| ticks and tick-borne pathogens in wild birds in greece. | wild birds are common hosts of ticks and can transport them for long distances, contributing to the spreading of tick-borne pathogens. the information about ticks on birds and tick-borne pathogens in greece is limited. the present study aimed to evaluate the prevalence and species of ticks infesting wild resident birds (mostly small passerines) in greece, and to assess borrelia and rickettsia infection in the collected ticks. detection of borrelia burgdorferi s.l. was performed by nested pcr tar ... | 2016 | 26847630 |
| light-dependent magnetoreception: quantum catches and opponency mechanisms of possible photosensitive molecules. | dozens of experiments on magnetosensitive, migratory birds have shown that their magnetic orientation behavior depends on the spectrum of light under which they are tested. however, it is not certain whether this is due to a direct effect on the magnetoreceptive system and which photosensitive molecules may be involved. we examined 62 experiments of light-dependent magnetoreception in three crepuscular and nocturnal migrants (48 for the european robin erithacus rubecula, ten for the silvereye zo ... | 2007 | 17766294 |
| aeromicrobium choanae sp. nov., an actinobacterium isolated from the choana of a garden warbler. | a gram-stain-positive, non-spore-forming actinobacterium, strain 9h-4t, isolated from the choana of a garden warbler (sylvia borin) was studied to examine its taxonomic position. on the basis of 16s rrna gene sequence analysis it was shown that strain 9h-4t belongs to the genus aeromicrobium with aeromicrobium flavumtyln1t (98.7 % similarity) and aeromicrobium tamlensessw1-57t (98.4 %) as the nearest neighbours and forms a separate branch in a neighbour-joining phylogenetic tree based on 16s rrn ... | 2017 | 27902232 |
| fuel deposition of three passerine bird species along the migration route. | the rate at which migrant birds replenish their energy stores at intermittent stopovers largely determines overall migration speed, the manner in which migration proceeds and success of migration. in this study, data on the fuel deposition rate (fdr) of three long-distance migrants from 17 ringing sites along their autumn migration route were used to examine: (1) effects of endogenous factors on fdr, and (2) how relationships between exogenous factors and fdr affect the organisation of migration ... | 2000 | 28308281 |
| photoperiod as a modifying and limiting factor in the expression of avian circannual rhythms. | in three species of birds that migrate long distances, the annual rhythms of gonadal activity, molt, and migratory restlessness (zugunruhe) persist for more than 1 year under certain constant conditions. the most important zeitgeber for these circannual rhythms is the annual cycle of photoperiod, which adjusts the overall period of circannual rhythms to exactly 1 year and also provides for the appropriate adjustment of seasonal activities to the temporal structure of the environment. this is ill ... | 2008 | 2519591 |
| avian magnetoreception: elaborate iron mineral containing dendrites in the upper beak seem to be a common feature of birds. | the magnetic field sensors enabling birds to extract orientational information from the earth's magnetic field have remained enigmatic. our previously published results from homing pigeons have made us suggest that the iron containing sensory dendrites in the inner dermal lining of the upper beak are a candidate structure for such an avian magnetometer system. here we show that similar structures occur in two species of migratory birds (garden warbler, sylvia borin and european robin, erithacus ... | 2010 | 20169083 |
| bird diversity and distribution in relation to urban landscape types in northern rwanda. | using the point count method, linear mixed models, shannon's diversity index, and bray-curtis cluster analysis, we conducted a study of the effect of urban fabric layout on bird diversity and distribution in northern rwanda. the results showed a significant effect of city landscapes on bird richness and relative abundance; residential neighborhoods, institutional grounds, and informal settlements had the highest species diversity in comparison to other microlandscape types. riversides were chara ... | 2014 | 25133203 |
| long- term effects of previous experience determine nutrient discrimination abilities in birds. | foraging behaviour is an essential ecological process linking different trophic levels. a central assumption of foraging theory is that food selection maximises the fitness of the consumer. it remains unknown, however, whether animals use innate or learned behaviour to discriminate food rewards. while many studies demonstrated that previous experience is a strong determinant of complex food choices such as diet mixing, the response to simple nutritional stimuli, such as sugar concentrations, is ... | 2008 | 18291043 |
| where in europe should we look for sources of the cutaneous trematode collyriclum faba infections in migrating birds? | cutaneous cysts with trematodes of collyriclum faba have been found in birds during their spring and post-breeding migrations in the czech republic. during spring migrations, c. faba was found in one dunnock prunella modularis, two european robins erithacus rubecula, three common nightingales luscinia megarhynchos, one song thrush turdus philomelos and one great reed warbler acrocephalus arundinaceus. during post-breeding migration, the same parasite was found in one garden warbler sylvia borin, ... | 2006 | 17125543 |
