I addressed how detection probability of Passive Integrated Transponder (PIT) tags is affected by depth, orientation of tags, and type of substrate. Seabirds consume wild salmonids that are implanted with PIT tags (Evans et al. 2012). These tags are often deposited at the seabirds’ colonies, providing a means to study their ecology (Evans et al. 2012). I tested if tags were detected in duff, sand, or no substrate- at different depths and with tags in the vertical, horizontal, or diagonal orientation. I also extensively scanned a plot at a multi-species heronry to get an estimated total of PIT tags, then rescanned the plot 10 times to determine how many tags were detected each trial. Detection probability decreased with depth, increased in the vertical orientation, did not differ between sand and duff substrates, and did not differ between diagonal and horizontal orientations. At the heronry site, there was a detection probability of 0.83 across the trials, which ranged from 0.74-1.00 detected. These findings provide beneficial information on what variables affect detection for future terrestrial PIT tag studies.