Publications

immunohistochemical characteristics of cutaneous herbst corpuscles from beak and rictus in domestic pigeon.	herbst corpuscles are the avian equivalent to the mammalian pacinian corpuscles. in this study we used indirect peroxidase-anti peroxidase (pap) immunohistochemistry to analyze the distribution in the pigeon cutaneous herbst corpuscles, of several markers which are known to specifically label the axon, the schwann-related and perineurial-related cells in pacinian corpuscles. the distribution of the assessed antigens on herbst corpuscles was as follows: i) the central axon displayed positive immu ...	1995	8534581
present state of research on house dust mites (pyroglyphidae) in the czech republic.	systematic research on house dust mites in the czech republic started in the early seventies, when mite fauna of human dwellings and distribution of pyroglyphid mites were studied. special attention was paid to old-age-pensioners' homes and children's sanatoria. pyroglyphidae were found also in the city air and in the dust of city pavements, especially in localities with high occurrence of domestic pigeons. while d. pteronyssinus and d. farinae mostly occurred in permanently inhabited flats, eur ...	1995	8553663
[tick-transmitted arbovirus in maghreb].	the problem of arbovirus infections in maghreb has been relatively neglected in the pst in spite of a rich diversity of biotopes, the presence of potential reservoirs and vectors, and their position on the flight path of the palearctic-african bird migration systems, western branch. moreover, west nile virus has been isolated from southern algeria since 1968. from 1979 to 1989, ticks were collected from wild birds, pigeons, bats, rodents, poultry, camels, wild boars, domestic mammals and man, an ...	1995	8555772
serum levels of prolactin and alpha-melanotrophin and structure of the ovary during the reproductive cycle of columba livia (domestic pigeon).	given the importance of the hormones prolactin and alpha-melanotrophin in the regulation of the mammalian reproductive cycle, it was decided to assess their serum levels during the reproductive cycle of columba livia (domestic pigeon). female pigeons were utilized in the stages of egg-laying, incubation and rearing. simultaneously, the structural changes of the ovary in the aforementioned periods were studied. the levels of prolactin and alpha-melanotrophin showed similar behaviour. the low conc ...	1994	8560068
anatomical evidence of a retino-thalamo-hippocampal pathway in the pigeon (columba livia).	the aim of the present study was to demonstrate the existence of a retino-thalamo-hippocampal pathway in the pigeon and, more specifically, to identify its thalamic relay (n. superficialis parvocellularis: spc). fluorescence axonal tracing techniques were used combining the orthograde axonal transport of ritc after its intraocular injection and the retrograde axonal transport of various other fluorescent tracers (fb, fg, eb) injected into the hippocampal complex. since the n.spc has also been sh ...	1995	8568219
borrelia in pigeons: no serological evidence of borrelia burgdorferi infection.	in order to clarify the supposed involvement of urban pigeons (columba livia livia) in the epidemiology of lyme disease, the presence of antibodies against borrelia burgdorferi and borrelia anserina in pigeons' sera, collected in 12 areas of northern and central italy, was evaluated. this evaluation was carried out using a classic immunofluorescence assay (ifa), a surface immunofluorescence assay (sifa) and a standard western blot (wb) assay. a total of 104 out of 3,186 (3.26%) serum samples wer ...	1995	8578924
visual search for natural grains in pigeons (columba livia): search images and selective attention.	the experiments reported here were designed to test the suggestion of many researchers that selective attention to visual features of a prey can account for search-image effects. in 3 experiments pigeons ate wheat and vetch grains presented on multicolored and gray gravel trays. in experiment 1 search-image effects were evident when grains were cryptic but not when they were conspicuous. experiment 2 demonstrated that search images can be activated when the grains encountered are either cryptic ...	1996	8618099
search images: selective attention to specific visual features of prey.	in 3 experiments, pigeons (columba livia) searched a digitized image of a gravel patch on a computer monitor for cryptic grains. experiment 1 demonstrated that the bird's ability to detect a type of grain improved over successive encounters, and detection of alternative targets was attenuated when a search image was active. experiment 2 demonstrated search-image effects independently for the 2 grains. perception was biased to detect wheat grains after wheat encounters and was biased to detect be ...	1996	8618100
operant discrimination learning in detelencephalated pigeons (columba livia).	operant discrimination learning was analyzed in pigeons after massive telencephalic lesions. twenty-one pigeons were divided into three groups: non-lesioned (n = 6), sham-lesioned (n = 5) and telencephalon lesioned (n = 10). lesion surgeries were carried out before any experimental training. learning procedures were run in the same sequence for all groups and under a food deprivation of 80% of the ad libitum weight. successive discrimination was programmed by the alteration of red and yellow lig ...	1995	8634682
centrifugal projections upon the retina: an anterograde tracing study in the pigeon (columba livia).	previous work has shown that the avian retina receives two types of centrifugal fibers from the brain. these types can be distinguished based on the size and the morphology of their terminal endings and have been termed convergent and divergent. the centrifugal fibers arise from the isthmooptic nucleus (ion) and the surrounding ectopic cell region (ecr). we used injections of anterograde tracers either to the ion/ecr or to the ecr only to determine the morphology, depth of termination, and regio ...	1995	8636463
[the morphofunctional characteristics of the interstitial endocrinocytes (leydig cells) of the testes in vertebrates under conditions of seasonal change in reproductive activity].	by means of light and electron microscopy the structural organization of leydig cells was studied in rana ridibunda, lacerta agilis, columba livia in the periods of reproductive activity and reproductive break. the dynamics of structural changes of some parameters of the testicles (interstitial tissue square, endocrinocytes number, state of the cytoplasm, structural components and the volume of nuclei) was shown in the process of the reproductive activity seasonal changes. nuclear volume and the ...	1995	8688941
central projections and somatotopic organisation of trigeminal primary afferents in pigeon (columba livia).	injections of cholera toxin b-chain conjugated to horseradish peroxidase into individual peripheral branches of the trigeminal nerve or into the trigeminal ganglion showed that an ascending trigeminal tract (tta) terminated in distinct ventral and dorsal divisions of the principal sensory nucleus (prvv and prvd, respectively), and a descending tract (ttd) terminated within pars oralis, pars interpolaris, and pars caudalis divisions of the nucleus of ttd (nttd) and within the dorsal horn of the f ...	1996	8725298
