[persistence of the foot-and-mouth disease virus in experimentally infected jackdaws]. 1975175553
jackdaws as potential source of milk-borne campylobacter jejuni infection. 19901971891
a comparative study of postnatal growth and organ development in some species of hypothesis has been formulated stating that the rate at which postnatal growth proceeds is at least partly determined by the distribution of growth between different organs. in order to test the hypothesis a series of studies of organ growth has been undertaken in some birds with widely varying growth rate capacities (geese, quail, turkeys, fieldfares and jackdaws). with regard to nidifugous birds the data show that the growth pattern of the goose, a species which has a high growth rate capac ...19836667891
paratuberculosis infection of nonruminant wildlife in scotland.recent reports of natural paratuberculosis (or johne's disease) in rabbits, foxes, and stoats has focused debate on the presence and importance of wildlife reservoirs in the epidemiology of this disease. this paper describes an extensive study investigating 18 nonruminant wildlife species for evidence of paratuberculosis. using both culture and histopathological analysis, fox, stoat, weasel, crow, rook, jackdaw, rat, wood mouse, hare, and badger were found to harbor mycobacterium avium subsp. pa ...200111283080
wild birds as a possible natural reservoir of borna disease virus.the natural reservoir of borna disease virus (bdv) is unknown. in this paper, we show that mallards (anas platyrhyncos) and jackdaws (corvus monedula) can be subclinically infected carriers of this virus. from faecal samples collected at a bird pond, we were able to amplify fragments of the bdv p24 and p40 genes. following cloning and sequencing, a phylogenetic analysis revealed that these birds carry strains of bdv closely related to but distinct from the reference strains bdv v and he/80. to o ...200111561971
Activity of transcription factor JACKDAW is essential for SHR/SCR-dependent activation of SCARECROW and MAGPIE and is modulated by reciprocal interactions with MAGPIE, SCARECROW and SHORT ROOT.Two GRAS family transcription factors, SHORT-ROOT (SHR) and SCARECROW (SCR), are required for ground tissue and quiescent center formation in Arabidopsis roots. The action of SHR and SCR is regulated by two INDETERMINATE DOMAIN (IDD) family proteins, JACKDAW (JKD) and MAGPIE (MGP). Although the reciprocal interaction of these transcription factors is considered to be involved in the modulation of SHR and SCR action by JKD and MGP, the underlying mechanism remains unclear. In this study, we use a ...201121935722
susceptibility of european jackdaws (corvus monedula) to experimental infection with lineage 1 and 2 west nile viruses.mass bird mortality has been observed in north america after the introduction of west nile virus (wnv), most notably massive die-offs of american crows (corvus brachyrhynchos). in contrast, wnv epidemic activity in europe has been characterized by very low incidences of bird mortality. as the general susceptibility of european corvids to strains of wnv remains in question, european jackdaws (corvus monedula) were inoculated with wnv strains circulating currently in greece (greece-10), italy (fin ...201424671752
neospora caninum in crows from israel.a cross-sectional neospora caninum seroprevalence study was performed on free ranging crows (corvus cornix, corvus monedula and corvus splendens) from israel in order to assess their exposure to this pathogen and evaluate their role as potential hosts or as sentinels of infection. using the modified agglutination test (mat) with a cutoff titer of 1:100, 30 out of 183 crows (16.4%) were found to be n. caninum seropositive. positive results were validated and confirmed by the indirect fluorescent ...201526359640
toxoplasma gondii prevalence in israeli crows and griffon vultures.a cross-sectional toxoplasma gondii seroprevalence study was performed on free ranging crows (corvus cornis, corvus monedula, corvus splendens) and griffon vultures (gyps fulvus) from israel in order to assess exposure to this pathogen in scavenger birds that feed on animal carcasses and their possible role in the epidemiology of toxoplasmosis. using the modified agglutination test (mat) with a cutoff titer of 1:25, 52 of 122 crows (42.6%) and 40 of 101 griffon vultures (39.6%) were found to be ...201322920844
on the study of the transmission networks of blood parasites from sw spain: diversity of avian haemosporidians in the biting midge culicoides circumscriptus and wild birds.blood-sucking flying insects play a key role in the transmission of pathogens of vector-borne diseases. however, at least for the case of avian malaria parasites, the vast majority of studies focus on the interaction between parasites and vertebrate hosts, but there is a lack of information regarding the interaction between the parasites and the insect vectors. here, we identified the presence of malaria and malaria-like parasite lineages harbored by the potential vector culicoides circumscriptu ...201323856348
[molecular genetic characteristics of the newcastle disease virus velogenic strains isolated in russia, ukraine, kazakhstan, and kirghizia].the f gene fragment of 79 newcastle disease virus (ndv) strains isolated from domestic and synanthropic birds in kazakhstan, kirghizia, ukraine, and russia in 1993 to 2007 was comparatively analyzed. phylogenetic analysis of test isolates and reference ndv strains obtained from the genbank was carried out by polymerase chain reaction with subsequent sequencing and comparative analysis of 154-bp nucleotide sequences in the main functional region of the f gene. all newly characterized isolates bel ...201020886710
jackdaws respond to human attentional states and communicative cues in different contexts.humans communicate their intentions and disposition using their eyes, whereas the communicative function of eyes in animals is less clear. many species show aversive reactions to eyes, and several species gain information from conspecifics' gaze direction by automatically co-orienting with them. however, most species show little sensitivity to more subtle indicators of attention than head orientation and have difficulties using such cues in a cooperative context. recently, some species have been ...200919345101
preference of birds for zinc phosphide bait formulations.zinc phosphide baits are used for controlling pest rodents but are also highly toxic to other vertebrates. the base for rodent baits containing zinc phosphide is usually wheat kernels which are highly attractive to birds. in this study, wheat-based pellets of different shapes and colours without zinc phosphide were tested for their attractiveness for pigeons (columba livia gmelin) and japanese quails (coturnix japonica temm. & schleg.) in aviaries and for pigeons and corvids (corvus monedula l., ...200818189327
