will sway gently like a twig in the breeze, or drop comatose to the ground, where can lay immobile for up to half an hour before reviving and climbing a tree again. The best way to find them is by beating. Hold a white sheet or umbrella under a tree or shrub and hit the branches sharply with a stick and down they’ll drop. Over the last few months the Whanganui Regional Museum has been doing that on field trips around Whanganui and the Manawatū, and we now have a half dozen stick insects of different species, sizes and colours in captivity.

Stick insects are easy to keep. They only need a regular supply of green leaves (pohutukawa seems to be a favourite) and an occasional spray with a plant mister. They’re happy to be handled, and are a great “gateway insect” for children who might be nervous about handling a creepy-crawly, as they’re completely harmless. They spend most of their time slowly munching on leaves and laying eggs.

2. stick insect cage

Stick insects live happily in a cage as long as it’s not too hot and dry, and there’s a constant supply of fresh leaves. Photograph: Whanganui Regional Museum.

It’s possible to breed stick insects even if you only have one, because some of the most common species, the spiky stick insects (Acanthoxyla), are parthenogenetic. This means that no males are needed, with mothers laying eggs from which hatch only daughters. In fact, until this year, no males had ever been seen. Then one was found, in England of all places. The species had been introduced to England in the 1920s and is doing well. Males seem to be very rare mutants, not required for reproduction.

Because some stick insect species have just one sex and others have both, their genetics are very interesting to entomologists. Studying their DNA has also revealed unknown species hiding in plain sight. One of the new species was recently given the scientific name rakauwhakanekeneke, te reo Māori for “the stick that walks”.

3. stick insect eggs

If kept in a damp dish, but not allowed to go mouldy, stick insect eggs will hatch after a few months into tiny versions of the adults. Photograph: Whanganui Reigonal Museum.

The stick insects in captivity in the Museum have been growing steadily, and we’ve collected dozens of eggs, which are currently incubating. The hatchlings will be released back into the bush. Unfortunately, stick insects have a short life expectancy. They hatch in spring, reach full size in a few months, and usually don’t survive the winter. When ours die, we’ll preserve the bodies and put them on display in a new insect exhibition ready for when the Museum re-opens in October. Visitors will be confronted by a case full of sticks and invited to work out how many of them are insects.

 

Dr Mike Dickison is the Curator of Natural History at Whanganui Regional Museum.