| no detection of avian influenza a viruses of the subtypes h5 and h7 and isolation of lentogenic avian paramyxovirus serotype 1 in passerine birds during stopover in the year 2001 on the island helgoland (north sea). | a total of 543 migrating passerines were captured during their stopover on the island of helgoland (north sea) in spring and autumn 2001. they were sampled for the detection of avian influenza a viruses (aiv) subtypes h5 and h7, and for avian paramyxoviruses serotype 1 (apmv-1). the goal of the study was to examine the role of migrating birds as potential vectors for these zoonotic viral diseases. for virus detection samples were taken from a) short-distance migrants such as chaffinches (fringil ... | 2005 | 16425631 |
| investigations on infection status with h5 and h7 avian influenza virus in short-distance and long-distance migrant birds in 2001. | the role of migrating birds as potential vectors for avian influenza virus (aiv) was investigated. we captured 543 migrating passerines during their stopover on the island of helgoland (north sea) in spring and autumn 2001. these birds were sampled for avian influenza a viruses (aiv), specifically the subtypes h5 and h7. for virus detection, samples were taken from 1) short-distance migrants, such as chaffinches (fringilla coelebs; n = 131) and song thrushes (turdus philomelos; n = 169); and 2) ... | 2007 | 17494601 |
| [trematodes of birds from lower silesia. iii. urotocus rossitensis (mühling, 1898)--new for poland species of trematode parasitism in passeriform birds]. | during the studies on trematode fauna of birds from lower silesia, the rare species--urotocus rossitensis (mühling, 1898)--was found. it parasitized in the bursa fabricii of sylvia borin, erithacus rubecula and turdus philomelos, and in the cloaca of turdus merula. all these birds are new hosts for u. rossitensis which was recorded for the first time in poland. it is worth mentioning that the localization of this trematode in the cloaca of t. merula is nontypical, since the parasite has underdev ... | 1991 | 1844788 |
| oxidative damage and anti-oxidant capacity in two migratory bird species at a stop-over site. | we quantified in the garden warbler (sylvia borin) and the barn swallow (hirundo rustica), two long-distance migratory songbirds, the early oxidative damage (roms) and plasma anti-oxidant capacity (oxy) variation of individuals caught at a stop-over site after a sustained flight across the sea, during spring migration. our main goal was to quantify the oxidative damage and anti-oxidant capacity variation in these two migratory species in relation to fat and muscle stores. the birds were sampled ... | 2007 | 17218158 |
| postexercise ketosis in night-migrating passerine birds. | this study investigated the postexercise metabolism of six species of free-living, night-migrating passerine birds (european robin, pied flycatcher, wheatear, redstart, blackcap, and garden warbler). the birds were caught during autumn migration out of their nocturnal flight, and their metabolism changed from a fasting, highly active state to a fasting, resting state. concentrations of six plasma metabolites of the fat, carbohydrate, and protein metabolism were measured during up to 10 h of reco ... | 2001 | 11226017 |
| complete sporogony of plasmodium relictum (lineage pgrw4) in mosquitoes culex pipiens pipiens, with implications on avian malaria epidemiology. | plasmodium relictum (lineage pgrw4) causes malaria in birds and is actively transmitted in countries with warm climates and also temperate regions of the new world. in europe, the lineage pgrw4 has been frequently reported in many species of afrotropical migrants after their arrival from wintering grounds, but is rare in european resident birds. obstacles for transmission of this parasite in europe have not been identified. culex quinquefasciatus is an effective vector of pgrw4 malaria, but this ... | 2015 | 25958156 |
| night-migratory songbirds possess a magnetic compass in both eyes. | previous studies on european robins, erithacus rubecula, and australian silvereyes, zosterops lateralis, had suggested that magnetic compass information is being processed only in the right eye and left brain hemisphere of migratory birds. however, recently it was demonstrated that both garden warblers, sylvia borin, and european robins have a magnetic compass in both eyes. these results raise the question if the strong lateralization effect observed in earlier experiments might have arisen from ... | 2012 | 22984416 |
| stopover durations of three warbler species along their autumn migration route. | in migrating birds, the success of migration is determined by stopover duration, the most important factor determining overall speed of migration, and fuel deposition rate. however, very little is known about stopover durations of small migrant birds, because appropriate methods for data analysis were lacking until recently. we used a new capture-recapture analysis to estimate stopover durations of 1st-year reed warblers acrocephalus scirpaceus, sedge warblers a. schoenobaenus and garden warbler ... | 2001 | 28547471 |
| magnetic orientation of garden warblers (sylvia borin) under 1.4 mhz radiofrequency magnetic field. | we report on the experiments on orientation of a migratory songbird, the garden warbler (sylvia borin), during the autumn migration period on the courish spit, eastern baltics. birds in experimental cages, deprived of visual information, showed the seasonally appropriate direction of intended flight with respect to the magnetic meridian. weak radiofrequency (rf) magnetic field (190 nt at 1.4 mhz) disrupted this orientation ability. these results may be considered as an independent replication of ... | 2014 | 24942848 |
