An albatross has died as heat stress and fly strike hit the protected population of northern royal albatross at Taiaroa Head on Otago Peninsula.
The Department of Conservation last week turned on its irrigation lines after adult birds started to show signs of heat stress, and fly strike became a major risk, DoC ranger Lyndon Perriman said.
"This is a really critical stage."
The system significantly reduced the risk of fly strike for eggs and chicks during hot weather. So far, five of the 20 chicks that had hatched had been affected by fly strike.
Staff were checking the eggs and chicks regularly. Once chicks were two days old, they moved enough to deter flies.
When an adult was too hot and left the nest, chicks could be exposed to the sun and, in one such case, Mr Perriman carried a chick with him to monitor its condition before putting it in an incubator until its mother returned to the nest.
An adult female albatross on her first visit to the colony since she fledged four years ago died last week.
She was not sitting on an egg and those that were not breeding usually headed for the sea when temperatures on land got too hot, he said. However, she was found caught in rushes and panting hard. She was released and placed where she could fly off, but was found dead the next morning.
Of the seven eggs remaining, five were in the process of hatching and another two expected to in the next few days.
If all survived to fledging, numbers would equal that of the colony's best year but there was a "long way to go before that", he said.
The predicted change in weather this weekend would be welcomed as the chicks would be large enough to cope and the risk of fly strike would drop, Mr Perriman said.