2006 Vol. 27, No. 2
2006, 27(2): 113-120.
Nesting is an important component of parental effort in birds. During the breeding seasons from 1990 to 2004, we surveyed the nests of twelve passerines and compared the distribution patterns and architecture traits of nests in Tibetan Plateau. The nest sites of twelve passerines have obviously different spatial patterns and can be categorized into overground, ground and underground types, among which most passerines nestings are ground type. The architecture of nests diversifies from simple to complex spectrum, showing from shallow to deep shape, open to close nest, single and little plant materials to multiple material of animal and plant. Despite these differences, we suggest that the nest choice of passerine in alpine meadow based on the trade-off between security and heat insulation.Every nest type in spectrum has own advantages and disadvantages, and genetic and environmental factors confine what kind of nest type passerine adopts. In addition, carrying nest material, as a parental effort, is an important component of reproductive investment. The ratio between mass of nest material and parent reflects the extent of nesting investment. The nest material of larks, which have open and ground nests, accounts for half of parental mass, but nest material of Pseudopodoces humilis, nesting underground, is 5 times of parent mass. Rest ratios of passerine lie in this range. In general, those investment diversities are the results of interactions of many biological traits to meet embryo and nestling development under the predation pressure and interspecies competition.
2006, 27(2): 121-143.
280 species and subspecies were documented on mammal biodiversity in the Yangtze River Basin. They belong to 11 orders, 36 families and 135 genera, of which, 14 species are endemic and 154 threatened, respectively. Based on the distribution characteristics of mammals, the Yangtze River Basin were divided into 19 regions by deep rivers and high mountains. Except the headwater of the basin, species richness, G-F diversity index and the proportion of endemic species decreased gradually from the headwater to the estuary of the basin with a gradient of the elevation, and formed three value scales by Sichuan Basin and Yuanjiang River. Based on the species distribution in 19 regions (Jaccard similarity), cluster analysis was used to analyze the similarity of mammals. The 19 regions were clustered into four groups: (1) the headwater of basin, (2) Hengduanshan Mountain region, Yunnan Plateau, Sichuan Basin and QinlingDabashan Mountains, (3) Guizhou Plateau, Jiangnan hills, the plains in Poyang Lake and the delta of the Yangtze River basin, (4) Huaiyang mountains, Dongting Lake plain and Jianghan plain (or the Two-Lake plains), and the Lower reaches of the Yangtze River Basin. This grouping results responds to the environmental characteristics of the total basin and three large topographic platforms of the Chinese mainland.
From December 2004 to May 2005, an avian study was undertaken in the artificial wetlands of 200-ha area behind the 1998's seawall in Chongming Dongtan, Shanghai. A total of 56 bird species of 8 orders and 15 families were counted in the winter of 2004, and the dominant species were waterbirds and shorebirds; 55 species of 10 orders and 19 families were counted in the spring of 2005, which were dominated by shorebirds. Meanwhile, the environmental factors including water level, water area, vegetation coverage, macrobenthos density, fishing status and human disturbance were measured quantitatively. Based on multi-regression analysis between bird community and environmental variables, the results indicated that in winter, the vegetation coverage positively correlated with bird species abundance; the water level, water area and fishing status impacted on the bird number and diversity of species, genus and family; and the macrobenthos density affected the number and evenness of birds. In spring, the water area had positive relationship with bird species abundance, but the water level became a negative factor on the bird species abundance and number; the birds species diversity and evenness were affected by water level, water area and vegetation coverage; macrobenthos density correlated with bird diversity positively. The research could not prove that the fishing activities produced a significant impact on the bird community.
Nest-making and egg-laying behaviors of the Chinese alligator (Alligator sinensis) under captive-breeding conditions were studied during a 3-year period field work from 2003 to 2005 using the infrared video camera. And for the first time, a behavior of digging a hole for the hind legs before the eggs were laid was observed. The eggs were not covered all at once, but were covered as the eggs were laid towards the late part of the egg-laying period. To understand the connection between climate and nest-making time, an analysis was conducted based on the theory of linear regression, which showed that the mean temperature of April had the strongest effect upon nest-making time: the higher the mean temperature of April, the earlier the nest-making time started. Principal Components Analysis was also conducted to ascertain the effect of surrounding environment factors upon the choice of nesting sites, which indicated that the level of vegetation canopy and the distance to the water sources were among the principal components.
