By Jo Hiscock, Senior Biodiversity Ranger
Late last year I visited New Zealand’s Antipodes Islands to count penguins.
This was part of a regular survey to check how the populations of erect-crested and eastern rockhopper penguins are doing.
The survey also monitored what effect recent slips have had on the penguin populations. Initial observations had suggested that up to one fifth of the colony had been affected by these natural slips.
We estimated that the slips occurred early in the year, which would have meant that chicks would have still been in the colonies.
I warned the survey team that the penguin count would be hard work, and it lived up to expectations, with strong southerly squalls and snow falls. The southerly persisted for the entire four days that we camped out on the south coast.
Erect-crested penguin nest numbers showed a 10% decline in areas where slips had affected colonies. However, it turned out that even in areas where slips had not occurred, nest numbers were down by 10%.
It’s possible that the penguins affected by slips may have moved colonies (boosting the non-slip colony figure). It’s also possible that pairs affected by slips may have had a year off breeding. Sea conditions may have caused a lower number of breeding attempts this year too. Penguins are notorious for yearly variation in breeding and nesting numbers.
The survey results for the eastern rockhopper penguin showed that there was no change from the 2011 count.
We are still working on teasing out the data to understand all of these results.