There are now more than 4400 protected areas throughout New Zealand, ranging from small backyard patches to large swathes of high country land, protecting more than 180,000ha of private land.
Mr Thomas recently hosted an informal gathering at his Strath Taieri property and more than 70 people turned up, from the southern end of the Catlins through to North Otago, the Otago Peninsula and "everywhere in between".
The intention was to be an informal opportunity for networking and giving people who had covenants the chance to talk to each other, as they sometimes did not get a chance to network with other covenanters, he said.
For those thinking about getting a covenant, or who had recently got one, it also gave them a chance to talk to those with experience.
Specialist native plant nursery propagator Anita Pillai provided advice on eco-sourcing or propagating native plants. There were also predator traps on display for anyone wanting to explore options.
There was a "huge" level of interest in the covenant process, something Mr Thomas attributed to a general awareness of the options that were available, and a desire by people wanting to see areas of interest protected in perpetuity.
"Landowners these days want to be seen to be engaged in protecting areas that are vulnerable or unique or special," he said.
There were many landowners with "little patches" on their property that they already looked after, whether it was bush or wetlands or "whatever", and it came to a point that they wondered what would happen in the future.
They wanted to see it protected in perpetuity and the work they had done recognised in the long-term, Mr Thomas said.
There were some "absolute jewels" within his Otago patch, including sites that were home to the Eldon's galaxias, one of New Zealand's rarest freshwater fish, which were found in eastern areas of Otago.
They lived in small tributaries of the Taieri, Waipori and Tokomairaro rivers, draining from the Lammerlaw range, downstream of Lake Mahinerangi.
Other sites had rare species, such as various geckos and skinks, as well as those with vegetation itself. A salt meadow just north of Dunedin was a "magnificent area".
What was very important was that it stayed private land, he said.
"It's their [the landowners] land, it's not QEII, Crown or Government, it remains their land."
The majority of landowners were happy for people to visit but the covenant did not give an inherent right of access to the public.
When it came to selling a property, having a covenant was often seen as being a positive aspect. It was legal protection and that had been tested a few times lately in court by developers wanting to develop a property. The integrity of covenants had been reinforced in court, he said.
Peter and Jeannie Hayden "inherited" a covenant when they bought their Portobello property.
They now had about 12ha covenanted, exactly half the property, on the steeper part.
It used to be a sheep farm 30 years ago and the bush had been regenerating ever since, including manuka, kanuka and a lot of broadleaf species.
Some of their neighbours also had covenants and, between them, it made a rather significant patch of regenerative bush, Mr Hayden said.
They were also all doing predator control and biodiversity was returning. The tiny rifleman had returned for the first time, and there were lots of tui, bellbirds, kereru and fantails.
Mr Hayden believed the "pendulum was swinging" towards the fact that not all land could be subdivided. Land had to be looked at differently these days and, as urban sprawl continued, there had to be an equivalent amount of land protected, he said.
Also living on the Otago Peninsula are John and Moira Parker who have two QEII covenants covering 36ha, the first on land they bought in 1993 which had not had any livestock grazing since then.
The native regeneration had been "quite astounding" and while it took a while, they now had totara saplings, a lovely mix of fern species and a lot of other species coming away, Mrs Parker said.
"That's all from what nature has done," she said.
They had removed a lot of exotics, such as hawthorn, elderberry and box thorn, and their problem at the moment was the banana passionfruit vine.
The dawn chorus of birds was now "really quite something" — and she attributed that to there being more food for them, along with the shelter.
There was no downside to having a covenant; it was up to the landowner how much effort they wanted to put in.
The network of covenanters on their area of the peninsula made it even more valuable, she said.
Many years ago, Mrs Parker worked with the trust's previous representative and they collected seeds from plants on the peninsula — that were now quite rare — and propagated them, some of which she now had on her covenant.
South Otago farmer David Vollweiler, who farms near Milton, said it was "fantastic" to have a gathering of like-minded people.
When the Vollweilers bought most of the farm next door, which belonged to Mr Vollweiler's cousin Bruce, nearly 20 years ago, Bruce Vollweiler had set in motion the covenant process, although it had not been officially done.
They decided to continue with that and they now had about 18ha protected in four different blocks.
The three original blocks were mid-altitude wetlands and, more recently, when it was discovered their property was home to the Eldon's galaxias, they fenced another area off.
All covenanted areas were on parts of the farm that were not grazing stock anyway.
It had been a "win-win" and it had enhanced the farm, particularly the wetland area, Mr Vollweiler said.
The area where the galaxias were was a steep kanuka-covered block and while they were not easy to spot, it was special to have them on the property. The family believed the wetlands area was also an attractive area.
