Most people think finding severely threatened birds means days in the wilderness, sleeping rough and spending hours, usually in pouring rain, waiting for a fleeting glimpse. Often, a small dot in the distance is all the reward even the most dedicated get.
Everyone knows threatened species and humans don’t mix; that’s why, when bird spotting, you have to go to such extremes. The Buller’s gull (tarāpuka) is the most threatened gull species in the world and is on the Department of Conservation’s list of ‘nationally critical’ species – those only one step from extinction.
In that case, someone should tell the Buller’s gull it’s making it far too easy for bird lovers to get a good view – they just have to visit Masterton. Most days, about a dozen adults are relaxing at Henley Lake and sometimes spill over into Queen Elizabeth Park. Grab a coffee, spend 10 minutes walking along a path, and you’re bound to spot a few.
The Buller’s is a small gull, which stands out from the crowd. Adults are easily identifiable by a long, straight black bill and black legs. From a distance, it looks similar to the New Zealand red-billed gull (tarāpunga), but at five or 10 metres, the Buller’s is no challenge, even to the most novice bird watcher.
The Buller’s gull is only found in New Zealand and, although it breeds in both islands, is mostly a southerner, with a real liking for Southland. A large decline in its main breeding colonies has fuelled its run to extinction. While Buller’s gulls are protected under the Wildlife Act, and there are severe penalties for those convicted of disturbing or killing the birds, their future looks grim, with ongoing decline greater than 70 per cent predicted by the Department of Conservation.
Wairarapa, however, is a happy exception. Counts of adult birds at Lake Wairarapa have shown a sustained increase over the past few years. There is one known nesting site at the Ruamahanga River, north of Masterton, and another found last summer at the mouth of the Tauherenikau River, where it enters Lake Wairarapa. Lake Wairarapa has long been a feeding ground for the gulls in winter.
Buller’s gulls mostly breed on sparsely-vegetated gravels on inland riverbeds. After the breeding season, distribution of adults and dispersal of juveniles are poorly known. Colonies are established in August-September, and are abandoned at the end of the breeding season in December to February, or occasionally earlier in response to floods, and predator or human disturbance.
The exact site of a colony may shift from year-to-year, but birds are generally faithful to one stretch of river. This made the colony at the Tauherenikau even more of a find as it may have been founded by birds that had abandoned the Ruamahanga, after high water swept through the colony earlier in the season.
The latest survey by the Department of Conservation along the eastern shore of Lake Wairarapa, in July this year, found a total of 781 Buller’s gulls. Lucky for us, something in Wairarapa seems to suit them.
Story by Tony Silbery.