Human exploitation of the short-tailed shearwater (Pujfinus tenuirostris)

The short-tailed shearwater or Tasmanian muttonbird Puffinus tenuirostris (Temminck, 1835) breeds mainly in Tasmania, particularly on Bass Strait islands. In Tasmania it is a partly protected species, subject to annual open seasons. Aboriginal exploitation of this species is shown by small amounts of material in several archaeological sites in Tasmania and the Australian mainland; such use was limited by seasonal, technological and cultural choice. Present-day Aboriginal Tasmanians view the muttonbirding industry as one of their major social and economic activities. On the decline of the seal industry established by Europeans in Bass Strait, some sealers settled on the islands hunting game. Farming and collecting shearwaters for their livelihood. Throughout the 19th and early 20th centuries, muttonbirding was the mainstay of the local economy, but in the last 60 years the industry has declined considerably, the annual catch falling from one million to about 300 000 chicks

DNA methylation levels in candidate genes associated with chronological age in mammals are not conserved in a long-lived seabird

© 2017 De Paoli-Iseppi et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Most seabirds do not have any outward identifiers of their chronological age, so estimation of seabird population age structure generally requires expensive, long-term banding studies. We investigated the potential to use a molecular age biomarker to estimate age in short-tailed shearwaters (Ardenna tenuirostris). We quantified DNA methylation in several A. tenuirostris genes that have shown age-related methylation changes in mammals. In birds ranging from chicks to 21 years of age, bisulphite treated blood and feather DNA was sequenced and methylation levels analysed in 67 CpG sites in 13 target gene regions. From blood samples, five of the top relationships with age were identified in KCNC3 loci (CpG66: R2 = 0.325, p = 0.019). In feather samples ELOVL2 (CpG42: R2 = 0.285, p = 0.00048) and EDARADD (CpG46: R2 = 0.168, p = 0.0067) were also weakly correlated with age. However, the majority of markers had no clear association with age (of 131 comparisons only 12 had a p-value < 0.05) and statistical analysis using a penalised lasso approach did not produce an accurate ageing model. Our data indicate that some age-related signatures identified in orthologous mammalian genes are not conserved in the long-lived short tailed shearwater. Alternative molecular approaches will be required to identify a reliable biomarker of chronological age in these seabirds

Shearwater Foraging in the Southern Ocean: The Roles of Prey Availability and Winds

Background Sooty (Puffinus griseus) and short-tailed (P. tenuirostris) shearwaters are abundant seabirds that range widely across global oceans. Understanding the foraging ecology of these species in the Southern Ocean is important for monitoring and ecosystem conservation and management. Methodology/Principal Findings Tracking data from sooty and short-tailed shearwaters from three regions of New Zealand and Australia were combined with at-sea observations of shearwaters in the Southern Ocean, physical oceanography, near-surface copepod distributions, pelagic trawl data, and synoptic near-surface winds. Shearwaters from all three regions foraged in the Polar Front zone, and showed particular overlap in the region around 140°E. Short-tailed shearwaters from South Australia also foraged in Antarctic waters south of the Polar Front. The spatial distribution of shearwater foraging effort in the Polar Front zone was matched by patterns in large-scale upwelling, primary production, and abundances of copepods and myctophid fish. Oceanic winds were found to be broad determinants of foraging distribution, and of the flight paths taken by the birds on long foraging trips to Antarctic waters. Conclusions/Significance The shearwaters displayed foraging site fidelity and overlap of foraging habitat between species and populations that may enhance their utility as indicators of Southern Ocean ecosystems. The results highlight the importance of upwellings due to interactions of the Antarctic Circumpolar Current with large-scale bottom topography, and the corresponding localised increases in the productivity of the Polar Front ecosystem

Vegetation patterns, environmental correlates and vegetation change in a Puffinus tenuirostris breeding colony at Cape Queen Elizabeth, Tasmania.

Variation in the vegetation in and adjacent to a Puffinus tenuirostris breeding colony at Cape Queen Elizabeth, Bruny Island, Tasmania is related much more closely to burrow density, bare ground and soil dryness than to either the phosphorus or organic content of the soils. Between 1977 and 1992, burrow density declined on average by 0.11 per m2. In the parts of the rookery where burrow density decreased, Rhagodia candolleana Moq. increased its cover. Where burrow density remained constant or increased, Pteridium esculentum (G.Forster) Cockayne and Lomandra longifolia Labill. had declining cover. The major overall changes were increases in the cover of the succulent scramblers Tetragonia implexicoma (Miq.)J.D.Hook and Rhagodia candolleana at the expense of Pteridium esculentum and Lomandra longifolia