Join our zoo community

Conservation on Rotoroa island

Discussion in 'New Zealand' started by vogelcommando, 22 Apr 2015.

  1. vogelcommando

    vogelcommando Well-Known Member

    Joined:
    10 Dec 2012
    Posts:
    12,074
    Location:
    fijnaart, the netherlands
  2. LaughingDove

    LaughingDove Well-Known Member

    Joined:
    16 May 2014
    Posts:
    1,998
    Location:
    Warsaw, Poland
    Wow, that's a very interesting project that I hadn't actually heard about before.

    It sounds like a great idea, but I really do wonder whether this is the appropriate way forward.

    It sounds like something in between a natural environment and a zoo, of course almost all - if not all - natural environments are managed in some way but creating this completely unsustainable 'natural' environment is... well, I'm just not sure about.

    I fail to see what this island accomplishes that can't be accomplished in a zoo or breeding centre of some kind. Keeping kiwis there until they are a certain age and then moving them just sounds a little pointless, why can't this be done in a zoo or breeding centre? Why is an island needed?

    Of course I appreciate that it is a habitat that is free of predators but so are the cages in a zoo and to be honest, the cages in a zoo aren't really much more natural than this island.

    Of course clearing farms and buildings and attracting back sea birds is fantastic but the hinting towards culling of weka is a tad worrying to me. Passenger pigeons were once common... I don't think that getting rid (even if only partially) of the common species and replacing them with rarer species is a brilliant idea.

    I'm not arguing that rare species like takahes shouldn't be protected - of course they should, and I realise that radical conservation action is needed around the world... but I do have some reservations about this idea.
     
  3. zooboy28

    zooboy28 Moderator Staff Member

    Joined:
    1 Aug 2010
    Posts:
    4,625
    Location:
    Melbourne, Aust (ex. NZ)
    I'm not sure I see any particular problem here laughingdove, in fact it seems to be a brilliant idea all around. There is a large information centre set up at Auckland Zoo that showcases Rotoroa and future plans.

    It might not be a natural ecosystem, but in reality its not far off, and for all intents and purposes the species on the island will find it much more natural than any zoo environment. And I can't see that it matters if its "unsustainable". The only thing the sustaining (I guess through additional food provision) is going to do is keep population numbers higher than the island can support itself, but is this an issue? I imagine that once species begin to properly establish, the island can be used as a source for repopulating other areas.

    I'm not sure I see your point about just having kiwi in zoos or breeding centres. In the wild, kiwi chicks almost never survive, but adults generally do quite well, so for many years the policy has been to raise chicks in captivity (often from wild eggs) and release them as young adults. In a zoo, this means they live in a cage and presumably get most of their food artificially, whereas on the island they can be left to their own devices, collecting their own food as they would in the wild, which should set them up better for life in the wild. And it should also be cheaper.

    Weka are a problem, and culling of any species is always going to elicit some strong reactions. But they are/were at numbers far too high for the island to cope with. It may be possible to relocate some to the mainland, which would probably go down better.

    All together, it seems like it should go very well and has a bright future ahead!
     
  4. Chlidonias

    Chlidonias Moderator Staff Member

    Joined:
    13 Jun 2007
    Posts:
    17,360
    Location:
    everywhere
    with regards to kiwi creches, LaughingDove is probably unaware of how Operation Nest Egg (ONE) works. Kiwi eggs are taken from the wild, incubated in captivity, and the chicks are kept in predator-free environments for the first six months or so of their life before being released into the wild again. Because of all the mammalian predators now in NZ (cats and stoats in particular) something like 95% of kiwi chicks are killed in the wild. Head-starting enables a far higher number to reach adulthood. Since ONE began in 1995 over 2000 kiwi chicks have been released.

    Most of the chicks are head-started on actual islands or on "mainland islands" (predator-fenced areas of forest). Only a very few are done so in captive situations (zoos). It doesn't really matter where in NZ the islands are, because the chicks aren't staying there, they are just growing up there. For example, most of the Okarito Brown Kiwi are head-started on islands in the Marlborough Sounds, and some of the Great Spotted Kiwi are head-started in a fenced forest in the middle of Christchurch city.

    Many other species in NZ have national populations which are entirely or partly artificially managed.
     
  5. LaughingDove

    LaughingDove Well-Known Member

    Joined:
    16 May 2014
    Posts:
    1,998
    Location:
    Warsaw, Poland
    I didn't realise that kiwi populations were managed to this extent. Are there any completely unmanaged wild populations?

