Hanging from the edge of a cliff, often in darkness, to assess a sea bird population, is not your average hobby, but it is one that gives Graeme Loh great pleasure.
About 70 times a year, Mr Loh abseils down the cliff at Tunnel Beach, south of Dunedin, to check on a small colony of fairy prions - the only known population on mainland New Zealand.
The hobby started 17 years ago when Mr Loh, in his role as Department of Conservation ranger, was looking for Blue Penguin colonies, but instead noticed sea bird burrows on a ledge about 45m above the sea.
"It was an accidental discovery."
So he got his climbing gear together and abseiled about 25m down the cliff to investigate the ledge, discovering the population.
His love of sea birds, the sea and the close proximity to his home in St Clair meant the fairy prions soon became a hobby.
Fairy prions are common sea birds in New Zealand waters and not endangered, so not a species Doc looked after.
"It looked like some positive and interesting things could be done."
Fairy prions weigh only about 120g each and are vulnerable to rats, gulls and skuas.
They feed on the open ocean, returning to the ledge at night.
There were about 400 birds at the colony, which often dug into each other's burrows on the ledge and were sometimes in danger of being flooded or washed out.
Mr Loh built nesting boxes for the birds in 1994, started monitoring them closely and then banded them in 2000, with the aim of finding out how long it took for young birds to come back and breed successfully.
His research, likely to be the longest study done on the species, found it sometimes took two years after fledging, but generally three years was most common.
There were now 100 nesting boxes dug into the cliff face and nesting success in the boxes was high, he said.
It was easier to study the birds in the boxes than in their own burrows.
"They seem to like everything I've done for them.
"I can tell a new bird is in a nesting box as it will bite me.
"They seem to know me."
The best time to visit the colony was a moonless night.
Mr Loh often took visitors along.
"It is not as scary as in daytime and I get great pleasure out of introducing other people to the place and fostering interest and excitement around sea birds."
University of Otago associate professor Dr Phil Seddon said in his nomination of Mr Loh the project had provided essential information on the endemic sea bird, especially about when laying, hatching and fledging occur.