cognitive adaptations of social bonding in birds.the 'social intelligence hypothesis' was originally conceived to explain how primates may have evolved their superior intellect and large brains when compared with other animals. although some birds such as corvids may be intellectually comparable to apes, the same relationship between sociality and brain size seen in primates has not been found for birds, possibly suggesting a role for other non-social factors. but bird sociality is different from primate sociality. most monkeys and apes form s ...200717255008
characterization of two novel polyomaviruses of birds by using multiply primed rolling-circle amplification of their genomes.polyomaviruses are small nonenveloped particles with a circular double-stranded genome, approximately 5 kbp in size. the mammalian polyomaviruses mainly cause persistent subclinical infections in their natural nonimmunocompromised hosts. in contrast, the polyomaviruses of birds--avian polyomavirus (apv) and goose hemorrhagic polyomavirus (ghpv)--are the primary agents of acute and chronic disease with high mortality rates in young birds. screening of field samples of diseased birds by consensus ...200616537620
a comparative study of geometric rule learning by nutcrackers (nucifraga columbiana), pigeons (columba livia), and jackdaws (corvus monedula).three avian species, a seed-caching corvid (clark's nutcrackers; nucifraga columbiana), a non-seed-caching corvid (jackdaws; corvus monedula), and a non-seed-caching columbid (pigeons; columba livia), were tested for ability to learn to find a goal halfway between 2 landmarks when distance between the landmarks varied during training. all 3 species learned, but jackdaws took much longer than either pigeons or nutcrackers. the nutcrackers searched more accurately than either pigeons or jackdaws. ...200212539930
[classification of the forebrain striatum neurons in birds].polymorphism of neurons in the basic fields of the forebrain striatum of birds was described using specially developed classification of neurons in nissl preparations. birds with different degrees of development of elementary rational activity were studied: corvus monedula, columba livia, coturnix coturnix, and melopsittacus undulatus. according to the proposed method, the neurons were classified in 3 basic types and 2 additional, 6 subtypes and 26 classes. it was found that in the higher brain ...200111605427
intestinal, segmented, filamentous bacteria in a wide range of vertebrate species.segmented, filamentous bacteria (sfbs) form a group of bacteria with similar morphology and are identified on the basis of their morphology only. the relationships of these organisms are unclear as the application of formal taxonomic criteria is impossible currently due to the lack of an in vitro technique to culture sfbs. the intestine of laboratory animals such as mice, rats, chickens, dogs, cats and pigs is known to harbour sfbs. to see whether this extends to other animal species, intestines ...19938501895
isolation and primary structure of a novel avian pancreatic polypeptide from five species of eurasian crow.chicken pancreatic polypeptide is the prototype of the neuropeptide y (npy)/pp superfamily of regulatory peptides. this polypeptide was appended the descriptive term avian, despite the presence of some 8600 extant species of bird. additional primary structures from other avian species, including turkey, goose and ostrich, would suggest that the primary structure of this polypeptide has been highly-conserved during avian evolution. avian pancreatic polypeptides structurally-characterised to date ...19938234905
[a delay in the development of hearing and a shift in the leading afferentation in the early behavioral ontogeny of birds].development of auditory sensitivity was studied by recording microphonic component of cochlear potentials during the period of opening the eyes in 6 species of birds with different types of ontogeny (anas plathyrynchos, larus canus and l. argentatus, sterna paradisaea, coloeus monedula and corvus frugeleus). the onset of opening the eyes is accompanied by a delay in development of auditory sensitivity and temporary decrease of upper frequency limit of the audible range. before such a delay acous ...19947879454
jackdaws and magpies as vectors of milkborne human campylobacter 1990 we reported that milk bottles pecked by jackdaws and magpies were a probable source of human campylobacter infection. during april to june 1990 an extended study of campylobacter infections was carried out in the gateshead area. prior to the study a health education programme was undertaken in an attempt to reduce human infection. fifty-nine cases of human infection were recorded and 52 were interviewed. thirty were entered into a case control study which demonstrated a very strong assoc ...19911936158
contamination of some avian species with viruses of the leukosis-sarcoma complex.contamination of 8 avian species with leukosis viruses was studied. an insignificant portion of sera from 4 and 24 months old chickens contained neutralizing antibody to 3 sero-types (a, b and d) of rous sarcoma virus (rsv). sera from guinea-fowl reacted positively in the neutralization test only with the rsv-rav-1 strain. none of the peking duck and semi-domestic maran fowl sera was found to contain antibody to rsv strains. twenty-five and 6.6% of embryos derived from 7-8 and 24 to 30 months ol ...1975235202
is caching the key to exclusion in corvids? the case of carrion crows (corvus corone corone).recently, two corvid species, food-caching ravens and non-caching jackdaws, have been tested in an exclusion performance (ep) task. while the ravens chose by exclusion, the jackdaws did not. thus, foraging behaviour may affect ep abilities. to investigate this possibility, another food-caching corvid species, the carrion crow (corvus corone corone), was tested in the same exclusion task. we hid food under one of two cups and subsequently lifted either both cups, or the baited or the un-baited cu ...201121751005
intestinal spirochetes isolated from wild-living jackdaws, hooded crows and rooks (genus corvus): provisionally designated "brachyspira corvi" sp. nov.intestinal spirochetes of genus brachyspira are commonly isolated from mammalian and avian hosts, and several species have been reported to cause enteric disease in pigs and birds. except for a previous publication on three isolates from corvid birds (order passeriformes, family corvidae, genus corvus), of which two are further studied in this paper, no other reports exist on brachyspira spp. of passerine birds. in this study, cloacal and intestinal swabs of small and large intestines were colle ...200818952187
