Movement patterns and home range of captive-bred Amur ratsnake (Elaphe schrenckii) juveniles in the natural habitat

Abstract

To determine the movement patterns, home range, and use of structural features of captive-bred one-or two-year-old Amur ratsnake (Elaphe schrenckii) juveniles in the natural habitat, we radio-tracked a total of 11 juvenile snakes in a mountain valley in Chiaksan National Park, South Korea, between August 21 and September 20, 2010 and between June 13 and July 13, 2011. During the first week of the release, most juveniles moved short distances, daily, but they increased their distances after the first week. The body weight of the juveniles was negatively related with the movement rate (dividing the number of movements by the number of relocations), which was positively related with the mean daily distances moved and the size of both a kernel 50% and 95% home range. During the study period, the juveniles moved daily, approximately 17 m, and the size of the minimum convex polygon and the 50% and 95% kernel home ranges were 1.8 ha, 0.4 ha, and 3.0 ha, respectively. The released captive-bred juveniles were more frequently confirmed underground or on the ground rather than on rocks or on trees. Our results suggest that the body condition of released individuals, the seasonal time of the release, and the existence of available prey and shelters in the habitat should be carefully considered when releasing captive-bred Amur ratsnake juveniles for the rehabilitation of field populations.

A field evaluation of two external transmitter attachment methods for small snakes

“…The transmitter attachment method to snakes is largely divided into surgical implantation and external attachment. Surgical implantation, which has been applied to various snake species (Gerald 2006;Kim et al 2012a;Lee et al 2011;Lee and Park 2011;Mohammadi et al 2014;Webb and Shine 1998), is a method of inserting the transmitter into the subcutaneous layer or the abdominal cavity of an individual, and if necessary, fixing the transmitter to the ribs (Reinert and David 1982;Weatherhead and Anderka 1984). Implantation of the transmitter into the abdominal cavity causes the fewest side effects caused by the transmitter for radio-tracking snakes, and its strong fixation makes stable long-term study possible.…”