New Zealand Cockatoo Populations

[OwenM]

Hi All, just wondering a bit about the populations of cockatoos in New Zealand. I have done extensive research on the subject but could find no estimates on the numbers for this year. My current estimate stands at 150 for west Auckland, with the core of that flock in the bethells river valley containing an estimated 45 birds and another flock which I’m not sure is just part of the bethells flock or seperate at cascades kauri falls. Another 200 for the Western Waikato spread between Port Waikato and Raglan, 300 For around Hunua and south Auckland, 100 for Miranda, 200+ for around Whanganui and Turakina And Pohangina Valleys, 100 For a few small flocks around Wellington, Just under 100 around Christchurch and around 50 other wild birds in small flocks scattered around New Zealand. Are these good estimates? I know they used to be much higher but the council has taken action with keeping them in check. I am most interested in the flocks around Auckland as that is where I am based. I also see some Ebird records from Tawharanui, are these records accurate? If so is there a somewhat established population in Tawharanui? I’d love some input on whether you think these estimates might be accurate. Thank you!

[andrewcrossland]

none around CHCH, but 60+ on Banks Peninsula. Almost certainly the progeny of 20 or more natural vagrants from Australia that arrived in 1986. They're controlled by shooting but this is probably ecologically and ethically wrong until provenance can be determined (which can probably be done through investigating their feather lice fauna)

[OwenM]

Completely agree with your about the killing of cockatoos. I don’t think it’s at all fair considering that it’s very possible that some of them are vagrants. Mistake of mine, by Christchurch I meant prices valley, really need to up my geography on that area

[Oscar Thomas]

A flock has been present south of Owaka in the Catlins (Otago) since at least the 1980s as well, high count of 12 in 2018 but usually 10 or 11 birds.

[OwenM]

Hi Oscar, yes I have heard of this flock but wasn’t sure if it was still active.

[paradoxdinokipi]

none around CHCH, but 60+ on Banks Peninsula. Almost certainly the progeny of 20 or more natural vagrants from Australia that arrived in 1986. They're controlled by shooting but this is probably ecologically and ethically wrong until provenance can be determined (which can probably be done through investigating their feather lice fauna)

Anymore information on this population and how likely could the 1980s flock have been a mass release? How much discussion was there around the time period and did any record committees accept these birds as vagrants?

[OwenM]

Hiya, Yes there probably was some sort of mass release in the 1980s as I heard there were huge flocks of 300+ in the waikato(and probably elsewhere too) although they may have already been there without the release. Still, there is a lot of evidence to suggest your theory is correct. Tomorrow I will probably be going out west to cascade kauri falls and bethells river valley to look for them, I’ll give updates if I find them

[paradoxdinokipi]

Nice, good luck to ya : )

[fras444]

Would the Cockatoo be a potential candidate for its status being upgraded from 'introduced' to 'native...??'

If we look at the black swan as the best example..

That species was documented as being introduced to New Zealand but because there was some evidence to suggest that birds were coming in from the tasman, that it was described as native...

This was going back to the early 19th century when records are not the most accurate...

There has been observations of fatigued birds around NZ.

What do you guys think..

As I say..

The black swan was introduced but its now described as a native species going of some quite... vague you could say, records on birds being blown over... I guess the Cockatoo is a very valid candidate...

[paradoxdinokipi]

I mean for the swans part of it is I assume that there was at least a very similar congener (plausibly only a subspecific difference??) that inhabited NZ until Maori colonisation whilst there's nothing really similar with cockatoos and also have not had near as much of a spread still being clustered to specific locations with some of these clusters being obviously introduced?