projection of the nucleus pretectalis to a retinorecipient tectal layer in the pigeon (columba livia).	the avian optic tectum is composed of at least 15 separate laminae that are distinguishable on the basis of their morphological features and patterns of afferent and efferent connectivity. layer 5b, a major retinorecipient layer, exhibits dense, dust-like, neuropeptide y-positive (npy+) immunoreactive labeling, whereas sparse, larger caliber npy+ fibers are found in laminae 4 and 7. anterograde and retrograde labeling techniques, immunohistochemistry, and retinal lesion studies were used to dete ...	1996	8725349
measurement of circadian rhythms of ocular melatonin in the pigeon by in vivo microdialysis.	ocular melatonin rhythms were measured in pigeons (columba livia) by in vivo microdialysis. the birds were placed in light-dark cycles with 12 h of light and 12 h of darkness (ld12:12) or continuous dim light (lldim) after ld12:12. under ld12:12, melatonin levels were low during the light and high during the dark. the rhythms persisted under lldim with lower levels during the subjective day and higher levels during the subjective night. two hours of light exposure in the middle of the night acut ...	1995	8742471
responsiveness of the glucocorticoid-suppressed pituitary-adrenocortical system of pigeons (columba livia domestica) to stimulation with arginine vasopressin.	this paper reports on the duration of the suppressive effects of single high and low doses of dexamethasone, cortisol, and prednisolone on the pituitary-adrenocortical (pa) system in pigeons. in addition, the effects of long-term daily administration of a high dose of dexamethasone are reported. in expt. 1, low and high doses of dexamethasone (0.5 microgram/kg and 0.5 mg/kg), cortisol (15 micrograms/kg and 1.5 mg/kg), and prednisolone (3.5 micrograms/kg and 3.5 mg/kg) were administered around th ...	1996	8790880
no evidence for diurnal variation in the responsiveness of the pituitary-adrenocortical axis of the pigeon (columba livia domestica) to stimulation with adrenocorticotrophin and vasopressin.	the responsiveness of the pituitary-adrenocortical axis of the pigeon (columba livia domestica) to intravenous administration of high and low doses of adrenocorticotrophic hormone (acth) and following arginine vasopressin (avp) was investigated at two different moments of the diurnal rhythm. administrations of acth and avp were performed at the moment of low plasma corticosterone concentration and during high plasma corticosterone concentration. plasma corticosterone concentrations following adm ...	1996	8790898
effect of subchronic and chronic exposure to 5-hydroxytryptophan (5-htp) on the aggressive behavior induced by food competition in undernourished dominant and submissive pigeons (columba livia).	the acute administration of 5-htp was reported to block in undernourished dominant pigeons the aggressive attacks induced in a submissive partner by food competition. in the present study, undernourished pigeons with previously consolidated dominance were submitted to subchronic and chronic 5-htp treatment. adult males (n = 28) were kept at 80% of their body weight by a restricted diet. these were divided in pairs made of a previously ranked dominant subject (total time spent in aggression highe ...	1996	8800647
effect of the i.c.v. injection of 5,7-di-hydroxytryptamine on the aggressive behavior of dominant and submissive pigeons (columba livia).	the acute and chronic treatment with 5-htp was reported to block the aggressive reaction induced by food competition in undernourished dominant pigeons. such treatment was not effective, however, in submissive pigeons. in this report we describe the effect of the neurotoxine 5, 7-dht on aggression, defense, emotion, feeder control, and other behaviors in dominant and submissive male pigeons maintained at 80% of their normal weight. these were ranked through daily food competition trials. to obta ...	1996	8801602
in ovo 2,3,7,8-tetrachlorodibenzo-p-dioxin exposure in three avian species. 1. effects on thyroid hormones and growth during the perinatal period.	thyroid hormones are important in the perinatal growth and development of avian species, and 2,3,7,8-tetrachlorodibenzo-p-dioxin (tcdd) and related compounds have been shown to cause alterations in these hormones in laboratory animals. since the decreased reproductive success in certain fish-eating bird populations exposed to tcdd and related compounds is characterized by high embryo and hatchling mortality, we examined the effects of in ovo tcdd exposure on plasma thyroid hormone concentrations ...	1996	8806844
in ovo 2,3,7,8-tetrachlorodibenzo-p-dioxin exposure in three avian species. 2. effects on estrogen receptor and plasma sex steroid hormones during the perinatal period.	as opposed to mammals, the heterogametic sex in birds is female, and sexual differentiation of the central nervous system away from the intrinsic male pattern is dependent on ovarian estrogen secretions during the perinatal period. the contamination of aquatic systems with 2,3,7,8-tetrachlorodibenzo-p-dioxin (tcdd) and related compounds has been suggested to be responsible for decreased reproductive success in certain wild fish-eating bird populations. since tcdd has been shown to alter estrogen ...	1996	8806845
in ovo 2,3,7,8-tetrachlorodibenzo-p-dioxin exposure in three avian species	as opposed to mammals, the heterogametic sex in birds is female, and sexual differentiation of the central nervous system away from the intrinsic male pattern is dependent on ovarian estrogen secretions during the perinatal period. the contamination of aquatic systems with 2,3,7,8-tetrachlorodibenzo-p-dioxin (tcdd) and related compounds has been suggested to be responsible for decreased reproductive success in certain wild fish-eating bird populations. since tcdd has been shown to alter estrogen ...	1996	8813006
the relative importance of location and feature cues for homing pigeon (columba livia) goal recognition.	homing pigeons were raised and trained in two lofts that differed with respect to their color features and location in space. during training, pigeons displayed accurate site preference for a particular loft. when tested for loft preference with the feature cues switched between the 2 lofts, the pigeons returned to the loft that occupied the correct location. in a 2nd experiment, pigeons were trained to find food hidden in 1 of 4 color bowls (feature cues) located next to a landmark beacon (prox ...	1996	8851555
bayesian analysis of foraging by pigeons (columba livia).	in this article, the authors combine models of timing and bayesian revision of information concerning patch quality to predict foraging behavior. pigeons earned food by pecking on 2 keys (patches) in an experimental chamber. food was primed for only 1 of the patches on each trial. there was a constant probability of finding food in a primed patch, but it accumulated only while the animals searched there. the optimal strategy was to choose the better patch first and remain for a fixed duration, t ...	1996	8865614
distribution of serotonin-immunoreactivity in the brain of the pigeon (columba livia).	the distribution of serotonin (5-ht)-containing perikarya, fibers and terminals in the brain of the pigeon (columba livia) was investigated, using immunohistochemical and immunofluorescence methods combined with retrograde axonal transport. twenty-one different groups of 5-ht immunoreactive (ir) cells were identified, 2 of which were localized at the hypothalamic level (periventricular organ, infundibular recess) and 19 at the tegmental-mesencephalic and rhombencephalic levels. ten of the cell g ...	1996	8881471
