Search results for "Systematics"
showing 10 items of 6702 documents
Chemical constituents from Anthocleista liebrechtsiana De Wild & T. Durand (Loganiaceae)
2018
Abstract A new steroid derivative, (24S)-3β-hydroxy-7β-methoxyergost-5-ene (1), was isolated along with eleven known compounds: 7α-hydroxysterol (2), β-sitosterol (3), oleanolic acid (4), betulinic acid (5), lupeol (6), swertiaperennin (7), decussatin (8), tetracosanoic acid (9) β-sitosterol-3-O-β- d -glucopyranoside (10), (2R,3S)-2,3-dihydro-2-(3,4-dimethoxyphenyl)-3-hydroxymethyl-5-(2-formylvinyl)-7-hydroxybenzofuran (11) and acacetin 6-C-β- d -glucopyranoside (12) from the tree bark and leaves of Anthocleista liebrechtsiana De Wild & T. Durand. Their structures were elucidated on the basis of spectroscopic (1D and 2D NMR) and mass spectrometric data. Compounds 2 and 7–10 have already bee…
Thilachium madagascariense (Capparaceae), a new species from eastern Madagascar with a key to the species of the genus
2021
SummaryThilachium madagascariense Fici, a small tree characterised by 1-foliolate leaves with articulate petioles, leaf blades elliptic or narrowly obovate with base attenuate and apex acuminate, flowers in groups of 2 – 3 at the top of lateral twigs and a high number of stamens, is described and illustrated from forest habitats of eastern Madagascar. The new species is similar to T. laurifolium Baker, a species endemic to central and eastern Madagascar, differing in the longer leaves with acuminate apex, flowers conferted at the top of lateral twigs, shorter pedicels, higher number of stamens and shorter gynophore. Its affinities are discussed and an updated key is provided for all the spe…
A peculiar new Orthotrichum species (Orthotrichaceae, Bryopsida) from central Argentina
2007
A new epiphytic Orthotrichum species (Orthotrichum spiculatum F. Lara, Garilleti & Mazimpaka sp. nov.) is described from the sierra of Cordoba (Argentina). The new species has most of the characteristics of subgenus Pulchella (Schimp.) Vitt, but it is unique because of having eight exostome teeth pairs and 16 broad, strongly papillose endostome segments. Additionally, its upper leaves have green, acuminate, dentate–spiculate apices. © 2007 The Linnean Society of London, Botanical Journal of the Linnean Society, 2007, 155, 477–482.
Do Tengmalm's owls see vole scent marks visible in ultraviolet light?
1997
Scent markings (urine and faeces) of small mammals are visible in ultraviolet (UV) light. Diurnal kestrels, Falco tinnunculususe them as a cue to find areas of food abundance. We studied whether vole-eating, nocturnal Tengmalm's owls, Aegolius funereuscan see vole scent marks using UV-vision. In a laboratory experiment, 14 young (less than 6 months old) and 14 adult (more than 6 months old) owls were individually given a choice between four adjacent arenas: (1) an arena with vole urine and faeces in UV light; (2) an arena with vole urine and faeces in visible light; (3) a clean arena in UV light; and (4) a clean arena in visible light. Owls did not prefer any of the four arenas. Our results…
Plumage colour and male-male interactions in the pied flycatcher
1993
Abstract Abstract. The influence of male colour on male-male interactions in the pied flycatcher, Ficedula hypoleuca , was studied using several types of field experiments. This species exhibits delayed plumage maturation, each male becoming more conspicuously black and white from the first to the second breeding summer. However, individual males vary even more, some old males being as brown as females. When territorial males were presented with a choice between brown and black male intruders (or brown males painted black) they directed more aggression towards the black males. Brown plumage did not help males obtain nestboxes close to other males. If anything browner males were at a disadva…
Factors Affecting Interspecific Aggression in a Year-Round Territorial Species, the Jewel Damselfish
2012
Vertebrates live in complex species networks in which interspecific interactions are common. In some contexts, the aggressive behaviours shown in these interspecific interactions are very similar to those shown in intraspecific interactions. It is still an open question whether intra- and interspecific aggression share common causality. We studied a year-round territorial species the jewel damselfish, (Plectroglyphidodon lacrymatus), which cultivate algae they feed on. Territory holders aggressively defend these algae that are an attractive resource for many other species. In this study, we recorded territorial aggression in free-living individuals and recorded aggressive responses to a sta…
Female-female aggression and female mate choice on black grouse leks.
2000
We studied female-female aggression in relation to female mate choice in black grouse, Tetrao tetrix, in central Finland, in 1994-1998. Aggression occurred on average every other minute when there was more than one female on a territory, and aggressive behaviour was most prominent when several females attended the lek. Interactions tended to be proportionally most frequent on the territories of the highest-ranking males, although not significantly so. Females that were chased by other females did not mate with lower-ranking males than their aggressors did. Furthermore, chased females were only rarely (6% of cases) forced to move off the territory by agonistic interactions and copulations we…
Bird assemblages in isolated Ficus trees in Kenyan farmland
2006
Over the last few decades a rapid and extensive conversion of tropical forests to agricultural land has taken place resulting in mosaics of fragmented forest patches, pastures and farmland. While the effects of forest fragmentation on biodiversity have been intensively studied within the remaining forests, relatively little is known about the biodiversity in tropical farmland (Daily et al. 2001, Pimentel et al. 1992). Frugivorous birds are an important group of species in tropical farmland ecosystems. Frugivorous birds are significant seed dispersers and can play a prominent role in transporting seeds into disturbed areas and setting the stage for the regeneration of these systems. Isolated…
Phytotoxic effects of Lantana camara, Eucalyptus camaldulensis and Eriocephalus africanus essential oils in weeds of Mediterranean summer crops
2009
Abstract The essential oil composition of Lantana camara , Eucalyptus camaldulensis and Eriocephalus africanus was analyzed by means of GC and GC–MS and bioassayed in order to determine their activity against Amaranthus hybridus and Portulaca oleracea . E. camaldulensis essential oil, with spathulenol as the main compound, was the most effective, completely inhibiting germination and seedling growth on both weeds. The essential oil of E. africanus , rich in artemisia ketone, showed activity similar to that of E. camaldulensis on A. hybridus , but it was not so effective against P. oleracea , and L. camara essential oil, with high percentages in sesquiterpene hydrocarbons, also showed higher…
Responses of Male and Female Black Grouse to Male Vocal Display
2010
The evolution of leks may be explained by several hypotheses. The ‘female preference’ hypothesis, which states that females favour males that have aggregated, has recently gained some empirical support. Low-quality, unattractive males may, however, settle near attractive males, as predicted by the ‘hotshot’ hypothesis. We tested whether black grouse Tetrao tetrix females use auditory cues to find the preferred leks, and whether males respond to vocal display emitted on leks. We conducted a playback experiment with male vocal display (rookooing) on leks, where the visiting females and displaying males were counted. The number of males tended to increase more on playback leks. Specifically, t…