Events like South Island tīeke fledging in the valley once more, a record number of resident takahē, or the dispersal of kākā towards the city. These are stories that inspire and connect communities with work undertaken by mana whenua, staff and volunteers since the sanctuary’s inception.
These same successes are entangled with constant challenges. Extreme weather, biosecurity risks and financial pressures all spur wider sanctuary preparations over winter towards another year of operation. Finding ourselves deep in the groundwork phase during the year’s shortest days, some positive guidance from taiao (nature) goes a long way. Of all the manu to lead us through Matariki mā Puaka, kererū might be the best qualified. As a "common" bird around Dunedin/Ōtepoti, they also risk being taken for granted.
Historically, these hefty endemic pigeons were once widespread throughout the region. Habitat loss, urbanisation and introduced predators caused populations to plummet through the 1900s before reaching lower, but vulnerable numbers that tend to stabilise when protected from pests and habitat disruption. Across much of the year, kererū have variable diets, seeking out juicy growing shoots, leaves, and flowers from both native rākau and introduced trees. The majority of their kai over sparser months comprises kōwhai, tree lucerne, willow, elm and broom.
Looking to preparation and renewal, it’s appropriate to recognise the kererū’s contributions to planting and habitat restoration. As one of the last remaining manu capable of swallowing and digesting large fruits (those exceeding 12 mm in diameter), kererū account for the majority of seed dispersal for old growth trees like Miro and Mataī, podocarps once common around Otago before heavy deforestation. Hundreds of years ago, seed spreading duties for large fruits were extended across various Moa species, as well as Weka before they were lost from the area. While Miro can fruit every year, their output skyrockets over masting seasons (like this last summer) and their large red berries quickly become the kererū’s primary food source, laying the foundations for countless future saplings.
Both kererū and old growth forests thrive when healthy tracts of habitat are protected and this vital seed dispersal work can continue on its own terms. With limited manpower at our disposal, our greatest preparations are those that facilitate taiao, nature itself, to be self-sustaining. Regular visitors will be familiar with the kererū track. Planted with nitrogen-fixing tree lucerne, the track provides a year-round food source, encouraging kererū to spend time in the valley, while also nourishing the soils of the regenerating upper grasslands.
While kererū are not actively banded or monitored in the same way as recovering sanctuary species like takahē or kākā, those that take time to notice the forest this Matariki mā Puaka may recognise signs of growing kererū numbers. Where previously one or two pigeons at a time were typical, there are now regular flocks of 10-20 kererū loudly flapping en masse. In recent years, it has become easier to spot their large twiggy nests in the forks of trees. Some lucky visitors have even begun encountering kererū grazing young shoots or drinking water from a stream on the forest floor within the safety of the predator exclusion fence. Finally and perhaps the best sign of years passed and years to come, we see the combined work of the sanctuary and local kererū in action: young, freshly branching Miro, ready to begin a centuries long journey to join the forests of Dunedin/Ōtepoti once more.
