The Use of Fluorescent Powedered Pigments as a Tracking Technique for Snakes
Fluorescent powder tracking provides an exact record of movement and is therefore useful in discovering how an animal moves through its environment. Using fluorescent powder is also noninvasive, inexpensive, and can be performed successfully with little training. However, application of fluorescent powder on body surfaces is an underused method for obtaining data on reptiles.

Benjamen Furman and colleagues describe a new technique for tracking snakes that is an alternative to radio-transmitters and thread trails. They coated the bodies of three species of garter snakes (Thamnophis) in fluorescent powder, then followed and marked the trails with a UV light at night. The use of a UV light allowed them to see very detailed paths left by the snakes.
The effectiveness of fluorescent powder tracking may vary among and within groups of reptiles based on morphological characteristics. For instance they found out that smaller garter snakes left shorter tracks than larger garter snakes, presumably because their smaller body surfaces collected less powder that dissipated over shorter distances. Habitat can also affect tracking success. Movement through grassy and herbaceous vegetation, such as used by garter snakes, tends to leave the best powder trails. Daily weather should also be taken into account as rain can reduce the visibility of the trails greatly. Of their tracked snakes, 10% ended up in tunnels or burrows, thus the use of fluorescent powder tracking may prove useful in finding hibernacula sites. Fluorescent powder tracking is proving to be an effective technique for tracking amphibians and reptiles, and was recommend its use for tracking snakes as part of ecological studies.

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(Source: Furman et al., 2011. The Use of Fluorescent Powedered Pigments as a Tracking Technique for Snakes. Herpetological Conservation and Biology 6(3):473−478.)