the muscarinic acetylcholine antagonist scopolamine impairs short-distance homing pigeon navigation.	the present study employed intramuscular (i.m.) injections of the acetylcholine (ach) receptor antagonist scopolamine hydrobromide (0.10 mg/kg) to investigate the possible involvement of ach in naturally occurring spatial navigation in homing pigeons (columba livia). control pigeons receiving injections of saline or scopolamine methylbromide, an ach antagonist that does not cross the blood-brain barrier, were oriented in a homeward direction when released from a location 8 km from home. in contr ...	1996	8884933
gabaergic inputs to the nucleus rotundus (pulvinar inferior) of the pigeon (columba livia).	the avian nucleus rotundus, a nucleus that appears to be homologous to the inferior/ caudal pulvinar of mammals, is the major target of an ascending retino-tecto-thalamic pathway. further clarification of the inputs to the rotundus and their functional properties will contribute to our understanding of the fundamental role of the ascending tectal inputs to the telencephalon in all vertebrates, including mammals. we found that the rotundus contains a massive plexus of glutamic acid decarboxylase ...	1996	8906494
excitatory and inhibitory neurotransmitters in the nucleus rotundus of pigeons.	rotundal neurons in pigeons (columba livia) were examined for the effects of glutamate and its agonists nmda and ampa, antagonists cpp and cnqx, as well as of gaba and its antagonist bicuculline, on visual and tectal stimulation-evoked responses. glutamate applied by iontophoresis excited all 48 rotundal cells tested, and this excitation was blocked by cnqx but not by cpp in 98% of cases, with 2% of cells being blocked by either cnqx or cpp. out of 21 cells excited by ampa, 20 were also excited ...	1995	8924406
visually elicited head rotation in pigeons (columba livia).	horizontal rotational head movements were video-taped from pigeons standing freely in a rotating cylinder. the cylinder carried vertically striped patterns approximating a sinusoidally modulated horizontal intensity distribution. we altered systematically various stimulus parameters: spatial wavelength and contrast of the pattern, angular velocity of the pattern motion and mode of motion onset. we found: (1) both gradual acceleration of the patterned cylinder as well as immediate onset of patter ...	1996	8944291
age-related changes in the medullary reticular epithelial cells of the pigeon bursa of fabricius.	the medulla of the avian bursal lymphoid follicles contains heterogeneous cell populations, including the so-called medullary reticular epithelial cells (rec). these cells may contribute to the bursal microenvironment for b-lymphocyte differentiation and maturation. the bursa of fabricius undergoes well-characterized posthatching developmental changes, but the age-related changes of the medullary rec have not been studied. the present study approaches this topic by analyzing hallmarks of epithel ...	1996	8955787
[mallophaga of pigeons in cracow].	infestation of columba livia domestica gmelin with mallophaga has been investigated in both, breeding and feral pigeons. all pigeons came from the area of cracow. five species of mallophaga have been distinguished: columbicola columbae columbae (l.), campanulotes bidentatus compar (burm.), coloceras damicornis fahrenholzi eichler, hohorstiella gigantea lata (piag.), neocolpocephalum (neocolpocephalum) turbinatum (denny). it appeared that the first two of the above-mentioned species showed the hi ...	1996	8967083
[ultrastructural surface properties in columbicola columbae s. str. (esthiopteridae, mallophaga-ischnocera) from domestic pigeons].	all post-embryonal stages of columbicola columbae columbae (l.), the common parasite of pigeon, were investigated with regard to morphology, particularly surface ultrastructures. many qualitative characters differing c. columbae s. str. from the investigated up to now species of mallophaga were found in sem. they are among others double lateral protuberances of head (clavus and clavulus) as well as parallel sculpture of pore organs on the last two segments of antennae. the structures showed at t ...	1996	8967084
nocturnal digestion, cloacal excretion, and digestion-related thermogenesis in pigeons (columba livia).	two indicators of nocturnal digestive activity were identified in pigeons. experiment 1 showed that a sizable amount of food empties from the crop while pigeons are inactive during the night. experiment 2 showed that the number and volume of cloacal droppings during the night were directly related to the volume of food consumed during the day. the temporal pattern of cloacal droppings in the night was systematically related to features of the nocturnal body temperature (tb) curves, suggesting th ...	1997	8976537
molecular characterization of the pigeon p-opsin gene.	the chicken gene encoding pineal gland-specific opsin (p-opsin) has been previously characterized. we report here the orthologous pigeon (columba livia) p-opsin gene. the deduced pigeon p-opsin lacks a potential n-glycosylation site in the n-terminus, but has multiple phosphorylation sites in the c-terminus, which are opposite from the characteristics of the chicken p-opsin.	1996	8982090
pigeons do not complete partly occluded figures.	one of the most common obstacles to object perception is the fact that objects often occlude parts of themselves and parts of other objects. perceptual completion has been studied extensively in humans, and researchers have shown that humans do complete partly occluded objects. in an effort to understand more about the mechanisms underlying completion, recent research has extended the study of perceptual completion to other mammalian species. monkeys and mice also seem to complete two-dimensiona ...	1996	8983050
projections of the dorsomedial nucleus of the intercollicular complex (dm) in relation to respiratory-vocal nuclei in the brainstem of pigeon (columba livia) and zebra finch (taeniopygia guttata).	injections of neuronal tracers were made into the dorsomedial nucleus of the intercollicular complex (dm) of pigeons and zebra finches in order to investigate the projections of this nucleus which has long been implicated in respiratory-vocal control. despite the fact that pigeons are nonsongbirds and zebra finches are songbirds, the projections were very similar in both species. most descended throughout the brainstem, taking ventral and dorsal trajectories, which merged in the medulla. those d ...	1997	8989654
pharmacokinetics and anti-trichomonal efficacy of a dimetridazole tablet and water-soluble powder in homing pigeons (columba livia).	the anti-trichomonal efficacy and pharmacokinetics of dimetridazole were investigated in the homing pigeon (columba livia). dimetridazole was formulated for drinking water medication and as a prolonged-release tablet. to suppress a trichomonas gallinae infection successfully, medicated drinking water containing dimetridazole (400 mg/l) had to be administered for at least 3 days. a two-day treatment with a dimetridazole tablet (20 mg/tablet) in fasted, as well as in fed, pigeons was shown to be i ...	1996	8992028
capacity of birds for transitive inference: the solution of the gillan test by corvids and pigeons.	a system of four to five differentiations forming a series, in which the magnitude of the reinforcement (r) of each succeeding color stimulus was greater than the preceding by one unit, was formed in pigeons (columba livia l.) and crows (corvus corone cornix l.). the number of units of the r that was associated with each of the stimuli increased successively from stimulus pair to stimulus pair from one up to four to five (1st series) and from five to ten (2nd series). after the development of th ...	1996	9000218
