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Great White Egret/Kotuko in NZ
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Jan
- Posts: 1987
- Joined: Fri Jul 03, 2009 10:43 am
- Location: Christchurch
Great White Egret/Kotuko in NZ
It seems like the Western Great White Egret now breeds in many sites in UK. It is described as being the same size as the Grey Heron. [Not the same as White-fronted Heron -it is much bigger]. Is the Western GWHeron significantly different to the Eastern GWH? Can our population not expand beyond the one Westland site for some reason we don't understand? Is it that NZ is too isolated and UK is close to a continent? Has UK had so much global warming that it's now almost semi-tropical, whereas NZ has escaped that, so far? Is thhis worth a discussion?
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RussCannings
- Posts: 1279
- Joined: Wed Sep 24, 2014 5:23 am
Re: Great White Egret/Kotuko in NZ
According to Google:
"Eastern Great Egret sizes that overlap with the Western Great Egret; however, the Eastern Great Egret is generally considered slightly smaller than the more cosmopolitan Western Great Egret. For example, the Eastern Great Egret measures 83–103 cm in length, while the Western Great Egret's length ranges from 80 to 104 cm, and its weight can be up to 1.5 kg compared to the Eastern's 0.7–1.2 kg. "
I suppose there could be a variety of reasons why kotuku haven't expanded their breeding range in NZ (And likely someone knows a lot more about this than I do!). If Okarito can support a colony then surely milder/less stormy parts of the North Island would be even better. It may just be that Okarito is where they happened to start but it's small enough and not quite ideal enough to promote growth yet (in-breeding maybe an issue too?).
Russ
"Eastern Great Egret sizes that overlap with the Western Great Egret; however, the Eastern Great Egret is generally considered slightly smaller than the more cosmopolitan Western Great Egret. For example, the Eastern Great Egret measures 83–103 cm in length, while the Western Great Egret's length ranges from 80 to 104 cm, and its weight can be up to 1.5 kg compared to the Eastern's 0.7–1.2 kg. "
I suppose there could be a variety of reasons why kotuku haven't expanded their breeding range in NZ (And likely someone knows a lot more about this than I do!). If Okarito can support a colony then surely milder/less stormy parts of the North Island would be even better. It may just be that Okarito is where they happened to start but it's small enough and not quite ideal enough to promote growth yet (in-breeding maybe an issue too?).
Russ