| evolution of seasonal transmission patterns in avian blood-borne parasites. | in temperate regions, many vector-borne parasites maximise their transmission prospects by adjusting reproduction to seasonal cycles of host susceptibility and vector availability. nevertheless, in these regions there are areas where environmental conditions are favourable throughout the year, so that parasites could benefit from a year-round transmission strategy. we analysed how different transmission strategies (strict summer transmission, extended summer transmission - including spring and a ... | 2015 | 25957160 |
| phenotypic flexibility of skeletal muscles during long-distance migration of garden warblers: muscle changes are differentially related to body mass. | mass changes of skeletal muscles occur in a variety of species during the migratory period. phenotypic flexibility of flight muscle mass is considered to represent adaptations of the flight muscle to changing power requirements associated with changes in body mass. we analyzed the relationship between muscle masses and body mass for garden warblers (sylvia borin) sampled during spring migration in tanzania, ethiopia, and egypt, and during autumn migration in turkey. flight muscle mass was positi ... | 2005 | 16055860 |
| protein loss during long-distance migratory flight in passerine birds: adaptation and constraint. | during long-distance flights, birds catabolize not only fat but also protein. because there is no storage form of protein, protein catabolism entails a structural or functional loss. in this study, we investigated which organs were most reduced in lean mass during different phases of fat store loss and whether protein loss can be regarded as adaptive or as a constraint. body and organ composition were analysed both during the autumn migration over continental europe (sample from switzerland) and ... | 2002 | 11907058 |
| very weak oscillating magnetic field disrupts the magnetic compass of songbird migrants. | previously, it has been shown that long-distance migrants, garden warblers (sylvia borin), were disoriented in the presence of narrow-band oscillating magnetic field (1.403 mhz omf, 190 nt) during autumn migration. this agrees with the data of previous experiments with european robins (erithacus rubecula). in this study, we report the results of experiments with garden warblers tested under a 1.403 mhz omf with various amplitudes (∼0.4, 1, ∼2.4, 7 and 20 nt). we found that the ability of garden ... | 2017 | 28794163 |
| [european species of mallophaga genus pleurinirmus]. | the genus pleurinirmus zlot. has been erected monotypically. in this paper, 4 further species are added. of these, the following 3 are described as new on the basis of polish and finnish material on: p. affectator n. sp. from sylvia borin, p. phylloscopi n. sp. from phylloscopus trochilus, and p. rarus n. sp. from phylloscopus collybita. | 1976 | 1008293 |
| lateralized activation of cluster n in the brains of migratory songbirds. | cluster n is a cluster of forebrain regions found in night-migratory songbirds that shows high activation of activity-dependent gene expression during night-time vision. we have suggested that cluster n may function as a specialized night-vision area in night-migratory birds and that it may be involved in processing light-mediated magnetic compass information. here, we investigated these ideas. we found a significant lateralized dominance of cluster n activation in the right hemisphere of europe ... | 2007 | 17331212 |
| fuelling in front of the barrier-are there age based behavioral differences in garden warblers sylvia borin? | garden warblers sylvia borin were studied during autumn stopover in crete before crossing the barrier of the mediterranean sea and the sahara desert. birds followed with transmitters show extensive stopover periods, which were longer in first-year birds, 16 days, compared with adult birds, 14 days. the distribution of body masses from birds trapped in fig trees were used to estimate the departure body mass and the results found indicate that both age categories on average depart with a fuel load ... | 2014 | 24711970 |
| circannual variation in blood parasitism in a sub-saharan migrant passerine bird, the garden warbler. | knowing the natural dynamics of pathogens in migratory birds is important, for example, to understand the factors that influence the transport of pathogens to and their transmission in new geographical areas, whereas the transmission of other pathogens might be restricted to a specific area. we studied haemosporidian blood parasites of the genera plasmodium, haemoproteus and leucocytozoon in a migratory bird, the garden warbler sylvia borin. birds were sampled in spring, summer and early autumn ... | 2013 | 23621369 |
| reduced body mass gain in small passerines during migratory stopover under simulated heat wave conditions. | for birds that migrate long distances, maximizing the rate of refueling at stopovers is advantageous, but ambient conditions may adversely influence this vital process. we simulated a 3-day migratory stopover for garden warblers (sylvia borin) and compared body temperatures (t(b)) and rates of refueling under conditions of a heat wave (t(a)=40 °c by day, and 15 °c at night) with those under more moderate conditions (t(a)=27 °c by day, and 15 °c at night). we measured t(b) with implanted thermo-s ... | 2011 | 21172449 |
