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Working memory is the cognitive capability to maintain and process information over short periods. Behavioral and computational studies have shown that visual information is associated with working memory performance. However, the underlying neural correlates remain unknown. To identify how visual information affects working memory performance, we conducted behavioral experiments in pigeons (Columba livia) and single unit recordings in the avian prefrontal analog, the nidopallium caudolaterale (NCL). Complex pictures featuring luminance, spatial and color information, were associated with higher working memory performance compared to uniform gray pictures in conjunction with distinct neural coding patterns. For complex pictures, we found a multiplexed neuronal code displaying visual and value-related features that switched to a representation of the upcoming choice during a delay period. When processing gray stimuli, NCL neurons did not multiplex and exclusively represented the choice already during stimulus presentation and throughout the delay period. The prolonged representation possibly resulted in a decay of the memory trace ultimately leading to a decrease in performance. In conclusion, we found that high stimulus complexity is associated with neuronal multiplexing of the working memory representation possibly allowing a facilitated read-out of the neural code resulting in enhancement of working memory performance.

We characterized naturally occurring pigeon herpesvirus (PiHV; Columbid alphaherpesvirus 1) infection in domestic pigeons in California. We retrieved and analyzed 62 pathology reports produced between 1991 and 2014 at the California Animal Health and Food Safety Laboratory System. In 56 of the cases, the diagnosis of PiHV infection was established based on histopathology, either alone (44 cases) or combined with virus isolation (VI; 8), transmission electron microscopy (TEM; 3), or PCR (1); in the remaining 6 cases, the diagnosis was established based on VI (5 cases) or TEM (1) alone. PiHV infection affected 1 system in 34, 2 in 16, and ≥3 systems in 6 cases; data were not available for the remaining 6 cases. Most commonly affected was the digestive system (55 cases), followed by the respiratory tract (5) and lymphoid system (2). The liver (39 cases), crop (17), and esophagus (14) were the organs affected most commonly. Many affected cells often bore single eosinophilic intranuclear inclusion bodies. PiHV infection was a secondary diagnosis or incidental finding in 35 cases. Most (55) cases had 1 (21), or up to 4 (34), other concurrent infections; the most common concurrent infections were pigeon circoviral infection (26), trichomonosis (24), aspergillosis (11), and colibacillosis (10).

We studied object-location binding in pigeons using a sequence learning procedure. A sequence of four objects was presented, one at a time at one of four locations on a touchscreen. A single peck at the object ended the trial, and food reinforcement was delivered intermittently. In Experiment 1, a between-subjects design was used to present objects, locations, or both in a regular sequence or randomly. Response time costs on nonreinforced probe tests on which object order, location order, or both were disrupted revealed sequence learning effects. Pigeons encoded location order when it was consistent, but not object order when it alone was consistent. When both were consistent, pigeons encoded both, and showed evidence of object-location binding. In Experiment 2, two groups of pigeons received training on sequences where the same object always appeared at the same location. For some pigeons a consistent sequence was used while for others sequence order was randomized. Only when sequence order was consistent was object-location binding found. These experiments are the first demonstrations of strong and lasting feature binding in pigeons and are consistent with a functional account of learning.

