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Articles reproduced here come from past Rottnest Society Newsletters and other documents up to 2005.

The HOLE truth: the ecosystem effects of burrowing by Wedge-tailed Shearwaters on Rottnest Island.

(Reprinted from a 2005 Newsletter)

Immediately after the AGM on Monday 29th August 2005 our guest speaker Wes Bancroft (previously of the School of Animal Biology at UWA) who talked about his work with the burrowing Wedge-tailed Shearwaters at Rottnest. 

A very brief precis of Wes' fascinating talk follows: "Wedge-tailed Shearwaters, or Muttonbirds, colonised Rottnest Island in 1889 and have expanded their colonies considerably since then.   Unlike most birds, shearwaters dig nesting burrows in which they lay their eggs and raise their young.  The West End of Rottnest is pock-marked with burrows, yet the birds are uncommonly seen by most tourists as they only return to the colonies after dark (having spent the day at sea foraging for fish and squid).  The burrows, however, are always present and are considerable structures.  I was interested in how digging and physical soil disturbance (termed biopedturbation) by the shearwaters was affecting the Rottnest Island ecosystem.  This physical modification of habitat is also known as ‘ecosystem engineering’ and constitutes a relatively new arm of ecological theory.  My research investigated the environmental response to the Wedge-tailed Shearwater colonies on Rottnest, with particular reference to the birds acting as ‘ecosystem engineers’.  This involved quantifying the number and size of the shearwater burrows, calculating how much soil the birds displace, and investigating the effects that the birds are having on the island’s soil, vegetation and fauna.  I will present some of the information that I collected throughout my studies, and chat about how I think the shearwaters are modifying their patch of Rottnest Island.”