Ask a Scientist

Zoology questions

I have been growing stinging nettle for admira butterflies. So far I have hatched and released 52 yellow admirals but to my great disappointment no red admirals. Do they not lay eggs on the same nettles if the yellow admirals have laid there first or am I growing the wrong type of nettle to encourage the red admiral?
Is chocolate poisonous to cats as well as dogs?
We are puzzled by a bird which has been in our garden frequently this summer and autumn, though not before that. It is the same size as a thrush, but has a plain brown chest. It's most distinguishing feature are several white spots, about the size of a fifty cent piece, on it's back and it has some white under its wing. It is mostly seen at ground level and is digging up the moss on the lawn to look for grubs. It appears to spend much of its time at ground level, though it is happy to sample the grapes we are growing on a pergola. What is this bird?
I love raising Monarchs and this year I have had around 200 caterpillars sent to me from up north. They have all hatched into butterflies. Some of these are just starting to lay again now. Do you think this lot has a chance of surviving our winter, or will they migrate north. If they do migrate what are my chances they come back in Spring? If I was to try and keep the butterflies alive inside for winter what would the best recipe be for nectar and would this be possible? I would so love to have my own stock to start off in Spring with rather than trying to get caterpillars sent to me.
What is the difference between white and black butterflies?
Do butterflies have memories? I notice that monarch butterflies hover over the exact spot in my garden where a swan plant used to grow.
Do butterflies have memories? I notice that monarch butterflies hover over the exact spot in my garden where a swan plant used to grow.
Is there evidence that saving endangered bird and animal species from extinction will, in all cases, have tangible benefits for human beings? If not, why do we do it?
Why doesn't New Zealand have colourful birds, as exist in almost any other country.
Can an old dog learn new tricks?
I enjoy getting cockles from a sandy beach near Dunedin, cooking and eating them. But I have realised that I know nothing about their life cycle and would appreciate an outline from conception; including an explanation of how their shells grow, what age they are when the shell reaches about 4 cm across, and why the shell "clicks" open suddenly when heated towards boiling temperature
Some years ago an American schoolgirl suggested sending spiders up into space and observe their construction of webs in a weightless environment. Was this ever done and if so what was the result?
I found an unusual slug in the grass verge of my vegie garden which doesn't get any sprays. It was about five cm long, about 1cm wide, quite flat and was black with a cobalt blue stripe down one side. The site is 20 metres above the sea and well away from the native bush line. What sort of slug could this be?
I found an unusual slug in the grass verge of my vegie garden which doesn't get any sprays. It was about five cm long, about 1cm wide, quite flat and was black with a cobalt blue stripe down one side. The site is 20 metres above the sea and well away from the native bush line. What sort of slug could this be?
I've heard that whereas salmon leave the sea and return to their fresh-water birth-place to spawn, some fresh-water fish go to the sea for the same purpose. This suggests that some fish can live and feed in both kinds of water. What differentiates fresh-water fish from sea-fish?
Where do quail go in winter? We have two breeding pairs on our property but they seem to vanish in wintertime.
How far at sea have salmon sold in New Zealand shops travelled?
As a regular observer of spiders, I have noticed that the number of spider webs near my home in Waikanae has decreased dramatically. Many possible reasons come to mind but is there a known reason for this?
I drive a lot, and have noticed that almost every bird flies away immediately on the sound of an approaching vehicle. Generally, most birds frighten easily, but Mynah birds don’t. On the road they seem to know how far they need to move from a vehicle and go that far only. Around town they will stand less than a metre away from moving cars. Does this mean they are capable of reason and judgment or is it just instinct?
What happens to poison once rabbits eat it? Do hawks and other predators get poisoned?
I recently cracked an egg and found it had three yolks, two small and one large. How rare is this?
I found an infestation of small insects in a drawer in my writing desk. (sample enclosed) I had recently thrown out a stained wheat bag stored in the drawer. What are they and why did they accumulate there?
Why does a daddy spider kill himself and how does he do it?
I photographed this insect whilst visiting my mother in Owera. What is it?
I found an unusual spider inside our pump-house. It has a red spot on its back and two red spots on its belly. In its web was a large water spider. What sort of spider is it and is it dangerous?
How do birds find worms under the ground?
Why are dogs better at smelling than people?
Why does the Sphynx cat have no hair? Is it to keep cool in a hot place like Egypt?
Our teacher's dog only chases rabbits when they dash away. Why doesn't it chase the ones sitting or hopping?
Why do lemmings run and leap off a cliff and kill themselves?