short-term observational spatial memory in jackdaws (corvus monedula) and ravens (corvus corax).observational spatial memory (osm) refers to the ability of remembering food caches made by other individuals, enabling observers to find and pilfer the others' caches. within birds, osm has only been demonstrated in corvids, with more social species such as mexican jays (aphelocoma ultramarine) showing a higher accuracy of finding conspecific' caches than less social species such as clark's nutcrackers (nucifraga columbiana). however, socially dynamic corvids such as ravens (corvus corax) are c ...200818504626
[ultrastructural study of liver cells from rooks living in ecologically unfavorable areas].the ultrastructure of liver cells was studied in rooks (corvus frugilegus) living in radioactive and chemical contamination areas. the ultrastructure of liver cells from rook as well as jackdaw (corvus monedula) and hooded crow (corvus cornix) (corvidae family) from a conventionally clean area was studied as control. control hepatocytes proved to contain a great number of mitochondria, many of which were swollen and had clear matrix and disorganized cristae. the cristae nearly lacked glycogen an ...201616634429
functional morphology and integration of corvid skulls - a 3d geometric morphometric approach.sympatric corvid species have evolved differences in nesting, habitat choice, diet and foraging. differences in the frequency with which corvid species use their repertoire of feeding techniques is expected to covary with bill-shape and with the frontal binocular field. species that frequently probe are expected to have a relatively longer bill and more sidewise oriented orbits in contrast to species that frequently peck. we tested this prediction by analyzing computed tomography scans of skulls ...200919128499
phylogeographic patterns in widespread corvid birds.intraspecific genetic diversity and phylogeography of corvus corone was investigated using the mitochondrial (mt) control region as a molecular marker. a split into two distinct mt lineages was observed. one represents individuals from a wide geographic range spanning from england to the russian far east (kamchatka), while the other one was found in the primorye and khabarovsk regions (southern parts of russian far east) as well as japan. for comparison, we investigated several widespread palear ...200717920300
when, what, and whom to watch? quantifying attention in ravens (corvus corax) and jackdaws (corvus monedula).complex social life requires monitoring of conspecifics. the amount and focus of attention toward others has been suggested to depend on the social relationships between individuals. yet there are surprisingly few experiments that have tested these assumptions. this study compared attention patterns toward conspecifics in two corvid species, ravens (corvus corax) and jackdaws (corvus monedula). birds were confronted with affiliated and non-affiliated conspecifics engaged in foraging and object m ...200718085921
[peculiarities of the contour feather microstructure in the corvidae family].the results of comparative electron microscope study of the fine structure of the definitive contour feathers often crows species (perisoreus infaustus, garrulus glandarius, cyanopica cyanus, pica pica, podoceus panderi, nucifraga caryocatactes, corvus monedula, c. frugilegus, c. cornix, c. corax) are presented. the results of the research allowed us to conclude that crows, along with the traditional elements of feather architectonics, have a number of species-specific microstructure characteris ...201621870493
what you see is what you get--reloaded: can jackdaws (corvus monedula) find hidden food through exclusion?choice by exclusion, that is, the ability to base the choice of a target on the rejection of potential alternatives, is becoming increasingly interesting for comparative cognition research. recently, ravens have been shown to solve an exclusion task and it had been suggested that this ability might benefit ravens in a food-caching context. to investigate this possibility, the raven study was replicated with a closely related, but noncaching, species, the jackdaw (corvus monedula). in the first t ...201121604851
molecular and morphological investigations of sarcocystis corvusi sp. nov. from the jackdaw (corvus monedula).one type of sarcocyst was found in two of eight investigated jackdaws (corvus monedula) and proposed as sarcocystis corvusi sp. nov. by light microscope, cysts resembled a thick thread and were very long (the largest fragment found amounted to 6 mm) and relatively thin (up to 60 μm). the cyst wall measured <1 μm and seemed smooth. using a computerized image analysis system, knolls, which resembled protrusions, were visible on the wall surface. ultrastructurally, the cyst wall was wavy and reache ...201323269511
test of magnetic sensitivity in seven species of european birds using a cardiac nociceptive conditioning attempt was made to show magnetic sensitivity in seven species of european birds captured during their migration. the test was done on the following species: streptopelia turtur (n=8), streptopelia decaocto (n=2), corvus monedula (n=6); one individual of the following: corvus corone c., turdus philomelos, turdus viscivorus, anas penelope. most of the individuals were first subjected to conditioning to a light stimulus. they were then subjected to differential nociceptive conditioning to 100 p ...197724896432
[the rate of digestive system development during the postnatal period of young corvus monedula l. jackdaws and corvus frugilegus l. rooks (a morphometric study)]. 20064476962
bird attack on milk bottles: possible mode of transmission of campylobacter jejuni to man.a case-control study was carried out to test the hypothesis that the rise in the rate of campylobacter jejuni infection in the brigend area of south wales during may was due to the consumption or handling of milk from bottles that had been attacked by birds. 32 of 36 cases meeting the case definition were interviewed, along with 2 controls per case, matched for age, sex, and area of residence. there were strong associations between campylobacter infection and doorstep delivery of milk bottles, a ...19901978882
[immune response of jackdaw (corvus monedula) to antigens of capillaria resecta (nematoda)-western blotting analysis].biotinylated surface and somatic protein extracts of the nematode capillaria resecta were analysed by sds-page followed by western blotting in order to examine their antigenic character. the antigens were probing with serum of c. resecta naturally infected birds (jackdaws). surface and somatic antigens were recognised by serum igg, iga and igm antibodies. the most intense reactivity of sera was evident with tbs-soluble surface proteins. the present paper has shown that surface proteins of c. res ...200116886412
