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Food deprivation may decrease selectivity in food; however, (1) whether animals can cross a selectivity threshold whereby they ingest non-nutritive items ('non-food') in lieu of food (engaging in pica/lithophagia), (2) their behaviour, or (3) the implications of these behaviours are not documented. By examining carcasses of seabirds that ingested pumice of known provenance prior to death, we provide insights into whether wild animals starve because they have eaten non-food, or whether they eat non-food because they are starving. We investigated ingestion of pumice and plastic in carcasses of short-tailed shearwaters Ardenna tenuirostris following a significant starvation mortality event (also known as seabird wreck), during which millions of shearwaters died along the eastern Australian coastline in 2013. We found that the stomachs of 96.5% of 172 seabirds sampled contained pumice or plastic at the time of death. We used global location sensors to track the 2013 shearwater migration and overlaid these tracks with the dispersing pumice raft from the 2012 Havre underwater volcanic eruption, Kermadec Islands, New Zealand. We determined that shearwaters in a starved state had ingested pumice 12-41 h before death, indicating that starving or food-stressed seabirds exhibit reduced prey discrimination. The provenance of the ingested plastic was not known. Ingestion of non-nutritive items has serious implications for wildlife, particularly long-lived or migrating species. Additional risk to already nutritionally compromised animals includes dietary dilution, gastric foreign body obstruction and toxicity. With a projected changing climate and increased marine pollution and over-exploitation of resources, this study has implications for the interaction of stressors, mass mortalities and exacerbation of existing threats to marine species.

Item Type:	Refereed Article
Keywords:	short-tailed shearwater, Ardenna tenuirostris, food selectivity, pica, lithophagia, geophagia, mass mortality, pumice, 2012 Havre eruption
Research Division:	Biological Sciences
Research Group:	Ecology
Research Field:	Marine and estuarine ecology (incl. marine ichthyology)
Objective Division:	Environmental Management
Objective Group:	Marine systems and management
Objective Field:	Rehabilitation or conservation of marine environments
UTAS Author:	Roman, L (Dr Lauren Roman)
ID Code:	146466
Year Published:	2021
Web of Science® Times Cited:	2
Deposited By:	Ecology and Biodiversity
Deposited On:	2021-09-08
Last Modified:	2021-11-29
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