Морфологічне дослідження філогенетичного напрямку дозволяє визначити екологічну зумовленість у характері розвитку близьких форм і поглиблює їх характеристику. Метою роботи було дослідження селезінки птахів родини Фазанові (курка, перепілка) і Голубові (голуб). Для вирішення завдання з встановлення особливостей морфологічної будови органа були виготовлені гістологічні препарати, зафарбовані гематоксиліном та еозином, проведена їх морфометрія. Мікроскопічна будови селезінки у птахів класів фазанові і голубоподібні характеризувалась наявністю однакових складових: строма і паренхіма. Опорно-скоротливий апарат складався з трабекул і капсули, пульпа поділялась на білу і червону. Однак, кожен вид птахів мав свої гістологічні та морфометричні особливості. У курки виявлялись лише пульпарні трабекули, у перепілки і голуба ще були наявні і капсулярні трабекули. Для селезінки голуба характерною особливістю є об’єднання сполучних трабекул з судинними, в яких розміщувалась велика кількість судин. Лімфоїдна тканина селезінки птахів була переважно структурованою. Однак, у селезінці голуба зустрічалась і неоформлена лімфоїдна тканина неправильних розмірів різної форми. Біла пульпа птахів складалась з лімфоїдних вузликів і периартеріальних лімфоїдних піхв. Додатково у білій пульпі селезінки Куроподібних виявляли еліпсоїди, у голуба вони майже не зустрічалися. У голуба лімфоїдні вузлики переважно розміщувались в підкапсулярній зоні селезінки та нерідко утворювали конгломеровані структури шляхом злиття 3–6 вузликів. Опорно-скоротливий апарат найкраще розвинений у голуба (9 %). Відносна площа білої пульпи найбільша у курки (18,6 %), червоної пульпи – у перепілки (82 %). Даною роботою ми зробили перший крок у з’ясуванні особливостей морфології селезінки птахів різних класів, для детального аналізу наші подальші дослідження будуть спрямовані на вивчення морфофізіології селезінки птахів у віковому та породному аспектах., Morphological study of the phylogenetic direction allows to determine the ecological conditionality in the nature of the development of related forms and deepens their characteristics. The work aimed to study the spleen of birds of the Phasianidae family (chicken, quail) and Columbidae (pigeon). The histological preparations were stained with hematoxylin and eosin. Their morphometry was performed for establishing the features of the morphological structure of the organ. The microscopic structure of the spleen in birds of the pheasant and pigeon classes was characterized by the presence of the same components: stroma and parenchyma. The musculoskeletal system consisted of trabeculae and capsules. The pulp was divided into white and red. However, each species of bird had its own histological and morphometric features. The pulpal trabeculae were found only in chickens. The capsular trabeculae were also present in quails and pigeons. A characteristic feature of the pigeon's spleen is the association of the connecting trabeculae with the vascular ones, in which a large number of vessels were located. The lymphoid tissue of the spleen of birds was predominantly structured. However, in the pigeon's spleen, there was also unformed lymphoid tissue of varying size of various shapes. The white pulp of birds consisted of lymphoid nodules and periarterial lymphoid sheaths. Additionally, ellipsoids were found in the white pulp of the hens' spleen, and they were almost non-existent in pigeons. In pigeons, lymphoid nodules were mainly located in the subcapsular zone of the spleen and often formed conglomerated structures by merging 3–6 nodules. The musculoskeletal system is best developed in pigeons (9 %). The relative area of white pulp is the largest in chickens (18.6 %), red pulp – in quail (82 %).In this work, we have taken the first step in elucidating the features of the morphology of the spleen of birds of different classes, for detailed analysis, our further research will f, Морфологическое исследование филогенетического направления позволяет определить экологическую обусловленность в характере развития близких форм и углубляет их характеристику. Целью работы было исследование селезенки птиц семейства Фазановых (курица, перепел) и Голубиных (голубь). Для решения задачи по установлению особенностей морфологического строения органа были изготовлены гистологические препараты, окрашенные гематоксилином и эозином, проведена их морфометрия. Микроскопическое строение селезенки у птиц классов фазановых и голубеобразных характеризовалось наличием одинаковых составляющих: строма и паренхима. Опорно-сократительный аппарат состоял из трабекул и капсулы, пульпа делилась на белую и красную. Однако, каждый вид птиц имел свои гистологические и морфометрические особенности. У курицы оказывались только пульпарные трабекулы, в перепелки и голубя еще имелись и капсулярные трабекулы. Для селезенки голубя характерной особенностью является объединение соединительных трабекул с сосудистыми, в которых размещалось большое количество сосудов. Лимфоидная ткань селезенки птиц была преимущественно структурированной. Однако, в селезенке голубя встречалась и неоформленная лимфоидная ткань неправильных размеров различной формы. Белая пульпа птиц состояла из лимфоидных узелков и периартериальных лимфоидных влагалищ. Дополнительно в белой пульпе селезенки Курообразных выявлены эллипсоиды, у голубя они почти не встречались. В голубя лимфоидные узелки преимущественно размещались в пидкапсулярний зоне селезенки и нередко образовывали конгломерованные структуры путем слияния 3-6 узелков. Опорно-сократительный аппарат лучше развит у голубя (9%). Относительная площадь белой пульпы крупнейшая в курицы (18,6%), красной пульпы - в перепела (82%). Данной работой мы сделали первый шаг в выяснении особенностей морфологии селезенки птиц разных классов, для детального анализа наши дальнейшие исследования будут направлены на изучение морфофизиологии селезенки птиц в возрастном и породн