happy to breed in the city? urban food resources limit reproductive output in western jackdaws.urban areas expand worldwide, transforming landscapes and creating new challenging habitats. some bird species, mainly omnivorous feeding on human waste and cavity nesters, commonly breed in these habitats and are, therefore, regarded as urban-adapted. although urban areas may provide new nesting sites and abundant human waste, the low breeding success found in some of these species suggests that the poor protein content in human waste might limit breeding parameters. we investigated whether the ...201728261449
ontogeny of object permanence in a non-storing corvid species, the jackdaw (corvus monedula).the aim of the present study was to investigate the ontogeny of object permanence in a non-caching corvid species, the jackdaw (corvus monedula). jackdaws are often presented as typical examples of non-storing corvids, as they cache either very little or not at all. we used uzgiris and hunt's scale 1 tasks to determine the age at which the certain stages set in and the final stage of this capacity that is reached. our results show that the lack of food-storing behaviour is not associated with in ...201323161215
a subpopulation of large calbindin-like immunopositive neurones is present in the hippocampal formation in food-storing but not in non-storing species of bird.the avian hippocampal formation (hp) is thought to play a role in the processing of spatial memory related to food-storing behaviour. the hp of two food-storing species (marsh tit (parus palustris) and magpie (pica pica)) and two non-storing species (great tit (parus major) and jackdaw (corvus monedula)) were compared following calbindin-like immunostaining. in the dorsal hippocampal region, both species of food-storing birds had larger calbindin-immunoreactive cells than did the two non-storing ...19938348321
transitive inference in jackdaws (corvus monedula).transitive inference (ti) refers to the cognitive ability to derive relationships between items that have never been presented together before. ti could be a useful tool for individuals living in large social groups, as these are confronted with an increasing number of possible dyadic relationships between group members. through ti, one could potentially identify rank relationships between group members and thereby avoid costly direct agonistic interactions. jackdaws seem ideal candidates to tes ...201323147227
wake analysis of drag components in gliding flight of a jackdaw (corvus monedula) during maintain the quality of the feathers, birds regularly undergo moult. it is widely accepted that moult affects flight performance, but the specific aerodynamic consequences have received relatively little attention. here we measured the components of aerodynamic drag from the wake behind a gliding jackdaw (corvus monedula) at different stages of its natural wing moult. we found that span efficiency was reduced (lift induced drag increased) and the wing profile drag coefficient was increased. b ...201728163873
[heterochronicity in the development of hearing in birds during ontogenesis].studies have been made on the development of hearing in the jackdaw coloeus monedula and sea-gulls larus canus and l. argenatus, by means of recording microphonic component of the cochlear potential under chronic experimental conditions. special attention was paid to changes in the regions of maximum sensitivity of the microphonic component during avian growth. it was shown that the range of the perceived frequencies at the beginning of functioning of the auditory analyser coincides completely w ...2006735600
social dominance in captive jackdaws (corvus monedula).social hierarchy was studied in two flocks (14 and 10 individuals, respectively) of captive jackdaws. parent birds acquired high-ranking positions during the nesting period. outside the breeding season the hierarchy seemed to be stable. males generally dominated females. when the top-ranking male arrived at the feeding place it tended to supplant one of the feeding birds rather than choose an unoccupied site.197724924254
[structure of the epididymis of coloeus monedula (aves, corvidae)]. 19695390612
wild jackdaws' reproductive success and their offspring's stress hormones are connected to provisioning rate and brood size, not to parental neophobia.many species show individual variation in neophobia and stress hormones, but the causes and consequences of this variation in the wild are unclear. variation in neophobia levels could affect the number of offspring animals produce, and more subtly influence the rearing environment and offspring development. nutritional deficits during development can elevate levels of stress hormones that trigger long-term effects on learning, memory, and survival. therefore measuring offspring stress hormone le ...201727838379
responses of urban crows to con- and hetero-specific alarm calls in predator and non-predator zoo enclosures.urban animals and birds in particular are able to cope with diverse novel threats in a city environment such as avoiding novel, unfamiliar predators. predator avoidance often includes alarm signals that can be used also by hetero-specifics, which is mainly the case in mixed-species flocks. it can also occur when species do not form flocks but co-occur together. in this study we tested whether urban crows use alarm calls of conspecifics and hetero-specifics (jackdaws, corvus monedula) differently ...201727796660
wake analysis of aerodynamic components for the glide envelope of a jackdaw (corvus monedula).gliding flight is a relatively inexpensive mode of flight used by many larger bird species, where potential energy is used to cover the cost of aerodynamic drag. birds have great flexibility in their flight configuration, allowing them to control their flight speed and glide angle. however, relatively little is known about how this flexibility affects aerodynamic drag. we measured the wake of a jackdaw (corvus monedula) gliding in a wind tunnel, and computed the components of aerodynamic drag fr ...201626994178
using the relational event model (rem) to investigate the temporal dynamics of animal social dynamics are of fundamental importance in animal societies. studies on nonhuman animal social systems often aggregate social interaction event data into a single network within a particular time frame. analysis of the resulting network can provide a useful insight into the overall extent of interaction. however, through aggregation, information is lost about the order in which interactions occurred, and hence the sequences of actions over time. many research hypotheses relate directly to ...201526190856
