Invisible but Identifiable: p-Chips as a Reliable Marking Method for Amazonian Bats

Juan Jesus Pellón, Naija Cuzmar, Jorge Luis Mendoza, Cristian Tirapelle, Nick Fluker, Gideon Erkenswick, Mrinalini Watsa

Marking techniques are essential for studying bat ecology and informing conservation efforts, yet many existing methods present challenges related to size, tag detectability, and long-term retention. p-Chips, ultra-miniaturized transponders detectable via red laser light, offer a promising alternative to traditional banding or passive integrated transponder (PIT) tags. While their use has been successfully demonstrated in captive bats, their effectiveness in free-ranging populations remains largely untested. Across three years of bat research in the Peruvian Amazon, we tagged with p-Chips individuals across 31 species. We documented 88 recaptures, with all p-Chips remaining functional over both short term (≤ 40 days) and long term (> one year) periods. Notably, no adverse effects such as scarring or tissue damage were observed. Red LED illumination facilitated rapid tag visual detection, reducing handling time. These findings support the use of p-Chips as a viable, detectable, minimally invasive, and cost-effective alternative to PIT tags, particularly for small-bodied species. We recommend further research to optimize p-Chip technology for broader application in wildlife tracking and conservation.