Investigation of the negative impacts of stress on reproduction has largely centered around the effects of the adrenal steroid hormone, corticosterone (CORT), and its influence on a system of tissues vital for reproduction-the hypothalamus of the brain, the pituitary gland, and the gonads (the HPG axis). Research on the action of CORT on the HPG axis has predominated the stress and reproductive biology literature, potentially overshadowing other influential mediators. To gain a more complete understanding of how elevated CORT affects transcriptomic activity of the HPG axis, we experimentally examined its role in male and female rock doves (Columba livia). We exogenously administrated CORT to mimic circulating levels during the stress response, specifically 30 min of restraint stress, an experimental paradigm known to increase circulating CORT in vertebrates. We examined all changes in transcription within each level of the HPG axis as compared to both restraint-stressed birds and vehicle-injected controls. We also investigated the differential transcriptomic response to CORT and restraint-stress in each sex. We report causal and sex-specific effects of CORT on the HPG transcriptomic stress response. Restraint stress caused 1567 genes to uniquely differentially express while elevated circulating CORT was responsible for the differential expression of 304 genes. Only 108 genes in females and 8 in males differentially expressed in subjects that underwent restraint stress and those who were given exogenous CORT. In response to elevated CORT and restraint-stress, both sexes shared the differential expression of 5 genes, KCNJ5, CISH, PTGER3, CEBPD, and ZBTB16, all located in the pituitary. The known functions of these genes suggest potential influence of elevated CORT on immune function and prolactin synthesis. Gene expression unique to each sex indicated that elevated CORT affected more gene transcription in females than males (78 genes versus 3 genes, respectively)

Hormones mediate physiological and behavioral changes in adults as they transition into reproduction. In this study, we characterize the circulating levels of five key hormones involved in reproduction in rock doves (Columba livia): corticosterone, progesterone, estradiol, testosterone, and prolactin using univariate and multivariate approaches. We show similar patterns as previous studies in the overall patterns in circulating levels of these hormones, i.e., testosterone (males) and estradiol (females) high during nest-building or egg-laying, prolactin increasing at mid-incubation and peaking at hatching (both sexes), and elevated corticosterone levels in later incubation and early nestling development. In our investigation of hormone co-variation, we find a strong correlation between prolactin and corticosterone across sampling stages and similarities in earlier (early to mid-incubation) compared to later (late incubation to nestling d9) sampling stages in males and females. Finally, we utilized experimental manipulations to simulate nest loss or altered caregiving lengths to test whether external cues, internal timing, or a combination of these factors contributed most to hormone variation. Following nest loss, we found that both males and females responded to the external cue. Males generally responded quickly following nest loss by increasing circulating testosterone, but this response was muted when nest loss occurred early in reproduction. Similar treatment type, e.g., removal of eggs, clustered similarly in hormone space. These results suggest internal drivers limited male response early in reproduction to nest loss. In contrast, circulating levels of these hormones in females either did not change or decreased following nest manipulation suggesting responsiveness to external drivers, but unlike males, this result suggests that reproductive processes were decreasing.

Presentamos nuevos aspectos de la biología reproductiva de la Yerutí Colorada Leptotila rufaxilla, de cinco nidos encontrados entre 2012 y 2014 en un fragmento de bosque de tierras bajas en el suroeste de Brasil. Los nidos con forma simple / plataforma se construyeron a una altura media de 1.90 m sobre el suelo. El tamaño de la puesta fue de dos huevos blancos y elípticos, incubados durante 15 días (basado en tres nidos). Registramos depredación en dos nidos aún en fase de incubación. El peso mínimo al nacer de los pichones fue de 10 g y los polluelos dejaron el nido con una masa media de 56 g. La tasa de crecimiento constante (K) de los pichones fue de 0.40 con una asíntota de crecimiento de 60.7 g. La tasa de supervivencia diaria, Mayfield y el éxito aparente de anidación en el período de incubación fue del 90, 20 y 56%, respectivamente, mientras que en el período de cría fueron todos del 100%. Nuestros datos y el aporte de la ciencia ciudadana mostraron que L. rufaxilla se reproduce durante el año, principalmente en la época de lluvias, tanto en el suroeste de la Amazonia como en otras regiones de ocurrencia.