| food availability but not melatonin affects nocturnal restlessness in a wild migrating passerine. | a large number of passerine species migrate at night, although most of them are diurnal outside the migratory seasons. this diurnal-to-nocturnal transition is a major life-history event, yet little is known about its physiological control. previous work showed that during the migratory periods captive birds showing nocturnal migratory restlessness (zugunruhe) have reduced concentrations of circulating melatonin at night compared to non-migratory periods. this suggested that the hormone melatonin ... | 2011 | 21110977 |
| fat stores in a migratory bird: a reservoir of carotenoid pigments for times of need? | carotenoids are well known for their immune-stimulant function in birds and other vertebrates. moreover, they have potential antioxidant capacity, scavenging free radicals and protecting cell compartments from oxidation. most essential carotenoids are fat soluble and could be stored for times of need especially in adipose tissues, built up by migratory birds as the main source of energy on long-distance flights. in an exclusive diet experiment, garden warblers (sylvia borin) were fed ad libitum ... | 2011 | 20878330 |
| carbon turnover in tissues of a passerine bird: allometry, isotopic clocks, and phenotypic flexibility in organ size. | stable isotopes are an important tool for physiological and behavioral ecologists, although their usefulness depends on a thorough understanding of the dynamics of isotope incorporation into tissue(s) over time. in contrast to hair, claws, and feathers, most animal tissues continuously incorporate carbon (and other elements), and so carbon isotope values may change over time, depending on resource use and tissue-specific metabolic rates. here we report the carbon turnover rate for 12 tissues fro ... | 2010 | 19785542 |
| food availability during migratory stopover affects testis growth and reproductive behaviour in a migratory passerine. | long-distance migratory passerines initiate testicular recrudescence during spring migration to meet the demands of timely reproduction upon immediate arrival on the breeding grounds. the degree of testicular development is known to depend on environmental factors like stopover habitat quality; reproductive performance may be strongly impacted by testicular maturation upon arrival on the breeding grounds. we investigated the effect of stopover food availability on subsequent reproductive perform ... | 2009 | 19171149 |
| basal metabolic rate, food intake, and body mass in cold- and warm-acclimated garden warblers. | we address the question of whether physiological flexibility in relation to climate is a general feature of the metabolic properties of birds. we tested this hypothesis in hand-raised garden warblers (sylvia borin), long-distance migrants, which normally do not experience great temperature differences between summer and winter. we maintained two groups of birds under cold and warm conditions for 5 months, during which their body mass and food intake were monitored. when relatedness (siblings vs. ... | 2004 | 15123171 |
| migratory stopover conditions affect the developmental state of male gonads in garden warblers (sylvia borin). | long-distance migrants face the challenge of a short window for reproduction that requires optimal timing and full functional gonads. male garden warblers (sylvia borin) meet these demands by initiating testicular recrudescence during spring migration, enabling them to reproduce immediately after arrival at the breeding grounds. in a combined field and laboratory study, we investigated testicular size, plasma levels of luteinizing hormone (lh), androstenedione (ae), 5alpha-dihydrotestosterone (d ... | 2008 | 18471816 |
| testicular development during long-distance spring migration. | in birds, gonadal size varies between fully functional and maximally sized during reproduction and a regressed state with limited function during the non-reproductive periods. recent findings show that testicular mass of the long-distance migratory garden warbler begins to increase during spring migration. therefore, we sampled garden warblers during spring migration from tanzania to ethiopia, and finally to egypt to determine if this mass increase is functional in terms of sperm and hormone pro ... | 2007 | 17254583 |
| chemical magnetoreception: bird cryptochrome 1a is excited by blue light and forms long-lived radical-pairs. | cryptochromes (cry) have been suggested to form the basis of light-dependent magnetic compass orientation in birds. however, to function as magnetic compass sensors, the cryptochromes of migratory birds must possess a number of key biophysical characteristics. most importantly, absorption of blue light must produce radical pairs with lifetimes longer than about a microsecond. cryptochrome 1a (gwcry1a) and the photolyase-homology-region of cry1 (gwcry1-phr) from the migratory garden warbler were ... | 2007 | 17971869 |
| seasonally changing cryptochrome 1b expression in the retinal ganglion cells of a migrating passerine bird. | cryptochromes, blue-light absorbing proteins involved in the circadian clock, have been proposed to be the receptor molecules of the avian magnetic compass. in birds, several cryptochromes occur: cryptochrome 2, cryptochrome 4 and two splice products of cryptochrome 1, cry1a and cry1b. with an antibody not distinguishing between the two splice products, cryptochrome 1 had been detected in the retinal ganglion cells of garden warblers during migration. a recent study located cry1a in the outer se ... | 2016 | 26953690 |
