Research Paper – ACCEPTED

The terrestrial vegetation and biota of Rangimata | Shag Rock, Te Whanga, Rēkohu | Wharekauri | Chatham

Peter J. de Lange1, *, Clay D. Heath1, Campbell J. James1, Andrew J. Marshall1, Hamish Tuanui-Chisholm2

Affiliation:
1 Applied Molecular Solutions Research Centre, School of Environmental and Animal Sciences, Unitec, Private Bag 92025, Victoria Street West, Auckland 1142, New Zealand.
2 1007 Waitangi-Tuku Road, Chatham Islands 8016, New Zealand
* Corresponding author: pdelange@unitec.ac.nz

Received: 24 October 2025 | Accepted: 2 December 2025 | Published: xx
Associate Editor: Matt Rayner
doi

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Abstract
The vegetation associations and landforms of Rangimata / Shag Rock, Te Whanga, Rēkohu / Wharekauri / Chatham Island are described, and the avifauna, flora and mycobiota (lichenized and non-lichenized) documented. Rangimata / Shag Rock is one of 21 karst (limestone) islands, islets and rock stacks that fringe the western side of Te Whanga the largest enclosed water body within the Chatham Islands group. Rangimata / Shag Rock is an important refuge and nesting ground for the threatened endemic papua | Chatham Island shag (Leucocarbo onslowi) and kawau o Rangihaute | Pitt Island shags (Phalacrocorax featherstoni), as it seems to be free of introduced predators. Eighteen vascular plants (Tracheophyta), two green algae (Chlorophyta), one rust fungus and six lichenised mycobiota were found on Rangimata / Shag Rock over three visits in between 2023 and 2025. Five landforms and vegetation associations are recognised for Rangimata / Shag Rock. The importance of this karst ecosystem within the context of the terrestrial ecosystems of Rēkohu / Wharekauri / Chatham Island is discussed and the plea made for more documentation of the Chatham Islands karst biota and ecosystem which is one of the more seriously threatened of that island groups ecosystems.

Cite as
de Lange, P. J., Heath, C. D., James, C. J., Marshall, A. J. & Tuanui-Chisholm, H. (2025). Observations of avifauna on Rēkohu / Wharekauri / Chatham Island, Chatham Islands group, in February 2023. Perspectives in Biodiversity, 4