Little penguins (Eudyptula minor) are the world’s smallest penguin and the only species that breeds on the Australian mainland. They are classified on the IUCN Red List as being of ‘least concern’ but recent population surveys indicate that some colonies are in decline. In Gulf St Vincent and KI region the current population is estimated at 5,226 breeding adults.
How are the little penguin populations monitored?
Between 2006 and 2014, NRKI undertook an annual community census of the Kingscote penguin colony in partnership with the KI Penguin Centre. Every year in September/October, up to 70 community volunteers counted and mapped penguin burrows along a five kilometre stretch of shoreline between Brownlow and Reeves Point. All burrows located were identified as either active or inactive. The count of active burrows was then used to estimate the total penguin population of breeding adult little penguins.
In 2011 and 2012, local community group Friends of Dudley Peninsula Parks was successful in obtaining a State Natural Resources Management grant to expand the census to include eight other colonies on the island. The 2013 Island-wide census and the 2014 Kingscote census were made possible with funding from Natural Resources Adelaide Mount Lofty Ranges.
What do the results tell us?
Census results from the past nine years at Kingscote suggest the penguin colony has declined from a peak of 868 in 2007 to 128 breeding adults in 2014. Despite only three years of data collected for the eight other colonies, early indications are that this trend is being repeated elsewhere. The reasons for the decline in little penguin numbers is not yet clear, threats are often site specific and cumulative which often makes it difficult to pinpoint the direct cause.
There are a number of collaborative research programs underway in South Australia led by South Australian Research and Development Institute (SARDI Aquatic Sciences) and Flinders University that are investigating the possible causes of these little penguin declines. These programs have researched long-nosed fur seal diets, terrestrial predation of penguins by native, feral and domesticated animals, and the impacts of pests and diseases. Outcomes from these research projects will provide important information for future management actions. As part of the research effort, necropsies are being performed on penguin carcasses by a wildlife pathologist at the South Australian Museum.
Penguin satellite tracking
In 2009, the Kangaroo Island NRM Board commenced a study to understand the foraging behaviour of little penguins from the Kingscote and Penneshaw colonies. Satellite transmitters were used in the study, with three penguins tracked from the Kingscote colony and three penguins tracked from the Penneshaw colony.
Three penguins undertook single day trips averaging 45 kilometres. The other three penguins were at sea for two to three weeks, travelling between 730 kilometres and 1400 kilometres. These long foraging trips appear to be a characteristic of KI penguins, as studies of other penguin colonies in the region have shown, that on average individuals travel 70 kilometres and rarely travel up to 500 kilometres.
Data collected from the satellite transmitters enable us to determine ‘feeding hot spots’ where penguins spend most of their time whilst at sea. Waters in Gulf St Vincent, west of Cape Jervis, are considered the main feeding hot spots, as all penguins tracked spent a significant amount of time in this area. Other feeding hot spots include Western Cove, Backstairs Passage, an area in the Southern Ocean 50 kilometres south of Encounter Bay, and an area offshore of the Coorong ocean beach, near Salt Creek.
How you can help little penguins?
Despite the uncertainty around little penguin populations on KI and GSV it seems that the sites where colonies are in greatest decline also receive the highest visitation from people and interactions with introduced or domestic animals. We can all help protect little penguins by;
- minimising our impacts to the coastal landscape by following defined paths and tracks
- ensuring our pets are prevented from accessing colonies particularly during the breeding season when chicks are extremely vulnerable to predators.
If you would like any further information about little penguins, please contact the KI Landscape Board Office on 8553 2476, or email firstname.lastname@example.org