Home Range, Homing and the Homing Mechanism of the Salamander, Desmognathus fuscus

Abstract

The home range of Desmognathus fuscus was studied along a gridsystem of stream consisting of 12 zones, each 3 m long. The mean activity radius (MAR) of recaptured animals averaged 1.14 ? 0.08 m; the mean distance traversed along the stream (x = 2.3 m) was about twice the MAR. Salamanders remained within 3 m of their original capture site for 15 to 87 days (x = 55.8 days). The home range was found to be less than 3 m along the stream. In the homing study, anosmic, blinded, sham treated, and normal salamanders were displaced downstream at 3 m intervals, ranging from 3 to 30 m; controls were returned to their original capture site. The homing performances of sham treated and blindeddisplaced animals were not significantly different from the normal-displaced animals; significantly fewer anosmic salamanders homed, most accepting the release site. The homing ability of the anosmic salamanders was significant since nearly all that homed returned from only a 3 m displacement. Only anosmic animals were disoriented after leaving the release site. Normal, sham treated, and blinded salamanders that homed remained home, some for at least 63 days. Over 95% of the control animals remained within 3 m of their home zone. These observations support the hypothesis that an olfactory mechanism rather than an optic and/or extraoptic mechanism dominates the homing behavior of D. fuscus.