Online media reveals a global problem of discarded containers as deadly traps for animals

Abstract

The widespread occurrence of litter is a severe threat to global ecosystems. We have analyzed online media, to assess the diversity of animals that are prone to getting trapped in discarded containers and check which kind of containers is the most common trap for animals. A total of 503 records from around the world (51 countries, 6 continents) have been found. These include invertebrates (17 taxa, ca.1050 dead individuals), and vertebrates (98 taxa, 496 individuals including 44 carcasses). The latter group was most frequently represented by mammals (78.5% of all cases), then reptiles (15.3%), birds (1.2%), fish (1.0%) and amphibians (0.4%). Nearly 12.5% of the determined vertebrates are classified as vulnerable, endangered or critically endangered, according to the IUCN. Although most trapped individuals were smaller animals, bigger ones such as monitor lizards (Varanus spp.) or large carnivores were also recorded. In most cases, animals were trapped in glass or plastic jars (32.4%), drink cans (16.5%), and steel cans (16.3%). Our results demonstrate that discarded containers can be a threat to all major groups of animals. In order to address this phenomenon, it is necessary to decrease a global production of debris, implement container deposit legislation and organize repeatable cleanup actions.

Figure 1

Number of reports concerning animals getting stuck in discarded containers shared on social media between July 1999–November 2019.

Figure 2

Examples of animals that got stuck in different type of discarded containers: (a) dor beetle Anoplotrupes stercorosus in beer can, translation of the caption in the photo: remains of ca. 60–70 dor beetles, photo by Konrad Hozler, source: https://www.youtube.com/watch?v=7o5aisetJDY, (b) harvest mouse Micromys minutus in Coca-Cola plastic bottle, photo by Olga Wojciechowska, source: https://www.facebook.com/photo.php?fbid=889881771382671&set=p.889881771382671&type=3&theater, (c) racoon dog Nyctereutes procyonoides in glass jar, photo by Bartosz Jaszewski, source: https://www.facebook.com/photo.php?fbid=2058677897551258&set=pcb.2058724980879883&type=3&theater&ifg=1.

Figure 3

Share of particular animals that got stuck in different types of discarded containers. Container symbols mean (from upper left corner): bottle, jar, drink can, steel can, cup.

Figure 4

Number of reptiles (a) and mammals (b) that got stuck in different types of discarded containers. Animal symbols mean: (a) lizards, snakes, turtles, and (b) small, medium and large size mammals, respectively. Container symbols as in Fig. 3.

Figure 5

Correspondence analysis showing relationships between the most common groups of animals: invertebrates, reptiles (lizards, snakes, turtles), mammals (small, medium, large) and different types of discarded containers (symbols as in Fig. 3).