The Home Range And Dispersal Ecology Of Crested Ibis(Nipponia Nippon)

The home range and dispersal behavior of animals are very important for the structure and dynamic of population, especially for the conservation and monitoring of endangered species. However, very little is known about the Crested Ibis(Nipponia nippon). Using ring resighting and radio tracking methods, the home range and dispersal behavior of the Crested Ibis in different ages were researched in Shannxi Crested Ibis National Nature Reserve, from 2010 to 2014. The results are as follows,1. The dispersal behavior of the Crested Ibis was studied using ring resighting method during 2008 and from 2010 to 2014. A total of 1288 Crested Ibis were ringed from 1987 to 2012. In our research, the Crested Ibis were seen for 371 times including 224 individuals. Using General Linear Mixed Model, the results show that there was significant difference about the distance from natal site among seasons and age (P< 0.05). The mean distance from natal site was 12.29±0.42 km in wandering,12.18±0.65 km in wintering and 8.66±0.90 km in breeding. The average of long dispersal distance was 38.10±2.53 km and the maximum dispersal distance was 55.02 km. The distance from natal site of female (15.10±2.60 km) was farther than the distance of male (12.38±2.06 km) (P= 0.413). The female individuals were more likely to disperse far away natal sites. The sibling dispersed from natal site in significant different distance (P< 0.05). The results support the inbreeding avoidance hypothesis.2. From 2011 to 2013,82 dead Crested Ibis were reported. The causes of death included wound, food shortage, predation, disease, electrocution of power lines, malnutrition and sibling competition. Using Capture-Mark-Recapture Methods, the survival was firstly estimated by Joint Live and Dead Encounters Data Model. The results show that the individual survival was affected by season and age rather than radio tag. The average survival was 0.97±0.01 in breeding season,0.85±0.08 in wandering season, and 0.83+ 0.09 in wintering season. The survival was positively related to the age. Using General Linear Model, the results show that the rate of foraging success was not significant affected by radio marker factor (P< 0.05).3. The post-fledging period was firstly defined strictly by the movements of 6 juveniles with radio tracking during 2011. The average duration of post-fledging period was 33.50±5.68 days. The average distance from natal site was 0.44±0.06 km with the maximum distance 1.53 km. The average step length was 0.26±0.04 km with the maximum length 1.94 km. The average distance from natal site and step length increased with time throughout the post-fledging period (P< 0.05). During the post-fledging period, the 95% fixed kernel home range was 1.06±0.30 km2, and the core home range (50% fixed kernel) was 0.20±0.59 km2. The birth rank has not significant effect on movement of juveniles(P> 0.05). Using the General Linear Model (GLM), the results show that the weight and duration of post-fledging period were the important effect for home range size in post-fledging period (P< 0.05). The duration of post-fledging period (P< 0.05) was important for the average distance from natal site and the weight (P< 0.05) for the average step length. The results support the hypothesis that the individual with poor body condition showed smaller home range.4. From 2011 to 2014,11 non-breeders were tracked by radio tags. The average home range size of non-breeders (95% fixed kernel) was 60.74±25.94 km2 (n= 7) in breeding season,20.42±7.31 km2 (n= 9) in wandering season, and 5.74±2.27 km2 (n= 4) in wintering season. The mean foraging distance was 2.42±0.08 km and the maximum distance was 13.02 km. The home range size and foraging distance of female non-breeders were larger than male, and the immature individuals than adults. The female and immature individuals were more likely to forage far away from roost site. Using General Linear Mixed-effect Model (GLMM), the results show that the home range size of non-breeders was affected by season factor (P= 0.02) rather gender or age factor (P> 0.05). The home range size was highest in breeding, and the size was lowest in wintering. The maximum foraging distance of non-breeders was farther in breeding than in wandering and wintering (P= 0.08). The home range size of non-breeders increased with decreasing of intake rate (P= 0.05).5. From 2011 to 2013,2 adult breeders were tracked by radio tags for the first time. The 95% fixed kernel home range size was 1.40-10.10 km2 in breeding season,1.55～10.4 km2 in post-breeding season, 8.81～84.1 km2 in wandering season, and3.25～5.85 km2 in wintering season. The foraging distance showed significant differences among seasons (P< 0.05). In the same period of season, there were significant differences on movements between breeders. During breeding, using the Mann-Whitney U test, the 95% fixed kernel home range size (P= 0.017), core home range size (P= 0.030), mean foraging distance (P= 0.053) and maximum distance (P= 0.017) of breeder were significant smaller than non-breeder’s. There were no difference on movements in wandering or wintering (P> 0.05).