Stark contrast for Fiordland v South Westland penguins

2015-09-15_3 Tawaki and chick at Jackson Head (Tawaki Project - Thomas Mattern)The Tawaki Project team have found stark contrasts in the foraging habits and breeding success of tawaki (Fiordland crested penguins) when comparing colonies at Jackson Head and Milford Sound.

Drs Thomas Mattern and Ursula Ellenberg (Otago and La Trobe Universities respectively) have just published a field report following a second season of their Tawaki Project. 

Tawaki chick at Jackson Head, Sept 2015 (Photo: Tawaki Project, Thomas Mattern)

Tawaki chick at Jackson Head, Sept 2015 (Photo: Tawaki Project, Thomas Mattern)

In addition to monitoring the foraging behaviour and travel of tawaki (Fiordland crested penguins) at the Jackson Head colony in South Westland, they extended their project to Harrison Cove, Milford Sound.   After a successful breeding season at Jackson Head in 2014, they were saddened to report chick mortality due to starvation during the 2015 season and attributed it to the far greater foraging range being seen, up to 100km.  It appears that El Niño conditions (i.e. prevailing southerly winds) caused a shift of ocean productivity to offshore regions.

Tawaki Project - foraging range Jackson Head and Harrison Cove 2015

Foraging range of tawaki from Jackson Head (green) and Harrison Cove (red), Sept-Oct 2015. (Credit: Tawaki Project, Thomas Mattern)

In contrast, penguins at the colony at Harrison Cove were foraging generally within just 2km, within Milford Sound.  It is normal for crested penguins to lay two eggs but generally raise one chick, the second smaller chick usually not being fed and dying within a few days of hatching.  At a quarter of the nests monitored here, two healthy chicks were observed 2-3 weeks after hatching, indicating an abundant food supply.

This year, the study was supported by the Global Penguin Society to purchase and apply depth recorders to the study penguins.  These devices showed that the Jackson Head penguins were diving up to 100m whereas the Harrison Cove birds went to 60m maximum.  This further indicates that the Jackson Head tawaki were expending more effort in their foraging activity.

Next season, for the third year of the five year study, a colony will be included at Whenua Hou, in the Southern Islands, providing coverage of the full breeding range of this penguin, one of the rarest in the world.

The full report is available here: Tawaki Project, Field Report 2015

The Tawaki Project website is also full of information, fascinating blogs and wonderful photos: Tawaki Project