BackgroundThe process of alternative splicing provides a unique mechanism by which eukaryotes are able to produce numerous protein products from the same gene. Heightened variability in the proteome has been thought to potentiate increased behavioral complexity and response flexibility to environmental stimuli, thus contributing to more refined traits on which natural and sexual selection can act. While it has been long known that various forms of environmental stress can negatively affect sexual behavior and reproduction, we know little of how stress can affect the alternative splicing associated with these events, and less still about how splicing may differ between sexes. Using the model of the rock dove (Columba livia), our team previously uncovered sexual dimorphism in the basal and stress-responsive gene transcription of a biological system necessary for facilitating sexual behavior and reproduction, the hypothalamic-pituitary-gonadal (HPG) axis. In this study, we delve further into understanding the mechanistic underpinnings of how changes in the environment can affect reproduction by testing the alternative splicing response of the HPG axis to an external stressor in both sexes.ResultsThis study reveals dramatic baseline differences in HPG alternative splicing between males and females. However, after subjecting subjects to a restraint stress paradigm, we found a significant reduction in these differences between the sexes. In both stress and control treatments, we identified a higher incidence of splicing activity in the pituitary in both sexes as compared to other tissues. Of these splicing events, the core exon event is the most abundant form of splicing and more frequently occurs in the coding regions of the gene. Overall, we observed less splicing activity in the 3'UTR (untranslated region) end of transcripts than the 5'UTR or coding regions.ConclusionsOur results provide vital new insight into sex-specific aspects of the stress response on the HPG axis

Located on the eastern margin of Eurasia, the Japanese Archipelago hosts a unique modern fauna of terrestrial vertebrates including landbirds which show a high proportion of endemic species/subspecies. Despite its potential importance in taxonomy and biogeography, the Pleistocene landbird fossil record has been scarce on Japanese islands, providing little information on the history of the unique fauna in the region. In this study, fossil remains of non-passeriform landbirds from the Middle–Late Pleistocene (Marine Isotope Stages [MIS] 9 and 5e) of Shiriya, northernmost Honshu Island, Japan, are revised with extensive osteological comparisons. As a result, the presence of at least six non-passeriform landbird species, represented by 71 specimens, was confirmed: Syrmaticus sp., Coturnicini gen. et sp. indet., Columbidae gen. et sp. indet., Apus sp., Haliaeetus sp., and Accipitridae gen. et sp. indet. The Shiriya paleoavifauna is the first substantial Pleistocene landbird fauna reported from the central Japanese islands so far, and suggests that the overall landbird fauna in northern Honshu in the last interglacial period (MIS 5e) was not drastically different from the present one, in contrast to the presence of several extinct land mammals and seabirds in the local fauna. The occurrence of Syrmaticus despite the supposedly colder climate in that time than today suggests that the distribution of modern S. soemmerringii might not be totally defined by climatic factors, but probably affected by a biogeographic barrier at the strait between Honshu and Hokkaido islands.

We've shown that pigeons can integrate separately acquired spatial maps into a cognitive map. Integration requires an element shared between maps. In two experiments using a spatial-search task in pigeons, we test spatial combination rules when no shared element was present during training. In all three experiments, pigeons first learned individual landmark-target maps. In subsequent tests involving combinations of landmarks, we found evidence that landmarks collaborate in guiding spatial choice at test (Experiment 1). In Experiment 2, pigeons were trained on two landmarks with different proximities to the target. On tests on a compound of both landmarks, pigeons showed stronger spatial control by the more proximal landmark, a performance overshadowing effect. Extinction of the proximal landmark shifted spatial control to the non-extinguished distal landmark. This reveals that the performance overshadowing effect was associative in nature, and not due to perceptual or spatial biases. This emphasis on spatial control during performance reflects the emphasis on performance processes that were a major focus in Ralph Miller's lab.

