Publications

sperm divergence in a passerine contact zone: indication of reinforcement at the gametic level.	postcopulatory sexual selection may promote evolutionary diversification in sperm form, but the contribution of between-species divergence in sperm morphology to the origin of reproductive isolation and speciation remains little understood. to assess the possible role of sperm diversification in reproductive isolation, we studied sperm morphology in two closely related bird species, the common nightingale (luscinia megarhynchos) and the thrush nightingale (luscinia luscinia), that hybridize in a ...	2019	30597549
interspecific competition promotes habitat and morphological divergence in a secondary contact zone between two hybridizing songbirds.	interspecific competition is assumed to play an important role in the ecological differentiation of species and speciation. however, empirical evidence for competition's role in speciation remains surprisingly scarce. here, we studied the role of interspecific competition in the ecological differentiation and speciation of two closely related songbird species, the common nightingale (luscinia megarhynchos) and the thrush nightingale (luscinia luscinia). both species are insectivorous and ecologi ...	2018	29603471
competition-driven niche segregation on a landscape scale: evidence for escaping from syntopy towards allotopy in two coexisting sibling passerine species.	the role of interspecific competition for generating patterns in species' distribution is hotly debated and studies taking into account processes occurring at both large and small spatial scales are almost missing. theoretically, competition between species with overlapping niches should result in divergence of their niches in sympatry to reduce the costs of competition. many species show a mosaic distribution within sympatric zones, with the syntopic sites occupied by both species, and allotopi ...	2018	29430650
multifractal analysis reveals music-like dynamic structure in songbird rhythms.	music is thought to engage its listeners by driving feelings of surprise, tension, and relief through a dynamic mixture of predictable and unpredictable patterns, a property summarized here as "expressiveness". birdsong shares with music the goal to attract its listeners' attention and might use similar strategies to achieve this. we here tested a thrush nightingale's (luscinia luscinia) rhythm, as represented by song amplitude envelope (containing information on note timing, duration, and inten ...	2018	29545558
molecular characterization and distribution of plasmodium matutinum, a common avian malaria parasite.	species of plasmodium (plasmodiidae, haemosporida) are widespread and cause malaria, which can be severe in avian hosts. molecular markers are essential to detect and identify parasites, but still absent for many avian malaria and related haemosporidian species. here, we provide first molecular characterization of plasmodium matutinum, a common agent of avian malaria. this parasite was isolated from a naturally infected thrush nightingale luscinia luscinia (muscicapidae). fragments of mitochondr ...	2017	28931453
candidatus neoehrlichia mikurensis in ticks from migrating birds in sweden.	candidatus neoehrlichia mikurensis (cnm; family anaplasmataceae) was recently recognized as a potential tick-borne human pathogen. the presence of cnm in mammals, in host-seeking ixodes ticks and in ticks attached to mammals and birds has been reported recently. we investigated the presence of cnm in ornithophagous ticks from migrating birds. a total of 1,150 ticks (582 nymphs, 548 larvae, 18 undetermined ticks and two adult females) collected from 5,365 birds captured in south-eastern sweden wa ...	2015	26207834
anomalous weather events and horizontal transfer of the thrush nightingale (luscinia luscinia) vocal models.		2015	26335967
investigation of musicality in birdsong.	songbirds spend much of their time learning, producing, and listening to complex vocal sequences we call songs. songs are learned via cultural transmission, and singing, usually by males, has a strong impact on the behavioral state of the listeners, often promoting affiliation, pair bonding, or aggression. what is it in the acoustic structure of birdsong that makes it such a potent stimulus? we suggest that birdsong potency might be driven by principles similar to those that make music so effect ...	2014	24036130
the causes and evolutionary consequences of mixed singing in two hybridizing songbird species (luscinia spp.).	bird song plays an important role in the establishment and maintenance of prezygotic reproductive barriers. when two closely related species come into secondary contact, song convergence caused by acquisition of heterospecific songs into the birds' repertoires is often observed. the proximate mechanisms responsible for such mixed singing, and its effect on the speciation process, are poorly understood. we used a combination of genetic and bioacoustic analyses to test whether mixed singing observ ...	2013	23577089
a coupled kinematics-energetics model for predicting energy efficient flapping flight.	a new computational model based on an optimal power, wake-only aerodynamics method is presented to predict the interdependency of energetics and kinematics in bird and bat flight. the model is divided into offline, intermediate and online modules. in the offline module, a four-dimensional design space sweep is performed (lift, thrust, flapping amplitude and flapping frequency). in the intermediate stage, the physical characteristics of the animal are introduced (wing span, mass, wing area, aspec ...	2013	23084891
composition of fuel stores and digestive limitations to fuel deposition rate in the long-distance migratory thrush nightingale, luscinia luscinia.	during their autumn migratory phase, thrush nightingales (luscinia luscinia) previously starved for 2 d were allowed to refuel under three different ambient temperature conditions (-7 degrees, 7 degrees, and 22 degrees c). during the refueling period, as well as during the preceding control and starvation periods, food intake, body mass, and feces production were monitored. in addition, daily energy expenditure was measured during the refueling period. the compilation of the energy balance durin ...	2013	9231384
