He X.-L.,Beijing Forestry University |
He X.-L.,Chinese Academy of Agricultural Sciences |
Qing B.-P.,Shaanxi Hanzhong Crested Ibis National Nature Reserve |
Han J.-L.,Chinese Academy of Agricultural Sciences |
And 2 more authors.
Sex Identification of monomorphic birds, especially endangered avian species, is essential for ecological study and biodiversity conservation. In this study, two popular primer sets of 2550F/2718R and P2/P8, which were designed to amplify different fragments of chromodomain-helicase-DNA binding protein 1 (CHD1) genes mapped on both Z and W chromosomes in birds, were used to identify for the first time the sex of individuals of the endangered species crested ibis (Nipponia nippon) in a large number of samples. An improved primer set of 2467F/2530R was re-designed to be specific to crested ibis following their conserved sequences derived from the 2550F/2718R primers. PCR products of the new primers were conveniently visualized with two bands of 552 base pairs (bp) and 358 bp for females, but a single band of 552 bp for males in routine 1.8% agarose gel. Similarly, the P2/P8 primer set amplified two fragments of 398 bp and 381 bp from females but one fragment of 398 bp from males; however, a high resolution involving 10% Polyacrylamide gel had to be employed to resolve the 17 bp insertions/deletions (in/dels) present between the two amplicons in females. In addition, a microsatellite locus NnNF05 was validated to be sex-linked and shown to be effective in the sexing of crested ibis, supporting its utility in non-invasive sampling. This study provides a rapid, convenient, and reliable molecular assay for improving sex identification in the monomorphic and monogamous crested ibis, and thus facilitates the selection of breeding pairs in captive programs and reintroduction initiatives. © 2013 Zoological Society of Japan. Source
Zhai T.,Shaanxi Hanzhong Crested Ibis National Nature Reserve |
Li X.,CAS Institute of Zoology
Shengtai Xuebao/ Acta Ecologica Sinica
The uncertainty of climate change and uncertainty of species-environment relationship cause great variability in the studies of climate change biology. To reduce such uncertainties, scientists started to use ensemble models in this field. Our objective is to introduce the approach of the ensemble models, and predict the future range shift of one endangered species, the crested ibis (Nipponia nippon) as an example. The crested ibis had been critically endangered, and currently its population is rapidly recovering. The range of the crested ibis is still small after its recovery from the critical endangered status, so that climate change might be a threat to its long term survival. We used the locations of nest site to represent the distribution of the crested ibis, which have a high accuracy level and has being accumulated from 1981 to 2010. We applied nine modes in BIOMOD (a package of R software) to predict the current (1950-2000) and future (i. e. 2020, 2050, and 2080) distribution ranges of the crested ibis using five climate variables (i. e. annual minimum temperature, annual maximum temperature, seasonal variance of temperature, annual total precipitation, and seasonal variance of precipitation) based on CCCM2 climate model A2a emission scenario in WorldClim database. The nice models are Generalized Linear Models, Generalized Additive Models, Classification Tree Analysis, Artificial Neural Networks, Mixture Discriminant Analysis, Multivariate Adaptive Regression Splines, Generalized Boosting Models, Random Forest, and Surface Range Envelope. We compared the current climate conditions with those in 2080, and found that the current habitat of the crested ibis would become warmer and wetter in the future. All nine models indicated that the crested ibis would have a northward range shift (actually a higher elevation shift), and the distribution center would be out of the current nature reserve. Therefore, it is necessary to develop a long term conservation plan for the crested ibis, e. g. adjusting the nature reserve border or design a new nature reserve. The nine models showed differences in predicted ranges, weights of explanatory variables, and goodness-of-fit (based on ROC curves and Cohen's Kappa indices). Among five climate variables, the seasonal variance of precipitation is the most important variable that associated with distribution of the crested ibis; and seasonal variance of temperature is the secondly important variable. The overall performance of all models are very high, indicated the distribution of the crested ibis had a strong pattern (The crested ibis is well constrained by environmental variables, not scattered randomly). The Random Forest has the highest model performance, and the Artificial Neural Networks ranks the second. The high performance of the two models is partly due to their high complexity. We should be cautious whenever using species distribution models to predict the effect of climate change, because such models are based on the assumption that climate variables are the limiting variables restricting the range of the species, and the current population is in its favorite climate niche. As to the crested ibis, the assumption can hardly be satisfied, because other environmental variables such as human disturbance, wetland, and vegetation are also important to the crested ibis. As a result, the predicted range shift of the crested ibis is only a trend or potential distribution pattern in the future. Because of the difference in model prediction and variability of model performance, we suggest to use ensemble models to deal with complex problem such as biological consequences of climate change to decrease the errors from models. Source
Wood C.,Zhejiang University |
Wood C.,Kyushu University |
Qiao Y.,Zhejiang University |
Li P.,Zhejiang University |
And 3 more authors.
