Northland kiwi struggling to keep cool in big dry

Male kiwi have been spotted sitting at the entrance to their burrows, possibly in an effort to keep their eggs cool. Photo / Todd Hamilton

Northland kiwi are resorting to sitting in streams to cool off and foraging for food in daylight as they struggle with the region's record-breaking drought.

Like Northland's human inhabitants the rain and lower temperatures of recent days will bring some respite to the birds, but it's not expected to last.

Kiwi Coast Far North coordinator Lesley Baigent said kiwi were resorting to a variety of survival tactics to get through the big dry.

''Firstly, they're seeking shade and cooler roosting sites. They're roosting in cool, damp areas like drains or culvert pipes, in deep rock crevices in the bush and waterways and in hollows in the banks of creeks and streams,'' she said.

This female kiwi was found badly dehydrated and unable to walk by tourists visiting Akeake Scenic Reserve near Kerikeri in February. After four days with a Paihia vet it had made a full recovery and was returned to its home. Photo / Kelly Belle Photography

Adult males on nests were doing it hard, especially if their nests were exposed to sun or far from reliable water. The male's solo incubation duties lasted up to 80 nights.

Some had been found with their egg close to the nest entrance, possibly to stop it overheating.

Baigent said kiwi also used techniques employed by other animals to keep cool such as panting.

''Birds have no sweat glands so they can't sweat to cool off like we do. Instead they pant, a little like a dog but more efficiently with less water loss. They breathe much faster and use the air to suck moisture from the lungs and mouth. This then evaporates using heat from the bird which is lost in the breath.''

Feather fluffing exposed more skin to the air which allowed more heat to be lost. Most birds could unfold their wings to expose more skin, but, alas, not the kiwi.

Baigent said she had fielded reports of kiwi in and around creeks, dams and water troughs, and egg-carrying females had even been seen sitting in streams.

''Whether this is to cool the body or take the weight off their legs is unknown. It's hard work carrying the world's largest egg per body size in this heat,'' Baigent said.

Transmitter data from wild kiwi showed their foraging hours had increased as food became harder to find. The birds were now active about 10 hours a night and venturing out in daylight hours in search of food and moisture.

The high activity of transmitter-carrying kiwi also indicated some weren't attempting a second nest this season or had abandoned it.

Despite those survival tactics not all kiwi were coping, Baigent said.

Scientists had found some adult males and juvenile females were underweight and in poor condition.

There was also a marked difference between chicks hatched earlier in the season, which weighed on average 900g, and later chicks which were small and hence at higher risk of predation.

Baigent said Northlanders concerned about their feathered neighbours could help by looking after shaded streams and wetlands and trapping pests to keep the forest healthy and predator numbers down.

She also urged people walking their dogs in the early mornings and evenings to be extra careful about keeping their pets on-leash and under control to protect kiwi coming out at odd times.

Kiwi Coast supports community-led kiwi recovery projects throughout Northland with the goal of creating a ''kiwi corridor'' stretching more than 200km from Mangawhai to the Aupōuri Peninsula.