| migratory birds use head scans to detect the direction of the earth's magnetic field. | night-migratory songbirds are known to use a magnetic compass , but how do they detect the reference direction provided by the geomagnetic field, and where is the sensory organ located? the most prominent characteristic of geomagnetic sensory input, whether based on visual patterns or magnetite-mediated forces , is the predicted symmetry around the north-south or east-west magnetic axis. here, we show that caged migratory garden warblers perform head-scanning behavior well suited to detect this ... | 2004 | 15530397 |
| cryptochromes and neuronal-activity markers colocalize in the retina of migratory birds during magnetic orientation. | migratory birds can use a magnetic compass for orientation during their migratory journeys covering thousands of kilometers. but how do they sense the reference direction provided by the earth's magnetic field? behavioral evidence and theoretical considerations have suggested that radical-pair processes in differently oriented, light-sensitive molecules of the retina could enable migratory birds to perceive the magnetic field as visual patterns. the cryptochromes (crys) have been suggested as th ... | 2004 | 15381765 |
| differential catabolism of muscle protein in garden warblers (sylvia borin): flight and leg muscle act as a protein source during long-distance migration. | samples of flight and leg muscle tissue were taken from migratory garden warblers at three different stages of migration: (1) pre-flight: when birds face an extended flight phase within the next few days, (2) post-flight: when they have just completed an extended flight phase, and (3) recovery: when they are at the end of a stop-over period following an extended flight phase. the changes in body mass are closely related to the changes in flight (p<0.001) and leg muscle mass (p<0.001), suggesting ... | 2001 | 11409626 |
| ghrelin affects stopover decisions and food intake in a long-distance migrant. | billions of birds migrate long distances to either reach breeding areas or to spend the winter at more benign places. on migration, most passerines frequently stop over to rest and replenish their fuel reserves. to date, we know little regarding how they decide that they are ready to continue their journey. what physiological signals tell a bird's brain that its fuel reserves are sufficient to resume migration? a network of hormones regulates food intake and body mass in vertebrates, including t ... | 2017 | 28167792 |
| birds see the true colours of fruits to live off the fat of the land. | communication is a characteristic of life, but its reliability and basic definition are hotly debated. theory predicts that trade among mutualists requires high reliability. here, we show that moderate reliability already allows mutualists to optimize their rewards. the colours of mediterranean fleshy-fruits indicate lipid rewards (but not other nutrients) to avian seed dispersers on regional and local scales. on the regional scale, fruits with high lipid content were significantly darker and le ... | 2014 | 24403330 |
| melatonin reduces migratory restlessness in sylvia warblers during autumnal migration. | a remarkable aspect of bird migration is its nocturnality, particularly common in passeriformes. the switch in activity from purely diurnal to also nocturnal is evident even in caged birds that during migratory periods develop an intense nocturnal restlessness, termed zugunruhe. the mechanisms that control this major change in activity are mostly unknown. previous work with sylvia warblers suggested an involvement of melatonin, a hormone associated with day-night cycles in most vertebrates. in a ... | 2013 | 24369961 |
| are long-distance migrants constrained in their evolutionary response to environmental change? causes of variation in the timing of autumn migration in a blackcap (s. atricapilla) and two garden warbler (sylvia borin) populations. | long-distance migratory birds often show little phenotypic variation in the timing of life-history events like breeding, molt, or migration. it has been hypothesized that this could result from low levels of heritable variation. if this were true, the adaptability of long-distance migratory birds would be limited, which would explain the vulnerability of this group of birds to environmental changes. the amount of phenotypic, environmental, and genetic variation in the onset of autumn migratory a ... | 2005 | 16055856 |
| the autumnal fattening of the long-distance migratory garden warbler (sylvia borin) is stimulated by intermittent fasting. | to investigate the proximate influence of a changing food availability on the seasonal fattening of migratory birds, garden warblers (sylvia borin) following postnuptial moult were food restricted once a week. body mass, food intake, plasma hormone and metabolite levels were measured and compared to birds which always had ad libitum food access. the food-restricted birds increased their body mass significantly earlier than the controls. the accelerated fattening was initially not accompanied by ... | 2000 | 11192268 |
| fasting increases the plasma glucagon response in the migratory garden warbler (sylvia borin). | acute pancreatic hormonal responses to oral glucose loads were investigated in garden warblers during the prolonged fast that follows their autumnal migratory fattening. plasma glucose, free fatty acids, beta-hydroxybutyrate, insulin (ins), and glucagon (gln) were measured prior to and 10 min after an oral glucose load in three groups of birds: one had food ad libitum, and the other two were either food restricted or food deprived down to a given (low) body mass level. ten minutes after the gluc ... | 1999 | 10375470 |