pair bond characteristics and maintenance in free-flying jackdaws corvus monedula: effects of social context and season.most birds rely on cooperation between pair partners for breeding. in long-term monogamous species, pair bonds are considered the basic units of social organization, albeit these birds often form foraging, roosting or breeding groups in which they repeatedly interact with numerous conspecifics. focusing on jackdaws corvus monedula, we here investigated 1) the interplay between pair bond and group dynamics in several social contexts and 2) how pair partners differ in individual effort of pair bon ...201525892848
social phenotype extended to communities: expanded multilevel social selection analysis reveals fitness consequences of interspecific social species, fitness consequences are associated with both individual and social phenotypes. social selection analysis has quantified the contribution of conspecific social traits to individual fitness. there has been no attempt, however, to apply a social selection approach to quantify the fitness implications of heterospecific social phenotypes. here, we propose a novel social selection based approach integrating the role of all social interactions at the community level. we extended mul ...201525688567
salient eyes deter conspecific nest intruders in wild jackdaws (corvus monedula).animals often respond fearfully when encountering eyes or eye-like shapes. although gaze aversion has been documented in mammals when avoiding group-member conflict, the importance of eye coloration during interactions between conspecifics has yet to be examined in non-primate species. jackdaws (corvus monedula) have near-white irides, which are conspicuous against their dark feathers and visible when seen from outside the cavities where they nest. because jackdaws compete for nest sites, their ...201424501271
mirror-mark tests performed on jackdaws reveal potential methodological problems in the use of stickers in avian mark-test studies.some animals are capable of recognizing themselves in a mirror, which is considered to be demonstrated by passing the mark test. mirror self-recognition capacity has been found in just a few mammals having very large brains and only in one bird, the magpie (pica pica). the results obtained in magpies have enormous biological and cognitive implications because the fact that magpies were able to pass the mark test meant that this species is at the same cognitive level with great apes, that mirror ...201424475085
role of mental representations in quantity judgments by jackdaws (corvus monedula).the representation of quantity by the preverbal or nonverbal mind is a question of considerable interest in the study of cognition, as it should be generally adaptive to most animals to be able to distinguish quantity. we already know that some primate species and human infants represent and enumerate objects in similar ways. considerable data also exist concerning such abilities in birds. our aim in this study has been to find out whether jackdaws (corvus monedula) are capable of performing rel ...201424060246
the influence of local enhancement on choice performances in african grey parrots (psittacus erithacus) and jackdaws (corvus monedula).being attentive to the behavior of others may be advantageous to gain important information, for example, on the location of food. often, this is achieved through simple local enhancement. however, this is not always beneficial, as it may override cognitive abilities, with negative consequences. grey parrots (psittacus erithacus) and ravens have already succeeded in exclusion tasks, but carrion crows do so only when controlling for local enhancement, and jackdaws (corvus monedula) fail entirely. ...201222866773
ordinality and novel sequence learning in jackdaws.a hallmark of higher cognition is the flexible use of information. this requires an abstract representation of the information. in sequence learning, ordinal position knowledge is seen as a more versatile representation when compared to chaining. here, we assessed which of these mental representations is the most natural and most dominant in jackdaws. two jackdaws (corvus monedula) were trained on 14 separate three-item sequences (triplets), made up of abstract images. on each trial, the three i ...201222570182
recipients affect prosocial and altruistic choices in jackdaws, corvus monedula.other-regarding preferences are a critical feature of human cooperation but to what extent non-human animals exhibit these preferences is a matter of intense discussion. we tested whether jackdaws show prosocial behaviour (providing benefits to others at no cost to themselves) and altruism (providing benefits to others while incurring costs) with both sibling and non-sibling recipients. in the prosocial condition, a box was baited on both the actor's and the recipient's side (1/1 option), wherea ...201222511972
stochastic modeling of length-dependent telomere shortening in corvus was recently shown that, within individuals, longer telomeres shorten at a higher rate. this explorative study deals with a mathematical model of this process. it is a nonlinear differential equation describing length-dependent decrease that can be linked to a poisson process. the model also takes in account telomere shortening due to the end replication problem. parameters are fitted using data from samples of red blood cells of free-living juvenile corvids. the poisson process can be relate ...201121570985
combinatory actions during object play in psittaciformes (diopsittaca nobilis, pionites melanocephala, cacatua goffini) and corvids (corvus corax, c. monedula, c. moneduloides).the playful (i.e., not overtly functional) combination of objects is considered a potential ontogenetic and phylogenetic precursor of technical problem solving abilities, as it may lead to affordance learning and honing of mechanical skills. we compared such activities in 6 avian species: 3 psittaciforms (black-headed caiques, red-shouldered macaws, and goffin cockatoos) and 3 corvids (new caledonian crows, ravens, and jackdaws). differences in the type and frequency of object combinations were ...201525437492
interspecies differences in mixed function oxidase activity in birds: relationship between feeding habits, detoxication activities and organochlorine accumulation.the relationship between feeding habits and interspecies differences in the detoxication ability of the mixed function oxidase (mfo) system was investigated in birds. the role of mfo (particularly aldrin epoxidase activity) in the detoxication/bioaccumulation of organochlorines was also investigated. euriphagic (yellow-legged herring gull (larus cachinnans), black-headed gull (larus ridibundus), jackdaw (corvus monedula), magpie (pica pica) and stenophagic (cormorant (phalacrocorax carbo), coot ...199515091496