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The subventricular zone (SVZ) is greatly expanded in primates with gyrencephalic cortices and is thought to be absent from vertebrates with three-layered, lissencephalic cortices, such as the turtle. Recent work in rodents has shown that Tbr2-expressing neural precursor cells in the SVZ produce excitatory neurons for each cortical layer in the neocortex. Many excitatory neurons are generated through a two-step process in which Pax6-expressing radial glial cells divide in the VZ to produce Tbr2-expressing intermediate progenitor cells, which divide in the SVZ to produce cortical neurons. We investigated the evolutionary origin of SVZ neural precursor cells in the prenatal cerebral cortex by testing for the presence and distribution of Tbr2-expressing cells in the prenatal cortex of reptilian and avian species. We found that mitotic Tbr2(+) cells are present in the prenatal cortex of lizard, turtle, chicken, and dove. Furthermore, Tbr2(+) cells are organized into a distinct SVZ in the dorsal ventricular ridge (DVR) of turtle forebrain and in the cortices of chicken and dove. Our results are consistent with the concept that Tbr2(+) neural precursor cells were present in the common ancestor of mammals and reptiles. Our data also suggest that the organizing principle guiding the assembly of Tbr2(+) cells into an anatomically distinct SVZ, both developmentally and evolutionarily, may be shared across vertebrates. Finally, our results indicate that Tbr2 expression can be used to test for the presence of a distinct SVZ and to define the boundaries of the SVZ in developing cortices.

Avian trichomonosis, a disease typically caused by the protozoan parasite Trichomonas gallinae , is a well recognized cause of death in many avian species. In California, US, trichomonosis has caused periodic epidemics in Pacific Coast Band-tailed Pigeons ( Patagioenas fasciata monilis). We summarize reported mortality events and investigate ecologic drivers and population impacts associated with epidemic mortality due to trichomonosis in Band-tailed Pigeons. Between 1945 and 2014, 59 mortality events involving Band-tailed Pigeons were reported in California with the number of reported events increasing over time. Estimated mortality for these events was variable, ranging between 10 and 10,000 pigeons. Events were most-frequently reported in Monterey (19%; 11/59) and San Luis Obispo (8%; 5/59) counties. Events often started in January (32%; 9/28) and February (50%; 14/28) and lasted 5-68 d. Impacts of mortality events on pigeon populations were indicated by Breeding Bird Survey and Christmas Bird Count abundance indices, which showed a decline in outbreak years compared to nonoutbreak years. Environmental conditions most associated with outbreak years included higher average temperatures between January and March, the period most associated with mortality events, and lower average precipitation in December just prior to mortality events. In Monterey County, events tended to occur in winters following higher acorn production of coast live oaks ( Quercus agrifolia ) in the fall. Weather and food abundance could be related to increased transmission or enhanced viability of Trichomonas spp. Although estimated mortality due to avian trichomonosis was highly variable across years, cumulative losses were substantial and likely to have a negative impact on population size.

Air pollution, especially haze pollution, is creating health issues for both humans and other animals. However, remarkably little is known about how animals behaviourally respond to air pollution. We used multiple linear regression to analyse 415 pigeon races in the North China Plain, an area with considerable air pollution, and found that while the proportion of pigeons successfully homed was not influenced by air pollution, pigeons homed faster when the air was especially polluted. Our results may be explained by an enhanced homing motivation and possibly an enriched olfactory environment that facilitates homing. Our study provides a unique example of animals' response to haze pollution; future studies are needed to identify proposed mechanisms underlying this effect.

BackgroundPigeons and doves (Columbiformes) are one of the oldest and most diverse extant lineages of birds. However, the nature and timing of the group's evolutionary radiation remains poorly resolved, despite recent advances in DNA sequencing and assembly and the growing database of pigeon mitochondrial genomes. One challenge has been to generate comparative data from the large number of extinct pigeon lineages, some of which are morphologically unique and therefore difficult to place in a phylogenetic context.ResultsWe used ancient DNA and next generation sequencing approaches to assemble complete mitochondrial genomes for eleven pigeons, including the extinct Ryukyu wood pigeon (Columba jouyi), the thick-billed ground dove (Alopecoenas salamonis), the spotted green pigeon (Caloenas maculata), the Rodrigues solitaire (Pezophaps solitaria), and the dodo (Raphus cucullatus). We used a Bayesian approach to infer the evolutionary relationships among 24 species of living and extinct pigeons and doves.ConclusionsOur analyses indicate that the earliest radiation of the Columbidae crown group most likely occurred during the Oligocene, with continued divergence of major clades into the Miocene, suggesting that diversification within the Columbidae occurred more recently than has been reported previously.

