Kangaroo Island Little Penguins
Kangaroo Island is home to Little Penguins. The Foundation for National Parks & Wildlife funded the purchase of a third satellite tracker, to add to the existing two, that researchers on the island have been using to monitor Little Penguin populations.
Transmitters weighing 30g each were attached to eight penguins in total, and the results are helping researchers to determine what Little Penguins get up to while spending over half of their lives at sea. The transmitters send a signal to 4 individual satellites every 40 seconds for about 30 days.
Satellite tracking reveals where penguins travel to, how long they spent in different locations and where their preferred feeding grounds are. The findings of this project allow for better management of the Kangaroo Island marine parks and of this particular penguin species in the future.
Meet the local penguins Bill, Pandora, Bella…
Researchers have named the eight tracked penguins from two separate colonies on Kangaroo Island. Bill, Pandora, Bella and Jacques are from the Kingscote colony and Thorpy, Dawn and Issac are from the Penneshaw colony. Results gleaned from the trackers varied quite widely between this bunch. Some penguins travelled 30 km during foraging trips whereas others travelled up to 1400 km or more.
Pandora, for instance, was tracked from the Kingscote colony over three consecutive one day trips, each averaging 34 km. These day trips took Pandora mainly out into the local waters of Western Cove.
Isaac from the Penneshaw colony, by contrast, went to sea for over 25 days and travelled more than 1400 km! Isaac’s marathon journey took him up into Gulf St Vincent, west into Investigator Strait and finally down past the Coorong, where, still 70 km from home, the batteries failed in the tracker and the researchers lost contact with him.
Amazingly, 3 weeks later—and 45 days after putting to sea—Isaac finally returned to his burrow, long after his chicks were successfully fledged by their single mum. Using Isaac’s average daily distance travelled, it is possible to estimate his total journey at over 2500km!
What are the Little Penguins doing?
The transmitters revealed that some Little Penguins were spending far more time at sea than first thought. Evidence of ‘single parenting’ was also found, which revealed that two penguin parents don’t always hang around together to feed their chicks. The parent who remains with the chicks has to work extremely hard!
The study also revealed that different penguin colonies on Kangaroo Island may share feeding grounds. Noticeably, however, the Kangaroo Island Little Penguins avoid feeding grounds used by penguins from other colonies in the region.
This project has provided an insight into the wide-ranging foraging behaviour of Little Penguins. The results illustrate the importance of lower Gulf St Vincent and Backstairs Passage as feeding hotspots for Kangaroo Island Little Penguins. The gulf has high abundances of small baitfish, particularly anchovy, which is the primary prey for little penguins across South Australia.
The segregated foraging areas of breeding penguins from different colonies suggest that that they avoid interacting with each other at sea. This may account for some genetic differences between colonies in South Australia, even those geographically close to one another. Limited inter-colony, at-sea interaction may also affect the rate of recolonisation into colonies that have experienced declines.
The study found that Penneshaw Little Penguins typically travelled less than 15km from the colony, which is similar to distances reported at other colonies (generally within 20km). In comparison, those from Kingscote travelled much further (up to 200km from their colony) and for longer periods. The foraging of penguins at Penneshaw suggests that there was good food available near their colony compared with Kingscote, where the penguins had to forage further afield. Issac must have just wanted a bit more adventure than his typical Penneshaw neighbours.