mnemonics for variability: remembering food delay.	three experiments with white carneaux pigeons (columba livia) investigated memory and decision processes under fixed and variable reinforcement intervals. response rate was measured during the unreinforced trials in the discrete-trial peak procedure in which reinforced trials were mixed with long unreinforced trials. two decision models differing in assumptions about memory constraints are reviewed. in the complete-memory model (j. gibbon, r.m. church, s. fairhurst, & a. kacelnik, 1988), all int ...	1997	9008863
transcription of lampbrush chromosomes of a centromerically localized highly repeated dna in pigeon (columba) relates to sequence arrangement.	a highly repetitive, centromerically localized dna sequence (pr1) has been isolated from the genomic dna of two species of pigeon (columba livia and c. palumbus). pr1 is approximately 900 bp long. it includes a sequence that is similar to the cenp-b box of mammals. it represents about 5% of the genome in c. livia and 2% in c. palumbus. in both species, tandem arrays of pr1 form part of larger repeating units. the organization of pr1 repeats and the larger repeating units is strikingly different ...	1996	9024976
[detection of doping compounds in the racing pigeon].	to overcome the doping problems in racing pigeons it requires reliable methods to detect illegally medicated drugs. difficulties applying specifically to pigeons caused the present investigation, since urine and blood commonly analyzed cannot be gathered from pigeons. drug detection is complicated by those compounds exhibiting an extremely high potency such as the anabolic boldenone, the glucocorticoid prednisolone, and the bronchodilator clenbuterol. the material for analysis selected was faece ...	1996	9054335
distribution and connections of inspiratory premotor neurons in the brainstem of the pigeon (columba livia).	we have recorded extracellular, inspiratory-related (ir) unit activity in the medulla at locations corresponding to those of neurons retrogradely labeled by injections of retrograde tracers in the lower brachial and upper thoracic spinal cord, injections that covered cell bodies and dendrites of motoneurons innervating inspiratory muscles. bulbospinal neurons were distributed throughout the dorsomedial and ventrolateral medulla, from the spinomedullary junction through about 0.8 mm rostral to th ...	1997	9067829
existence of parvalbumin and biochemical characterization in quail and pigeon skeletal muscles with different fiber type compositions.	the localization of parvalbumin was determined in skeletal muscles with different fiber type compositions from quails (coturnix japonica) and pigeons (columba livia) by sandwich elisa. the biochemical profiles of these muscles were evaluated by the assay of total lactate dehydrogenase (ldh) activity as well as the ldh isozymes for anaerobic metabolism, and by the analysis of myoglobin for aerobic metabolism. the quail fast posterior latissimus dorsi (pld) with a lower myoglobin content and highe ...	1997	9097460
development of the retinotectal system in the pigeon: a cytoarchitectonic and tracing study with cholera toxin.	the optic tectum of the pigeon (columba livia) is marked by morphological dorso-ventral and left-right differences. both features seem to be related to functional specializations, but the responsible developmental mechanisms are unclear. since the visual system becomes functional only after hatching, the developmental processes might be extended into the post-hatching period. the development of the asymmetries in the tectofugal system, however, depends on an asymmetric light stimulation acting a ...	1997	9193729
[appearance of antibodies against borrelia burgdorferi in different populations of pigeons (columba livia var. domestica vel urbana].	borrelia burgdorferi, the causative agent of lyme borreliosis, can infect both mammals and birds. the purpose of the present survey was to determine the presence of antibodies against b. burgdorferi in different populations of pigeons. 1043 sera from pigeons (carrier-, urban-, show-pigeons) were examined by standard serological methods. b.burgdorferi shows crossreaction with b. anserina. therefore all sera were evaluated by ifat and elisa for both borrelia species. the results demonstrate no evi ...	1997	9198966
projections of the nucleus of the basal optic root in pigeons (columba livia) revealed with biotinylated dextran amine.	the nucleus of the basal optic root (nbor) of the accessory optic system is known to be involved in the analysis of the visual consequences of self-motion. previous studies have shown that the nbor in pigeons projects bilaterally to the vestibulocerebellum, the inferior olive, the interstitial nucleus of cajal, and the oculomotor complex and projects unilaterally to the ipsilateral pretectal nucleus lentiformis mesencephali and the contralateral nbor. by using the anterograde tracer biotinylated ...	1997	9259487
the orientation of the e-vector of linearly polarized light does not affect the behaviour of the pigeon columba livia	orientation with reference to the time-compensated sun-azimuth compass has been established for the homing pigeon columba livia. previous qualitative studies claim that pigeons are sensitive to the orientation of a polarizer and it has been suggested that these animals are able to use sky-light polarization as an indirect reference to the sun's position when the latter is shielded from view. we report experiments which were undertaken to quantify the sensitivity of the homing pigeon to the orien ...	1994	9317437
flight kinematics of black-billed magpies and pigeons over a wide range of speeds	to investigate how birds that differ in morphology change their wing and body movements while flying at a range of speeds, we analyzed high-speed (60 hz) video tapes of black-billed magpies (pica pica) flying at speeds of 4-14 m s-1 and pigeons (columba livia) flying at 6-20 m s-1 in a wind-tunnel. pigeons had higher wing loading and higher-aspect-ratio wings compared with magpies. both species alternated phases of steady-speed flight with phases of acceleration and deceleration, particularly at ...	1996	9317775
effects of pineal indoles and parachlorophenylalanine on seasonal reproduction in the pigeon	the effect of melatonin, methoxytryptophol (ml), methoxytryptamine (mt) and parachlorophenylalanine (p-cpa) on the mass and histology of the testes and the adrenal and thyroid glands and on serum thyroid hormone levels have been studied in the recrudescent phase of the feral pigeon columba livia. all the pineal indoles showed a common anti-gonadal effect, resulting in the arrest of spermatogenesis and the degeneration of germ cells. treatment with melatonin resulted in adreno-cortical enlargemen ...	1996	9318563
functional morphology of the vanes of the flight feathers of the pigeon columba livia	the functional morphology of feather vanes was examined by combining morphological examination with mechanical tests. a geometrical model was derived which related the in-plane behaviour of the vane to the orientation of the barbs and barbules. this predicted that the small branching angles of both barbs and proximal barbules should result in a vane which is easier to move distally than proximally. these predictions were verified by mechanical tests on primary and secondary feathers of the pigeo ...	1995	9319072
