Seabird sensory ecology: Exploring if the colours of plastic resemble the colours of seabird prey items
Ariel-Micaiah Heswall1*, Aidan Sarginson1, Matt Rayner2, Brian Wijaya1, Agustina Dominguez3, Lynn Miller3, Kristal Cain1, Megan Friesen4 and Anne Gaskett1
1 School of Biological Sciences, University of Auckland, Building 110, Room 256B, 3A Symonds Street, Auckland 1010, New Zealand / Te Kura Mātauranga Koiora, Waipapa Taumata Rau, Aotearoa (ahes107@aucklanduni.ac.nz, asar973@aucklanduni.ac.nz, bwij901@aucklanduni.ac.nz, k.cain@auckland.ac.nz, a.gaskett@auckland.ac.nz)
2 Auckland War Memorial Museum, Parnell, Auckland, 1010, New Zealand (mrayner@aucklandmuseum.com)
3 BirdCare Aotearoa, 74 Avonleigh Road, Greenbay, Auckland, New Zealand
(agustinadomz@gmail.com, lynn.miller@birdcareaotearoa.org.nz)
4 Department of Biology, Saint Martin’s University, 5000 Abbey Way SE, Lacey, WA 98503, United States (mfriesen@stmartin.edu)
Plastic is an environmental issue affecting a diverse array of animal groups including seabirds. Previous studies show that plastic could be acting like a sensory trap where the seabird mistakes the smell of plastic for the smell of prey. Little research uses sensory ecology to understand if the colour of plastic is also acting like a sensory trap, resembling the colour of the seabird’s prey. Our aim is to explore if plastic ingestion is selective and if plastic colour resembles the colour of seabird prey items. We used online databases to obtain colours of plastic found along New Zealand (NZ) coastline. We then performed gut dissections of NZ procellariformes to obtain ingested plastic. Using a spectrometer, we measured the spectral reflectance of the ingested plastics and compared it with the spectral reflectance of the seabirds’ prey items. There was no correlation between ingested plastic colours and plastic colours found on NZ coastlines. This suggests that NZ seabirds could be selecting certain plastic colours since they are consuming different colours compared to what is available in the environment. Also, when modelled into a seabird’s vision, seabirds cannot tell apart most plastic colours from prey items. Therefore, the colour of the plastic could be acting as a sensory trap, resembling the colour of seabird prey. Sensory ecology is a useful tool to analyze plastic ingestion from the seabird’s perspective as it displays that NZ seabirds could be selecting certain plastic colour, and also highlights the importance of exploring it on local scales.
*PhD student