Environmental DNA from woodpecker peck marks

Monitoring species' occurrences is essential for understanding ecosystem dynamics, tracking biodiversity changes, and guiding conservation efforts. Traditional monitoring methods, such as visual surveys, are challenging, particularly for elusive and endangered species. This study evaluates the potential of environmental DNA (eDNA) collected from peck marks as a non-invasive tool for woodpecker species detection and identification. In total, we collected nine samples from fresh peck marks on birch and spruce trees in the forests of Swedish Lapland. In two samples, we successfully amplified 81-bp of the woodpecker mitochondrial 16S rRNA gene. Taxonomic assignment revealed the sequence originated from the Eurasian three-toed woodpecker (Picoides tridactylus), a species classified as “Near Threatened” in Sweden. We collected further 15 samples from 4-19 years old peck marks preserved inside the trunks of birch and pine trees in the same area, although woodpecker DNA was not detected in these samples, potentially due to DNA degradation. Our findings demonstrate the potential of eDNA as a non-invasive approach for monitoring elusive woodpecker species from fresh peckmarks.