A Christchurch researcher may have found a way to dramatically increase the effectiveness of possum traps.
At present the success rate for possum traps can be as low as 30 percent, but a new lure which replaces icing sugar with possum urine has increased the kill rate by as much as 25 percent.
Lure creator and Landcare Research scientist Janine Duckworth said possums spent more time at the traps set with urine and were more likely to trigger the trap.
"Animals communicate with scent quite a lot. By smelling the possum urine they can tell the sex of the possum, how old it is, whether it's interested in mating."
The idea came to Dr Duckworth after she helped rid Kapiti Island of a male stoat that was wreaking havoc on endangered birds.
"They hadn't been able to get their food lures to work and they knew there were stoats there from November through to February and we happened to have female stoats in our facility that were in season.
"So we sent up some bedding material to them and they caught the male within that week."
Dr Duckworth said another advantage of using possum urine was that it only caught possums.
"There are traps out there ... that use food as a bait and that attracts the possums but it also attracts rats.
"They're not designed to kill rats very effectively and they're wasting a lot of their gas propellant. If they only had possums they'd have a better success rate."
Poison remains the most effective means of controlling possums, but trapping is preferred near towns and cities and where water supplies need to be protected.
A six to eight month trial of a synthetic version of the new lure will begin this month.
If it is successful, Janine Duckworth hopes to develop another one for stoats.