- 70 -Slide4: So looking here at the number of eradications in New Zealand over time, you can see that in the early years the eradications were still quite a rare event, until around the 1990s when our techniques and available tools improved dramatically, and you can see since that time that the number of eradications has risen very sharply reaching almost 500 today. And I would just like to acknowledge that the data for this graph came from Island Conservation’sonline database of all invasive species eradications, you can see the web address for that on the monitor screen there.Slide5: When we look at the sizes of the islands where eradications have been completed, we see a similar pattern. These data come from a paper by my colleagues Clout and Russell in New Zealand and they are looking at eradication of rodents from New Zealand islands. And we can see that until the 1990s all of the islands where rodent eradications took place were very small, just a few hectares or a few tens of hectares. But since the mid-1990s we had developed an ability to eradicate those from much, much larger islands, the largest one being Campbell Island o the coast of New Zealand, which is 12,000 hectares in size.Slide6: Looking now at eradications of feral cats from islands around the world, once again the data here come from the Island Conservation database, and there have been 101 successful eradications of cats from various islands, most of which as you can see on the map there have been in Australia, New Zealand and Mexico. Slide7: And once again, we see over time a sharp increase in the size of islands where the cat eradications have been successful. So the very rst eradication of feral cats in the world was in New Zealand, and it took place on a very small island, which you can see in the photograph on the top right there, called Stephens Island which is only 1.5 square kilometers in size. But as you can see on the graph below, over the years we have taken on islands of increasing size. with the largest is Marion Island, which is o the coast of South Africa, where feral cats were eradicated in 1991.That island is almost 300 square kilometers in size.Slide8: As I might have said there have been a lot of the very positive outcomes that have arisen from eradicating feral cats from islands and rst among these have been some very dramatic increases in the abundance of native birds, mammals and reptiles on these islands. In addition on some islands locally extinct species which still survived on other islands elsewhere have been successfully reintroduced after feral cats have been removed. And this is what we can see in the photographs on the bottom here. This is an island in Australia where these endangered
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