Problems caused by endemics

Any experienced NZ birder can tell you of at least one occurrence in which they have seen a tui chase away another bird for no apparent reason.

They are bona fide bullies when it comes to how aggressive they are to other birds, despite not usually having anything to protect.

Because some people are quick to come to the conclusion that the aggression that such birds as eastern rosellas, mynas, and starlings show towards other birds means that they are effecting their numbers, I'm wondering if anyone has ever thought about this for tui, and considered studying whether or not their aggression has a more serious impact on other birds than previously thought?

This is an example of how an endemic species can be a notable problem to the natural or cultural environment. Though conservationists are more lenient regarding the killing and control of natives, such as black-backed gulls, spur-winged plovers, and shovelers, the possibility of endemic species being a problem is more-or-less a taboo subject to them. The weka is the only endemic species I know of which has been widely accepted among conservationists as being a 'troublemaker'.

There are examples of endemic birds apart from the tui causing problems to the natural or cultural environment. There is some evidence that native robins can cause tomtits to die out easily via competition, kereru are occasionally considered a pest to fruit crops, just as eastern rosellas are, and South Island pied oystercatchers have been accused of taking too many shellfish and being a major nuisance in other ways.

I am not suggesting that any of these species should be culled for their apparent negative impacts. Neither of the complaints about the oystercatchers are reason enough to cull them, and they were most likely being used as scapegoats for why there seemed to be fewer shellfish around.

As for the impacts that kereru and robins have, however, perhaps further investigation should be made (especially in the case of the robins).

Perhaps there will come a time when the weka is not the only endemic bird species that has been killed in defence of something or someone else.

My point is that it's time for it to be more widely acknowledged that, in one way or another, endemic birds can be pests too. The fact that they are found nowhere else on earth has nothing to do with their environmental impacts.