We had a 4 days of no yellow-eyed penguin chick deaths and when we were just about to breathe a sigh of relief we have more dead. We are now down to 52 chicks all together (started with 85!) - three fewer than last year and a 39% mortality all up. It's been a terrible few weeks and we are disappointed that despite our best efforts we have been unable to keep more alive. We are at a loss as to what else we could do. Even chicks with Diphtheria that had been on antibiotics for 3 or 4 days have now died. They were young but should not have succumbed.
The photo is of two chicks that have made it without meds so far! These are the strong ones!

Things are not good. We had really good hatching in our yellow-eyed penguin colonies with a total of 85 chicks. Now we have lost a third of them. Every one of them died younger than 2 weeks old. Five went missing - no idea, 17 died so quickly we could not diagnose, never mind treat them and of the 23 chicks we treated with antibiotics 8 have died anyway. So a total of 30 chicks have died so far and we don't know what else we can do. They are all checked every other day once they reach 5 days old but many died before then. Others were fine on one visit and dead 2 days later. 
The photo shows a 10 day old chick with classic Diphtheria symptoms of loss of feathers on the flippers and upper back, a sunken neck but no plaques in the mouth anymore. Here it is getting it's last dose and it will be ok. We only wish all our chicks had a good outcome as this one. 

and not in a good way. Over the last couple of years the surplus of yellow-eyed penguin males in our colonies has increased and our trail cameras have picked up a new issue: single - and lonely - males have tried to take over the neighbouring nests and the fights that have ensued have resulted in the loss of an egg (this happened in two different nests). The video below shows such a vicious fight. When we realised this was happening we took the remaining egg and fostered it to a pair without these problems and gave these a plaster egg. The fights did not stop and now that their egg is due to hatch we decided that a fragile newly-hatched chick would not survive despite the best efforts of its parents to protect it. We took their plaster egg away and they are having the summer off to sort out their differences with their neighbour - maybe move away to another nest site.
Every year we are learning something new about these penguins and we need to be vigilant to protect the next generation. ​