The economic returns to erecting an efficient exclusion fence can often be difficult to quantify. Invariably it is reliant on an observation based on experiences before and after the erection of a fence.

The biggest issue facing western Queensland communities is the fight against feral dogs and Dingoes, farmers across the state have struggled to ensure their stock's safety, at a time when up to 20 per cent of livestock are massacred
from every farm in Barcaldine each year.

Barcaldine sheep farmer Willie Chandler has seen a 90 per cent increase in sheep production after employing high voltage fences to his properties. At its worst, his enterprise was losing around 300 sheep every year.

However, since installing electric fencing he has seen a huge increase in lamb production.

''Yes, it has been massive. We were losing so many sheep to dingoes each year. We have seen an increase of 80 to 90 per cent in sheep production, a percentage in lambs being born as well.''

Following a series of serious predation by foxes on a tern colony resulting in many nests being destroyed so affecting plans to increase the numbers of the birds it was decided to erect an electric fence to exclude foxes. This resulted in an increase in chick survival and the following comments by the RSVP

"Tracks and scats of the foxes were first noticed near the colony on 28th. May, and almost daily thereafter. On 18, 19, and 20th. June, observers recorded that the incubating terns seemed "skittish, nervous and uneasy." This phenomenon was first thought to be associated with hatching but no chicks were noted. Nest numbers decreased from 138 to 129 on 20th. June, to 61 on 22nd. June. By 23rd.June only 45 tern nests remained. Fox tracks crisscrossed the colony.

On 24th. June the electric fence was erected. On 25th. June we noted a slight increase to 48 nests; a week later, 2nd. July, we counted 60 nests, and by 6th. July, 85 nests. Fresh fox tracks were seen near the colony but no tracks were found in the trial area. New nests outside the fence were consistently taken bythe Foxes - none survived."

Despite having a "Rabbit Proof" fence a horticultural farmer in SW England was losing in the region of 25% of his Cauliflower crop to rabbits. After erecting a netting system he reduced this to zero (his estimation). The yield per Ha increased and he felt he had recovered the cost of the fence in the first year. The photo shows the impact an abundant rabbit population can have on an agricultural crop behind the fence.

A commercial citrus farm in Zimbabwe was losing a considerable quantity of oranges to ostriches who were invading the fields on a nightly basis. Despite having a physical presence it was only when an Electric fence was installed did this predation cease and his yield revert to what was expected.