Bashania fargesii, one of the dominant bamboo species distributed at the elevation between 1 000-1 900 m of Qinling Mountains, is an important food source for the Giant Panda (Ailuropoda melanoleuca). The habitat preference of the Giant Panda for different bamboo forests is hardly known. To investigate the relationship between the bamboo and Giant Pandas, we conducted a study on the food selection of the Giant Pandas on the B. fargesii at Foping National Nature Reserve, Shaanxi Province in the winter of 2004 and the spring of 2005. Forty-five transects (about 17.3 km/Each) across the reserve and 159 large samples (20 m×20 m each) were surveyed. The data about the density, coverage, basal diameter, average height and proportion of the young B. fargesii were collected in the sample and the characteristic of the bamboo previously bitten by the Giant Pandas. The result indicated that pandas mainly foraged on old bamboo in the B. fargesii forest in which the proportion of young bamboo was as low as the proportion of died bamboo in the winter. In the spring, however, the pandas showed strong preference for B. fargesii forests with lower densities, larger basal diameters and higher proportion of young bamboos. Most pandas selected to habitat with a large density of growing B. fargesii, and young bamboos were the pandas' favorite food. When bamboo shoots bourgeoned, the thick shoots among the sparse B. fargesii forests with larger basal diameters became the major food source for those pandas.
The diversity of night migratory birds was studied in Fenghuang Mountains, Nanjian County, Yunnan Province from 16th September to 28th November 2002, from 6th to 26th April and from 9th September to 26th November 2003. 6677 of 176 species, which belong to 29 families, 13 orders, were caught and banded. The quantity of passerines, such as Ficedula parva, Luscinia calliope, Luscinia cyane etc., is predominance and more than 59.14%, which showed that the medium or small birds such as passerines were main species in the migration spot. Shannon-Wienner diversity index, Pielou evenness index and G-F index is 3.89, 4.13 and 25.56, respectively, which suggested that the diversity of migratory birds species, genus and family was in a high level. T-test results indicated that birds numbers and varieties observed were significantly different in different months during autumn of the year 2002 and 2003, i.e., the dynamic change of migratory birds in Fenghuang Mountains was obvious.
Forty-eight mated verrucous digging frogs (Kaloula verrucosa), collected from the suburb of northeast Kunming City, were compared and measured. Meanwhile their mating behavior was observed in the field. Pearson correlation coefficients of snout-vent length (SVL), body weight and head width were bigger than 0.5. Regression analysis of SVL and body weight was made among variables. The results showed that the selection of body length and the mating relationship of individual weight between male and female submitted good linear relation. Female of K. verrucosa often chose the most suitable male whose SVL was (81.8±5.7)% in its SVL and body weight was (53.1±10.7)% in its body weight. Female chose male who had longer SVL and lighter weight, which would help creating a better dimension for mating relationship, including the male skin derivative length and cloaca position between male and female while mating etc. K. verrucosa belonged to the pattern of female selection. Female was attracted by male's calling and positively moved to male. They would mate if the cases of male were suitable for female.
2006, 27(2): 175-180.
Sex determination/differentiation is the only developmental process involving two types of cell divisions (mitosis and meiosis). Analysis of transcription of key gene DMRT1 in the process showed that DMRT1 gene on the chromosome Z was trans-spliced with CENP C1 on the chromosome 4, CD5R on the chromosome 5 and 37LRP/p40 on the chromosome 2, which composed a rare form of transcripts DMRT1-CENP C1, DMRT1-CD5R and DMRT1-37LRP/p40 respectively. Overlapping regions between splicing sites on both chromosomes were observed, which would play an important role in the interchromosomal trans-splicing. The findings that multiple genes on different chromosomes are trans-spliced simultaneously with the DMRT1 during transcription undoubtedly help in understanding diversity of gene regulations at transcriptional level and sex determination and differentiation mechanisms.
2006, 27(2): 181-188.
