| The Crested Ibis (Nipponia nippon), endemic to East Asia, is an endangered species of the world. In the past 28 years, the great conservation efforts have been taken by Chinese government and researchers to restore the populations and received a great success both in situ and ex-situ conservation. By the end of 2008, the number of individuals in the wild population had increased to more than 600 and with another 630 birds in captivity. But there is a single wild population in Yangxian County at present. Once it comes down with the malignant incident, they will probably bring the crushing consequence to wild population in existence. So a reintroduction programme of the Crested Ibis was launched at Zhaigou Village, Ningshan County in Shannxi Province in 2007, in order to establish a new colonizing population which can make the quantity increase continually and steadily, and getting rid of the endangered state completely. In 2007 and 2009,26 and 10 healthy captive-bred Crested Ibises were released to the wild, respectively. Five pairs subsequently formed in the wild amongst the reintroduced population and eleven nestlings fledged successfully in the following three years. We considered that the reintroduction programme has therefore had a promising result.In order to determine the birds' ability to survive in the new environment, the daily behaviour and activity rhythm was observed in Ningshan County from June 2007 to September 2009, and the results have been showed as follows:The results of annual activity rhythm of reintroduced Crested Ibis are as follows.The daily activity pattern was dissimilar in different stages when the Crested Ibis awakens at the average moment of 5:34,6:34 and 7:42 in the morning during the breeding season, wandering stage and wintering period, respectively. Contrarily, the mean roosting time in the dusk was 17:44, 18:38 and 19:55 during the breeding season, wandering stage and wintering period, respectively. Consequently, the activity time span in the daytime in the breeding season (14.35h) was longer than that of the wandering stage (11.92h) and the winter period (10.03h).The feeding behaviour spent most of the daytime during the breeding season, wandering stage and wintering period, and the time budget is 43.99%,65.99% and 59.11%, respectively. The breeding behavior (36.61%) including nesting, incubation and nestling brooding was another major activity during the breeding stage. The time budget of various behaviour such as foraging, preening, movement and breeding was significantly different during the three stages (One-way ANOVA: F=15.792,Df=37,P<0.01;F=13.384,Df=37,P<0.01;F=10.948,Df=37,P<0.01;F=177.492, Df=37, P<0.01).The Crested Ibis showed an unobvious rhythm of activity in the daytime during the breeding season. But in the wandering stage, the feeding were recorded at 8:00～10:00 and 14:00～16:00, the resting at 12:00～13:00 and 19:00～20:00, the movement at 5:00～6:00 and 18:00～19:00, and the preening and other behaviors at 5:00～7:00 and 18:00～20:00. Similarly, the feeding frequently occurred from 9:00 to 17:00 without obvious peaks, and the resting, preening and other behaviors were almost recorded at 7:00～8:00 and 18:00～19:00, and that of the movements was at 7:00～8:00 in winter.Statistical analysis of differences of the reintroduced Crested Ibis' behaviour time budget and the activity rhythm during different stages indicates, illumination, temperature and own needs have some impact on time budgets and activity rhythms.The results of different groups of reintroduced Crested Ibis are as follows.The research of differences the reintroduced Crested Ibis' behaviour time budget and the activity rhythm between different gender shows that:the mean length of daytime of female Crested Ibises(11.71h) is longer than the male(11.41h). Female Crested Ibises spend more time on feeding(45.26%)during breeding season,and feeding(63.82%) and moving(3.77%) during non-breeding season, while male Crested Ibises spend more time on resting, preening and other behaviors both in breeding and non-breeding season. T-test show insignificant variations in the proportion of daytime spent on feeding, resting, preening, moving, breeding and other activities (P>0.05) between male and female Crested Ibises. Similarly, Wilcoxon test of daily rhythm shows insignificant differences in various behaviors between different gender. As a result, according to the analysis on morphology and ethnology, the male's ability to survive in the wild is slightly higher than the female's.The research of differences of the reintroduced Crested Ibis'behaviour time budget and the activity rhythm between different age shows that:the mean length of daytime of juvenile Crested Ibises (13.65h) is longer than the adult (10.73hh). The fledgling spend more time on feeding (58.50%) and resting (23.08%), while little time on preening(11.30%), moving(3.07%) and other behaviour (2.61%) than the adult. Different from other individuals, the fledgling spend a little time on begging for food from the adult (1.65%). At the same time, the time budget and activity rhythm have insignificant differences between the fledgling and the adult (P>0.05). The results indicate that, although, the ability to survive of the fledgling is lower than the adult, through the study from the adult, they can adapt to the new environment quickly.The research of differences the reintroduced Crested Ibis' behaviour time budget and the activity rhythm between different released time shows that:the Crested Ibis released lately, spend more time on feeding (73.24%) than the earlier (57.29%) significantly(P<0.01), and then the rhythm on feeding has significant difference between the earlier released and the late ones(P<0.05). The result indicates that the ability of survive in the wild, such as the ability of feeding, of the late released are lower than the earlier, and which should spend a long time to adapt to the new environment. |
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