two distinct populations of tectal neurons have unique connections within the retinotectorotundal pathway of the pigeon (columba livia).	the tectofugal pathway is a massive ascending polysynaptic pathway from the tectum to the thalamus and then to the telencephalon. in birds, the initial component of this pathway is known as the tectorotundal pathway; in mammals, it is known as the tectopulvinar pathway. the avian tectorotundal pathway is highly developed; thus, it provides a particularly appropriate model for exploring the fundamental properties of this system in all amniotes. to further define the connectivity of the tectorotun ...	1997	9335427
incidence of air pollution in the pulmonary surfactant system of the pigeon (columba livia).	the integrity of both pulmonary surfactant and surfactant producing cells, type ii pneumocytes, is essential for normal pulmonary function. almost all studies about air pollution effects on the pulmonary surfactant system have been performed by biochemical techniques, using atmospheric pollutants in a much higher concentration than that found in polluted city air. a comparative study of the number of lamellar bodies (lb) (pulmonary surfactant precursors) from type ii pneumocytes of pigeon lungs ...	1997	9335466
intestinal cryptosporidiosis in pigeons (columba livia).	an intestinal disease in pigeons (columba livia) from the canary islands characterized by diarrhea and body weight loss is described. intestinal cryptosporidiosis was identified in three young pigeons. cryptosporidia were associated with hyperplasia of the intestinal crypts and moderate inflammatory infiltration in lamina propria. this is the first report of cryptosporidiosis in pigeons.	1997	9356726
the contractile properties of the m. supracoracoideus in the pigeon and starling: a case for long-axis rotation of the humerus	wing upstroke in birds capable of powered flight is kinematically the most complicated phase of the wingbeat cycle. the m. supracoracoideus (sc), generally considered to be the primary elevator of the wing, is a muscle with a highly derived but stereotyped morphology in modern flying birds. the contractile portion of the sc arises from a ventral sternum, but its tendon of insertion courses above the glenohumeral joint to insert on the dorsal surface of the humerus. to clarify the role of the sc ...	1997	9359888
habituation to sound during morning and night sessions in pigeons (columba livia).	habituation to acoustic stimulation was analyzed through night and morning sessions in pigeons submitted to a 12:12 h light-dark (ld) cycle. we demonstrate a lack of habituation in nocturnal sessions as compared to typical habituation curves in morning sessions. temporal organization of the habituation process raises issues concerning the biological meaning of sound in adaptation to the environment and/or the possible interaction of well known endogenous physiological rhythms with learning. a se ...	1997	9383103
goal recognition and hippocampal formation in the homing pigeon (columba livia).	stimulus control of food-site recognition and role of the hippocampal formation (hf) were investigated. control and hf-lesioned pigeons were trained to find food located in a colored bowl, near a landmark beacon, in a constant room location. during later test trials, the sources of information were individually removed and/or disassociated. for all test trial types, hf-lesioned pigeons consistently chose bowls associated with one of the training stimuli. controls were more sensitive to the chang ...	1997	9438793
thermal control of metabolic cold defence in pigeons columba livia	metabolic rate (mr) and various body temperatures were recorded in pigeons columba livia during gradual lowering of the ambient temperature (ta) and during cold exposure (-10 degrees c) for an entire circadian cycle. the aim was to study how changes in mr accorded with the observed body temperature displacements and our knowledge of regional cold sensitivity. when ta was lowered from 28 to -10 degrees c, the threefold increase in mr was accompanied by a significant increase in deep-body and spin ...	1998	9464960
some bacterial enteropathogens in wildlife and racing pigeons from trinidad.	fecal and cloacal swabs or feces of wild mammalian, avian and reptilian species, either farmed or free-ranging, and of racing pigeons (columba livia) kept in lofts were cultured for salmonella spp., campylobacter spp., and yersinia spp. of 291 free-ranging mammals tested, 6 (2%) and 1 (< 1%) yielded positive cultures of salmonella spp. and campylobacter spp., respectively. salmonella newport was the predominant serotype isolated and the opossum (didelphis marsupialis insularis) had the significa ...	1998	9476228
receptive field properties of visual neurons in the avian nucleus lentiformis mesencephali.	the receptive field (rf) properties of visual neurons extracellularly recorded from the nucleus lentiformis mesencephali (nlm) in pigeons (columba livia) were quantitatively analyzed using a workstation computer. these cells were actively spontaneous, and direction-and velocity-selective. using spatial gratings as visual stimuli, these cells could be divided into three groups: uni- (74%), bi- (17%), and omnidirectional (9%) cells in terms of their directionality. on the basis of their velocity s ...	1998	9547098
coxiellosis in domestic and wild birds from japan.	serological evidence of infection with coxiella burnetii was found in 41 (2%) of 1,951 domestic birds and in 167 (19%) of 863 wild birds from 17 and 5 prefectures in japan, respectively, by microagglutination (ma) test. the bacteriological evidence of the infection was found in 17 (41%) of 41 domestic birds and 37 (22%) of 167 wild birds by the nested polymerase chain reaction (pcr). in addition, c. burnetii was isolated from five each of serum, spleen and fecal specimens from five jungle crows ...	1998	9577778
visual pigments and oil droplets from six classes of photoreceptor in the retinas of birds.	microspectrophotometric examination of the retinal photoreceptors of the budgerigar (shell parakeet), melopsittacus undulatus (psittaciformes) and the zebra finch, taeniopygia guttata (passeriformes), demonstrate the presence of four, spectrally distinct classes of single cone that contain visual pigments absorbing maximally at about 565, 507, 430-445 and 360-380 nm. the three longer-wave cone classes contain coloured oil droplets acting as long pass filters with cut-offs at about 570, 500-520 a ...	1997	9578901
lead concentration in the bones of the feral pigeons (columba livia): sources of variation relating to body condition and death.	this paper reports on lead concentrations in the tarsometatarsi of 84 individuals of adult feral pigeons columba livia found dead or experimentally captured in bratislava, slovakia. the interrelationships between lead concentrations and time of death, place of death, body measurements, sex, condition, and plumage phenotype were investigated. size and shape of pigeons was not correlated with bone lead contamination. sex and plumage color and pattern were slightly associated with variation in bone ...	1998	9601922
drug discrimination history: pigeons trained to discriminate opioids with activity at different receptor types.	in pigeons (columba livia; n = 5) trained to discriminate the mu (mu) opioid butorphanol from saline, various mu (morphine, fentanyl) but not kappa (kappa; bremazocine, u50,488, u69,593) opioids produced at least 80% drug-appropriate responding. subsequently, pigeons were retrained to discriminate the kappa opioid bremazocine from saline; in this condition, both mu and kappa opioids produced at least 80% drug-appropriate responding, naloxone was more potent as an antagonist of the butorphanol st ...	1998	9608345