I photographed these ducks, which are smaller than mallards but have a larger beak and are shy. What are they and what is known about them?
I photographed these ducks, which are smaller than mallards but have a larger beak and are shy. What are they and what is known about them.
I have some young fallow deer which I have been feeding on crushed oats and lucerne. A couple died. Could their diet or the cold have been a problem?
I recently arrived back from Canada and the USA with a tick attached to my leg which my doctor photographed, removed and sent away for identification. Does this happen much and is the tick dangerous to me or biosecurity?
This animal was resting against our house in the sun in Hampden. The body was 140mm, the feelers were 90mm, and the legs approx 75-85 mm long. What is the name and what do they live on? We shifted it into a tree and it got quite aggressive.
Why isn't pea straw fed to animals the way hay is?
We have bones and a letter re a moa called Dinornis torosus. What is known of this species of moa?
What are the bugs we found in the bottom of Nan and Pops water fountain? They are like a stick, and walk along the bottom of the water.
Bee-like insects were hovering at a corner of my house, behind the lemon tree, apparently wanting to get in under the weatherboards. They were there three days then vanished. There were lots of similar looking insects on the Senecio Greii a few days later. What was going on?
Recently I observed a group of red-billed gulls, many of whom appeared to be standing on one leg until they moved which showed they had two good legs. Is this normal bird behaviour and why do they do it?
On a recent climbing trip to Mt McKenzie on the main divide, my companions and I came across some amazing patterns created in the snow by an unknown creature. A circle was being formed the rebate was approximately 4mm wide and 2-3mm deep. On our return journey passing the same position, the circle was nearer to being completed by about 10mm in 1hr. A closer examination of the creature revealed it was about 4-5mm long, 3mm wide, and looked like a small chip of rock. On the underside showed some sucker like feet . The position of it in the groove indicated that it was moving sideways.
Our cat sleeps on our bed but since we left him at a cattery for five days he has been "kneading" us at night, keeping us awake. How can we discourage him from kneading?
How does one get rid of cluster flies?
Why do most land birds have a tuneful song, whereas most sea birds seem to have a raucous call?
Why do dogs drag their bottom over the ground?
I have two whitetail spiders in my house. Can you enlighten me about them please?
In winter in the Whakatipu Basin we feed the waxeyes and are normally inundated with them. This winter, not a one. Where are they?
Are there any blind insects?
Are there blind insects?
I found some odd shells on Ocean View Beach. They were shaped a bit like a butterfly. What are they?
What colour are ladybird's eggs?
Why do lady birds have the colours and spots they do?
Do we need insects?
How many different kinds of bugs are there?
What kinds of insects can fly?
Do insects see colour?
Do insects see colour?
Can spiders climb?
Do Tarantulas eat mice?
How many spiders are there?
Why are some animals camouflaged and some not?
How are spiders poisonous?
Why are insects so small?
Since leaving our cat at a cattery for five days he has been "kneading" us at night. He walks around in circles, kneading and purring. No matter how many times we lift him off the bed he comes back and will carry on before going to the end of the bed to sleep. This is depriving us of sleep. What causes his kneading?
A hen lays an egg a day. Where do the eggs laid by seagulls, sparrows, and other birds go?
Why don't animals today grow as big as dinosaurs?
Tuis appear to vanish for two months during the winter. Where do they go to?
I have a keen interest in helping the city and bush birds through the winter months. I put out sugar-water and seed on a daily basis and also bread. I was recently told to be careful about feeding bread to the birds when they begin nesting because it can actually harm the baby birds when the parents feed them. Is this true? I would hate to think I was harming them rather than helping them.
How do nectar feeding birds, such as tuis, feed their young?
Why do short-tailed New Zealand bats eat nectar?
What is the proper name for the pink mould that grows in bathrooms? Why does it like the bathroom so much and what is the easiest way to get rid of it, preferably for a decent length of time?
We provide fat and seeds for birds over winter. Often in a group of silvereyes, there will be one bird that will sit on a branch near the food or on the feeder and ruffle its wings at the other birds as if to say "go away this is my food source!" We've also observed this bird sometimes fly at and chase other silvereyes away from the food. Sometimes they will also try the wing ruffling at Greenfinchs, who ignore it! What does this ruffling signify?
Sandfly, and mosquito, bites itch and itch heaps! But why? And by that I mean what is the evolutionary advantage to the sandfly, or mosquito, in making it's victim suffer so much?
How does a dust bath clean a chicken's feathers?