| glucose utilization rate and pancreatic hormone response to oral glucose loads are influenced by the migratory condition and fasting in the garden warbler (sylvia borin). | substrate utilization and regulatory mechanisms of metabolism were studied in migratory garden warblers by measuring plasma levels of glucose, free fatty acids (ffas), beta-hydroxybutyrate, insulin and glucagon in response to oral glucose loads. three different physiological states were examined: (a) the autumnal migratory period on a high and (b) on a fasted low body mass level, and (c) the postmigratory period with low body mass. glucose tolerance was better in the postmigratory lean than fat ... | 1998 | 9771462 |
| body fat influences departure from stopover sites in migratory birds: evidence from whole-island telemetry. | migration remains one of the great mysteries of animal life. small migratory birds rely on refuelling stopovers after crossing ecological barriers such as deserts or seas. previous studies have suggested that fuel reserves may determine stopover duration but this hypothesis could not be tested because of methodological limitations. here, we provide evidence that subcutaneous fat stores determine stopover duration by measuring the permanence of migratory garden warblers (sylvia borin) on a small ... | 2010 | 20164077 |
| night-migratory garden warblers can orient with their magnetic compass using the left, the right or both eyes. | several studies have suggested that the magnetic compass of birds is located only in the right eye. however, here we show that night-migrating garden warblers (sylvia borin) are able to perform magnetic compass orientation with both eyes open, with only the left eye open and with only the right eye open. we did not observe any clear lateralization of magnetic compass orientation behaviour in this migratory songbird, and, therefore, it seems that the suggested all-or-none lateralization of magnet ... | 2010 | 19889693 |
| variation in hypothalamic gonadotrophin-releasing hormone content, plasma and pituitary lh, and in-vitro testosterone release in a long-distance migratory bird, the garden warbler (sylvia borin), under constant photoperiods. | changes in concentrations of hypothalamic gonadotrophin-releasing hormone (gnrh), pituitary and plasma lh, testicular mass, in-vitro release of testosterone, body mass and migratory activity were measured in male garden warblers (sylvia borin) kept from november to june under a constant photo-period of 12.8 h. under such conditions garden warblers gradually change from the photorefractory to the photosensitive state and gonadal recrudescence then occurs. hypothalamic gnrh content was low from de ... | 1991 | 2013742 |
| the effect of constant light and phase shifts on a learned time-place association in garden warblers (sylvia borin): hourglass or circadian clock? | garden warblers are able to learn an association between time of day and feeding place. in constant dim light and constant food availability, the learned feeding pattern (successive visits to four feeding rooms for approximately 3 hr each) persisted for at least 1 day in three birds and for at least 6 days in one bird. the free-running feeding rhythm had a period of slightly greater than 23 hr. in response to a 6-hr phase advance of the light-dark cycle, the birds advanced their learned feeding ... | 1991 | 1773101 |
| effects of food-deprivation on migratory restlessness and diurnal activity in the garden warbler sylvia borin. | the present study describes the effects of food-deprivation on migratory restlessness and diurnal activity in the garden warbler, a long-distance migrating passerine. fourteen first-year birds were held from august through march in individual registration cages and exposed to daylength changes experienced by birds that winter at the equator. with the beginning of the fall migratory season the birds increased their body weights due to fat deposition and showed nocturnal migratory restlessness cha ... | 1988 | 28311944 |
| nutritional requirements for maintenance of body weight and fat deposition in the long-distance migratory garden warbler, sylvia borin (boddaert). | intake of food, protein, fat and carbohydrates and their fecal output and the birds' weights were recorded during different feeding trials with specific nutrient reduced diets in the old-world long-distance migratory garden warbler. the birds' body weights were affected by low dietary protein as well as low dietary fat levels. low dietary protein and fat levels were associated with significant changes in daily gross and net food intake and in the efficiency of food and nutrient utilization. bird ... | 1987 | 2881675 |
| efficiency of food utilization during fat deposition in the long-distance migratory garden warbler, sylvia borin. | 1 intake of food, fat, protein and carbohydrates and their fecal output were recorded during the annual body weight cycle of the garden warbler, and old-world longdistance migratory bird species, and the efficiencies of food and nutrient utilization, defined as the ratio (intake-fecal output)/intake, were calculated. 2. gross food intake and food and nutrient utilization differed significantly between different phases of the birds' body weight cycle. 3. during premigratory fattening, both in "au ... | 1985 | 28310920 |
| the effect of celestial cues on the ontogeny of non-visual orientation in the garden warbler (sylvia borin). | it was the aim of this study to find out whether additional information from the sun and the stars during early development leads to an improvement in the young birds' non-visual orientation performance during their first autumn migration period. the results indicate that the birds' ability to determine their migratory direction can mature independently of celestial information. celestial cues, however, appear to be involved in the normal maturation process of migratory orientation, since the av ... | 1980 | 7434990 |
