Crested ibis 2001: conservation biology and environment pollution monitoring

Chang-Qing Ding

The Crested Ibis is a globally threatened species and ranked as critical endangered (Collar,1994). After the rediscovery of the wild birds in Yangxian, Shaanxi province in 1981, great conservation efforts have been taken. The wild population increased from 7 to about one hundred. Since there is only one wild population presently, in order to save the Crested Ibis essentially, an reintroduction programme have to be conducted as early as possible. Thus, the studies on habitat selection and environmental evaluation are needed to provide reference data for finding out the releasing site. The environmental pollution, esp. the residues of pesticide was one of the main reasons causing the extinction of wild Crested Ibis in Japan. However, DDT and other organo-chlorine pesticides are still used in Yangxian county and there are six fertilizer factories and cement plants close to the feeding areas of the Crested Ibis. The number of aquatic species decreased due to the released of polluted water in Hanjiang river system, a major feeding area for the Crested Ibis. According to our observation, the frequency of the Crested ibis feed at Hanjiang river beach in September and October, 2000 is only 36% of what we observed in the same period of 1999. This project consists of three aspects:(1) According to the radio-tracking results, we will find out the typical habitats and feeding areas and use Neu's method and factor analysis to investigate the main factors influencing the habitat selection of the Crested ibis. (2) In the meantime, we will also collect water, mud, food samples and the eggshells and mounted feathers of the Crested Ibis to examine the pollution status of the environment and the residues in the birds.(3) We will use satellite image and GIS techniques to evaluate the habitat qualities and study the distribution of suitable habitats in Yangxian. The radio-tracking study was started from 1999 and 9 birds have been tagged. The movement data we got from radio-tracking will help us to locate the typical habitats and feeding areas. Through the proposed project, we could find out whether and how much the human activities, esp. the pollution to the environments, will threat the Crested Ibis and other waterbirds. We will produce detailed reports and management recommendations to the Crested Ibis Conservation Station in Yangxian, Shaanxi Forestry Bureau in Xi'an and the State Forestry Administration in Beijing. Some of our results could be applied in practical conservation in Yangxian quickly. In the meantime, establishing local GIS facilities, we can contribute much more to the local government when they design and make out the application for promoting the Yangxian Crested Ibis Conservation Station to a National Nature Reserve. Moreover, the applicant has been asked by SFA to prepare the reintroduction Action Plan for the Crested Ibis in China. The results of this project will be used to facilitate the reintroduction programme.