Apparent Zealandia Kaka Bite Marks in Avocado
Images of damage to Avocado Crop near Zealandia Reserve in Wellington, New Zealand. The crescent shape is consistent with bite marks from parrots on humans (1). I could not find any photos of Kaka bite marks but I can't see how it can be anything other than the NZ parrot known as Kaka from the recently instituted Zealandia Native Reserve.
It looks like the Kaka attacked the fruit on at least three occasions separated by several weeks, but they did not destroy all of the crop, about half were damaged and in earlier years none were (the trees are young, so far bearing small crops of fruit for about four years). I get the impression the Kaka are investigating the fruit, being intelligent curious animals, having checked them out them it appears they had no further interest in them. So far it does not appear they are obsessed with eating the fruit or fruit in general but it is too soon to be certain. Avocados do not ripen on the tree and are "said to be toxic"(4) when unripe, at least to humans, it is hard to imagine any human getting any pleasure from eating the hard unripe fruit, I don't know about parrots.
Still, if this is damage from Kaka I find this rather annoying, I'm not against reserves or natives, I plant quite a few natives myself, but always edible ones where I live, alongside edible exotics. I think realistic environmentalism promotes local self-reliance through edible and useful plant and animal species near where people live to reduce unnecessary resource depletion, waste and pollution associated with transportation. Unproductive untouched reserves like Zealandia are, in my opinion, better located in remote locations away from people for the good of both people and pristine native ecosystems.
Having a few reserves in central city areas may even be ecologically counterproductive if it people think it excuses all the damage they are doing everywhere else (a phenomenon known as the 'licensing syndrome' (2)). Reserves may also be bad for the planet if they protects species that destroy efforts at sustainable land use such as self-sufficiency in food. I suppose Zealandia may also have a rather high carbon footprint if travel for tourist visitors is taken into account, although probably no tourists travel to New Zealand just to visit Zealandia.
To say kaka should be able to run rampant because they are "natural" is a little like saying we should we should drink untreated water because it is "natural" (although admittedly probably not quite as extreme). Pristine wilderness is dangerous to humans despite the fact that it is often romanticized by people thoroughly insulated from it, as the environmental thinker Rene Dubos pointed out (3).
I emailed these photos to the Zealandia, Forest & Bird and the Department of Conservation, they suggested nets and planting something more desirable to distract them, perhaps that's the best we can hope for, unfortunately I find nets ugly & oppressive. They also pointed out it is illegal to "disturb" such species, so it sounds like Zealandia Kaka can destroy your property (such as home fruit trees which are much "greener" property than Zealandia I've argued) and you'll go to prison if you try to scare them off (!%#@!!???). Actually they mentioned (unsuccessful) attempts to scare them with balloons without any suggestion this was wrong so I assume reasonable attempts to scare them are legal. As far as I can see in the legislation "disturb" is only mentioned in the context of hunting protected species (as it should be), reasonable, humane, shooing of wildlife does not appear to be a concern, which seems like common sense surely.
I did recently realize the Kaka essentially ignored the bitter unripe green fruit of a Pawpaw/babaco cross "Rainbow Valley" a few feet away from the Avocado. It appears they may have sampled them just a little (picture) and decided they didn't like them.
These unripe fruit are supposed to be edible, I eat them cooked sometimes, but they are quite bitter. Apparently birds can detect at least some types of bitterness in order to avoid poisonous plants. Seems like a (non-toxic) bitter spray might be a possibility for some crops, especially if it can be washed off the fruit when harvested & somehow made so it doesn't seep into the flesh. There does seem to be a least one commercial bird repellant spray for protecting fruit. It seems like a major long shot but perhaps sprays could even be used to prevent Kaka from stripping bark off of privately owned trees looking for edible moth larvae.
I also caught a Kaka in the act of eating some of my first crop of Loquat fruit (Eriobotrya japonica). I told it to bugger off, it obliged but was lurking around again shortly after. Interestingly the fruit had just reached full ripeness that day, apparently birds detect ultra-violet light coming from ripe fruit we can't see, though doesn't explain the damage unripe avocados, probably they are more curious than most birds.
I've found Loquat fruit can be picked when partly green, not fully ripe, and ripened indoors, which may also be an option but reportedly the taste is not as good (4), I think this is true but have not had enough to be sure. An exquisite tasting fruit at its best, rather like pineapple and apricot jam.
Above : Large conifers that were killed by Kaka on private land close to Zealandia. The Kaka killed it by tearing off the bark. The trees had to be cut down as they were endangering the road below, costing over $3000. I told the city council, who self-righteously reintroduced kaka to the area via Zealandia, but they didn't offer to pay.
Research indicates kaka are much more likely to attack certain exotic confers, Lawson cyperus, Japanese cedar and macrocarpa in particular though apparently they may attack any tree, especially if encouraged by feeding for instance. They have ignored many other non-coniferous natives and exotics in this area.
I'm pretty sure my damaged trees are Cupresssocyparis x leylandii (close up photo below), which is a cross between macrocarpa and another conifer. So if you're wonder what trees NOT to plant in Wellington you might want to skip these. They have also killed several Norfolk Island pines (Araucaria heterophylla) nearby. They also attacked a redwood nearby.
It is unfortunate they attack such enormous conifers as they can become very dangerous and are expensive to cut down.
I believe it has always been known kaka tear bark off of trees looking for grubs to eat, this fact was probably ignored in the self-righteous zeal of government conservation decision makers when they decided to reintroduce kaka to Wellington.
References.
1. http://forums.avianavenue.com/index.php?threads/bird-bite-photos-warning-graphic.2394/
2. The Willpower Instinct. K McGonigal. 2012.
3. The Wooing of Earth. R Dubos. 1980.
Dubos argues convincingly the "natural" places we really like being in have been significantly modified by humans. Few would want to spend time in the New Zealand bush if the world's largest ever predatory eagle, the Haast's Eagle, had not been made extinct by early Maori settlers (apparently by causing the extinction of its main food source, the Moa). It is considered likely this eagle preyed on the first human settlers. Perhaps if genetic engineering advances sufficiently we should bring this species (or Tyrannosaurus rex) back in the name of conservation, to prey on humans, because it is "natural" and "pure". Better still trying to defend yourself when they attack would of course have to be illegal because they're "native" and "pure".
Obviously the cause of nationalistic purity has characterized well known, and once very popular, devastating ideologies such as Nazism. I'm not saying nationalist conservation zealots are as bad as Nazis but the use of reserves as something that excuses destroying the planet , while making self-sufficient homesteads difficult or impossible because of destructive protected species, may be in the end be far more harmful to humanity, despite "good intentions".
( http://www.wingspan.co.nz/extinct_birds_of_prey_new_zealand_haasts_eagle.html)
4. Discovering Fruit and Nuts. S Lyle. 2007.
