Fire on Mauao
The January 2016 fire on Mauao (Mount Maunganui) put at risk an important colony of grey-faced petrels which has been
one of New Zealand's longest running mainland seabird project [1990-2013]. The grey-faced petrel is about the size of a
gull but with a harder beak.
Approximately 500-700 birds use the colony at Mauao, spread around the base of the mountain under the skirts of the
pohutukawa forest, with some burrows higher up to a maximum of c.75m above sea level. In a “good year” with a low or
absent number of pests, the Mauao grey-faced petrels can lay up to 200 eggs, with 100 hatching, and 50 birds fledging.
Over late December and early January, the Mauao Area Wildlife Trust has been busy across Mauao, banding the new
grey-faced petrel fledgings as they leave their nests. The colonies are off-limits to casual visitors.
Each pair of petrels lays one egg per season. This means they are a slow breeder but they live up to 40 years. These
birds hatch in burrows, and are fed by their parents until they're considered plump enough to brave the world for
themselves. The parents then abandon their chicks during which time the young birds lose fat and gain muscle. Their
eventual hunger drives them to leave their burrows and once outside their internal on-board natural computer immediately
synchs their location with the stars overhead. For the next few nights before lift-off they're at risk from predators
such as stoats, rats, dogs and cats. Thus is when the wildlife team is out banding them, an important task, as it means
they can be monitored and important information about their life cycle and "commuting to work" patterns can be gained.
[Image: A grey-faced petrel fledging being banded after leaving the nest, a week before the fire on Mauao]
Once they leave to fly out to sea they may not return for up to 7 years, but when they do, they arrive right back where
they hatched. That's quite an amazing little "GPS unit" right there. Before this, because they're in a burrow for about
3 months through winter, good pest control over Mauao is essential during this period. With no pest control the colony
halves in 50 years and would be gone in 200 years. Current pest control methods, which are a combined effort between
Mauao Area Wildlife Trust, Forest & Bird and Tauranga City Council, are currently maintaining the numbers of birds. Any fire on Mauao puts this colony as
well as the penguins, tuis, pied shags and other wildlife at risk.
The life cycle of a Grey-faced Petrel:
April/May: Adults return to the colonies to establish pair bonds and territorial burrows
July/August: A single egg is laid in a burrow. If the egg is lost, no relaying occurs.
September/October: chicks hatch
December/January: chicks fledge
As far as can be determined, no penguins or grey-faced petrels were harmed as a result of the fire.
To learn more about the Mauao Area Wildlife Trust, become a member or make a donation to support the trust’s efforts
towards wildlife visit www.mauaowildlife.org
ENDS