telomere shortening and survival in free-living corvids.evidence accumulates that telomere shortening reflects lifestyle and predicts remaining lifespan, but little is known of telomere dynamics and their relation to survival under natural conditions. we present longitudinal telomere data in free-living jackdaws (corvus monedula) and test hypotheses on telomere shortening and survival. telomeres in erythrocytes were measured using pulsed-field gel electrophoresis. telomere shortening rates within individuals were twice as high as the population level ...200919520803
comparative intralimb coordination in avian bipedal locomotion.analyses of how intralimb coordination during locomotion varies within and across different taxa are necessary for understanding the morphological and neurological basis for locomotion in general. previous findings suggest that intralimb proportions are the major source of kinematic variation that governs intralimb coordination across taxa. also, independence of kinematics from habitat preference and phylogenetic position has been suggested for mammals. this leads to the hypothesis that among eq ...201222899525
yolk androgens and the development of avian immunity: an experiment in jackdaws (corvus monedula).maternally derived androgens have been shown to influence offspring phenotype in various ways. in birds, the benefits of prenatal androgen exposure, such as increased competitiveness and accelerated growth in nestlings, have been suggested to be balanced by costs, such as reduced immune function. in this study, we used an integrative approach to examine the influence of yolk androgens on the development of immune function in jackdaw (corvus monedula) nestlings. specifically, we tested whether th ...200919251998
a comparison of four corvid species in a working and reference memory task using a radial maze.birds were tested in an open-room radial maze with learned spatial locations that varied from trial to trial (working memory) and locations that remained spatially stable (reference memory). three of the species, the clark's nutcracker (nucifraga columbiana), pinyon jay (gymnorhinus cyanocephalus), and western scrub jay (aphelocoma coerulescens) store food to varying degrees. the other species, the eurasian jackdaw (corvus monedula) does not. pinyon jays and scrub jays performed better than the ...200011149538
finding missing interactions of the arabidopsis thaliana root stem cell niche gene regulatory network.over the last few decades, the arabidopsis thaliana root stem cell niche (rscn) has become a model system for the study of plant development and stem cell niche dynamics. currently, many of the molecular mechanisms involved in rscn maintenance and development have been described. a few years ago, we published a gene regulatory network (grn) model integrating this information. this model suggested that there were missing components or interactions. upon updating the model, the observed stable gen ...201323658556
[discrimination of muscle time and rhythm in jackdaws]. 19655888489
the annual gonad cycle of the male jackdaw corvus monedulus; quantitative aspects. 195613413926
the annual gonad cycle of the male jackdaw corvus monedulus; qualitative aspects. 195613413925
preferential learning from non-affiliated individuals in jackdaws (corvus monedula).it has been suggested that affiliated social relations may facilitate information transfer between individuals. we here tested this rarely examined hypothesis with juvenile and adult jackdaws (corvus monedula) in three stimulus enhancement tasks, both in a non-food context (experiment 1) and in a food context (experiments 2 and 3). we first show that siblings and pair partners maintain stronger bonded social relations than do non-siblings and non-pair partners. we therefore tested individuals in ...200818674604
food offering in jackdaws ( corvus monedula).food sharing among unrelated same-sex individuals has received considerable interest from primatologists and evolutionary biologists because of its apparent altruistic nature and implications for the evolution of complex social cognition. in contrast to primates, food sharing in birds has received relatively little attention. here we describe three types of food sharing in jackdaws, with the initiative for the transfer either with the receiver or the giver. the latter situation is of particular ...200312743708
gliding flight in a jackdaw: a wind tunnel study.we examined the gliding flight performance of a jackdaw corvus monedula in a wind tunnel. the jackdaw was able to glide steadily at speeds between 6 and 11 m s(-1). the bird changed its wingspan and wing area over this speed range, and we measured the so-called glide super-polar, which is the envelope of fixed-wing glide polars over a range of forward speeds and sinking speeds. the glide super-polar was an inverted u-shape with a minimum sinking speed (v(ms)) at 7.4 m s(-1) and a speed for best ...200111222131
development of hippocampal specialisation in a food-storing bird.previous studies demonstrated that amongst food-storing passerine birds the hippocampal region (dorso-medial cortex) is enlarged relative to the rest of the telencephalon. it has been hypothesised that this hippocampal specialisation is related to the spatial memory requirements of retrieving large numbers of stored items. here we compare the development of the hippocampus in a food-storing and a non-storing corvid, the adults of which differ in relative hippocampal volume. the volume, cell dens ...19938466658
daily distribution of sleep states in the jackdaw, corvus monedula.polygraphic and behavioral studies of the jackdaws corvus monedula have revealed a strong influence of the natural day-night cycle on their daily wakefulness-sleep activity. the jackdaws were behaviorally active during the light part of the photoperiod. the daily distribution of slow wave sleep (sws) was symmetric and that of paradoxical sleep (ps) was asymmetric. the amount of ps was greater in the second half of the night than in the first. short and intermediate length episodes occurred almos ...20033792119
on some trematode parasites from the jackdaw, corvus monedula in britian. 195813575803
[adaptation in propagation of coloeus monedula l]. 200614777152
serologic evidence of west nile virus and usutu virus infections in eurasian coots in the netherlands.west nile virus (wnv) and usutu virus (usuv) are arboviruses that are maintained in enzootic transmission cycles between mosquitoes and birds and are occasionally transmitted to mammals. as arboviruses are currently expanding their geographic range and emerging in often unpredictable locations, surveillance is considered an important element of preparedness. to determine whether sera collected from resident and migratory birds in the netherlands as part of avian influenza surveillance would also ...201728688117