| evidence for an innate magnetic compass in garden warblers. | | 1974 | 4437640 |
| flexible remodeling of organ size during spring migration of the garden warbler (sylvia borin). | the energetic demands of long-distance migratory birds change drastically, depending on the stage of their life cycle. changing demands are reflected in the up and down regulation of adipose tissue and organ mass. this paper presents new data on organ size changes during different stages of spring migration of garden warblers (sylvia borin). phenotypic mass changes were quantified in 13 organs of birds caught in tanzania, ethiopia and egypt. we also sampled birds after a simulated stopover in eg ... | 2005 | 16351958 |
| a separate circadian oscillator controls nocturnal migratory restlessness in the songbird sylvia borin. | when confined to a cage, migratory songbirds exhibit nocturnal migratory restlessness (also called zugunruhe) during the spring and autumn migratory periods, even though these birds are exclusively diurnal during the remainder of the year. zugunruhe, which has been demonstrated to be under the direct control of a circannual timer, is characterized by a stereotypic "wing-whirring" behavior while the bird is perched. to elucidate the role played by the circadian system in the regulation of zugunru ... | 2005 | 16275772 |
| increased endoparasite infection in late-arriving individuals of a trans-saharan passerine migrant bird. | earlier migration in males than in females is the commonest pattern in migrating passerines and is positively related to size dimorphism and dichromatism. the early arrival of males is a costly trait that may confer reproductive advantages in terms of better territories and/or mates. given the physiological cost of migration, early migrants are those in best condition and accordingly the prevalence, load, and/or diversity of parasites is expected to increase in both sexes for late migrants. to t ... | 2013 | 23620731 |
| time of day, age and feeding habits influence coccidian oocyst shedding in wild passerines. | protozoan coccidia are one of the most common intestinal parasites in birds. ordinary coccidian detection and quantification techniques have proved to be inaccurate for wild passerines due to the existence of marked oocyst shedding rhythms throughout the day. previous studies have suggested that these rhythms should be taken into account when analysing coccidian load and prevalence data, but their pattern and magnitude still remain poorly known. in this study we characterised shedding rhythms in ... | 2007 | 17289051 |
| magnetic compass of garden warblers is not affected by oscillating magnetic fields applied to their eyes. | the magnetic compass is an important element of the avian navigation system, which allows migratory birds to solve complex tasks of moving between distant breeding and wintering locations. the photochemical magnetoreception in the eye is believed to be the primary biophysical mechanism behind the magnetic sense of birds. it was shown previously that birds were disoriented in presence of weak oscillating magnetic fields (omf) with frequencies in the megahertz range. the omf effect was considered ... | 2020 | 32103061 |
| behavioural ecology: sleeping safely carries energetic costs. | trade-offs shape animal behaviour. for decades, the study of trade-offs has provided insight into how animals make decisions, but they have rarely been explored in relation to sleep. a new study reveals a role for sleep in saving energy in garden warblers on a stopover during a northward migration, but with ecological costs. | 2019 | 31430478 |
| sleeping unsafely tucked in to conserve energy in a nocturnal migratory songbird. | each spring and fall, millions of normally diurnal birds switch to migrating at night. most of these are small songbirds (passerine) migrating long distances that need to alternate their migratory flights with refueling stopovers [1, 2], which can account for up to 80% of the total migratory period [3]. after a long nocturnal flight, these birds face the contrasting needs to recover sleep and refill depleted energy stores, all while vulnerable to predation [4, 5]. here, we investigated how garde ... | 2019 | 31430467 |
| a role for pancreatic hormones in the regulation of autumnal fat deposition of the garden warbler (sylvia borin)? | glucagon and insulin were measured by heterologous immunoassays in plasma samples of 17 garden warblers (sylvia borin) kept under constant ad libitum or fasting-refeeding conditions during the migratory season from september to may. plasma levels of key metabolic indicators (glucose, triglycerides, cholesterol, and free fatty acids) were measured every 2 weeks. measurements of the two hormones concur with the general assumption of a higher glucagon:insulin ratio, indicating a more pronounced cat ... | 1997 | 9245524 |
| the direction of celestial rotation influences the development of stellar orientation in young garden warblers (sylvia borin) | the study presented here was conducted in order to analyze the role of the direction of celestial rotation in the development of stellar orientation in young migratory birds. the test birds were garden warblers, sylvla borin, which leave their breeding ground on a southwesterly compass course. the birds were hand-raised and, during the premigratory period, exposed to an artificial 'sky' in the local geomagnetic field. for the control group c, the star pattern was rotating in the natural directio ... | 1997 | 9320019 |
