Pumice ingestion in seabirds: interannual variation, and relationships with chick growth and plastic ingestion

Abstract Many species of seabird ingest or are provisioned with pumice stones, buoyant volcanic rocks that thought to aide in digestion, occasionally during times poor prey availability. Unlike other indigestible matter, like plastics, the effect on chick growth, its relationship ingested and variation among years has not yet been examined. We analysed amount from 739 Flesh-footed ( Ardenna carneipes ) 173 Wedge-tailed Shearwaters A. pacifica Lord Howe Island, Australia sampled using stomach lavage between 2011 2022. The total mass was positively related plastics Flesh-footed, but Shearwaters, when mean stone mass. Pumice did vary over time, except for one higher year each (2016 2014 Shearwaters), there no body size at fledgling. Our results consistent coexistence geological time seabirds floating pumice, future work should focus aspects retention digestive system potential interactions efficacy presence novel materials, plastics.