you sound familiar: carrion crows can differentiate between the calls of known and unknown group-living animals, it is adaptive to recognize conspecifics on the basis of familiarity or group membership as it allows association with preferred social partners and avoidance of competitors. however, animals do not only associate with conspecifics but also with heterospecifics, for example in mixed-species flocks. consequently, between-species recognition, based either on familiarity or even individual recognition, is likely to be beneficial. the extent to which animals can distinguish ...201222538713
multi-cored vortices support function of slotted wing tips of birds in gliding and flapping flight.slotted wing tips of birds are commonly considered an adaptation to improve soaring performance, despite their presence in species that neither soar nor glide. we used particle image velocimetry to measure the airflow around the slotted wing tip of a jackdaw (corvus monedula) as well as in its wake during unrestrained flight in a wind tunnel. the separated primary feathers produce individual wakes, confirming a multi-slotted function, in both gliding and flapping flight. the resulting multi-core ...201728539482
does oxidative stress shorten telomeres?oxidative stress shortens telomeres in cell culture, but whether oxidative stress explains variation in telomere shortening in vivo at physiological oxidative stress levels is not well known. we therefore tested for correlations between six oxidative stress markers and telomere attrition in nestling birds (jackdaws corvus monedula) that show a high rate of telomere attrition in early life. telomere attrition was measured between ages 5 and 30 days, and was highly variable (average telomere loss: ...201728468913
indeterminate domain protein binding sequences in the 5'-untranslated region and promoter of the scarecrow gene play crucial and distinct roles in regulating scarecrow expression in roots and leaves.scarecrow (scr) and short-root (shr), which belong to the gras transcription factor family, are key regulators of root and leaf growth and development. despite the importance of scr expression for proper plant development, the mechanism of scr regulation has not been clarified. a previous study showed that an indeterminate domain transcription factor, jackdaw (jkd), is essential for the expression of scr in combination with scr and shr. in this study, we characterized possible binding sequences ...201728324206
ravens, new caledonian crows and jackdaws parallel great apes in motor self-regulation despite smaller brains.overriding motor impulses instigated by salient perceptual stimuli represent a fundamental inhibitory skill. such motor self-regulation facilitates more rational behaviour, as it brings economy into the bodily interaction with the physical and social world. it also underlies certain complex cognitive processes including decision making. recently, maclean et al. (maclean et al. 2014 proc. natl acad. sci. usa 111, 2140-2148. (doi:10.1073/pnas.1323533111)) conducted a large-scale study involving 36 ...201627152224
social life histories: jackdaw dominance increases with age, terminally declines and shortens lifespan.behaviour may contribute to changes in fitness prospects with age, for example through effects of age-dependent social dominance on resource access. older individuals often have higher dominance rank, which may reflect a longer lifespan of dominants and/or an increase in social dominance with age. in the latter case, increasing dominance could mitigate physiological senescence. we studied the social careers of free-living jackdaws over a 12 year period, and found that: (i) larger males attained ...201425100696
reproductive effort accelerates actuarial senescence in wild birds: an experimental study.optimality theories of ageing predict that the balance between reproductive effort and somatic maintenance determines the rate of ageing. laboratory studies find that increased reproductive effort shortens lifespan, but through increased short-term mortality rather than ageing. in contrast, high fecundity in early life is associated with accelerated senescence in free-living vertebrates, but these studies are non-experimental. we performed lifelong brood size manipulation in free-living jackdaws ...201424818237
nestling telomere shortening, but not telomere length, reflects developmental stress and predicts survival in wild birds.developmental stressors often have long-term fitness consequences, but linking offspring traits to fitness prospects has remained a challenge. telomere length predicts mortality in adult birds, and may provide a link between developmental conditions and fitness prospects. here, we examine the effects of manipulated brood size on growth, telomere dynamics and post-fledging survival in free-living jackdaws. nestlings in enlarged broods achieved lower mass and lost 21% more telomere repeats relativ ...201424789893
object caching in corvids: incidence and caching is a paramount model for studying relations between cognition, brain organisation and ecology in corvids. in contrast, behaviour towards inedible objects is poorly examined and understood. we review the literature on object caching in corvids and other birds, and describe an exploratory study on object caching in ravens, new caledonian crows and jackdaws. the captive adult birds were presented with an identical set of novel objects adjacent to food. all three species cached objects, ...201424333834
an essential protein that interacts with endosomes and promotes movement of the short-root transcription factor.plant cells can communicate through the direct transport of transcription factors [1-7]. one of the best-studied examples of this phenomenon is short-root (shr), which moves from the stele cells into the endodermis and root tip of arabidopsis, where it specifies endodermal cell identity and stem cell function, respectively [8-10]. in the endodermis, shr upregulates the transcription factors scarecrow (scr) [2] and jackdaw (jkd), which in turn inhibit movement of shr from the endodermis [11]. alt ...201121924907
jackdaw controls epidermal patterning in the arabidopsis root meristem through a non-cell-autonomous arabidopsis, specification of the hair and non-hair epidermal cell types is position dependent, in that hair cells arise over clefts in the underlying cortical cell layer. epidermal patterning is determined by a network of transcriptional regulators that respond to an as yet unknown cue from underlying tissues. previously, we showed that jackdaw (jkd), a zinc finger protein, localizes in the quiescent centre and the ground tissue, and regulates tissue boundaries and asymmetric cell division b ...201020356954
arabidopsis jackdaw and magpie zinc finger proteins delimit asymmetric cell division and stabilize tissue boundaries by restricting short-root the arabidopsis root, the short-root transcription factor moves outward to the ground tissue from its site of transcription in the stele and is required for the specification of the endodermis and the stem cell organizing quiescent center cells. in addition, short-root and the downstream transcription factor scarecrow control an oriented cell division in ground tissue stem cell daughters. here, we show that the jackdaw and magpie genes, which encode members of a plant-specific family of zinc ...200717785527