bionomics and laboratory transmission of haemoproteus columbae kruse by pseudolynchia canariensis maquart (diptera: hippoboscidae) to two bird hosts in egypt.	pseudolynchia canariensis succeeded to feed and survive normally on both streptopelia senegallus and s. turtur. the feeding period, blood meal ratio and longevity of both male and female flies did not differ significantly (p > 0.05) from the corresponding values for the natural host columba livia. infection of s. senegallus with haemoproteus columbae through flies bites, injection with either infected salivary glands suspension or infected macerated lung tissue of c. livia revealed a high parasi ...	1998	9617043
role of pseudolynchia canariensis in the transmission of haemoproteus turtur from the migrant streptopelia turtur to new bird hosts in egypt.	pseudolynchia canariensis flies offered the naturally infected migrant dove streptopelia turtur with haemoproteus turtur succeeded to induce weak infection in the raised streptopelia turtur only. intraperitoneal, intramuscular and subcutaneous injection of their salivary glands together with intraperitoneal injection of macerated lung and liver tissues of infected doves revealed the appearance of low and moderate grade parasitaemia in s. senegallus and the raised s. turtur. flies offered laborat ...	1998	9617059
starvation induced hypothyroidism involves perturbations in thyroid superoxide-sod system in pigeons.	this study investigated the influence of starvation over seven days on avian thyroidal superoxide radical levels and superoxide dismutase activity profiles in the indian rock pigeon columba livia intermeida, in relation with iodine metabolism. the serum thyroid hormone profile was assayed to correlate the thyroidal redox status with the circulating thyroid hormone levels. the spin-trapping results suggest a role for thyroidal superoxide anion (o2.-) in causing a hypothyroid state in pigeons duri ...	1998	9635131
[comparative investigations on inhalation anesthesia with isoflurane (forene) and sevoflurane (sevorane) in racing pigeons (columba livia gmel., 1789, var. domestica) and presentation of a reference anesthesia protocol for birds].	a conventional inhalation anaesthesia using an isoflurane and sevoflurane-oxygen-nitrous oxide-mixture was performed in each six domestic pigeons (columbia livia gmel., 1789, var. domestica). over a period of 60 minutes routine anaesthetic monitoring including reflex score (12 reflexes, cloacal body temperature and pulse oximetry) was performed. for anaesthesia maintainance 4.0 +/- 0.3 vol. % sevoflurane compared to 2.0 +/- 0.2 vol. % isoflurane were used. the induction period using sevoflurane ...	1998	9646418
identification of two y-box binding proteins that interact with the promoters of columbid annexin i genes.	two annexin i (anxi) genes, called cp35 and cp37, are expressed from the pigeon (columba livia) genome, but they are regulated differently at both the transcriptional and post-transcriptional levels. the proximal promoter elements of these two genes are very similar. a conserved sequence from the cp35 and cp37 promoters bound specifically with proteins present in cropsac cell extracts. this sequence of dna was used to screen a lambdagt11 cdna expression library. clones encoding two pigeon y-box ...	1998	9651510
morphological and immunohistochemical considerations on the basal ganglia in pigeon (columba livia).	morphological and immunohistochemical studies carried out particularly around the level of the basal ganglia (bg) in birds, are reported and commented on. our results showed, on paraffin embedded avian bg, both the histological features and the immunohistochemical findings on immunofluorescence distribution of some neuropeptides (especially metenkephalin) in the striatal complex. by comparing our results of metenkephalin immunoreactivity (menkir) with the referred analogous ones of substance p ( ...	1998	9652145
glutamatergic neurotransmission from the optic tectum to the contralateral nucleus rotundus in pigeons.	neuronal responses of 114 cells to electrical stimulation of the optic tectum were extracellularly recorded from the contralateral nucleus rotundus (nrt) in pigeons (columba livia), and the effects of two glutamatergic antagonists cnqx and cpp, as well as those of gaba, were examined on rotundal cells. the results show that tectal stimulation evokes excitation in neurons of the contralateral nrt and that the excitatory responses are blocked by microiontophoretically applied cnqx, cpp and gaba. i ...	1998	9667809
pharmacokinetics and efficacy of amoxycillin in the treatment of an experimental streptococcus bovis infection in racing pigeons (columba livia).	the pharmacokinetics of amoxycillin in pigeons (columba livia) and the efficacy of amoxycillin treatment in pigeon streptococcosis, were investigated. after intravenous administration of 150 mg.kg-1 amoxycillin, the drug plasma concentration-time profile fitted an open two-compartment model. amoxycillin was quickly cleared from the circulation with a mean half-life of 66 min and showed a distribution volume of 0.9 l.kg-1. the absolute oral bioavailability of amoxycillin was 50.1%. a 5-day drinki ...	1998	9691852
do female pigeons trade pair copulations for protection?	male pigeons, columba livia, employ intense mate guarding and frequent copulation apparently as strategies to ensure their paternity. the aim of this study was to investigate the benefits to females of mate guarding by males and frequent copulation. field observations showed that females initiated the majority of copulations and females that solicited copulations more frequently were guarded more closely by their partner. experimental removal of guarding male partners showed that: (1) unguarded, ...	1998	9710482
expression of myosin heavy chain isoforms during development of domestic pigeon pectoralis muscle.	the pectoralis muscle of birds provides virtually all the power for the downstroke of the wing during flight. in adults it consists almost entirely of fog (fast-twitch oxidative-glycolytic) and/or fg (fast-twitch glycolytic) fiber types. the aims of this study are to contrast myhc (myosin heavy chain) transitions occurring within avian fg and fog fibers during development, and to test the hypothesis that the pectoralis matures before the acquisition of flight. pectoralis was obtained from pigeon ...	1998	9712520
furadan sp50 induced haematological responses of blue-rock pigeon, columba livia gmelin.		1998	9724351
in vivo and in vitro sensitivity of trichomonas gallinae to some nitroimidazole drugs.	a study was carried out in order to establish the in vivo efficacy of two nitroimidazole drugs against the flagellate trichomonas gallinae. the results obtained showed a high proportion of therapeutic failures. thus, carnidazole and dimetridazole failed to eliminate infection in 13 of 17 and 20 of 21 racing pigeons, respectively. the in vitro susceptibility of four t. gallinae isolates to five nitroimidazolic drugs, that is, carnidazole, dimetridazole, metronidazole, ornidazole and ronidazole, w ...	1998	9786623
in vivo strains in pigeon flight feather shafts: implications for structural design	to evaluate the safety factor for flight feather shafts, in vivo strains were recorded during free flight from the dorsal surface of a variety of flight feathers of captive pigeons (columba livia) using metal foil strain gauges. strains recorded while the birds flew at a slow speed (approximately 5-6 m s-1) were used to calculate functional stresses on the basis of published values for the elastic modulus of feather keratin. these stresses were then compared with measurements of the failure stre ...	1998	9787125