| hippocampal volume in migratory and non-migratory warblers: effects of age and experience. | we tested the hypothesis that experience of migration from europe to tropical africa by garden warblers is associated with changes in the relative volume of the hippocampus, a brain region thought to be involved in processing spatial information, including that used in navigation. relative hippocampal volume was larger in birds at least one year old that had migrated to and from africa, than in naive birds approx. 3 months old. further comparisons between groups of differing age and experience o ... | 1996 | 8950002 |
| twenty-four hour melatonin profiles in a nocturnally migrating bird during and between migratory seasons. | the garden warbler sylvia borin is a long-distance migrating bird that travels exclusively at night. during the migratory seasons caged warblers develop intense nocturnal activity which may become even more intense than that during the day. it is demonstrated that in spite of dramatic seasonal changes in the 24-h pattern of locomotor activity measured in caged garden warblers, the corresponding pattern of plasma melatonin changed only very little. as in other species melatonin levels were genera ... | 1993 | 8504916 |
| the isolation and identification of bacteria on feathers of migratory bird species. | worldwide, bacteria are the most ubiquitous microorganisms, and it has been extensively demonstrated that migratory wild birds can increase bacterial global scale dispersion through long-distance migration and dispersal. the microbial community hosted by wild birds can be highly diverse, including pathogenic strains that can contribute to infections and disease spread. this study focused on feather and plumage bacteria within bird microbial communities. samples were collected during ornithologic ... | 2018 | 30563109 |
| no evidence for the use of magnetic declination for migratory navigation in two songbird species. | determining the east-west position was a classical problem in human sea navigation until accurate clocks were manufactured and sailors were able to measure the difference between local time and a fixed reference to determine longitude. experienced night-migratory songbirds can correct for east-west physical and virtual magnetic displacements to unknown locations. migratory birds do not appear to possess a time-different clock sense; therefore, they must solve the longitude problem in a different ... | 2020 | 32330188 |
| migrating songbirds on stopover prepare for, and recover from, oxidative challenges posed by long-distance flight. | managing oxidative stress is an important physiological function for all aerobic organisms, particularly during periods of prolonged high metabolic activity, such as long-distance migration across ecological barriers. however, no previous study has investigated the oxidative status of birds at different stages of migration and whether that oxidative status depends on the condition of the birds. in this study, we compared (1) energy stores and circulating oxidative status measures in (a) two spec ... | 2015 | 26355277 |
| a new view on an old debate: type of cue-conflict manipulation and availability of stars can explain the discrepancies between cue-calibration experiments with migratory songbirds. | migratory birds use multiple compass systems for orientation, including a magnetic, star and sun/polarized light compass. to keep these compasses in register, birds have to regularly update them with respect to a common reference. however, cue-conflict studies have revealed contradictory results on the compass hierarchy, favoring either celestial or magnetic compass cues as the primary calibration reference. both the geomagnetic field and polarized light cues present at sunrise and sunset have b ... | 2016 | 26941631 |
| stopover decision during migration: physiological conditions predict nocturnal restlessness in wild passerines. | during migration, a number of bird species rely on stopover sites for resting and feeding before and after crossing ecological barriers such as deserts or seas. the duration of a stopover depends on the combined effects of environmental factors, endogenous programmes and physiological conditions. previous studies indicated that lean birds prolong their refuelling stopover compared with fat birds; however, the quantitative relationship between physiological conditions and stopover behaviour has n ... | 2009 | 19324648 |
| photoactivation of cryptochromes from drosophila melanogaster and sylvia borin: insight into the chemical compass mechanism by computational investigation. | although behavioral studies demonstrated light-induced magnetoreception in the insect drosophila melanogaster, gaining insight into the possibility that a radical-pair mechanism accounts for the magnetic response of the cryptochrome (dmcry1) is complicated by a number of factors. in addition, the mechanism of magnetoreception for the cryptochrome from the garden warbler bird sylvia borin (gwcry1a), which demonstrated a long-lived radical pair by transient optical absorption measurements, has als ... | 2015 | 25710635 |
| animal migration research takes wing. | in the beginning there was great confusion about animal migration. aristotle, noting that the types of birds around him changed with the seasons, concluded that summer redstarts turned into robins at the onset of winter, and that garden warblers became blackcaps [1]. others thought that birds disappear in winter because they hibernate submerged in mud. in a case of art decidedly not imitating life, a 16th century illustration accompanying the writings of swedish archbishop olaus magnus showed a ... | 2018 | 30205070 |