psychiatrists' education in psychology: jackdaw or sponge? 19863961038
[attack on a child by a jackdaw]. 196314088852
structure of the shr-scr heterodimer bound to the bird/idd transcriptional factor jkd.the plant-specific gai, rga and scr (gras) family proteins play critical roles in plant development and signalling. two gras proteins, short-root (shr) and scarecrow (scr), cooperatively direct asymmetric cell division and the patterning of root cell types by transcriptional control in conjunction with bird/indeterminate domain (idd) transcription factors, although precise details of these specific interactions and actions remain unknown. here, we present the crystal structures of the shr-scr bi ...201728211915
contagious risk taking: social information and context influence wild jackdaws' responses to novelty and risk.although wild animals increasingly encounter human-produced food and objects, it is unknown how they learn to discriminate beneficial from dangerous novelty. since social learning allows animals to capitalize on the risk-taking of others, and avoid endangering themselves, social learning should be used around novel and unpredictable stimuli. however, it is unclear whether animals use social cues equally around all types of novelty and at all times of year. we assessed whether wild, individually ...201627282438
effects of host sex, body mass and infection by avian plasmodium on the biting rate of two mosquito species with different feeding preferences.the transmission of mosquito-borne pathogens is strongly influenced by the contact rates between mosquitoes and susceptible hosts. the biting rates of mosquitoes depend on different factors including the mosquito species and host-related traits (i.e. odour, heat and behaviour). however, host characteristics potentially affecting intraspecific differences in the biting rate of mosquitoes are poorly known. here, we assessed the impact of three host-related traits on the biting rate of two mosquito ...201930867014
the jackdaw series on the history of medicine and science. 19704192893
social learning about dangerous people by wild jackdaws.for animals that live alongside humans, people can present both an opportunity and a threat. previous studies have shown that several species can learn to discriminate between individual people and assess risk based on prior experience. to avoid potentially costly encounters, it may also pay individuals to learn about dangerous people based on information from others. social learning about anthropogenic threats is likely to be beneficial in habitats dominated by human activity, but experimental ...201931598321
arabidopsis bird zinc finger proteins jointly stabilize tissue boundaries by confining the cell fate regulator short-root and contributing to fate specification.plant cells cannot rearrange their positions; therefore, sharp tissue boundaries must be accurately programmed. movement of the cell fate regulator short-root from the stele to the ground tissue has been associated with transferring positional information across tissue boundaries. the zinc finger bird protein jackdaw has been shown to constrain short-root movement to a single layer, and other bird family proteins were postulated to counteract jackdaw's role in restricting short-root action range ...201525829440
free-ranging avifauna as a source of generalist parasites for captive birds in zoological settings: an overview of parasite records and potential for cross-transmission.captive birds in zoological settings often harbor parasites, but little information is available about the potential for free-ranging avifauna to act as a source of infection. this review summarizes the gastrointestinal parasites found in zoo birds globally and in seven common free-ranging avian species [mallard (anas platyrhynchos), eurasian blackbird (turdus merula), common starling (sturnus vulgaris), eurasian jackdaw (corvus monedula), house sparrow (passer domesticus), european robin (erith ...202033005675
comparative analysis of avian hearts provides little evidence for variation among species with acquired endothermy.mammals and birds acquired high performance hearts and endothermy during their independent evolution from amniotes with many sauropsid features. a literature review shows that the variation in atrial morphology is greater in mammals than in ectothermic sauropsids. we therefore hypothesized that the transition from ectothermy to endothermy was associated with greater variation in cardiac structure. we tested the hypothesis in 14 orders of birds by assessing the variation in 15 cardiac structures ...201930667083
gastrointestinal parasites in captive and free-ranging birds and potential cross-transmission in a zoo environment.gastrointestinal parasites are commonly reported in wild birds, but transmission amongst avifauna in zoological settings, and between these captive birds and wild birds in surrounding areas, remains poorly understood. a survey was undertaken to investigate the occurrence of gastrointestinal parasites in captive and free-ranging birds at bristol zoo gardens between may and july 2016. a total of 348 fecal samples from 32 avian species were examined using the mini-flotac flotation method. parasites ...201829517437
population genetics and characterization of campylobacter jejuni isolates from western jackdaws and game birds in finland.poultry are considered a major reservoir and source of human campylobacteriosis, but the roles of environmental reservoirs, including wild birds, have not been assessed in depth. in this study, we isolated and characterized campylobacter jejuni from western jackdaws (n = 91, 43%), mallard ducks (n = 82, 76%), and pheasants (n = 9, 9%). most of the western jackdaw and mallard duck c. jejuni isolates represented multilocus sequence typing (mlst) sequence types (sts) that diverged from those previo ...201930552190
regulation of hormonal control, cell reprogramming, and patterning during de novo root organogenesis.body regeneration through formation of new organs is a major question in developmental biology. we investigated de novo root formation using whole leaves of arabidopsis (arabidopsis thaliana). our results show that local cytokinin biosynthesis and auxin biosynthesis in the leaf blade followed by auxin long-distance transport to the petiole leads to proliferation of j0121-marked xylem-associated tissues and others through signaling of indole-3-acetic acid inducible28 (iaa28), crane (iaa18), woode ...201829233938
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