Science badge: Large animals: task 3

Task: 3** Write notes on 3 introduced animals e.g. opossum, deer, goat, stoat, rat etc, stating the effect they have on our environment.

Animal 1: Red deer: more than 250 Red deer were introduced between 1861 and 1919 for sport. These were usually brought directly from the UK. The Red deer is the most widespread type of deer in New Zealand.

Effect on the enviroment: The deer feed primarily on understory vegetation, which has led to a reduction in the abundance of seedlings and saplings and threatens to change the forest composition. They preferentially browse certain species, which alters forest composition and allows only the least favorable plants to recover. Therefore, the introduction of deer has caused a serious decline understory herbs and shrubs. As of 2009 the government of conservation has declared them a threat.
Controlling the numbers: At the moment there are actions towards restricting the population, hunters are encouraged to kill as many as they want.

Animal 2: Pacific rat: The Pacific rat was introduced 700 years ago in the boats of polynesian seafarers. At the time of the first landings there were 50-500 rats.

Effect on the enviroment: Nowadays the Pacific rat has almost no effect on the enviroment as ship and european rats pushed their numbers down but back when they first arrived is a whole different story. The Pacific rat is believed to have put multiple species onto the extinct list when the first came. In 1920 the Pacific rat were considered extinct due to the ship and european rats but a few still survive on Fiordland, on Stewart Island and on several offshore islands.

Controlling the population: Because of the small numbers they have no actions towards controlling the population. You could almost say that the places they live restricts the population.

Animal 3:Common Myna:  around 200 Common Mynahs (yes that's it’s plural) was introduced between 1870 and 1877 by Acclimatisation Societies and private individuals.www.nzbirds said this “Mynahs persisted in the South Island until about 1890. They were once numerous in the southern part of the North Island but now are mainly found in the northern North Island farmland, orchards, and suburban gardens”.

Effect on the enviroment: Mynahs have had both postive and negative effect on the enviroment. The positive side is that they take out crop eating insects so basically they’re living insecticides. The bad side is that they are a threat to native species as they are bigger than them so can steal food, nests and even kill chicks.

Controlling the population: Unfortunately there is nothing currently controlling the Myna population due to the good things they do on farms (also the government doesn't care but whatever) although some people do kill them.