Vanessa says another bonus has been encounters with rarely seen birdlife including the threatened whio, the at risk kārearea and the New Zealand falcon.
The couple says their native forest block has also proved invaluable for giving their city-dwelling grandchildren experience of the New Zealand bush and waterways.
Their forest remnant is on the Taranaki Regional Council's register of Key Native Ecosystems (KNEs), under which a tailored Biodiversity Plan has been drawn up.
This supports their fencing and predator-control programme and opened the way for a variety of assistance including providing traps and advice from experienced field officers.
Mat says their expertise has been useful.
Taranaki Regional Council, QEII National Trust and New Plymouth District Council helped assist with the cost of the fencing by contributing funds.
The Council's Environment Services Manager, Steve Ellis, says the voluntary KNE programme is getting good results, with 293 sites on the register covering almost 123,400ha.
In recent years the Council has boosted its funding for Biodiversity Plans, with officers now preparing 20 to 25 a year.
"So if anyone thinks they might have something special on their property, they should call us so we can arrange an ecological assessment," he says.
"If everything falls into place, and the area can be legally protected with a QEII covenant or the like, then the way may be open for the sort of assistance Mat and Vanessa are benefiting from."
The Vujcichs see this protected and restored forest remnant as their responsibility and eventual legacy.
"It's all about using the land for what it's best suited to and that doesn't mean chasing every last blade of grass."
■ To contact Taranaki Regional Council about an ecological assessment, call 0800 736 222.