Rats threaten penguins

Press, 28 February 1986, Page 29

Rats threaten penguins

PA Wellington Rats are eating into the numbers of some rockhopper penguin colonies on Campbell Island, scientists report ‘ A Wildlife Service scientist Dr Phil Moors, and technician, Mr Duncan Cunningham, have returned from a two-month expedition to find out why penguin numbers have declined so dramatically since the 19405. Once the island was considered to be one of the most important rockhopper breeding areas in the world. The penguins then numbered about a million but now were only a fraction of that. “It has gone from something that was really rather special to an also ran without us really knowing why,” Dr Moors said.

Initially it was thought the rats did not threaten the birds. They could not

break into the eggs or eat the older chicks.

But this trip they found how vulnerable the newly hatched chicks were. “One of the more unpleasant discoveries was that the rats might not be able to eat the eggs but they can cetainly eat the young chicks,” Dr Moors said. The first week after hatching was the critical period.

But it was not a matter of blaming the rats for the declining numbers. With some of the colonies on the island, for no apparent reason the rats did not bother the birds. Disease was another aspect the team considered. There was circumstantial evidence to suggest this was a possible cause of the deaths, Dr Moors said.

The team also looked at the penguins’ food supply to see if it was deficient. Material has been brought back for analysis.