what is a feral

To: "Birding-aus" <>, "david taylor" <>
Subject: what is a feral
From: "Greg & Val Clancy" <>
Date: Fri, 11 Jan 2008 10:32:47 +1100

Canada Geese are not in the came category as the other vagrants that you mention. They were introduced into New Zealand and therefore are quite different to the Northern Pintail, Northern Shoveler etc. These vagrants are mostly northern hemisphere breeding species and are unlikely to breed in Australia, even if more than one was to arrive. However if they did establish it would be a natural event and not a human induced introduction. If they stow away on ship, like the House Crow, then that is a different situation again, as they are human assisted. A native New Zealand bird that found its way without human intervention to Australia would not be treated as feral. The Kelp Gull has done just that and I don't hear anyone suggesting that the Kelp Gulls in Australia are feral. The Cattle Egret, Monarch (butterfly) and Asian House Gecko are in a different category again - self introduced species that only occur because of human modification to the natural environment in Australia. They probably don't pose the same sort of threat to natural ecosystems as do the Canada Geese as they have exploited human made, and otherwise vacant, niches. In fact Cattle Egrets may provide some protection to nesting Great, Intermediate and Little Egrets by increasing colony size and therefore improving security from predation. Cattle Egrets feed in different microhabitats to the other egrets and therefore don't compete directly for food.

Greg Clancy

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