vigilance states and body temperature during the circadian cycle in fed and fasted pigeons (columba livia).	fasting induces nocturnal hypothermia in pigeons. slow-wave sleep (sws) and paradoxical sleep (ps) are associated with reduced heat production in pigeons. the possibility that fasting-induced nocturnal hypothermia is related to increased sws and ps was examined by comparing body temperature (tb) and vigilance states when pigeons were fed and fasted. the results showed that when tb is decreasing near the beginning of the dark phase, the percentage of total recording time (%trt) spent in sws and p ...	1998	9791092
[reaction of melanocytes in vertebrate retina to the exposure to constant magnetic field].	the influence of a constant magnetic field (strain 40 ka/m) on retina pigmentary cells of grass frog (rana temporaria) and grey pigeon (columba livia) eyes was investigated. changes in the number and length of melanocytes appendixes were noticed accompanied by formation of thickenings in which melanosomes sized from 0.1 to 0.5 micron are moving. it is established that magnetic properties of eye retina pigmentary cells depend on the presence of fe3+ in melanin. a theoretical model of paramagnetic ...	1998	9793181
how to stay cool in a hot desert--a lesson from the rock pigeon.	this review presents an overview of the puzzle called "cutaneous water evaporation (cwe) cooling mechanism" in birds. heat acclimation of the rock pigeon induces cellular modifications that affect the myocardium, cutaneous vasculature, and the epidermis, and hence enable the initiation of cwe. these cells are the targets for adrenergic signals that participate in the mechanism that controls the initiation and intensity of cwe. as a result the cardiac performance of the heat acclimated pigeon is ...	1998	9793801
pigs in space: spatial memory and its susceptibility to interference.	this study provided basic information about spatial memory in the domestic pig, sus scrofa and examined how susceptible it is to disruption by environmental stimuli. eight male pigs were tested individually in a foraging arena. each day, they entered the arena to search for food randomly located in one of 10 enclosed areas (search trial). after finding and eating the food, they were removed from the arena for a retention interval, and then allowed back in to relocate the food in the same area as ...	1997	9794774
in vivo pectoralis muscle force-length behavior during level flight in pigeons (columba livia)	for the first time, we report in vivo measurements of pectoralis muscle length change obtained using sonomicrometry combined with measurements of its force development via deltopectoral crest strain recordings of a bird in free flight. these measurements allow us to characterize the contractile behavior and mechanical power output of the pectoralis under dynamic conditions of slow level flight in pigeons columba livia. our recordings confirm that the pigeon pectoralis generates in vivo work loop ...	1998	9817827
radiographic monitoring of the ossification of long bones in kori (ardeotis kori) and white-bellied (eupodotis senegalensis) bustards.	a serial radiographic study was conducted on eight kori bustard (ardeotis kori) and four white-bellied bustard (eupodotis senegalensis) chicks to determine the pattern of long bone development and to establish radiographic standards for assessing skeletal maturity. the ossification pattern, appearance of secondary ossification centres, and epiphyseal fusion of the long bones in kori and white-bellied bustards were similar to those in houbara bustards (chlamydotis undulata macqueenii), rufous-cre ...	1998	9839896
bioaccumulation of manganese and its toxicity in feral pigeons (columba livia) exposed to manganese oxide dust (mn3o4).	manganese tetroxide (mn3o4) is a product from the combustion of methylcyclopentadienyl manganese tricarbonyl. exposure to high levels of manganese can lead to serious health effects especially to the central nervous and respiratory systems. very few studies on the effects of long-term low level exposure to mn3o4 have been reported. the present study was therefore conducted to examine the bioaccumulation and toxicity of manganese in various organs of feral pigeons (columba livia) when exposed to ...	1998	9841807
trigeminal disynaptic circuit mediating corneal afferent input to m. depressor palpebrae inferioris motoneurons in the pigeon (columba livia).	corneal afferent projections to the trigeminal brainstem nuclear complex (tbnc) and associated structures, as determined by transganglionic transport of various tracers, were found to be predominantly concentrated in two distinct patches in the dorsolateral medulla at periobex levels. one was in the external cuneate nucleus, and the other was in the ventralmost part of the ophthalmic division of the tbnc. the projections of putative second-order neurons in these regions, as determined by injecti ...	1999	9886038
influence of a melatonin implant on the free radical load in avian thyroid and its relation with thyroid hormonogenesis.	the primary aim of this study was to evaluate the effect of melatonin on the oxiradical load in avian thyroid. the superoxide free radicals have been spin trapped by epr spectroscopy in the thyroid gland of indian rock pigeon columbia livia following melatonin implantation for two weeks. melatonin implantation resulted in augmentation in the levels of superoxide radical in the thyroid gland of pigeons with a concomitant decrease in the levels of the total superoxide dismutase activity. this was ...	1998	9891859
characteristics of slow and fast phases of the optocollic reflex (ocr) in head free pigeons (columba livia): influence of flight behaviour.	the effect of behavioural context on the properties of slow and fast phases of the horizontal optocollic reflex (ocr) were investigated in head free pigeons for two situations, i.e.: (i) animals were hung in a harness ('resting condition'); (ii) animals were additionally submitted to a frontal airflow that provoked a flight posture ('flying condition') [bilo and bilo (1983) j. comp. physiol., 153, 111]. a 'transient flight' was also provoked in the 'resting condition' by tapping the breastbone r ...	1999	9987020
therapeutic effects of some antihaematozoal drugs against haemoproteus columbae in domestic pigeons.	three antihaematozoal drugs were tested for the treatment of pigeons naturally infected with haemoproteus columbae. butalex (buparvaquone) was found effective against the parasite either by using the recommended dose (r. d.) or the double (d. d.) dosis. the r. d. of berenil (diminazene aceturate) was not effective while the d. d. reduced the number of gametocytes circulating in the infected blood. triquine was found very toxic to the pigeons both the r. d. and the d. d.	1999	10085582
streptomycin ototoxicity and hair cell regeneration in the adult pigeon utricle.	the purpose of this study was to develop a technique to investigate the regeneration of utricular hair cells in the adult pigeon (columba livia) following complete hair cell loss through administration of streptomycin.	1999	10089957
efferent projections of the ectostriatum in the pigeon (columba livia).	the ectostriatum is a major visual component of the avian telencephalon. the core region of the ectostriatum (ec) receives visual input from the optic tectum through thalamic nuclei. in the present study, the efferent projections of the ectostriatum were investigated by using the anterograde tracers phaseolus vulgaris leucoagglutinin and biotinylated dextran amine. projection patterns resulting from these tracers were confirmed by the retrograde tracer cholera toxin subunit b. when anterograde t ...	1999	10102499
