865 resultados para Climate Change Litigation


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There are clear signs that the agro-pastoralists in the Himalayan and Hindu-Kush mountain ranges will have less cropping opportunities due to reduced possibilities for irrigated agriculture as a result of climate change. The importance of extensive livestock production based on well adapted livestock species may once again increase. This calls for a better documentation and understanding of the adaptation capabilities of indigenous breeds considering a changing environment. The current study investigates the adaptive traits of the Azikheli buffalo to mountain environments through calculating mean, standard error and percentages for different variables. Results from this study suggest that the brown coat color, the small body size and the high fertility are adaptive traits of the Azikheli buffalo that may well suit harsh mountainous environment conditions with greater climate variability. Local farmers find it hard to sustain the Azikheli buffalo’s key adaptive traits because of a low bull to buffalo ratio, possibility of insemination with semen from imported breeds and a lack of institutional support to conserve the Azikheli breed. The breed is crucial for sustaining custodian communities in these mountains and thus needs to be conserved.

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Aim Parrots are thought to have originated on Gondwana during the Cretaceous. The initial split within crown group parrots separated the New Zealand taxa from the remaining extant species and was considered to coincide with the separation of New Zealand from Gondwana 82-85 Ma, assuming that the diversification of parrots was mainly shaped by vicariance. However, the distribution patterns of several extant parrot groups cannot be explained without invoking transoceanic dispersal, challenging this assumption. Here, we present a temporal and spatial framework for the diversification of parrots using external avian fossils as calibration points in order to evaluate the relative importance of the influences of past climate change, plate tectonics and ecological opportunity. Location Australasian, African, Indo-Malayan and Neotropical regions. Methods Phylogenetic relationships were investigated using partial sequences of the nuclear genes c-mos, RAG-1 and Zenk of 75 parrot and 21 other avian taxa. Divergence dates and confidence intervals were estimated using a Bayesian relaxed molecular clock approach. Biogeographic patterns were evaluated taking temporal connectivity between areas into account. We tested whether diversification remained constant over time and if some parrot groups were more species-rich than expected given their age. Results Crown group diversification of parrots started only about 58 Ma, in the Palaeogene, significantly later than previously thought. The Australasian lories and possibly also the Neotropical Arini were found to be unexpectedly species-rich. Diversification rates probably increased around the Eocene/Oligocene boundary and in the middle Miocene, during two periods of major global climatic aberrations characterized by global cooling. Main conclusions The diversification of parrots was shaped by climatic and geological events as well as by key innovations. Initial vicariance events caused by continental break-up were followed by transoceanic dispersal and local radiations. Habitat shifts caused by climate change and mountain orogenesis may have acted as a catalyst to the diversification by providing new ecological opportunities and challenges as well as by causing isolation as a result of habitat fragmentation. The lories constitute the only highly nectarivorous parrot clade, and their diet shift, associated with morphological innovation, may have acted as an evolutionary key innovation, allowing them to explore underutilized niches and promoting their diversification.