Kaka Damage to Crops & Trees

[Dave Houston]

This from John Heaphy in Tauranga;

Over the last few years we have had increasing numbers of NI kaka wintering over around the rural western BOP area & even living within Tauranga city itself. They are coming over from Tuhua (Mayor Island) & out of the Kaimai/Mamaku ranges. Probably several hundred of them now & wonderful news but....

Our message to horticulturalists and orchardists has been to put up with their damage but the kaka numbers are now increasing to such an extent that this message is wearing thin.

One tree cropper has complained today about 8 kaka stripping bark to probably source sap from the heads of 20 yr old Cupressus lusitanica over the last couple of months, to the extent that 2 trees have so far died and another 15 are severely impacted on so far this winter. They seem to favour this particular species of tree & every year we get a number of complaints although not usually this severe.

Kaka always disperse in the spring back to the forests and Tuhua, but in the interim we need to deal with and respond to this damage. Loud random noises dont work with these parrots for long.

Has anyone tried any different methods to disuade kaka from attacking trees &/or fruit such as avocados & kiwifruit? Any polite construction suggestions welcomed.

A reply from Halema Jamieson on Great Barrier Island;

This is a problem we have had for several years out here on GBI with some locals taking the mater into their own hands – not a desirable outcome. We have tried many options and also canvassed the L\species group in the past for suggestions. I’ll send you another e-mail with all of the suggestions we have received and/or tried. In addition there is a good publication (Managing Bird Damage to Fruit and other Horticultural Crops by the Australian Government.) available on line at http://www.dpi.nsw.gov.au/agriculture/horticulture/pests-diseases-hort/multiple/managing-bird-damage

Good luck!

Any more sage advice out there?

[Stumbler]

I've had many trees killed or damaged by Kaka. Mainly Macracarpa species, but also Cherry and Birch.
They savagly use their beak to open and lever the bark up ....like an old style can opener, they then gently dab their tongue on the sap.
Usually they are predomoinantly young males, around November.
I've tried stringing up nylon with plastic supermarket bags attached between the rows, they just ignore this and carry on!; no amount of noise etc bothers them.
I think if it wasn't for all the squabbling and play, it woud be worse.
Pictures are of 17 yr old 6m pruned Macracarpa.

[Stumbler]

Another picture

[Lynn Adams]

I've copied a variety of comments recieved by email.

• Sturdy netting over the fruit trees
• I know somebody that's got bird-of -prey type kites on long bamboo sticks.  They do pretty well in the wind.
• We have the same problem over here - saying "aren't you lucky" is not the answer - but I don't have one.  They ring bark people's tree crops, eat fruit - have demolished one farms Pecan crop.  I had wondered about having "feeding stations" set up away from vulnerable sites - to keep 'em fed & lure them elsewhere, but that may just lead to more birds next year.
• Suggest doing all you can to encourage people to report the problem first.
• We have a similar problem for falcon, kereru and kea.  I'm convinced that publicity, hefty fines and public outrage are the only answer
  
