"We received a different signal and thought there was a problem, but we had hoped that it had resulted from [her beacon] being dropped, so we have all taken it pretty hard."
She said it takes about one month for a falcon to grow fully but Hine-o-te-Rangi was still learning a lot, including how to fly, land and gain strength.
Another falcon which was released at the same time, a male juvenile Ihenga, still survives.
"If we are to draw anything from this, this is the first time this kind of thing has happened so quickly after being released [during this project]," Stewart said.
Stewart said most deaths and injuries which Wingspan come across, inflicted on falcons, were from gun shots. She said awareness of these endangered birds was very important as there was only about 4000 pairs left in New Zealand.
On The Wing volunteer co-ordinator Julie Parsons said there was about 30 volunteers who monitored Hine-o-te-Rangi during most hours of the day, and it was very sad to see her die.
The remaining falcons, from earlier releases, are still regularly spotted around Rotorua, near the Redwoods and the Government Gardens.