What animals are colour blind?
My sister and I caught a little fish in Sawyers Bay Creek. It was unusual in that it had a sac on its tail. Can you tell us about the fish and the sac? P.S. We put the fish back.
Around our home we have about 12 brown striped skinks. What do they eat and what are their mating habits?’
About 4 years ago, we noticed that the starlings that used to roost on Pudding Island changed their behaviour, and started to come in huge flocks to roost in the gum trees behind our house, making a very loud and cheerful chattering to brighten up our winter dawns and dusks.
Is there any research going on concerning farming snails in New Zealand?
My goldfish was swimming on its side and the pet shop told me to put a pea in his bowl to eat. He died but we were wondering what a pea has in it to make him better?
What sea creatures use a "cats-eye" to seal the entrance to their shell and what functions does it serve?
Have the native birds of NZ influenced non-native birds to alter and improve their songs?
Why are flowers fragrent? Can bees smell?
I found a large ant in the roots of a Clivia from Tauranga obtained more than five years ago. Is it unusual being so large and does it bite? Is it common, is it strange for Dunedin, and is it normally so long-lived?
In removing an attractive rock on dry mud I was amazed to see a small frog underneath it. There appeared to be no crevices by which it could get in or out. Why was it there and how did it survive?
A blackbird in our garden has more white than black on its body. The white parts are stark white. It used to be chased by the black blackbirds but now chases them. Is it unusual for a blackbird to be born like this?
I have been observing slaters in my garden. Why do slaters and centipedes have so many legs?
The frogs in my neighbour's pond vanished three years ago. My neighbour said a heron and kingfish ate them all. Could there be other causes and is the pond likely to get repopulated?
Living on Otago Peninsular for 15 years I have noticed over the past three years that there has been no swarming of Munida (scarlet shoals) and no Peruvian mackeral in the harbour. Is this connected with global warming?
What animal wags its tail the fastest?
My Nana has bugs flying around her tree. It looks like a short skinny wasp, black and white with orange legs and white feet. It flies with its back legs pointing back. What are they?
How did platypus come about?
Why do birds build nests that are identical to their species? Where does the nest design and building knowledge come from in the bird?
How do Paua reproduce?
How do mother Emperor penguins know if their chick is a boy or a girl?
Whilst cleaning out a shed at Taieri we found a mushroom-shaped, shell-like object. What could it be?
Which is the most poisonous spider in the world?
I observed baby? wax-eyes fluttering and vibrating their wings a lot. What are they saying?
When a seagull swallows a fish whole, what happens to the bones?
Why do some species of animals like human company but others not?
Where do flies live when it is cold?
Friends of mine in Germany paint bird sillouettes on their large windows. Is there any evidence that this deters birds from flying into the glass?
Having dived the East Coast, why are there only small crayfish found in North Otago and they get bigger as one goes around the south coast towards the Fiordland sounds?
How come when I put out sugar and water in my bird feeder, within minutes a tui, bellbird, or waxeye, appears, followed by lots of its mates. Can they communicate?
Why do sharks sink when they stop swimming?
Why do fish need gills?
Whilst whitebaiting during a heavy flood the dirty water was full of tiny eels. Where did they come from?
When whitebaiting we often catch smelt and small fish called cucumber fish? What is a cucumber fish and what is known about it? eg what does it grow into?
Why do crayfish go on walks around the South Island?
If animals have such sensitive hearing how can they live with household noises?
What did sandflies live on BC (Before Campers)?
In a family flash photo our eyes appeared red but our old dog's were yellow. Why the difference?
Whilst tramping around the coast we found a waxy blob washed up. Could this be ambergris?
Why are there eggs and what are they made of?
While walking around the edge of a Central Otago dam, when the water was very low, I found about 10 white, chalky, hemispherical, button-like objects about 14mm in diameter. What are they likely to be?
Do bumble bees make honey, live in hives, sting, and have a queen bee, just like honey bees?
Why do I see only bumble bees pollinating Rhododendron flowers?
Why are eggs different shapes and colours, and how do the chicks get out?
Why are the ponds at the Grassmere Salt Works pink?
In tussock and snow grass of the hills of Central Otago I came across two very hairy caterpillars. The were dark brown, the hair was very dense which gave them a velvety appearance, and they were about 25mm long and about 4 mm in body diameter. They were very active and seemed to be travelling. When picked up they curled into a ball like a hedgehog does. Can they be identified from this description?
How do venomous snakes get the poison in their teeth?
How do zebras get their stripes and why?
How long do elephants live?
