The Effects of Fluorescent Tracking Powder on Oxygen Consumption in Salamanders Using Either Cutaneous or Bimodal Respiration

Abstract

Fluorescent powder is gaining attention as an effective method for tracking terrestrial amphibian movements, particularly for species that are too small for conventional tracking equipment. The technique requires coating portions of an animal with fluorescent powder, releasing the animal, and following the trail of powder as it is progressively lost during movement. Recent studies have shown that fluorescent powder has no negative effects on survival or growth. However, a substance that coats the skin, a major respiratory organ in most amphibians, may have sublethal effects on performance and consequently behavior. We tested the effect of fluorescent powder application on the respiration of lungless Red-Backed Salamanders, Plethodon cinereus, and lunged terrestrial Red-Spotted Newts, Notophthalmus viridescens. In comparing species with contrasting skin textures and primary modes of respiration, we expected to find P. cinereus, the species relying solely on cutaneous respiration, more sensitive to fluorescent powder. Standard metabolic rate (SMR) and total oxygen consumption for both species were measured before and after application of the powder. We found no significant differences in respiration between control and powdered salamanders. Independent of treatment, SMR was 6–16% higher during the post-treatment trial in both species, and likewise, total oxygen consumed increased by 8–20% in P. cinereus and by 7–10% in N. viridescens. Our results, in combination with other recent work, suggest that fluorescent powder is a safe technique for tracking amphibians.