Transmitter-equipped darts in a protocol for chemically immobilizing free-ranging red deer (Cervus elaphus) in Central Italy

Abstract

Twenty-two free-ranging red deer (Cervus elaphus), 9 males and 13 females (7 months to 13 years old), were captured in October-November 2006 and December 2007, along the Apenninic ridge (44°06’N, 11°00’E) between the Pistoia (Tuscany) and Bologna (Emilia-Romagna) provinces, as part of a reintroduction project in Gran Sasso and Laga’s Mountains National Park (42°33’N, 13°28’E), Italy. The aim of the study was to evaluate the effectiveness of a red deer capture protocol, using equipped transmitter darts, in Apennine areas where other methods had not been successful. The red deer were darted (by an operative team of 5-7 operators during dark hours) with a mixture of Zoletil® (Z) and xylazine (X) and, whenever secondary dosages became necessary, a mixture of ketamine (K) and X were used. Twenty-five animals were shot, only 3 of which could not be approached to re-dart them. All animals were darted, during dark hours, from a vehicle at a distance of 10-30 m and then recovered, using 3-cc disposable Pneu-dart® transmitter darts, 50-280 m (median 80 m) from the dart site. These technical choices were forced by an uneven and wooded environment of the study area. Before the transport to the reintroduction site, the animals were kept in a lairage stable, arranged in single boxes, provided with water and food. This accommodation was necessary to collect a reasonable number of animals to arrange the transport. The immobilized animals were brought to the stable and haemoglobin saturation and heart rate were constantly monitored with a pulse oximeter. Oxygen was insufflated into a nostril at a rate of 10 litres/min for 20-35 min. Atipamezole was administered two thirds intramuscularly (IM) and one third intravenously, 45 to 120 min after the last IM narcotic injection, to revive the animals. No side effects other than different levels of meteorism, were displayed. In conclusion, the protocol applied, which proved safe for the animals and had optimal success in the recovery of darted subjects, can be considered effective to capture free-ranging deer in areas that are thickly wooded and difficult to traverse as areas of the Apennine.