Why are elephants grey?
Do all cheetahs have the same number of spot patterns?
How do giraffes get their patches and why are there three types of girrafe?
Our house has a lot of glass and in early summer typically half a dozen thrushes fly into the windows. There are many other types of birds around but they all seem to avoid the window collisions. Why is it thrushes dont?
We have wind chimes and a spider has made its home in one. Can spiders hear?
Are cock-a-bullies seasonal?
Are any insects extinct?
I found a stick insect, with a body length of 9.5cm, on a house wall. Is this one fully grown or do they get bigger?
Do fish sleep?
Do fish sleep?
How did insects first come to be?
What colour is spider blood?
How do birds develop in an egg?
How long do tarantulas live?
Why do insects make noises?
How many types of butterflies are there in the world?
What do leeches eat and do they occur as far south as Otago?
What is an algal bloom and how do they affect people?
Where do whitebait go, and why, in the off-season?
How do seahorses swim and how big do they get?
How many types of seahorses are there in New Zealand and what do they eat?
How can whales spout water out of their spouts?
Why is an Octopus slimy and how do they make the slime?
How can whales stay under water for so long?
Why do hammerhead sharks have heads that shape?
How can we tell a male turtle from a female turtle?
Why do sharks have cartilage rather than bones?
Do crabs only live in the salty sea?
What are jellyfish, how do they move and what do they eat?
How do starfish breathe, eat and move?
How do sea animals protect themselves?
How do jellyfish sting?
How do fish survive under water?
What different types of animals live in the sea?
Last season we released some whitebait into our small garden pond which has a rocky edge with long grasses. During the winter they vanished, so we assumed they had been eaten by predators. But in spring they reappeared. Where had they been hiding?
I found the enclosed spiders in my wood-pile. It isn't a species I have seen before. Can you tell me anything about the spider and is it dangerous?
Why do cats have litters with so many different colours?
How do baby birds inside a fluid filled egg, and without an umbilical cord to their mother, survive so long without oxygen?
Whilst tramping in the West Matukituki Valley in Mt Aspiring National Park in January, I saw a very hairy black caterpillar about 4cm long scurrying across a boulder near the river. With each curl-up it made one or two thin lines of bright red/orange visible under its black hair. What can you tell me about this caterpillar?
I have never before seen this butterfly/moth. What is it?
We have on our property a pure white sparrow and a pitch-black fantail. Neither have any markings on them. What causes such colouring?
How and why do lizards drop their tail when under attack?
When scientists are trying to form a clone of an animal how do they get the cells to multiply?
Does a tiger have different organs to a snake?
Why are there so many species of animals?
Do dogs see the same colours we do?
I found a small white crab inside a wild green lip mussel. Is this a parasite or does it have a symbiotic relation with the mussel?
How did the first insects get to New Zealand?
What is the biggest bird in the New Zealand Native Forest?
What kind of native insects are there in New Zealand.
Why are tropical fish brightly coloured but New Zealand fish are dull?
Do hedgehogs hibernate and how should I care for one?
My daughter in Wellington recently discovered tiny tree frogs in baskets hanging about the eaves of her house. How do they get there?
Parental imprinting by infants, fixing upon the appearance, behaviour and calls of the adults, is so critical to the successful breeding of bird species that the cuckoo, brought up by other birds, must be singularly handicapped. How does a cuckoo, having never seen nor heard its parents during the crucial imprinting period, recognise the bird it must mate with to continue the cuckoo species?
How do parrots talk?
We feed all sorts of food scraps to all sorts of birds that visit our school. How can a bird eat all these different types of food which are foreign to them?
How do spittle bugs, which dont appear to have wings, travel to spread to other plants?
If things on Earth just evolved, why aren't there any mistakes or things that evolved wrong?
Why are the eyes of the yellow-eyed penguin yellow?
Why do dogs chase cats?
Why do bees make their honey holders as hexagonal arrays?
Why are there so many different types of worms?
Why do some worms glow?
How do flying fish fly?
By early winter the Red Admiral butterflies have all gone but Yellow Admirals are here and in the tussock covered hills nearby. Is there a reason for these changes?
Many Monarch butterflies hatched in the Oamaru Gardens. Where have they gone?
How can we tell the difference between a male and a female monarch butterfly?
What is the most common animal in NZ fresh water lakes?
Why do dogs wag their tails when they are happy, while cats swish their tails when they are cross?
Why are dogs born with their eyes closed?
Why do frogs hop?
Are mosquitos attracted to colour or to smell?
