Here is an experience from one of our Growers in Queensland who has had success with Bird Control in Olives:

“After trying almost every bird scaring devices in the last 5-10 years which included Gas Guns, Sound recorded scare devices, running out into the grove every 30 mins with ATV’s to scare them away, placing fake snakes (and some not so fake) in strategic parts of the grove… nothing seemed to work!  Roger says “We were going out of our minds!”  Then we came across a product called D-Ter.  Now, re the DETER. Recommended rate is 50g/litre.

Last season just gone, I cut it back to 15g/litre, but it was a quite rainy ripening season, and the combination of low rate and less than ideal weather led to a reduced effectiveness.

In a previous year, I’d used 20g/litre and I was happy with that result.  The directions state that the product loses it’s effectiveness in wet weather but that the effectiveness returns once the foliage dries out.  That may be so, but I believe that every shower washes some of it away, so in constantly wet weather, it just will not last the 8 to 10 weeks they say it can.
This other thing they say is to apply it BEFORE the bird pressure starts! Ha! That’s fine for them to say – they’re selling the stuff. So next season, I’ll try to schedule my one spraying (at 20g/litre) for about 8 weeks before harvest and hope for a dry couple of months, while using other bird deterrent techniques simultaneously.

Hope that helps. It’s not a silver bullet, and one has to look at the cost/benefit quite closely and make up your own mind. If you’re the stressful type and the birds are taking their toll on your sanity, you have to put a price on that too.

Ironically, my take is that DTER is for small producers like us, with few trees. The big guys, with thousands of trees, can probably tolerate bird intrusion around the edges, and just write off the loss. For us, the edges join up in the middle!!!

Keep up your tireless good work, Amanda – I don’t know where you find the energy.
All the best
RH, QLD”