Search results for "SYSTEMATICS"

Pollination biology in Roepera (Zygophyllaceae): How flower structure and shape influence foraging activity

2019

The foraging behavior of bees is a complex phenomenon that depends on numerous physical features of flowers. Of particular importance are accessibility of floral rewards, floral proportions, symmetry and orientation. The flowers of Roepera are characterized by the presence of staminal scales (SS), which play an important role in nectar protection. We studied two species of Roepera with different symmetry and flower orientation, which are mainly visited by honeybees (Apis mellifera). We aimed to show how the foraging behavior of honey bees is affected by the function of SS, floral symmetry and orientation. The foraging behavior was documented by video photography. Handling time, access to ne…

FLUCTUATING TEMPERATURE LEADS TO EVOLUTION OF THERMAL GENERALISM AND PREADAPTATION TO NOVEL ENVIRONMENTS

2013

Environmental fluctuations can select for generalism, which is also hypothesized to increase organisms' ability to invade novel environments. Here, we show that across a range of temperatures, opportunistic bacterial pathogen Serratia marcescens that evolved in fluctuating temperature (daily variation between 24°C and 38°C, mean 31°C) outperforms the strains that evolved in constant temperature (31°C). The growth advantage was also evident in novel environments in the presence of parasitic viruses and predatory protozoans, but less clear in the presence of stressful chemicals. Adaptation to fluctuating temperature also led to reduced virulence in Drosophila melanogaster host, which suggests…

Small-scale life history variability suggests potential for spatial mismatches in Atlantic cod management units

2015

Genetic variability in Peregrine falcon populations of the Western Palaearctic region

2018

We analyzed variation in ten polymorphic microsatellites and a portion of cytochrome b mitochondrial DNA in 4 populations of the Peregrine falcon (Falco peregrinus). living in northern and southern Italy. Spain and Czech Republic to assess species diversity in the poorly investigated Western Palearctic region. The Spanish population lives in the contact zone between F. peregrinus peregrinus and F. p. brookei. both the northern Italian and the Czech populations live within the range of F. p. peregrinus and the southern Italian is within the F. p. brookei. We added to our cytochrome b sequence dataset comprising 81 samples. previously published mitochondrial DNA sequences (n = 31) of English …

Relative Efficiency of Two Models of Ugglan Special Live-Traps for Capturing Small Rodents in Boreo-Nemoral Forest

2018

Live trapping is an invaluable and commonly used technique for studying small mammal populations. There are several types of commercially available live-traps, but some models have been shown to differ in terms of species-specific efficiency. Such differences could lead to biased results, and knowledge of such bias is important when comparing results of different studies. The Ugglan Special live-trap is one commonly used type, and it is available in several different models. I studied performance of the two most common models (No. 1 and No. 2) to find out whether they differ in terms of overall efficiency and body-mass-dependent efficiency, when trapping small rodents. I used 48 traps of ea…

Spring weed communities of rice agrocoenoses in central Nepal

2016

AbstractRice field weed communities occurring in central Nepal are presented in this study. The research was focussed on the classification of segetal plant communities occurring in paddy fields, which had been poorly investigated from a geobotanical standpoint. In all, 108 phytosociological relevés were sampled, using the Braun-Blanquet method. The analyses classified the vegetation into 9 communities, including 7 associations and one subassociation. Four new plant associations and one new subassociation were proposed: Elatinetum triandro-ambiguae, Mazo pumili-Lindernietum ciliatae, Mazo pumili-Lindernietum ciliatae caesulietosum axillaris, Rotaletum rotundifoliae and Ammanietum pygmeae. D…

Replicated marine protected areas (MPAs) support movement of larger, but not more, European lobsters to neighbouring fished areas

2018

The European lobster Homarus gammarus is heavily exploited in the Norwegian fishery, and several management actions have been implemented to protect the species. Three marine protected areas (MPAs) excluding all but hook and line type fishing gear were established along the Skagerrak coast in 2006, effectively banning the trap-based fishery for European lobster. Lobster populations within MPAs and adjacent control areas were studied by capture-mark-recapture and recovery methods every year from prior to MPA establishment to the present. During 2006-2014, a total of 4682 and 3317 lobsters were captured (including recaptures) in the MPAs and control areas, respectively. In all MPAs, protectio…

A new algorithm for the identification of dives reveals the foraging ecology of a shallow-diving seabird using accelerometer data

2017

International audience; The identification of feeding events is crucial to our understanding of the foraging ecology of seabirds. Technology has made small devices, such as time-depth recorders (TDRs) and accelerometers available. However, TDRs might not be sensitive enough to identify shallow dives, whereas accelerometers might reveal more subtle behaviours at a smaller temporal scale. Due to the limitations of TDRs, the foraging ecology of many shallow-diving seabirds has been poorly investigated to date. We thus developed an algorithm to identify dive events in a shallow-diving seabird species, the Scopoli’s shearwater, using only accelerometer data. The accuracy in the identification of…

Forecasting ocean warming impacts on seabird demography: a case study on the European storm petrel

2016

Bottom-up climatic forcing has been shown to be influential for a variety of marine taxa, but evidence on seabird populations is scarce. Seasonal variation in environmental conditions can have an indirect effect on subsequent reproduction, which, given the longevity and single-brooding of seabirds, may affect population dynamics. Our study focuses on linking the effect of oceanographic conditions (from 1991 to 2013) to the fecundity and consequently pop - ulation growth rate of the Mediterranean subspecies of the European storm petrel Hydrobates pelagicus melitensis. In this study, we examined 23 yr of > 5400 capture–mark−recaptures (CMR) and modelled the probability of skipping reproductio…

2019

Abstract Salvage logging after disturbances in forests substantially modifies vegetation structure and dead wood availability, but empirical evidence on its impact on biodiversity, especially in European boreal forest, is sparse. In this study we investigated the short-term effect of post-fire salvage logging on species richness and abundance of birds in recently burned mixed coniferous forest. Using point counts we estimated local species composition at 49 salvaged sites and 55 non-intervention sites (burnt forest left for natural regeneration) that were not logged after a fire in south-central Sweden. Local species richness, abundance and Simpson's species diversity index were significant…