The variation of the exon 2 of the major histocompatibility complex (MHC) class Ⅱ gene DRB locus in three feline species were examined on clouded leopard (Neofelis nebulosa), leopard (Panthera pardus) and tiger (P. tigris altaica). A pair of degenerated primers was used to amplify DRB locus covering almost the whole exon 2. Exon 2 encodes the β1 domain which is the most variable fragments of the MHC class Ⅱ molecule. Single-strand conformational polymorphism analysis was applied to detect different MHC class Ⅱ B haplotypes. Fifteen recombinant plasmids for each individual were screened out, isolated, purified and sequenced. Totally eight sequence haplotypes of exon 2 were obtained in 4 individuals. Within 237 bp nucleotide sequences from 4 samples, 30 variable sites were found, and 21 putative peptide-binding sites were disclosed in 79 amino acid residues. The ratio of nonsynonymous substitutions (dN) was much higher than that of synonymous substitutions (dS), which indicated that balancing selection probably maintain the variation of exon 2. MEGA neighbor joining and PAUP maximum parsimony methods were used to reconstruct phylogenetic trees among species, respectively. The results displayed a more close relationship between leopard and tiger; however, clouded leopard has a comparatively distant relationship from the other two.
Genetic diversity of grass carp was studied by using microsatellite DNA markers, on the wild population from Jiangsu Hanjiang National Four Major Chinese Carps Seed Farm and the cultured populations from Freshwater Fisheries Research Center Aquatic Breeding Farm and Wuxi Qianzhou Aquatic Breeding Farm. The number of alleles generated from each locus ranged from two to eight at the ten assessed loci. The number of effective alleles (ae), polymorphic information content (PIC), expected heterozygosity (He) and the average observed heterozygosity (Ho) were all the highest in Hanjiang wild population as 3.9, 0.506 8, 0.693 9, 0.7 respectively. Meanwhile Wuxi Qianzhou cultured stock had the lowest value: 2.2, 0.179 6, 0.523 5, 0.528 6 respectively. All these parameters of FFRC population were between the above mentioned data, being: 3.5, 0.290 2, 0.541 8, 0.542 9 respectively. All those results showed that the genetic diversity of wild population was more sufficient than that in the cultured populations. Coefficients of gene differentiation (Gst) between Hanjiang wild population and FFRC population, as well as Qianzhou population being 0.219 and 0.246, which were larger than those between the two cultured populations being 0.034. This indicated that the gene differentiated more seriously between wild and cultured populations than those between cultured ones. χ2 significance test for the relative magnitude of genetic differentiation (FST) showed that three loci GM18, MFW1-1, MFW1-2, differentiated most significant among populations; GM03-2,MFW5 significant, others insignificant. HardyWeinberg equilibrium was detected for each population over per loci. The results showed that GM03-1, GM03-2, GM18 deviated from the equilibrium in cultured population for heterozyosis deficiency and GM19 in wild ones for heterozyosis excess. According to our study, inbreeding may decrease the genetic diversity and accelerate homozygotes of the offspring.
Although the Suidae animals were one of the most prosperous mammals, their taxa and phylogeny were poorly studied. To bridge this research gap, the complete mitochondrial DNA cyt b sequences (1 140 bp)of one red river pig (Potamochoerus porcus), one bearded pig (Sus barbatus), and several Eurasian wild boars (Sus scorfa) were determined with direct PCR sequencing method. Incorporated with the sequences of other Suidae species obtained from GenBank, the phylogentic trees of Suidae species were constructed by Neighbor-Joining and Most Parsimony method. Our results showed that the babirousa was sister group of all other species. The African species clustered into a single clade, while the Eurasian species formed the other clade. The phylogenetic positions of the Sus species were consistent with their geographical distribution. Based on our phylogeographical results, the Sus species could be classified into three groups: (1) the relatively primitive animals from Philippine Islands (such as S. cebifrons and S. philippensis), Sulawesi and it's adjacent islands (S. celebensis), (2) the Eurasian wild boars (S. scrofa and the mysterious S. salvanius), and (3) other pigs (such as S. barbatus and S. verrucosus), which might further diverged as the islands type (such as S. barbatus from Sumatra and Borneo) and the continental type (such as Malay Peninsula wild boar).
