| Parasites are quite common in wild birds. They can increase the host mortality, or reduce the birth rate, and then adjust the bird population. Parasite has been generally thought to affect the dynamics and sustainability of the bird population, and has become an important part of Conservation Biology. Waterbirds are more susceptible to parasite infection, due to the wide range of migration and group living, especially some endangered species that would suffer more. Hooded Cranes are large migratory waterbirds, as well as rare and endangered species. However, the species, roles, effects, temporal and spatial dynamic characteristics of parasites in wild Hooded Cranes are still unknown, forming the vacancies in protection and management of this precious species. To explore the parasite dynamics of wild Hooded Cranes, fresh faecal samples were collected from the three lakes (Poyang, Caizi and Shengjin Lake) in the lower and middle Yangtze River flood plain during November2012to April2013, followed by detection with saturated brine floating and centifugal sedimentation methods.About57.7%of821collected faecal samples showed parasitic infection, and11parasites were recovered, including2coccidium(Eimeria gruis, E.reichenowi),5nematodes(Capillaria sp., Strongyloides sp., Ascaridia sp., Trichostrongylus sp., Ancylostomatidae),3trematodes (Echinostoma sp., Echinochasmus sp., Fasciolopsis sp.) and1cestode(Hymenolepis sp.). All species of parasites were found in three regions, except the missing of Hymenolepis sp. in Poyang Lake. Compared with previous research results of other cranes, Hooded Cranes wintering in the middle and lower reaches of Yangtze River showed lower levels of intestinal parasite infection rate.The infection frequency of most samples ranged from1to2species. The highest infection of parasites is Eimeria spp.(53.1%), and followed by Ascaridia sp.(6.1%), Strongyloides sp.(4.1%) and Capillaria sp.(3.7%). Nematodes and trematodes detected in Poyang Lake were higher than that of Shengjin and Caizi Lake, but have no significant statistical difference. Pearson Chi-Square test and Fisher’s exact test results showed that between early overwintering and late overwintering, there are significant differences in protozoon infection (x2=32.174, df=1, P<0.01) and nematode infection (%2=6.012, df=1, P<0.05), while no significant differences found in trematode infection (%2=0.07, df=l, P=0.791) and cestode infection (P=0.119).Shannon-Wiener index (H1) of parasite infection shows Poyang Lake (1.436)> Shengjin Lake (1.395)> Caizi Lake population(1.369), and Pielou evenness index (J) shows Poyang Lake (0.624)> Shengjin Lake (0.582)> Caizi Lake population (0.571). From the statistical data analysis of the three lakes, parasite species richness index (F2,15=0.666, P=0.656), diversity index (F2,15=0.756, P=0.598) and evenness index (F2,15=0-733,.P=0.612) showed no significant difference. The highest parasite diversity index (H’=1.571) appeared in late wintering, and the lowest diversity index (H’1.340) was in the early wintering. There were no significant difference in parasite species richness index (F1,4=0.200, P=0.678) and evenness index (F1,4=1.925, P=0.238) between wintering periods, but a strong difference in diversity index (F1,4=12.317,P=0.025). Our study suggests that the parasite diversity is more sensitive to the changes in the overwintering period than that in the geographical area. This also indicates that with the limitations of migration distance, the parasites may not form the differentiation in Hooded Crane populations of the three lakes. |
PDF Full Text Request