North Island robins have been introduced to Shakespear Regional Park in Auckland, making the trip across from Tiritiri Matangi Island in the Waitematā Harbour.
They are the second load of robins, or toutouwai, to be introduced to the predator-free regional park.
Twenty robins were introduced early last month from King Country, but the trip for this new load of birds is significantly shorter. Tiritiri Matangi Island is located just 4km from Shakespear Regional Park.
North Island robins were once widespread across the North Island. The birds are now restricted to extensively forested areas of the central North Island, as well as some satellite populations on pest-free islands and mainland locations.
The birds are small -- about the size of a sparrow -- with dark grey feathers on top and a paler grey plumage on their breast. They forage for food near the ground, largely feeding on insects. They will eat anything from the size of an aphid to a weta or stick insect. Large prey is broken up and stored in tree holes and crevices for later consumption.
A North Island robin (Getty)
Robins are particularly vulnerable to pest species when nesting with eggs. Adult females and nestlings are preyed upon by introduced predators such as rats, cats, possums and stoats.
Shakespear Regional Park is a pest-free open sanctuary located at the tip of the Whangaparaoa Peninsula, 50km north of Auckland's CBD.
A 1.7km pest-proof fence protects the park's native wildlife. The fence has been in place since March 2011, costing $750,000 to build. Local support group Shakespear Open Sanctuary Society Incorporated raised half the necessary funds, which were then matched by Auckland Council.
Tiritiri Matangi Island, a sanctuary free of all mammalian predators and home to takahe and tuatara, is located just a few kilometres offshore of Shakespear Regional Park.
The island is too far for the robins to fly from, but Shakespear Open Sanctuary Society says other birds, such as bellbird and kakariki, have flown from the island to the park.
Auckland Council Open Sanctuary co-ordinator Matt Maitland says the relocation will require bit of an adjustment for the birds.
"They've been literally picked up from their homes and dropped off somewhere else. We could call it assisted migration or we could call it alien abduction, but the habitat here is very similar to where they've come from."
Mr Maitland says the birds are likely to compete for territory before settling in.
"They've still got native predators -- moreporks [ruru] and the like -- to contend with. They've got to jostle around with each other for territories, which can get quite brutal at times. They've got to survive winter, but come springtime, they'll start breeding and numbers will increase and we'll be away."
Ngāti Kahu iwi occupied the Whangaparaoa Peninsua for about 1000 years. Evidence of a Māori pā remains overlooking Te Haruhi Bay.
There are a number of walking tracks in the park, including a one-hour loop lookout track and a two-hour heritage trail.