Changes in grassland management and linear infrastructures associated to the decline of an endangered bird population

European grassland birds are experiencing major population declines, mainly due to changes in farmland management. We analyzed the role of habitat availability, grazing management and linear infrastructures (roads and power lines) in explaining spatial and temporal variation in the population density of little bustards (Tetrax tetrax) in Portugal, during a decade in which the species population size halved. We used data from 51 areas (totaling ca. 1,50,000 ha) that were sampled in two different periods (2003–2006 and 2016). In 2003–2006, when the species occurred at high densities, habitat availability was the only factor affecting spatial variation in bustard density. In the 2016 survey, variation in density was explained by habitat availability and livestock management, with reduced bird numbers in areas with higher proportions of cattle. Population declines across the study period were steeper in areas that initially held higher densities of bustards and in areas with a higher proportion of cattle in the total stocking rate. Areas with higher densities of power lines also registered greater density declines, probably due to avoidance behavior and to increased mortality. Overall, our results show little bustards are currently lacking high quality grassland habitat, whose persistence depends on extensive grazing regimes and low linear infrastructure densitiesinfo:eu-repo/semantics/publishedVersio

Complete mitochondrial genomes of Bos taurus and Bos indicus provide new insights into intraspecies variation taxonomy and domestication

The taurine and zebuine cattle breeds comprise the majority of the world cattle population but their taxonomic status is still controversial. The two forms of cattle are currently classified as Bos taurus and Bos indicus species and are differentiated primarily by the presence or absence of a hump. However, these two species hybridize readily, producing fully fertile offspring. We have determined and analyzed complete B. taurus and B. indicus mitochondrial genome sequences to investigate the extent of sequence divergences and to study their taxonomic status by molecular dating. The sequences encompassed 16,338 and 16,339 nucleotides, respectively, and differed at 237 positions. Estimated divergence times indicated that the two cattle lineages separated 1.7-2.0 million years ago. Combined phylogenetic analyses of 18 new and 130 previously reported extant B. taurus and B. indicus control region sequences with data from 32 archaeological specimens of the extinct wild aurochs (Bos primigenius) identified four major maternal lineages. B. primigenius haplotypes were present in all but the B. indicus lineage, and one B. taurus sequence clustered with B. primigenius P haplotypes that were not previously linked with domestic cattle. The B. indicus cluster and a recently reported new B. primigenius haplotype that represents a new lineage were approximately equidistant from the B. taurus cluster. These data suggest domestications from several differentiated populations of B. primigenius and a subspecies status for taurine (B. primigenius taurus) and zebuine (B. primigenius indicus) cattle.S. Hiendleder, H. Lewalski, A. Jank

Co-occurrence patterns for abundant marine archaeal and bacterial lineages in the deep chlorophyll maximum of coastal California

Microorganisms remineralize and respire half of marine primary production, yet the niches occupied by specific microbial groups, and how these different groups may interact, are poorly understood. In this study, we identify co-occurrence patterns for marine Archaea and specific bacterial groups in the chlorophyll maximum of the Southern California Bight. Quantitative PCR time series of marine group 1 (MG1) Crenarchaeota 16S rRNA genes varied substantially over time but were well-correlated (r2=0.94, P<0.001) with ammonia monooxygenase subunit A (amoA) genes, and were more weakly related to 16S rRNA genes for all Archaea (r2=0.39), indicating that other archaeal groups (for example, Euryarchaeota) were numerically important. These data sets were compared with variability in bacterial community composition based on automated ribosomal intergenic spacer analysis (ARISA). We found that archaeal amoA gene copies and a SAR11 (or Pelagibacter) group Ib operational taxonomic unit (OTU) displayed strong co-variation through time (r2=0.55, P<0.05), and archaeal amoA and MG1 16S rRNA genes also co-occurred with two SAR86 and two Bacteroidetes OTUs. The relative abundance of these groups increased and decreased in synchrony over the course of the time series, and peaked during periods of seasonal transition. By using a combination of quantitative and relative abundance estimates, our findings show that abundant microbial OTUs—including the marine Crenarchaeota, SAR11, SAR86 and the Bacteroidetes—co-occur non-randomly; they consequently have important implications for our understanding of microbial community ecology in the sea

The database of the PREDICTS (Projecting Responses of Ecological Diversity In Changing Terrestrial Systems) project

The PREDICTS project-Projecting Responses of Ecological Diversity In Changing Terrestrial Systems (www.predicts.org.uk)-has collated from published studies a large, reasonably representative database of comparable samples of biodiversity from multiple sites that differ in the nature or intensity of human impacts relating to land use. We have used this evidence base to develop global and regional statistical models of how local biodiversity responds to these measures. We describe and make freely available this 2016 release of the database, containing more than 3.2 million records sampled at over 26,000 locations and representing over 47,000 species. We outline how the database can help in answering a range of questions in ecology and conservation biology. To our knowledge, this is the largest and most geographically and taxonomically representative database of spatial comparisons of biodiversity that has been collated to date; it will be useful to researchers and international efforts wishing to model and understand the global status of biodiversity