• Perhaps you could suggest that people plant more fruit trees to compensate for the fruit that the kakas get to?,  I assume bird netting doesn't work? Other wise this could be a suggestion.  What about planting some non-invasive fruit trees along road edges wasteland so the kakas are free to eat/destroy these.  Which fruits do they like best, perhaps these would be the first choice.
• I heard of old cd's   suspended on nylon stretched  across ones backyard or tapes of NZ falcon's hunting call, quite kaka are pretty bomb proof, I have weka at home they are dynamite on everything below a metre, car keys #**%&!
• You are unlikely to achieve more than a temporary deterence for birds, particularly parrots.  Birds very quickly acclimatise to scaring devices etc and soon ignore them.  Presence of a real threat (e.g. your harrier trick) or falcons will work, but it's hard to keep them around and protecting a localised area when their ranges are so large.  Same problem, but on a bigger scale, is faced in Australia.  Planting of decoy crops has proven successful.  These crops are planted earlier (or for fruit trees, varieties that fruit earlier than the trees of value) and nearer to the habitat that the pest birds are coming from.  Works for parrots, etc that form big social feeding aggregations, e.g. cockatoos.  Might have some affect for less social species, such as kaka, but the fruit trees and birds are probably so widely dispersed that you'd need lots of pockets of decoy crops.  Don’t know if it's practical (or desireable) to have fruit trees all over the place.  Pines (Pinus or Cupressus) are a desireable food for parrots, including kaka, but again may not be desireable for conservation reasons.
  I have heard from farmers that firing a few shots into the air to scare birds away when they first start on a crop/fruit trees can encourage them to go elsewhere, but if they really want the fruit they'll come back.
• In the end people might just have to accept that fruit damage is the price they pay for living on such a unique island - a similar understanding seems to have been reached between the majority of high-country farmers and the kea population.
• I know kaka are pretty intelligent animals but bird scaring devices are used routinely in fishing operations to stop petrels and albatross taking baits from surface long line hooks. The best one is a streamer line that sits over the long line with light weight plastic streamers that flap randomly in the breeze. There doesn't seem to be a record of habituation. Reduces bird strike by up to 70%. What about trying streamers strung on poles above a few trees as an experiment. The other option could be nets over trees
• Not sure if this will work - You could try what I have seen my parents use in their vege garden:  Make a cardboard-cut-out shape of a harrier and hang it off a string tied between 2 poles -  above the fruit tree height. Here it will "fly" in the wind like a natural harrier. They also covered their predator birds with tinfoil to make them reflect the light.   This worked well for urban birds, but the Kaka may be too smart for this!
• Have the sonic bird scaring devices being used in vineyards been trialled with kaka?  Perhaps one could be borrowed or purchased and trailed on Great Barrier.  It could be loaned out when there were problem kaka.  The sonic device in combination with other non fatal detraction methods might work.  My father has found the sonic devices more effective than the traditional bangers used for bird scaring in vineyards.
• To deter black-backed gulls from airports. We made a styrofoam ( I guess one could use cardboard - not that it would be rain proof, or use plywood even) model of a dead bird - that is a cut out a life size silhouette of a dead bird with its wings outstretched and its head to one side so the whole model is displayed in a cruciform shape.  Paint it with the appropriate colours (easy for bb gulls, they're are black & white!) and then lay the model on the ground and when the offending birds turn up give them a blast of kaka distress/alarm calls.
• Maybe they could set up sensor water system that is triggered when kaka flying into tree.  Our captive and wild kaka seem to object to water being squirted around when we clean things and keep well clear.  Of course may not be good idea for area with water shortage (which I'm thinking may be a problem on GBI?), but then again trees would get an occasional watering as well courtesy of the helpful kaka!
• There are a variety of bird scarers available. These include recorded alarm calls, gas guns (which fire off a regular boom which can annoy the neighbours), bird scaring/hazing tape, raptor kites and all sorts of other objects. With most species the constant repetition of these devices leads to habituation in the birds and they quickly learn to ignore them. Some vineyards are using birds of prey with falconers to scare birds away.  Another option is excluder devices which mostly are some form of bird netting. I don’t think any of the ones I’ve seen will be kaka proof.   Finally, there is the human version of scaring which includes riding 4 wheel bikes around at peak feeding periods (dawn and dusk) and shooting at feral birds in the hope that kaka will get the message and push off.  For most orchardists, rotation of a bunch of bird scaring devices mixed with human scaring and judicious shooting is used to keep problem parrots out of Australian orchards, but there is also a heavy annual death toll from less concerned farmers.
• They have fruit trees and they put an owl (porcelain, very real-looking) in the tree, and kaka "stay away".   Said kaka are terrified of owls?    xx said that they took some peaches off the top of the tree, but left all the rest as the owl was in the centre of the tree.   They said they have got all their fruit this year - plums, peaches, ......
• There is a company based in Rakaia (mid Canterbury) that make large black hawk kites that are attached to poles and move around.
  I don't know how effective they are but a number of cropping farmers down this way use them.   We have a similar problem with Kereru and cherries at our holiday property in North Otago. While it is frustrating to get no cherries it is fantastic to have large flocks of birds. When we eventually move down there I will just cover the trees with bird netting.
• To the best of my knowledge there is no effective lasting deterrent that the Kakas will not eventually learn to adapt to. They are one of the most intelligent birds on the planet and will soon adapt to what ever you put out. I have seen this time and time again with other birds. If people are concerned then netting will deter most Kakas but when they are in their pre breeding hunger phase then nothing short of encasing the trees in concrete will stop them.

Good luck to those with this problem