staying in plastic containers interferes with the orientation of clock-shifted homing pigeons.	staying in plastic containers ventilated with natural air during transport and while waiting at the release site was found to affect the initial orientation of pigeons, columba livia f. domestica, that were exposed to a 6-h clock-shift. the deflection from the mean direction of controls was significantly smaller, and the mean vector length was significantly shorter, than that of clock-shifted pigeons transported in conventional wooden cages. this effect was most pronounced when the birds stayed ...	1999	10196061
the social transmission of spatial information in homing pigeons.	we adapted a technique to explore the social transmission of spatial information in homing pigeons columba livia. five demonstrator pigeons were first trained to find a food goal within an indoor arena. this arena consisted of nine lidded cups laid out within a 12x12 grid on the floor. the task was to find the goal cup and flip the lid to obtain the food hidden within. once the demonstrators had reached criterion the experiment proper began. during stage 1 of the experiment, 10 target birds, whi ...	1999	10196063
afferent and efferent connections of the caudolateral neostriatum in the pigeon (columba livia): a retro- and anterograde pathway tracing study.	the avian caudolateral neostriatum (ncl) was first identified on the basis of its dense dopaminergic innervation. this fact and data from lesion studies have led to the notion that ncl might be the avian equivalent of prefrontal cortex (pfc). a key feature of the pfc is the ability to integrate information from all modalities needed for the generation of motor plans. by using antero- and retrograde pathway tracing techniques, we investigated the organization of sensory afferents to the ncl and t ...	1999	10213093
alpha-chloralose immobilization of rock doves in ohio.	to improve capture efficacy of rock doves (columba livia) in nuisance situations, we reevaluated the effectiveness of three dosages (60, 120 and 180 mg/kg) of alpha-chloralose (ac). responses to immobilization using 180 mg/kg ac also were compared in rock doves deprived of food for 16 hr and not food deprived. mean (+/- se) time to first effects (33 +/- 2 min) and mean time to capture (94 +/- 5 min) were significantly less for rock doves receiving 180 mg/kg than for rock doves receiving lower do ...	1999	10231749
equal frequencies of recombination nodules in both sexes of the pigeon suggest a basic difference with eutherian mammals.	the total number of recombination nodules (rns) in the autosomal synaptonemal complexes (scs) is statistically equivalent in oocytes and spermatocytes from the domestic pigeon columba livia. the distribution on rns along the three longest autosomes is also equivalent in oocytes and spermatocytes. the numbers of rns show a linear relationship when plotted against sc length both in oocytes and spermatocytes. on the other hand, the zw pair shows a single and strictly localized rn near the synaptic ...	1999	10231963
visual discrimination in the pigeon (columba livia): effects of selective lesions of the nucleus rotundus.	the nucleus rotundus is a large thalamic nucleus in birds and plays a critical role in many visual discrimination tasks. in order to test the hypothesis that there are functionally distinct subdivisions in the nucleus rotundus, effects of selective lesions of the nucleus were studied in pigeons. the birds were trained to discriminate between different types of stationary objects and between different directions of moving objects. multiple regression analyses revealed that lesions in the anterior ...	1999	10321471
effects of food restriction on food avoidance and risk of acute poisoning of captive feral pigeons from fonofos-treated seeds	fonofos is a highly toxic insecticide to birds that, when used as a cereal seed treatment, has caused mortality of free-living feral pigeons (columba livia). pigeons kept individually under ad libitum feeding conditions in the laboratory do not suffer lethal poisoning because they develop a strong avoidance response to fonofos-treated seed, which restricts consumption to below lethal levels. two laboratory experiments were conducted to assess the role of avoidance in reducing the risk of acute p ...	1999	10341049
shiga toxin-producing escherichia coli o157 in feedlot cattle and norwegian rats from a large-scale farm.	a total of 365 faecal samples from different categories of cattle, 12 samples of untreated slurry, 50 samples of fresh droppings of feral domestic pigeons, 20 samples of fresh droppings of domestic sparrows and stool samples of 19 synanthropic rodents were examined for the presence of escherichia coli by broth enrichment culture and a subsequent immunomagnetic separation. escherichia coli o157 was found in 72 (20%) bovine samples, six (50%) samples of untreated slurry and four (40%) of 10 rats ( ...	1999	10389259
haemoproteus columbae in domestic pigeons in sebele, gaborone, botswana.	mature and immature stages of haemoproteus columbae gametocytes, an avian haemosporidian protozoan parasite were found in 75% of blood smears prepared from 30 healthy domestic pigeons in sebele location, gaborone, botswana. parenteral administration of an immuno-suppressive dose of dexamethasone, lowered the level of parasitaemia, the packed cell volume and the heterophil:lymphocyte ratio in the test pigeons. however, both the dexamethasone-treated and the control pigeons remained clinically nor ...	1999	10396759
distribution and time course of hair cell regeneration in the pigeon utricle.	vestibular and cochlear regeneration following ototoxic insult from aminoglycoside antibiotics has been well documented, particularly in birds. in the present study, intraotic application of a 2 mg streptomycin paste was used to achieve complete vestibular hair cell destruction in pigeons (columba livia) while preserving regenerative ability. scanning electron microscopy was used to quantify hair cell density longitudinally during regeneration in three different utricular macula locations, inclu ...	1999	10416861
shivering thermogenesis in leg and breast muscles of galliform chicks and nestlings of the domestic pigeon.	we studied the ontogeny of shivering thermogenesis in breast and leg muscles of precocial galliforms (domestic fowl, grey partridge, and japanese quail) and the altricial domestic pigeon using electromyography (emg) and indirect calorimetry. galliforms were able to increase heat production by shivering in leg muscles at the youngest age studied (1-2 d). pectorals contributed to heat production from days 7-10 onward, but in the partridge and especially in the fowl, shivering by the pectorals was ...	1999	10438684
neurochemical evidence for at least two regional subdivisions within the homing pigeon (columba livia) caudolateral neostriatum.	the distributions of one neurotransmitter, two neurotransmitter-related substances, and five neuropeptides were examined within the homing pigeon caudolateral neostriatum (ncl). all eight neuroactive substances were found within a tyrosine hydroxylase (th)-dense region that defines the ncl. overall regional variation in the relative density of these substances suggested at least two neurochemically distinct portions of ncl. dorsal ncl contained relatively dense staining for th, choline acetyltra ...	1999	10441234