The snowberry is that low-growing, woody shrub of the alpine zone, with its small white or pink bell-shaped flowers and its bright white berries that feed the birds through the winter. It is a tough little plant, a survivor of frost and wind. But there was once a snowberry that grew larger than any alive today – a shrub that reached nearly a metre high, with leaves as thick as leather and berries as big as your thumb. It was the giant alpine berry, and it is gone.
Size and its fruit made it special. An 80-centimetre shrub in the alpine zone is a giant – a woody tower in a world of low-growing herbs and mosses. Its berries were large and juicy, rich in sugars and fats – a critical food source for the birds that survived the alpine winter. The tūī, the
bellbird, the pipit – all would have fed on these berries, carrying the seeds across the mountain.
It fed the alpine zone. In the harsh environment above the treeline, food is scarce. The giant alpine berry produced a crop of berries each autumn, just before the snow arrived. The birds ate the berries, fattened up for winter, and dispersed the seeds across the mountain. The shrub was a keystone species, a living larder for the alpine community. Its leaves were tough and leathery, adapted to cold and wind. Its roots spread wide, holding the thin alpine soil in place. Its flowers – probably small, white or pink, bell-shaped like its relatives – provided nectar for alpine insects in the short summer.
It flowered in spring, after the snow melted. Its flowers were pollinated by insects – native bees, moths, flies. Its berries ripened in autumn. The seeds required passage through a bird's gut to germinate. That strategy worked when the birds were abundant and the climate was stable. It failed when the birds declined and the mountain warmed.
Climate warming and bird decline destroyed it. When the climate warmed at the end of the last ice age, the alpine zone shrank. The giant alpine berry, adapted to cold, found its habitat contracting up the mountain. There is only so far up you can go. Eventually, there was no mountain left. At the same time, the birds that dispersed its seeds declined. The tūī and the
bellbird were hunted, their habitat destroyed, their populations fragmented. Without the birds, the seeds fell under the parent shrub and could not spread to new locations.
By the 1910s, it was gone. The last plants probably withered in a warmer summer, their berries uneaten, their seeds ungerminated. No one knew they were the last.
The smaller snowberries survived. They are lower-growing, more adaptable, able to survive in a wider range of conditions. They are the survivors, the low ones, the shrubs that kept their heads down. But the giant alpine berry is extinct. A few pressed specimens in a herbarium, a few seeds in a core sample, and the memory of a shrub that used to feed the alpine birds, its berries bright on the grey mountain.
The climate warmed. The birds declined. Then we wondered why the mountain felt so hungry.