female heterogamety and speciation: reduced introgression of the z chromosome between two species of nightingales.	several lines of evidence suggest that the x chromosome plays a large role in intrinsic postzygotic isolation. the role of the z chromosome in speciation is much less understood. to explore the role of the z chromosome in reproductive isolation, we studied nucleotide variation in two closely related bird species, the thrush nightingale (luscinia luscinia) and the common nightingale (l. megarhynchos). these species are isolated by incomplete prezygotic isolation and female hybrid sterility. we se ...	2010	19796142
information from the geomagnetic field triggers a reduced adrenocortical response in a migratory bird.	long-distance migrants regularly pass ecological barriers, like the sahara desert, where extensive fuel loads are necessary for a successful crossing. a central question is how inexperienced migrants know when to put on extensive fuel loads. beside the endogenous rhythm, external cues have been suggested to be important. geomagnetic information has been shown to trigger changes in foraging behaviour and fuel deposition rate in migratory birds. the underlying mechanism for these adjustments, howe ...	2009	19717671
food intake and fuel deposition in a migratory bird is affected by multiple as well as single-step changes in the magnetic field.	recent studies have shown that migratory thrush nightingales (luscinia luscinia) experimentally treated with multiple changes of the magnetic field simulating a journey to their target stopover area in northern egypt, increased fuel deposition as expected in preparation to cross the sahara desert. to investigate the significance of food intake on the body mass changes observed, in the work described here we analysed food intake of the nightingales under study in those earlier experiments. furthe ...	2008	18281326
fuelling decisions in migratory birds: geomagnetic cues override the seasonal effect.	recent evaluations of both temporal and spatial precision in bird migration have called for external cues in addition to the inherited programme defining the migratory journey in terms of direction, distance and fuelling behaviour along the route. we used juvenile european robins (erithacus rubecula) to study whether geomagnetic cues affect fuel deposition in a medium-distance migrant by simulating a migratory journey from southeast sweden to the wintering area in southern spain. in the late pha ...	2007	17609189
maximum daily energy intake: it takes time to lift the metabolic ceiling.	conventionally, maximum capacities for energy assimilation are presented as daily averages. however, maximum daily energy intake is determined by the maximum metabolizable energy intake rate and the time available for assimilation of food energy. thrush nightingales (luscinia luscinia) in migratory disposition were given limited food rations for 3 d to reduce their energy stores. subsequently, groups of birds were fed ad lib. during fixed time periods varying between 7 and 23 h per day. metaboli ...	2006	10685904
the relationship between wingbeat kinematics and vortex wake of a thrush nightingale.	the wingbeat kinematics of a thrush nightingale luscinia luscinia were measured for steady flight in a wind tunnel over a range of flight speeds (5-10 m s(-1)), and the results are interpreted and discussed in the context of a detailed, previously published, wake analysis of the same bird. neither the wingbeat frequency nor wingbeat amplitude change significantly over the investigated speed range and consequently dimensionless measures that compare timescales of flapping vs. timescales due to th ...	2004	15531647
magnetic cues and time of season affect fuel deposition in migratory thrush nightingales (luscinia luscinia).	bird migration requires high energy expenditure, and long-distance migrants accumulate fat for use as fuel during stopovers throughout their journey. recent studies have shown that long-distance migratory birds, besides accumulating fat for use as fuel, also show adaptive phenotypic flexibility in several organs during migration. the migratory routes of many songbirds include stretches of sea and desert where fuelling is not possible. large fuel loads increase flight costs and predation risk, th ...	2003	12639316
magnetic cues trigger extensive refuelling.	long stretches of sea and desert often interrupt the migration routes of small songbirds, whose fat reserves must be restored before these can be crossed as they provide no opportunity for refuelling. to investigate whether magnetic cues might enable inexperienced migratory birds to recognize a region where they need to replenish their body fat, we caught and held thrush nightingales (luscinia luscinia) in sweden just before their first migration and exposed them to a magnetic field simulating t ...	2001	11689932
computer simulation of fat and muscle burn in long-distance bird migration	the mechanical power required from a bird's flight muscles was recalculated at regular intervals (default 6 min), and the energy consumed in the interval was accounted for by reducing fuel reserves, which also reduced the all-up mass and the body cross-sectional area. part of the energy requirement was met by consuming flight muscle tissue, according to one of three alternative "muscle burn criteria". these were (1) specific work held constant, (2) power density held constant and (3) muscle mass ...	1998	9593656
wingbeat frequency and the body drag anomaly: wind-tunnel observations on a thrush nightingale (luscinia luscinia) and a teal (anas crecca)	a teal (anas crecca) and a thrush nightingale (luscinia luscinia) were trained to fly in the lund wind tunnel for periods of up to 3 and 16 h respectively. both birds flew in steady flapping flight, with such regularity that their wingbeat frequencies could be determined by viewing them through a shutter stroboscope. when flying at a constant air speed, the teal's wingbeat frequency varied with the 0.364 power of the body mass and the thrush nightingale's varied with the 0.430 power. both expone ...	1996	9320660