    Whilst this particular project may be good in terms of protecting endangered species in a predator free environment, the thing that I was questioning was the idea of protecting species by moving them to places away from their threats where they are not native. As the article said, the idea of "creating an ecosystem anew" and we already know with countless examples (cane toads etc.) that people don't know what they're doing when they create an "ecosystem anew" (or - as what is really the case because of the fact that there is already an ecosystem on the island - messing with an existing ecosystem). I just wonder about unforeseen effects of introducing non-natives.

    Of course, the habitat on this island is going to be similar to the mainland so I don't the there will be (as many) unforeseen effects of introducing these species but if this idea was to extend further with species from somewhere completely different (such as - as was suggested on a different thread - the idea of introducing red wolves to the UK if wolves were to be introduced rather than grey wolves) then there could be huge effects that people didn't see coming at all.
     
  6. Chlidonias

    Chlidonias Moderator Staff Member

    Joined:
    13 Jun 2007
    Posts:
    17,360
    Location:
    everywhere
    yes there are. Stewart Island kiwi are not managed at all, because there are no mustelids on the island: the primary killer of kiwi chicks are stoats. On the main islands (the North and South Islands) any unmanaged populations will become extinct. Kiwi live a long time (over forty years) so populations will remain present for decades but if almost all the chicks are being eaten every year then when those adults start dying off the entire population will just crash. Operation Nest Egg started (back in 1995) with North Island Brown Kiwi because that was the species for which there was the most knowledge. Great Spotted, Okarito Brown and Haast Brown Kiwi came in more recently. A majority of the eggs from Okarito and Haast Kiwi are collected and hatched in captivity each year because there are only a few hundred birds of each.

    the island's ecosystem has already been destroyed. It was a forested island which was turned into farmland. The project is restoring it to a forested island. They are replanting the trees, and most of the wildlife will have to be returned to the island by humans; very little would find its own way back. It really isn't important if a lizard from the Auckland region is introduced there or a lizard from the Nelson region, or if it is used for creching kiwi or if they put some takahe there. It is never going to be a complete ecosystem anyway (not least because a lot of the species are now extinct). An important thing to know also is that very many of the "natural" ranges of NZ species are actually relict ranges; especially with the reptiles and invertebrates you will find a species now found only on one offshore island or at two mainland sites a thousand kilometres apart, but which was once spread over the entire mainland until rats arrived in the country. A good example from kiwi is the Okarito Brown Kiwi - now it is found only around Okarito which is a swamp town halfway down the West Coast of the South Island; formerly it was found right up the west side and top of the South Island and across the lower half of the North Island. One of the best-known island sanctuaries in NZ is Tiritiri Matangi, and that is no more natural than Rotoroa. It was farmland returned to forest, and most of the species now present were introduced there. The takahe there are not native (they are a South Island species - the North Island takahe is extinct), and the stitchbird population there depends almost entirely on humans to survive (there is only one truly self-sustaining stitchbird population left in the country [read: world]). It is the way it is in NZ now - if the native species aren't managed then many of them simply aren't going to exist any more.

    that is a whole different situation. Red wolves to the UK instead of grey wolves would be the equivalent of something like introducing harpy eagles to NZ to replace the Haast's eagle. Not even remotely similar to the Rotoroa Island project.
     
  7. DavidBrown

    DavidBrown Moderator Staff Member

    Joined:
    12 Aug 2008
    Posts:
    3,808
    Location:
    California, USA
    Are there any substantial natural areas on the North or South Island that have retained their natural vegetation and wildlife intact? Obviously the removal of the moas and Haast's eagles have likely impacted some ecosystems in ways that no one can know.
     
  8. Chlidonias

    Chlidonias Moderator Staff Member

    Joined:
    13 Jun 2007
    Posts:
    17,360
    Location:
    everywhere
    not really. There are still extensive tracts of forest on the main islands, but they are ravaged by deer and possums, and the wildlife is destroyed by cats, rats, mustelids and wasps. What is extremely noticeable in NZ forests is the silence. The birds are almost all gone. Something foreign birders always comment on is how the first birds they see on arriving in NZ are invariably English species. I think NZ's post-human extinction level is second only to that of Hawaii. It is only on the offshore islands where you can get a sense of what NZ used to be like, and even there the ecosystems are missing half their components. Fortunately NZ has an abundance of offshore islands.

    Regarding non-forest areas, the alpine regions are degraded by goats, chamois and tahr; the lower altitude tussocklands and scrublands have largely been turned into farmland; and the wetlands are mostly either tamed or drained.