What harm could a slimy little critter slowly crawling on the forest floor possibly do to a bird? A lot, it turns out. Slugs are shell-less mollusks that have a specialized mouth with a sandpaper-like structure. That rough surface can easily rip the skin and eyes off of a baby bird, leaving the chick to fight for its life.
Many don’t survive.
To be sure, this chick-icide by slugs is rare, European scientists now report. Still, they note, it could become a problem for ground- and shrub-nesting birds if slug numbers climb.
Justyna Chachulska is a graduate student at the University of Zielona Góra in Poland. Katarzyna Turzańska studies at the University of Wrocław, also in Poland. In 2014, both PhD students were monitoring nests of the common whitethroat (Sylvia communis), a mid-size European warbler. They were on the outskirts of the city of Wrocław.
The season was wet and cold. As a result, the ground teemed with slugs. One day, the young scientists noticed a slug in a nest with three newly-hatched chicks. They couldn’t imagine this slug posed a threat to the baby birds. So, they carried on with their work on other nests. But when they returned to the same nest the next day, two nestlings were dead. The third was missing.
To know how this avian murder mystery was solved, read the full story over at Science News for Students.
Photo Credit: Andrzej Wuczyñski