Vulture plastic ingestion
This research evaluated the extent and type of plastic ingested by black vultures and turkey vultures in an urban environment.
This research has been published in Frontiers of Ecology and Evolution and can be found here!
This research has received media attention! See below for a few articles covering these findings.
Most plastic eaten by city vultures comes straight from food outlets
Birdwatching Daily, 2023
Vultures consume enormous amounts of plastic waste
Earth.com, Eric Ralls, 2023
Urban vultures are feasting on plastic waste from local restaurants and stores
ZME Science, Fermin Koop, 2023
What are urban and rural vulture populations ingesting? How much plastic?
After observing black vultures forage from dumpsters day in and day out, we began to wonder what they are eating, and specifically how much of it is plastic.
To answer the question, we collected regurgitated pellets from underneath known vulture roosting sites from January 2021 to July 2022. We then dissected all collected pellets and analyzed how the plastic composition of regurgitated vulture pellets is associated with features such as developed landcover, restaurant density, and the density of livestock and game producers in multiple different landscapes.
Finally, we analyzed some of the plastic materials using Fourier transform infrared spectroscopy to identify the types of plastic most commonly being ingested by vultures. You can read more about Fourier transform infrared spectroscopy here.
What have we found?
We collected and dissected 1,087 vulture pellets!
Approximately 60% of pellets contained plastic materials.
We analyzed 187 plastic samples using Fourier transform infrared spectroscopy.
Vultures ingest more plastic in areas with more developed landcover.
They are most often ingesting silicone rubber and polyethylene.
This graph shows the spectra from one of our samples (the white line) and how well it matches that of high density polyethylene (the red line)!