Pest Inquiry (Norway Rat)

Introduction,

Sometime during 1870, the Norway rat was introduced to New Zealand. They didn’t know it then, but they would wreak havoc for many years to come. It is partially responsible for the endangerment of a variety of native species. We feel that covering a range of rat-infested bush using a variety of rat traps would in some ways mitigate the growth of Norway rats. Now it's stealing even more eggs, eating even more baby chickens and now they are all over New Zealand! This report is warning the public of this pest problem and how to mitigate the deleterious effect of Norway rats in the BOP.

Background

Norway rats were accidentally brought into New Zealand on the sailing ships of the first European explorers, who arrived in Aotearoa in the late 1700s. Once off the sailing vessels, they rapidly spread across the country leaving disease and destruction in their path. Norway originated in northern China despite its name. Around the world, it is also known as the barn rat, brown rat, common rat, grey rat, house rat, water rat, wharf rat, sewer rat, and super rat -because of its size.

Food Web

Rats are predators and eat little bugs, bird eggs and insects. Rats are secondary consumers meaning that they eat things that feast on plants. The Norway rats are very competitive and will readily drive out other rats or mice -competitors- just to have a little more food. Their diet includes seeds, grains, bird eggs, baby birds, grasshoppers, bugs and insects.

Effects - Native animals

The Brown rat has either caused or contributed to most or if not, all of the extinction events or territory loss of our native mammals, birds, reptiles, bugs and invertebrates through hunting and competition. It restricts the regeneration of many plant species by eating its seeds and seedlings. It will eat food crops and ruin stored human food by urinating and defecating in them -pooping on them-. By eating the seeds and fruit of many native plants they are also preventing them from reproducing and so they are slowly dying away and becoming less common.

Effects - Ecosystem

Some of the most dramatic impacts of our dreadful neighbours have been seen on islands where they cause a tremendous amount of damage to seabird populations by killing and eating eggs. They also feed on chicks and occasionally adults larger than themselves. This causes the food chain to crack and threatens all the animals in it. They threaten animals living, roosting or nesting near the ground. They do this by taking birds’ eggs and nestlings, native insects and lizards to feed their large appetite. This causes some wildlife to starve or thrive and eat too much, nearly making the food chain crumble as well.

Behaviour

What do we know about brown rat behaviour? Well for certain we all know that they eat and collect trash but that's just the brink of their ultimate knowledge. First, we need to know when they are awake and active, reasons: Gives info on where to put traps, distinguishes where to spread poison (1080) and study them. So with the info, I have gathered they are most active around dusk, at this time they dig barrows and make nests commonly around water. There is a lot of learning capacity in Norway rat’s brains, they can navigate through a complex sewer and burrow networks. The brown rats can live in packs, if so, they would live in male-dominated groups, and their nests are made of any efficient forged materials including leaves, garbage, twigs etc.

(Their average territory size is 2000 m2) and finally, to sum this up they are excellent swimmers capable of swimming 400 meters or more.

Control methods - Trapping

Trapping can range from just your regular spring mousetrap in your garage to industrial-grade rat traps that are out in our native forests trying to keep the pests at bay. Trapping is one of the best methods to eradicate the rats in New Zealand because it does not impact the environment and they are reusable -to an extent. However, this is not the best thing about the trap as there are many traps built in different ways. For example, we have a normal rat trap and a spring-loaded pressure trap with a metal clamp to break its neck. Then we have the A24, a gas-powered automatic skull-crushing trap where a rat or stoat puts its head up a hole to get a delicious treat and BAM! A plastic crusher crushes its head. Then the gas kicks in and pulls the crusher back up for its next kill. These examples are just the beginning as they are reasonably priced and can be spread over great distances without much cost.

Control methods - Poison

Setting out rat poison in the form of bait is a very effective option as the poison is ingested and then the rat dies. However, it's highly recommended that you do not put rat poison near the house, why? Because we contacted an expert from the pest trip we did on Tuesday and I asked a few questions “what are Rats attracted to?”, “How often do they catch rats?” and have you noticed Rats evolving of late?” they replied with Rat poison attracts Rats, Rats are the most common thing they catch and did not answer the last. Yes, rats will hang around the poison dropping dead one by one. Unfortunately, when a rat has been poisoned it does not go out and look for food it dies in its nest which is probably under the house. If a rat feels unwell it will have no energy to go out and look for food it will lie down and die. Another way of killing rats with poison is bait stations with rat poison set out far from the house. It will attract Rats from their nests and then they will go back and die just the same way as the bait poison. 1080 is a poison called sodium fluoroacetate - it's made synthetically, dropped down from a high place covering a range of land. A good amount of 1080 costs around 17 dollars. This poison is very effective and costs less than a large chocolate bar, however, it also has effects on the other wildlife in the area.

Conclusion

In this report we have gone over control methods for rats, the effects they have on our Ecosystem, and the effects on native animals. We also showed how they got here and what their food web looks like. You should know all about traps and poisons because the chance is that you will be using one of those in the future, which means that you should know what damages they do to the ecosystem and our native animals. We listed every given name for the Norway rat along with tons of other information. Don't forget, that they have blood on their paws from setting up the extinction event for multiple of our native birds. The best way to get rid of these killing machines are, 1080, a poison made for death, the doc200, a rat trap that is 100% effective, and the best for last the Goodnature A24, the best rat killing machine there is out there with about 3,000+ of kills under its belt.

PMI Analysis