Conservation experts are nervous about what heavy snow in North Island conservation areas will mean for the start of this season’s kiwi egg collection and incubation programme. This year the annual kiwi conservation milestone was met with significant snowfalls in the central North Island, hampering collection efforts and making foraging difficult for younger birds.
Staff at the Maungataniwha Kiwi Project, one of the country’s most prolific and successful kiwi conservation initiatives, are experiencing difficulty accessing some of the nests from which they are scheduled to retrieve kiwi eggs. They fear these eggs may hatch before they can be collected and transported to the incubation centre at Rainbow Springs’ Kiwi Encounter in Rotorua.
If this happens the chicks have just a five percent chance of surviving predators. And the wintry conditions will reduce this chance of survival still further.
The Maungataniwha Kiwi Project had to helicopter its first eggs of the 2016/2017 kiwi egg collection and incubation season out of the Maungataniwha Native Forest on Saturday [subs: 13 August]. Normally these would have been driven to Rotorua but heavy snow has made roads in the area impassable.
Choosing the optimal time to remove a kiwi egg from a nest is vital. Too soon and the egg could fail. Not only that, it takes many more resources to keep it alive, warm and well in a captive rearing facility. Too late, and the egg may be predated or flooded out, or may hatch, which means its parents are less likely to lay another clutch that season. This in turn means that the population will not grow as quickly.
The aim is to collect eggs that are at least 25 days old. If less than 10 days old, there is just a one percent chance of hatching success. If 10-20 days old, the likelihood of success reaches 20 percent. If the kiwi egg is 30 days old, success is 75 percent, and by 70 days the chance of hatching a chick reaches 90 percent.
The Trust fears for the well-being of its younger birds which are set to become the foundation of its breeding programme in coming years. When the ground freezes the invertebrates on which kiwi feed burrow deeper. They’re then inaccessible to younger kiwi with shorter bills.
“The frozen ground and wintry conditions in the forest will make it more difficult than usual for the younger birds to forage successfully, particularly the ones that have come from our coastal crèche and have only recently been released into this high altitude forest,” said Simon Hall, Chairman of the Forest Lifeforce Restoration Trust which runs the Maungataniwha Kiwi Project.
“They are not used to these conditions and don’t have as many reserves as some of the older birds, which can lose 10 percent of their body weight before they risk damaging their vital organs.”
The Maungataniwha Kiwi Project team have received meal-worms from Kiwi Encounter to supplement the diet of nesting kiwi if required.
Heavy snowfalls are thought to discourage breeding in the South Island. Mr Hall said his team would learn a lot about kiwi conservation from this season’s kiwi egg collection and incubation programme.
“Of course, it’s possible that the birds will cope just fine with the lousy conditions and that our fears and concerns will have been for nothing. But either way we will be considerably wiser and will have learned a lot about this iconic creature’s ability to breed successfully in harsh conditions.”
Kiwi typically produce two clutches of eggs between September and February, so this is only the start of the six-month kiwi egg collection and incubation season.
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About the Forest Lifeforce Restoration Trust
The Forest Lifeforce Restoration Trust manages the second-largest private conservation initiative in NZ. It was established in 2006 to provide direction and funding for the restoration of threatened species of fauna and flora, and to restore the ngahere mauri (forest lifeforce) in native forests within the Central North Island.
In addition to the Maungataniwha Kiwi Project the Trust runs a series of seven native flora and fauna regeneration projects. These include a drive to increase the wild-grown population of Kakabeak (Clianthus maximus), an extremely rare type of shrub, and the re-establishment of native plants and forest on 4,000 hectares currently, or until recently, under pine.