Spatial distribution of late Holocene bird bones in the Mason Bay dune system, Stewart Island, New Zealand

Abstract

Many of New Zealand's coastal sand dune systems contain naturally accumulated deposits of late Holocene bones, providing an important archive of our pre-settlement faunas. However, the accumulation and taphonomic processes that operate in natural dune deposits are poorly understood. Here, I contribute to our understanding of these processes through analysing spatial patterns of bone distribution in an extensive late Holocene dune system at Mason Bay, Stewart Island. The bone assemblage was collected between December 2002 and February 2003, and included 2880 identified bones from at least 28 bird species. These included extinct species (South Island piopio, Turnagra capensis), regionally rare species (e.g. weka, Gallirallus australis and New Zealand falcon, Falco novaeseelandiae) and locally rare species (e.g. South Island kākā, Nestor meridionalis meridionalis). Significant effects of distance to beach, and distance to the edge of woody vegetation, were found for bones of certain bird groups. The results indicate three main sources of bird bones for the Mason Bay dune system assemblage: 1. nesting colonies within the dunes; 2. storm-wrecked seabirds; and 3. birds inhabiting woody vegetation bordering the dunes. Understanding source biases for dune bone deposits will allow more informed interpretations about the composition of the local prehistoric faunal communities.

Contrasting responses of lizard occurrences to burrowing by a critically endangered seabird

“…Seabirds like the Whenua Hou Diving Petrel would have facilitated shuttling behaviour, and potentially social behaviours, in skinks throughout New Zealand prior to the arrival of invasive predators. It is likely that the interspecific interactions between the Whenua Hou Diving Petrels, Stewart Island green skinks, and southern grass skinks were once widespread throughout the historical range of these three species, but disappeared following local extinctions of the Whenua Hou Diving Petrel (Taylor 2000b, Holdaway et al 2003, Wood ˆ︠ ︡ ︠ ︡ˆ and Briden 2008, Wood 2016, Fischer et al 2017b, Jewell 2017, Fischer et al 2018b. For example, both skink species have relict populations on Stewart Island, while the Whenua Hou Diving Petrel is extirpated from its dune systems (Wood and Briden 2008, Wood 2016, Jewell 2017.…”

“…The recently described Whenua Hou Diving Petrel (Pelecanoides whenuahouensis) is one of the most endangered species in the world. Only one Whenua Hou Diving Petrel colony on Codfish Island (Whenua Hou) survived historic extirpations throughout southern New Zealand caused by invasive predators (Taylor 2000b, Holdaway et al 2003, Wood and Briden 2008, Wood 2016, Fischer et al 2017b, 2018b. Furthermore, storms and storm surges threaten the remaining breeding habitat of this species (i.e., fragile foredunes; Cole 2004, Fischer et al 2018b.…”

Integrated conservation of the Whenua Hou Diving Petrel

“…In other words, skinks are less likely to flee with more vegetation cover around them, and thus more likely to be detected. (Taylor 2000b, Holdaway et al 2003, Wood & Briden 2008, Wood 2016, Fischer et al 2017b, Jewell 2017. For example, both skink species have relict populations on Rakiura, while the WHDP is extirpated from its dune systems (Wood & Briden 2008, Wood 2016, Jewell 2017.…”

“…The WHDP was split from the South Georgian Diving Petrel based on preliminary genetic, phenotypic, and ecological differences (Paterson et al 2000, Fischer et al 2018b, Tizard et al 2019 Ōrau/Sandfly Bay), and Rēkohu (Chatham Islands) (Fig. 4; Falla et al 1979, Worthy 1998, Taylor et al 2000b, Holdaway et al 2003, Wood & Briden 2008, Wood 2016, Fischer et al 2017b, Tennyson 2020). However, predation and habitat destruction by invasive species (and New Zealand sea lions Phocarctos hookeri on Dundas Island) caused multiple local extinctions (Falla et al 1979, Taylor 2000b).…”

“…Only one WHDP colony on Whenua Hou (Codfish Island) survived historical extirpations throughout southern Aotearoa caused by invasive predators (Fig. 4;Taylor 2000b, Holdaway et al 2003, Wood & Briden 2008, Wood 2016, Fischer et al 2017b. Furthermore, storms and storm surges threaten the remaining breeding habitat of this species (i.e., fragile foredunes; Cole 2004.…”