We’ve had a fantastic year for birds at Windy Hill. After 13 long hard
years of managing to keep pests down to low levels the birds have really
bounced back – up to 20 kereru have been counted a number of times and
50 kaka in one count in the Medlands valley alone. Birds are benefitting
from the food abundance created by reduced rats and the wetter summer
early this year.
The 620 HA sanctuary managed by the Windy Hill Rosalie Bay Catchment
Trust now employs seven people – five of these people make up the field
team who carry out the integrated pest management, one administers the
Trusts finances, and a contractor carries out specialist monitoring as
well as the Biosecurity Programme operating at the island’s main wharves
and the airport. Conservation and biosecurity is a growing ‘business’ on
island.
Rats have continued to be a worthy adversary – immensely responsive to
good conditions a female rat can up the number of litters, and the
number of babies per litter, she has per year. It is estimated that one
pair of rats and their surviving progeny can produce 15,000 rats a year!
This fecundity and their capacity to access the highest tree tops and
every nook and cranny in any habitat is the reason for the slow but
unstoppable decline of Great Barrier’s biodiversity. Even with 4800
stations for bait and traps checked on a regular basis we still trapped
2050 rats and a small number of mice between January and the end of
October this year.
Kiore, the Pacific rat is similar and dominated by the black rat.
What is interesting is that most of the rats trapped are kiore – they
bounce back after ship rat numbers are reduced, for some reason taking
longer to respond to traps or bait. This has also been the situation at
Glenfern Sanctuary. We are the only large island with both these species
of rats which makes our pest dynamics incomparable to mainland
sanctuaries – some research into the behaviour of, and between, the two
species could reveal better ways of targeting them.
Next year we are planning a booster robin translocation from Pureora
Forest to Glenfern and Windy Hill – this will increase the number of
breeding pairs in the sanctuaries and bring in a new line of DNA. At
Windy Hill there are currently five breeding females and 3 males who are
very busy servicing all the females and feeding chicks in five nests.
Their energy to keep their lineage going is impressive.
We look forward to continuing to increase the volume and diversity of
our dawn chorus.
