AginED
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FOR E FUTURIA G R R S! U PR EN E
Volume 101 I April 18th, 2022 I email: agined@globalHQ.co.nz I www.farmersweekly.co.nz/agined Are you a parent or teacher and want to receive AginED every week directly to your email inbox? Send us an email to sign up at agined@globalhq.co.nz
Easter Edition!
For most people Easter brings images of eggs and bunnies (can anyone tell me how rabbits and not chickens came to be associated with easter?)
Anyway, with the fact that rabbits play a big role in easter proceedings we thought that we would take a look at the history of rabbits in NZ and the issues surrounding them. It is thought that the first rabbits were probably brought to the South coast of the South Island in New Zealand by whalers. They were an article of trade at shore stations, so were shipped from Sydney during the two decades of the 1820’s-1830’s along with other supplies. Rabbits were brought to New Zealand to provide game for sportsmen to hunt, for food, and to remind British settlers of home. It wasn’t long before they started causing problems through burrowing and pasture damage and by the mid-1870’s there was a serious reduction in sheep numbers, wool clip and lambing percentages associated with malnutrition of breeding ewes. 1
How could rabbits be responsible for reducing lambing percentages?
In a three month period in 1876 a leading Southland runholder killed 26,000 rabbits on his own 11,750 acres (4,755 ha) alone, by the efforts of men with spades, dogs and one gun. 1
How many rabbits a day would they have been killing? Soon the idea of introducing predators to control rabbit populations became a hot topic. Though there were a number of people who were not in favour of predator introduction including several ornithologists. 1
Runholders set fire to their properties in order to stimulate growth of tender new plants. The burning destroyed the tussocks but with it was the decimation of the plants that grew in their shelter, these lower grasses had provided the main fodder for sheep and anchored the soil. So even before the introduction of rabbits the tussock country was showing signs of weariness and by 1865 many of the runs needed 3.2 hectares to feed just one sheep. 1
What is a runholder?
2 What is the current average per hectare stocking rate for sheep? 3 How many sheep would now be produced on 3.2 hectares? 4 Why did landholders burn off the tussock and all other cover on their land? The owners of some stations began paying their men for rabbit tokens. Some managers paid for pairs of ears, and the men thought nothing of reaching into burrows, snipping off the ears and then putting the rabbits back—still alive, of course. For a while the sight of earless rabbits in traps or on poison lines was quite common. Some managers paid for tails. If a tail-collecting station was next door to an earcollecting station, the men used to meet in secret at the boundaries, swapping ears for tails, so that each rabbit provided two tokens, and two sets of pocket money. 1
Modern rabbit control methods More recently biological control has been introduced in the form of a virus commonly known as rabbit calicivirus 1
What is the full name of RHDV (calicivirus)?
2 How do rabbits catch RHDV? 3 Does it affect other animals? 4 How does the virus kill rabbits? 5 Is there more than one variant in NZ? 6 Who is responsible for rabbit control in NZ?
When did full time rabbiters arrive in greater numbers in NZ?
2 What was introduced in the 1880’s that allowed an export trade in rabbits to grow? (think about transportation over long distances)
What predators were introduced?
2 What is an ornithologist? 3 What concerns did they have about the introduction of predators to control rabbit populations. (Hint: think about the other things these predators may affect). Ferrets became the predator of choice for many landholders and private imports had been going on since the late 1860’s. However, ferrets were found to be bad travellers particularly on long sailing journeys and with carers who did not have knowledge of how to look after them. Losses were costly “600 ferrets were imported by George Bullen of Kaikoura, but every one of that consignment died. He started again with 700 and got two ferrets out of the 1,300”. Ferret breeding and poaching became lucrative. Rabbits spread through the North Island later. Mr C. R. Carter is said to have brought rabbits with him when he arrived in New Zealand in 1857. He liberated seven pairs at Carter's Hill, near Carterton, and within twelve years their progeny had covered a nineteen kilometre square area; twelve years later they had taken over an area of twenty thousand hectares. This incredible rate of reproduction led to what farmers called 'rabbit arithmetic'—that two times three equals nine million (the progeny of two rabbits in three years). Back in the South Island central Otago became desert-like. However, this was not due to rabbits alone.
Rabbiting became better regulated and rabbiters were persuaded to use poison which gave them only the profits from the skin alone. Jam was often used as bait and through informal experiments they found that quince and apple and raspberry jams were favoured while the rabbits were not at all interested in apricot jam.
Head to https://www.doc.govt.nz/ globalassets/documents/parks-andrecreation/places-to-visit/nelsonmarlborough/lake-tennyson-interpinfo.pdf and read about the impact of rabbits on Molesworth Station, New Zealand’s largest high country station which covers 182,000 hectares or 500,000 acres. 1
When were rabbits introduced to the Marlborough district?
2 The impact of rabbits caused the station to be returned to the Crown in what year? In 1893 over 17 million skins were exported, and this figure was maintained by the activities of rabbiters, until in 1919 over 20 million were sent overseas. In 1900 exports of frozen carcasses, in skin, had reached sixand-a-half million. 1
Using the number of frozen carcasses exported in 1900, can you work out how many rabbits were killed each month, week and day?
Early methods of controlling rabbits included hunting with dogs, digging out warrens, trapping and shooting. The rabbit boards favoured gas for killing rabbits in warrens. Rabbit proof fences were erected.
DO SOME RESEARCH. 1 How many rabbit proof fences were erected? 2 Where were the fences? 3 How effective were they?
3 What is Rabbit Calicivirus Disease and why was it introduced illegally? 4 How long was the Waiau rabbit fence and what materials was it constructed from? 5 Was the rabbit fence successful?
How many words can you make from the word RABBITER? There are 2 seven letter words that can be made and 16 six letter words? Can you make any of these?