Tropické lesy ostrova Borneo v jihovýchodní Asii jsou celosvětově výjimečné vysokou biodiverzitou různých skupin organismů. Jejich podoba byla formována mimo jiné během čtvrtohorního kolísání hladiny světových oceánů, kdy byly ostrovy sundské oblasti vzájemně propojeny či odděleny, což mělo vliv na migraci organismů. Současná diverzita lesů Bornea sleduje gradient nadmořské výšky a vlastnosti substrátů, přičemž můžeme rozlišit několik hlavních typů lesa. V posledních desetiletích jsme svědky masivní těžby lesů, které jsou mnohde převáděny na plantáže palmy olejné., Tropical forests of the island of Borneo in South East Asia harbour an extraordinary high biodiversity of various groups of organisms. They have been shaped, among other influences, by the Quaternary fluctuations of the level of world’s oceans, connecting or dividing islands within the Sundaland, which has affected migration of species. The present diversity of forests in Borneo follows an elevational gradient and substrate properties, thus forming several main forest types. Over the past few decades, we have witnessed massive logging and transformation of forests into oil palm (Elaeis guineensis) plantations., Radim Hédl., and Obsahuje seznam literatury
nvestigating the function of both male and female mating behaviours is essential in our attempts to understand the evolution of mating systems. Variation in mating behaviours among different populations within a species provides a useful opportunity to explore how behaviours may co-vary, although comparative studies are still rather few in number. Population variation in mating behaviour may also have important implications in terms of the evolution of reproductive isolation, the distribution of genetic diversity within and between populations, and the associated ability of those populations to adapt. Here we consider male and female mating behaviour in two populations of the two-spot ladybird, Adalia bipunctata, from the UK and Russia. We find that male and female mating behaviours differ between the populations in terms of the length of female rejection behaviour and the duration of mating, and that this variation is independent of which population an individual's mating partner is from. Our data confirm that patterns of sexual selection and reproductive behaviour are likely to vary across populations in the two-spot ladybird. The extent to which this variation is due to current ecological factors or population history remains to be verified for this species, as for many others., Penelope R. Haddrill, Michael E.N. Majerus, David M. Shuker., and Obsahuje seznam literatury
Although there is a considerable amount of information on the ecology, genetics and physiology of life-history traits there is little information on the morphological variations associated with flight ability within species. In this paper, the morphology and ultrastructure of certain organelles in the flight muscles of Gryllus firmus are recorded using transmission electron microscopy. The ultrastructure of the flight muscles of 7-day-old female adults reveals that the ratio of thick to thin filaments is 1 : 3. Each thick filament is surrounded by 6 thin filaments in a hexagonal arrangement. The length of the sarcomere of each myofibril is significantly shorter and diameter of the myofibrils significantly smaller in long-winged than in short-winged morphs. However, the thick filaments in the long-winged morph are denser than those in the short-winged morph. Furthermore, in the long winged morph there are a greater number of mitochondria than in the short-winged morph. These differences correspond with the fact that long-winged crickets are stronger fliers than short-winged crickets., Cheng-Ji Jiang ... [et al.]., and Obsahuje seznam literatury
Soutěžní přehlídka Věda je krásná vznikla v r. 2009 jako interní fotografická soutěž Přírodovědecké fakulty Univerzity Karlovy v Praze. Od třetího ročníku je přístupná všem zaměstnancům a studentům Univerzity Karlovy a ve čtvrtém ročníku se v nové objevitelské kategorii otevřela mimofakultní veřejnosti, která se jí může účastnit prostřednictvím popularizačního projektu Přírodovědci.cz. Cíl projektu je velmi jednoduchý - oslavit českou fotografii a ilustraci s přírodovědnou tematikou a upozornit na krásu skrytou běžnému pohledu, tedy na půvab vědeckých objektů a vědy samotné, protože zůstávají často přístupné jen úzkému okruhu badatelů nebo nadšenců., This competition run by the Faculty of Science at Charles University in Prague and its supportive web www.prirodovedci.cz aims to show the beauty and aesthetics revealed by scientific research, either via photography, illustrations or computerized visualizations of natural phenomena., and Alena Ječmíková.
The great capricorn beetle or Cerambyx longicorn (Cerambyx cerdo, Linnaeus, 1758) is an internationally protected umbrella species representing the highly diverse and endangered fauna associated with senescent oaks. For the conservation and monitoring of populations of C. cerdo it is important to have a good knowledge of its microhabitat requirements. We investigated determinants and patterns of C. cerdo distribution within individual old, open-grown oaks. Trees inhabited by this species were climbed, and the number of exit holes and environmental variables recorded at two sites in the Czech Republic. Distribution of exit holes in relation to height above the ground, trunk shading by branches, orientation in terms of the four cardinal directions, diameter, surface and volume of inhabited tree parts were investigated. This study revealed that the number of exit holes in the trunks of large open-grown oaks was positively associated with the diameter of the trunk and openness and negatively with height above the ground, and the effects of diameter and openness changed with height. The number of exit holes in the surface of a trunk was also associated with the cardinal orientation of the surface. Approximately half of both C. cerdo populations studied developed less than 4 m and approximately a third less than 2 m above the ground. This indicates that most C. cerdo develop near the ground. Active management that prevents canopy closure is thus crucial for the survival of C. cerdo and searching for exit holes is an effective method of detecting sites inhabited by this species., Jan Albert, Michal Platek, Lukas Cizek., and Obsahuje seznam literatury
V této práci sumarizujeme data o výskytu invazních druhů řas a sinic v České republice a mapujeme reálná či potenciální rizika jejich rozšíření. Seznam invazních druhů v ČR obsahuje 10 druhů sinic, 9 rozsivek, 1 obrněnku, 1 zástupce třídy Ulvophyceae, 2 zelené řasy třídy Chlorophyceae a jednu krásivku., This paper summarizes data on alien species of algae and cyanobacteria in the Czech Republic; we identified actual or potential risks resulting from their spread. The list of aliens contains 10 species of Cyanobacteria (Cyanophyta), 10 species of Bacillariophyceae, one species of Dinophyta, one species of Ulvophyceae, two species of Chlorophyceae, and one species of Desmidiales., and Jan Kaštovský ... [et al.].
Caterpillars of the poplar lutestring moth, Tethea or, construct leaf shelters that they defend against intruding conspecifics using a combination of vibratory signals and physical aggression. Staged interactions between a resident caterpillar and introduced conspecific were recorded with a video camera and laser vibrometer. Residents crawl towards the intruder and perform three behaviours: lateral hitting, pushing, and mandible scraping. Vibrations caused by mandible scraping result from the caterpillar repeatedly scraping opened mandibles laterally against the leaf surface in bouts lasting 1.16 ± 0.39 s, with an average of 4 ± 1 scrapes per bout. We propose that these scrapes function in leaf shelter defense against conspecifics for the following reasons: Mandible scrapes are produced only by residents; they are generated when a resident is approached by an intruder; the rate of scraping increases as the intruder approaches the shelter; and residents in all trials retain their shelters, with the intruder leaving the leaf within 127.9 ±104.3s from the beginning of the trial. The function and evolutionary origins of vibration-mediated territoriality in caterpillars are discussed. and Jaclyn L. Scott, Jayne E. Yack.