被动式电子标签用于花鼠种群动态研究的可行性

在野生动物研究过程中经常需要对动物个体进行标记。传统的标记方法存在着标记物易脱落、可能影响被标记动物的生理和行为、难于进行个体识别等缺点。被动式电子标签(passive integrated transponder, PIT)是基于射频识别技术的电子标签，可用于体内标记，具有不易脱落消失且能够进行个体识别的优点。我们在凉水国家级自然保护区以PIT标签为标记物，采用标志重捕技术开展花鼠(Eutamias sibiricus)的种群动态研究，同时对应用PIT标签的可靠性进行了研究。2011年秋季至2012年春季共标记花鼠个体140只，其中86只被重捕至少1次。2011年秋季标记的72只个体中有38只在2012年春季被重捕。重捕的花鼠个体注射口愈合完好，体重无明显降低。结果表明PIT标签是一种安全可靠、识别迅速、数据准确、不易丢失、可循环使用的体内标记电子标签，适用于基于个体识别的小型哺乳动物生态学研究。

Feasibility analysis of passive integrated transponders in population ecology studies of Siberian chipmunk

In wildlife studies, individual animals are usually uniquely marked to collect data related to population ecology and behavior such as social structure, migration and dispersion, growth and age identification, seasonal fluctuation of physical features, reproductive patterns, life-history strategy, nesting territory and home range. Wild animals are mainly superficially marked with ear tags, ear-rings, neck collars, cut toes, foot bands, hair shearing, clipped ears, colored hair, brands, and tattoos. Using cut toes, colored hair and ear tags to mark individuals are normal techniques in population ecology studies on small rodents. However, all of these marking methods have various disadvantages. For example, clipped ears and cut toes physically harm animals and may affect their normal behavior as well as physiological condition. Because ear-rings are easily lost and colored hair lasts only a short time, these two methods are not suitable for long-term ecological research. Furthermore, all regular marking methods are difficult to use for marking individuals in a large population. These obvious disadvantages may potentially affect the reliability of results obtained. A passive integrated transponder (PIT) is part of an electronic marking system based on radio frequency identification allowing each marked animal to bear a unique international code. The PIT tag remains dormant until activated at close-range by a handheld reader, which generates an electromagnetic field. PIT tags are small and light, giving them an advantage over traditional marking methods in that they can be implanted inside animal bodies and have a minimal affect the physiology and behavior of marked animals. PIT tags were first used in measuring fish movement in 1983. Since then, PIT tags have been widely applied in animal research among invertebrates, amphibians, reptiles, birds and mammals and are popular worldwide especially for use in zoos, aquiculture and animal trade. Nevertheless, the application of PIT tags is restricted to a few aquatic animals in China. We adopted PIT tags and mark-recapture techniques to investigate the population dynamics of Siberian chipmunks (Eutamias sibiricus) during five time periods from October, 2011 to June, 2012 in Liangshui National Nature Reserve in Heilongjiang Province, China. A total of one hundred and forty chipmunks were marked, of which eighty-six were recaptured at least once. Seventy-two chipmunks were marked in autumn, 2011, thirty-eight of which were recaptured in spring, 2012. The injection wounds of all recaptured chipmunks had healed well and they exhibited no significant decrease in body weight. We estimated the dynamics of the chipmunk population based on mark-recapture data. The results showed that the average population density of chipmunks in the Korean pine forests of the Reserve was 8.91 ? 2.76 per hectare in autumn, 2011 and 6.14 ? 1.29 per hectare in spring, 2012. After the analysis of individual recapture records, we found that the maximum movement distance of studied chipmunks was not significantly different in autumn (65 ? 8 m) and in spring (67 ? 4 m). Chipmunks exhibited a clumped distribution pattern in autumn and uniform pattern in spring. These results indicated that PIT tags provide an ideal internal safe and reliable electronic marking system because they allow rapid and accurate identification of individuals when collecting data, last a long time when worn inside animal bodies, are less harmful to marked animals than other marking techniques, are rarely lost and are reusable. In summary, PIT tags allow the identification of individual small mammals, are mainly useful in wildlife ecology, and are especially suitable for population ecology.