To study the basic properties of neuron response to sound stimulation in the inferior colliculus of Rhinolophus pusillus, one kind of CF/FM (constant frequency/frequency modulated) bats, single unit was recorded with microelectrode under free field stimulation conditions. The results from 110 recorded neurons showed that there were five different types of discharge patterns in the inferior colliculus, including phasic (54.5%), tonic (25.5%), sustained (7.3%), chopper (7.3%), and pauser (5.4%). Ranges of recording depth, best frequency (BF), minimum threshold (MT) and response latency at 10 dB above MT of these neurons were 208-1 855 μm (829.0±328.1 μm), 16.7-75.6 kHz (38.9±15.7 kHz), 5-74 dB SPL (34.7±13.6 dB SPL) and 5.0-27.5 ms (15.2±3.9 ms), respectively. BFs of neurons increased with the increase of recording depth (r=0.9578, P<0.001). The V-shaped FTCs of 54 neurons were obtained and divided into two types, i. e. single peak and double peak. The most (69.2%, 36/52) of FTCs were wider (Q 10-dB value<5) and the few (30.8%, 16/52) were narrower (Q 10-dB value>5). Moreover, FTCs with double peaks were with milder slope in low-frequency limb and steeper in highfrequency limb and their Q 10-dB values are 1.95, 8 and 2.89, 6.51. There are three kinds of rateintensity functions in 34 neuron including monotonic, non-monotonic and saturated. In combination with our previous observation of Pipistrellus abramus, the differences of acoustic response properties of the neurons and their behavioral significance were analyzed and discussed.
It is hypothesized that if oocyte can be cultured in vitro under condition that maintains meiotic arrest at the germinal vesicle (GV) stage, then they may have the opportunity to acquire greater developmental competence. In this study, goat oocytes were cultured within follicle hemi-sections, which can inhibit GVBD and prolong the duration of GV stage. The changes of ultrastructure of goat oocyte before and after co-culture with follicle hemi-section and after resumption culture were observed. The purpose is to find out the proofs of further capacitation of oocytes, and to observe the feasibility of two-step protocol for oocytes maturation. Before co-culture with follicle hemi-section: perivitelline space have not been formed in the oocyte, neither have the microvilli been released from the zona pellucida, the cortical region have a lot of oraganelles, clusters of cortical granules exit in the cortical region, mitochondrias amass in the cortical region, a number of vacuoles are presented. After co-culture with follicle hemi-section, the results are as follows: perivitelline space is obvious, the microvilli have been released from the zona pellucida and pile up in stacks in the perivitelline space, mitochondria have begun to migrate toward the center of oocyte inclusters, the bulk of the cortical granules are distributed at solitary positions along the oolemma in the part, the number of vacuoles increase obviously, part of cortical region lack organelles. After resumption culture: perivitelline space develops further, the number of microvilli stacks have decreased and become more erect, mitochondria have distributed evenly in the central oolemma, cortical granules are distributed at solitary positions along the oolemma, the number of vacuoles decrease obviously, more parts of cortical region are free of organelles. In contrast to maturation in vitro, inhibition culture by follicle hemi-section contributes more to the formation of perivitelline space, decrease of number and erection of microvilli and the further formation of organelle-free cortex.
The field research on five black crested gibbon groups, recently performed at Dazhaizi, Mt. Wuliang, Central Yunnan, China, showed that all groups in the local population consisted of one adult male, two adult females and 2-5 sub-adults, juveniles and infants. The mean group size was 6.2 in August 2003 and 6.4 in August 2005. Two subadult males disappeared from their natal home range and three newborns were given birth in Group 3 (G3) and G4 during this study. The two adult females in G1, G2 and G3 gave births and/or carried babies but at different times. There was no aggressive or dominating behaviour observed between the two adult females. One floating female was first seen in G3's territory on April 15, 2005. The two resident females interrupted her duet with adult male and chased her. We did not observe adult male chased this floating female and she left G3's territory 10 days later. Sub-adult males often kept distance with the family, and they often sang solo bouts in their natal territory before they dispersed. The sub-adult males and females dispersed from natal territory and two adult resident females rejected the third one, which might were the reasons why the black gibbon groups were polygyny in Dazhaizi.
Habitat selection of Snow Leopard (Unica unica) in Beita Mountain of the Altay Mountain system in northeast Xinjiang was conducted from September to October 2004. Six habitat features of 59 sites used by Snow Leopard and 30 random plots were measured by locating 15 transects surveys in the study area. Vanderploge and Scavia's selectivity index was used to assess Snow Leopard's selection for the different habitat parameters. Principal Component Analysis was used as the primary factor. The results indicated that Snow Leopard preferred the altitude between 2 000-2 200 m and avoided 2 600-3 000 m; selected cliff base, ridgeline and avoided hillside and valley bottom; utilized the shrub and rejected the forest; selected the non-grazing area and avoided the slightly broken region; preferred north orientation and rejected the south orientation. The results show that grazing status, vegetation type, topography and the ruggedness are the primary factors for the habitat selection of Snow Leopard.