A Suspected Scavenging Event by Red Foxes (Vulpes vulpes) on a Live, Stranded Harbour Porpoise (Phocoena phocoena)

Loop-mediated isothermal amplification (LAMP) assay—A rapid detection tool for identifying red fox (Vulpes vulpes) DNA in the carcasses of harbour porpoises (Phocoena phocoena)

“…Confirmation of DNA residues in wounds is not an easy task and brings challenges for the sampling and analysis process. Although previous studies succeeded in isolating predator DNA of grey seals from wounds of harbour porpoises via PCR [ 3 , 5 ], this was not successful for detecting red fox DNA [ 1 ]. This shows that PCR analyses might not always be the method of choice when the objective is to detect scavenger DNA residues.…”

“…When it comes to forensic studies it is not only important to confirm the actual “offender”, but also to identify and distinguish between predation and postmortem scavenging. Haelters et al [ 1 ] described a case of a live stranded harbour porpoise ( Phocoena phocoena ), which had suffered several injuries. However, these wounds did not meet the typically described injuries of grey seal ( Halichoerus grypus ) attacks, which are known to hunt harbour porpoises [ 2 ].…”

“…However, these wounds did not meet the typically described injuries of grey seal ( Halichoerus grypus ) attacks, which are known to hunt harbour porpoises [ 2 ]. These injuries usually appear as “puncture injuries left by teeth and claws; strips of blubber removed or hanging loose; sometimes muscle partly removed” [ 1 ]. Several investigations demonstrated that harbour porpoises are victims of attacks from grey seals [ 2 – 6 ] and in some cases, the DNA of grey seals was isolated from the bite marks of harbour porpoises and confirmed via PCR [ 2 , 3 ].…”

“…Several investigations demonstrated that harbour porpoises are victims of attacks from grey seals [ 2 – 6 ] and in some cases, the DNA of grey seals was isolated from the bite marks of harbour porpoises and confirmed via PCR [ 2 , 3 ]. However, in the case study of Haelters et al [ 1 ], the authors suspected that certain wounds were caused by a red fox scavenging the animal. Unfortunately, it was not possible to prove this assumption because a PCR yielded negative results.…”

“…In the present study, a target sequence of the cytochrome b gene of red fox ( Vulpes vulpes) was selected, primers were designed and the LAMP method was validated in vitro and successfully tested on a harbour porpoise which had been stranded on the coastline of Northern Germany and showed possible red fox bite marks. These are typically deep, focal, the blubber being penetrated with bleeding occurring in the underlying tissue [ 1 ]. Applying this method it was possible to identify the red fox as a scavenger by directly testing swab samples without previous DNA isolation.…”