Preliminary study of gull (Laridae) scavenging and dispersal of vertebrate remains, Shoals Marine Laboratory, Coastal New England

Abstract

The taphonomic effects of avian taxa upon forensic scenes has been little researched, and shore species including gulls (Laridae) have received even less attention, despite their well-known behavior as scavengers of human food waste. In order to begin assessing their potential impact, a pilot study was undertaken on Appledore Island, Maine, USA, at the Shoals Marine Laboratory. This location was chosen for its isolation from most other vertebrate scavengers and its large, seasonal breeding colonies of gulls, primarily great black-backed (Larus marinus) and herring (L. argentatus) gulls. Two locations with fresh bones were monitored for scavenging activity, using trail cameras and Tile Mate® tracking chips. In addition, portions of the breeding colonies nesting areas along the rocky coast were surveyed for bones that must have derived at some distance from human-generated trash sources. All (n=16) fresh bones underwent dispersal by gulls, with an average distance of 10m and a maximum distance (in one case) of 85 m. Multiple bones from trash sources were transported a minimum of 150 m if locally acquired and a minimum of 10km if acquired from the mainland. These bones had a maximum length of 192 mm and mass of 46.0g. Gulls, with their global distribution, have the potential to be significant dispersers of human skeletal remains and should undergo additional taphonomic research.