Search

Abstract—The results of our long-term monitoring of a family of larks (Alauda arvensis L., Melanocorypha calandra L., M. leucoptera Pallas, M. yeltoniensis J.R. Forster, and Calandrella rufescens Vieillot) in the semi-desert zone of the Saratov Trans-Volga region are presented. Bird censuses were carried out at four key sites on permanent routes during the nesting period; the total length of the census transects was 792 km. Statistical indicators of the population dynamics were calculated, namely, the growth rates (Tnp) and average density values (ind./100 ha) of each lark species. A statistical multivariate factor analysis (F-test) was carried out, with the help of which we were able to reveal the influence of a whole range of factors on the lark density dynamics. Changes in habitat conditions in the key areas (Fcrit = 1.30, p = 0.003), as well as weather factors (Fcrit = 1.39, p = 0.004) of particular years, have a significant impact on the density dynamics of larks. Evaluation of the variance showed the heterogeneity of the sample (St = 0.119, p = 0.006); therefore, the average densities of larks differ significantly from each other. Thus, the structure of the lark community and the annual density of each species are the result of the environmental conditions of the habitats at each key site, and the weather conditions of particular years. [ABSTRACT FROM AUTHOR]

Abstract—This work was carried out in the Dzhanibek and Bokey Orda districts of the West Kazakhstan region of the Republic of Kazakhstan in two key areas. The possibility to study the relationship between the distribution of the abundance of various lark species and their nesting habitats detected using high-resolution satellite images, ground geobotanical descriptions, and bird counts on routes with a variable width of the accounting band was evaluated. The image heterogeneity in a snapshot was analyzed by cluster analysis in the ILWIS software (Heckbert quantization algorithm) using three rasters as variables: infrared and red channel images and NDVI. The correlation between the number of some lark species and the share of some plant associations in the band of accounting routes was established using correlation analysis and approximation of empirical distributions by theoretical ones. A reliable relationship was established between the distribution of three lark species living in the Trans-Volga semi-desert of the Caspian lowland with certain plant associations which they prefer to use as nesting stations. [ABSTRACT FROM AUTHOR]

and 8 taxa of its allied genera, Australian Astereae. Statistical tests regarding correlations between changes in chromosome number, total chromosome length, mean chromosome length, karyotypic asymmetry and chromosome length heterogeneity and changes in habit were performed based on the matK molecular phylogenetic tree. The reductions in chromosome number and total chromosome length, and the increases in mean chromosome length, chromosome length heterogeneity and karyotypic asymmetry were found to be correlated with the change in habit from perennial to annual. A reduction in total chromosome length is favored to shorten the mitotic cell cycle and to produce smaller cells conducive to more rapid development of smaller annuals under the time-limited environment. Stepwise dysploidal reductions in chromosome number were achieved through the translocation of large chromosome segments onto other chromosomes, followed by the loss of a centromere, resulting in one fewer linkage group and one fewer haploid chromosome. The correlations between the dysploidal reduction in chromosome number and the increases in mean chromosome length, length heterogeneity and asymmetry in karyotype can be attributed to this mode of chromosomal change. These changes occurred independently in several different lineages in Brachyscome. [ABSTRACT FROM AUTHOR]