Search Results
Abstract
Tetraophasis (Galliformes; Phasianidae) includes T. obscurus and T. szechenyii, which are endemic and distributed in the west and central parts of China. The phylogenetic status of Tetraophasis in the Phasianidae and the divergence of the two species are still controversial. We performed a phylogenetic study using DNA sequences of 828bp of the mitochondrial cytochrome b (Cytb) genes of Tetraophasis and of selected species of several other genera of Phasianidae. The phylogenetic trees suggest that Tetraophasis species belong to Phasianinae, which is inconsistent with the traditional taxonomic view that these species belong to Perdicinae. Sequence difference between T. obscurus and T. szechenyii was 3.0-3.1% and the divergence time was 1.88-1.94 Myr based on molecular clock estimate. Compared with other genera, T. obscurus and T. szechenyii should be classified as two distinct species. Our data suggest that the divergence of Tetraophasis may have been induced by the uplift of the Qinghai-Tibet Plateau and by environmental changes.
Abstract
Phrynocephalus vlangalii, a toad-headed viviparous sand lizard, is endemic in the Northern Tibet (Qinghai) Plateau in China. Lizards were collected from 14 localities along the large altitudinal gradient (2289-4565 m a.s.l) to analyze the variation of reproductive traits among localities. Both litter size and mean offspring (scaled embryo) mass were positively correlated with female snout-vent length (SVL). Females produced fewer and larger offspring with increasing elevation when the effect of body size (SVL) was removed. This strategy may possibly be correlated with early survival and growth of offspring. The decreased litter size cline along altitudinal gradient might be correlated with more anatomical constraints at higher altitudes. The lizard has lower coefficient of variation (CV) of litter size at higher environments. Moreover, females from higher elevations had less reproductive investment (relative litter mass, RLM). Study concluded that P. vlangalii fit into the common pattern of higher elevation animals that have smaller clutches of larger offspring and lower reproductive effort.
Abstract
We compared diets of little owls (Athene noctua) and long-eared owls (Asio otus) in the Minqin Desert in northwestern China. Based on prey numbers, little owls fed mainly on mammals (51.0%) and beetles (46.9%), whereas long-eared owl fed almost exclusively on mammals (96.4%). Based on biomass, both species fed mainly on mammals. Mus musculus, Cricetulus barabensis and Meriones meridianus were the three most common mammals taken by both species. Seasonal variation was found in the diets of both species. Food niche breadth was 3.4 for little owls vs 2.9 for long-eared owls. Dietary overlap between the two species was 49.6%, but varied from 4.0% in April to 96% in January. Dietary overlap of mammals was 97.9%, indicating that both owls fed on similar rodent assemblages. Mean mass of prey was 25.8 ± 22.7 g for long-eared owls and 15.5 ± 22.7 g for little owls. The mean length of tibias of mammals in pellets also indicted that, on average, long-eared owls (18.1 ± 5.6 mm) took larger prey than little owls (16.2 ± 4.7 mm).
Abstract
In the present study, relationships among all Chinese species of lacertids in the genus Eremias, E. velox, E. grammica, E. vermiculata, E. przewalskii, E. multiocellata, E. arguta, E. brenchleyi, and E. argus, were assessed using 574 aligned base positions of 16S rRNA mitochondrial DNA sequences from 103 individuals collected from 28 populations. Three kinds of phylogenetic tree (MP, ME, and NJ) were reconstructed and were found to be concordant. All eight species well form a monophyletic group. The resulting genetic distance between E. przewalskii and E. multiocellata is surprisingly low, only 0.008. The result could be due to introgression of the mtDNA molecule. All Eastern-Asia lacertids except E. vermiculata grouped together and formed a monophyletic clade. E. vermiculata are closely related to E. arguta, a Central-Asia species. E. brenchleyi and E. argus formed a monophyletic clade as the sister group of E. multiocellata. The Central-Asia species (E. arguta, E. grammica and E. velox) originated from Central-Asia and Eastern-Asia species (the rest) from China. The phylogenetic relationships among E. grammica, E. velox, E. arguta-vermiculata, E. argus-brenchleyi, and E. multiocellata-przewalskii are unclear in the study, which needs more comprehensive taxonomic sampling from Western Asia and Europe, and additional genetic evidence to resolve it.
Abstract
Regurgitated pellets (n = 584) of Long-eared Owl (Asio otus) were collected for three seasons from Gansu Endangered Animal Research Center, Gansu Province, China. From these pellets, a total of 1011 individual prey items – representing seven species of rodents and two undetermined species of birds and one undetermined sorex-species – were identified. Long-eared Owls depend mainly on small mammals both based on prey numbers (95.5%) and prey biomass (97.0%). The composition of the diet of Long-eared Owls varied significantly among seasons by frequency and by biomass. The individual species groups indicated significant variation among seasons for Mus musculus, Meriones meridianus, Cricetulus barabensis, Phodopus roborovskii, Dipus sagitta and Rattus norvegicus by biomass. And the difference of seasonal variation of prey items were significant but not for Mus musculus by frequency. Based on prey numbers, Mus musculus was the main food item (50.5%) in its diet; this species was most common in autumn (56.9%) and least common during spring (36.7%). Main prey species, based on prey biomass, was Rattus norvrgicus which comprised 27.5% of total biomass from our pellet samples. The mean length of tibias of mammals in pellets of Long-eared Owls was 18.6 ± 5.4 mm. Long-eared Owls utilize a wide range of prey items in respect to their habitats. Results suggest that Long-eared Owls are selective predators at some levels.
Abstract
We have used phylogeographic methods to investigate the genetic structure and population history of the endangered Himalayan snowcock (Tetraogallus himalayensis) in northwestern China. The mitochondrial cytochrome b gene was sequenced of 102 individuals sampled throughout the distribution range. In total, we found 26 different haplotypes defined by 28 polymorphic sites. Phylogenetic analyses indicated that the samples were divided into two major haplogroups corresponding to one western and one eastern clade. The divergence time between these major clades was estimated to be approximately one million years. An analysis of molecular variance showed that 40% of the total genetic variability was found within local populations, 12% among populations within regional groups and 48% among groups. An analysis of the demographic history of the populations suggested that major expansions have occurred in the Himalayan snowcock populations and these correlate mainly with the first and the second largest glaciations during the Pleistocene. In addition, the data indicate that there was a population expansion of the Tianshan population during the uplift of the Qinghai-Tibet Plateau, approximately 2 million years ago.