Which is stronger weight for weight, an ant or a human being?
How can you tell a male fish from a female fish?
Why do monarch butterflies gather in parks in late autumn?
How do stingrays eat their food when they are facing the ground?
When and where do carrot flies lay their eggs? I dislike using poisons but they are a pest in my garden so is it possible to attack them at an early stage?
Carrot flies are a pest in our garden. What is the life cycle of the carrot fly and how can we get rid of them?
How long have snakes been on Earth?
How does a case moth make its cocoon? I thought it was made out of skin on the inside.
What was the largest dinosaur?
Why do snails foam when I put salt on them?
Why do earth worms come to the surface when it rains?
How were different breeds of dogs created from the first animal, presumeably the wolf?
Why do rabbits sleep in the day time and not at night?
Why do cats purr, and how is the sound made?
How fast can the fastest bird in the world fly?
How fast do bumblebee wings flap and how can it fly when it is so fat?
Why do flies put a bit of spit on you before licking you?
Why are some sheep black and some white when they are the same breed?
Why do bees die when they sting but wasps live after they sting?
Why do bulls charge at red objects?
Why do bulls charge at red objects?
Can a fantail fly straight?
Why do rabbits pluck out their hair?
When Dalmation puppies are born why dont they have spots?
If an animal which has venom bites itself, will it die?
Why are some animals born knowing exactly what to do?
Why do some animals have beards?
Why don't cats and dogs live to 100 like humans?
What is the difference between a fox and a fox terrier?
Why do merino sheep stand in a huddle in the hot, hot sun?
What is the difference between a seal and a sealion?
How does a spider know how to spin a web?
How do flies walk on the ceiling upside-down?
People say that cats are colour-blind or only see black and white? If this is true how do they know this?
Is it true that cats and dogs don't respond to their names, just the sounds at the end of their names?
Why do flies rub their legs together?
On a class insect hunt we found a large slug which appeared to be laying eggs out of the side of its head. Is this what was happening?
We learn that respiration supplies energy to keep warm blooded animals warm. So why doesn't respiration do the same for cold blooded animals?
We have a hen's egg shell which is green. Why can an egg shell be green?
What makes a dinosaur different from a lizard?
Do horses get the stitch?
Why are tuatara, and other reptiles that were alive in the time of the dinosaurs, not extinct?
How do different species start?
Why can people talk but animals can't?
Amy, of Sawston Village College (UK), asked:-
Why does this world only have boys and girls?
Why are rats used in most experiments?
How do shells get their colour?
If crabs have teeth where are they?
How do crabs breathe both in and out of water?
Why do tigers have stripes?
Why do tigers have stripes?
Recently I saw two seagulls stomping on grass. Is this a mating ritual or is it done to force food to the surface?
Why do moths go to the lights at night?
How many species of penguins are there?
Where do penguins sleep?
How much food does a grasshopper eat a day?
Why do cats fall on their feet even when dropped upside down?
What was the first dinosaur in the world?
What is the biggest type of snail in New Zealand?
Can birds detect colour?
My pet lamb 'Pirate' is so called because she has a patch of black wool around one eye. Why do some white lambs get black patches of wool?
Do fish sleep in their fish bowls at night and if so do their gills still work when they sleep?
Why are cat tongues dry and human tongues wet?
Can dolphins communicate with humans?
Why are gorilla's arms longer than their legs and why are our arms shorter?
What makes a hen lay an egg and why so regularly?
How many different kinds of dinosaurs are there?
Why do whales beach themselves?
How do Chameleons change colour?
What is the most scientifically amazing thing you have come across?
What do pauas breathe out?
Simon York, of King's High School, asked:-
Why do alpacas spit?
Why do dogs chase cats?
How does a spittle bug make its spit?
Why do magpies go for shiny things?
Why do all birds wake up at the same time?
Can snails get indigestion?
Why do native earth worms secrete a bioluminescent substance?
How do sharks communicate?
What was the first bird in the estuary?
What do oysters eat?
Why are there so many types of animals in the Estuary?
Kimberly Stuart, of Otago Girl's High School, asked:-
Are all earth worms native?
Were any dinosaurs warm blooded?
Why do birds travel in a flock?
How many different kinds of birds use a large estuary?
Why do fish have scales?
If a container of alcohol is left out for slugs and snails will they become intoxicated or die?
How do dolphins sleep?
Do insects have brains?
Do insects have brains?
Why are there no monkeys in New Zealand?
Why can't penguins fly?
Do all animals grow?