Data on wild birds in rice fields in China are scarce. The potential significance of Chinese rice fields, which represent about 6% of the world's wetland area, is considerable but whether this potential is met is largely unknown. In this review, traditional and modern Chinese rice agriculture are compared, including detailing historical changes and their implications for wild birds. Traditional practices, with one crop each year and long periods of fallow flooding, provide greater benefit to biodiversity and species such as the Crested Ibis (Nipponia nippon). The method and alternatives, such as rice-fish, duck-rice and swidden agriculture, are contrasted with modern techniques which, through associated water regimes and chemical use, have been implicated in the decline of biodiversity and of species such as the Black-faced Spoonbill (Platalea minor). Agrochemical use is particularly pertinent because China is likely to have been the world's largest pesticide consumer since the mid-1990s, with use greatest in rice (Oryza sativa). However, few studies have measured the direct effects of agro-chemicals on wild birds in China. The most detailed information on birds in China's rice fields comes from charismatic species such as the Crested Ibis and Red-crowned Crane (Grus japonensis). Preliminary data from possibly the first systematic bird survey of a Chinese rural county are presented. More detailed and widespread studies of the implications of rice agriculture to wild birds in China are required. Source
Mochizuki S.,Niigata University |
Liu D.,Chinese Academy of Forestry |
Sekijima T.,Niigata University |
Lu J.,Chinese Academy of Forestry |
And 6 more authors.
Journal for Nature Conservation
The Crested Ibis, became extinct in the wild in Japan in 1981; however, a captive breeding facility was established on Sado Island, Niigata Prefecture in 1999 in the hope of conserving the species. Following successful breeding at the facility, a group of birds was released on Sado Island on 25th September 2008, with further reintroductions in subsequent years. Habitat restoration is also necessary to facilitate the re-introduction program of this endangered species. The aim of this study was to detect suitable nesting areas for the released ibises on Sado Island for subsequent nature restoration. Since little ibis nesting information was available for Sado Island, the nesting model was constructed from nesting information from China, from which results were extrapolated for Sado Island. Land usage was assessed using LANDSAT/ETM+ data for China and SPOT/HRG images for Sado Island. In this study, land-use information was used to define the environmental parameters related to nest site selection of the Crested Ibis. For the nesting model, a generalized linear mixed model, with seven environmental factors, was employed. The multi-spatial scale for Crested Ibis nesting was also analyzed. We took the spatial scale into consideration at intervals of 100. m from a buffer size of 100. m to 2500. m. Because nest site selection was influenced by the results of the previous year, nesting location data in 2005 and 2006 were distinguished and models built accordingly. Several important environmental factors were identified for nest site selection: the ratio of broadleaved deciduous forest to coniferous forest; the shape of the forest edge; and, the distance from rice fields and other wetlands. The model's accuracy was verified using the Boyce index, and shows the validity of the model's results. Suitable nesting areas for the Crested Ibis were found mainly on: the Kuninaka plain; the ridgeline between the Kuninaka plain and the Osado or Kosado mountain ranges; the area around Lake Kamo; and, the midwestern area of the Kosado region. Suitable nesting sites for the Crested Ibis were all found to be concentrated in what is known as Yatsuda, a traditional Japanese landscape structure providing a complex mosaic of forest and rice fields with complex ecotones. Eastern Kosado, the region that has been designated by the Ministry of the Environment as the conservation area for the reintroduced birds, was not judged to provide suitable nesting habitat for the Crested Ibis. Unfortunately, no evaluation of habitat suitability was made prior to the release of the first captive-bred Crested Ibis into the wild on Sado Island. Had an evaluation of habitat suitability been performed prior to release, more effective nature restoration could have been planned. © 2015 Elsevier GmbH. Source