The plucky little battler was seen at Sandymount recently by yellow-eyed penguin researcher and former Department of Conservation ranger Mel Young.
It was not known what caused Tendon Boy’s injury, but nine months ago he was admitted to the 2017 temporary wildlife hospital with a deep laceration on his left leg, his hock joint was exposed and his leg tendons (hence his nickname) were severed.
Wildlife veterinary surgeon Lisa Argilla said it was one of the worst injuries a penguin could get and there were significant complications associated with it.
"These are namely septic arthritis, due to dirt getting into the joint, as well as the difficulty in repairing a tendon that is so vital to locomotion."
There were doubts he would ever be able to return to the wild because there was no evidence of a severed leg tendon ever being successfully treated.
Despite the prognosis, Dr Argilla decided to treat Tendon Boy with a series of intensive medical interventions.
"Yellow-eyed penguins are endangered. Every bird counts and each time we try a procedure, we learn more.
"Even if it fails, the learnings are important," she said.
It took several operations to clean the wound and suture the tendons, and after several months of rehabilitation at Penguin Place, the question was raised about whether Tendon Boy was ready to be released back into the wild.
"Even though Tendon Boy was apparently doing well in rehab, his leg was still stiff and his range of movement restricted."
Despite concerns about his mobility, he was released.
"We acknowledged that we couldn’t provide enough physio for him in captivity.
"In comparison, while out in the wild he could swim for 12 hours a day or more, which would provide amazing physio.
"It was our hope he would regain better range of movement in that leg."
After Ms Young discovered Tendon Boy successfully living back in the wild recently, Dr Argilla said it appeared the treatment had worked wonders.
Ms Young said she could not believe it was the same bird at first, but further investigation confirmed it was indeed Tendon Boy, and he had completely recovered from the severe injury.
"His plumage was looking a bit rugged and his tail rectrices were thinned out, but otherwise he seemed to be getting on in the wild just fine as a non-breeder."