Avian trichomonosis, a disease typically caused by the protozoan parasite Trichomonas gallinae , is a well recognized cause of death in many avian species. In California, US, trichomonosis has caused periodic epidemics in Pacific Coast Band-tailed Pigeons ( Patagioenas fasciata monilis). We summarize reported mortality events and investigate ecologic drivers and population impacts associated with epidemic mortality due to trichomonosis in Band-tailed Pigeons. Between 1945 and 2014, 59 mortality events involving Band-tailed Pigeons were reported in California with the number of reported events increasing over time. Estimated mortality for these events was variable, ranging between 10 and 10,000 pigeons. Events were most-frequently reported in Monterey (19%; 11/59) and San Luis Obispo (8%; 5/59) counties. Events often started in January (32%; 9/28) and February (50%; 14/28) and lasted 5-68 d. Impacts of mortality events on pigeon populations were indicated by Breeding Bird Survey and Christmas Bird Count abundance indices, which showed a decline in outbreak years compared to nonoutbreak years. Environmental conditions most associated with outbreak years included higher average temperatures between January and March, the period most associated with mortality events, and lower average precipitation in December just prior to mortality events. In Monterey County, events tended to occur in winters following higher acorn production of coast live oaks ( Quercus agrifolia ) in the fall. Weather and food abundance could be related to increased transmission or enhanced viability of Trichomonas spp. Although estimated mortality due to avian trichomonosis was highly variable across years, cumulative losses were substantial and likely to have a negative impact on population size.

The subventricular zone (SVZ) is greatly expanded in primates with gyrencephalic cortices and is thought to be absent from vertebrates with three-layered, lissencephalic cortices, such as the turtle. Recent work in rodents has shown that Tbr2-expressing neural precursor cells in the SVZ produce excitatory neurons for each cortical layer in the neocortex. Many excitatory neurons are generated through a two-step process in which Pax6-expressing radial glial cells divide in the VZ to produce Tbr2-expressing intermediate progenitor cells, which divide in the SVZ to produce cortical neurons. We investigated the evolutionary origin of SVZ neural precursor cells in the prenatal cerebral cortex by testing for the presence and distribution of Tbr2-expressing cells in the prenatal cortex of reptilian and avian species. We found that mitotic Tbr2(+) cells are present in the prenatal cortex of lizard, turtle, chicken, and dove. Furthermore, Tbr2(+) cells are organized into a distinct SVZ in the dorsal ventricular ridge (DVR) of turtle forebrain and in the cortices of chicken and dove. Our results are consistent with the concept that Tbr2(+) neural precursor cells were present in the common ancestor of mammals and reptiles. Our data also suggest that the organizing principle guiding the assembly of Tbr2(+) cells into an anatomically distinct SVZ, both developmentally and evolutionarily, may be shared across vertebrates. Finally, our results indicate that Tbr2 expression can be used to test for the presence of a distinct SVZ and to define the boundaries of the SVZ in developing cortices.

Air pollution, especially haze pollution, is creating health issues for both humans and other animals. However, remarkably little is known about how animals behaviourally respond to air pollution. We used multiple linear regression to analyse 415 pigeon races in the North China Plain, an area with considerable air pollution, and found that while the proportion of pigeons successfully homed was not influenced by air pollution, pigeons homed faster when the air was especially polluted. Our results may be explained by an enhanced homing motivation and possibly an enriched olfactory environment that facilitates homing. Our study provides a unique example of animals' response to haze pollution; future studies are needed to identify proposed mechanisms underlying this effect.

BackgroundPigeons and doves (Columbiformes) are one of the oldest and most diverse extant lineages of birds. However, the nature and timing of the group's evolutionary radiation remains poorly resolved, despite recent advances in DNA sequencing and assembly and the growing database of pigeon mitochondrial genomes. One challenge has been to generate comparative data from the large number of extinct pigeon lineages, some of which are morphologically unique and therefore difficult to place in a phylogenetic context.ResultsWe used ancient DNA and next generation sequencing approaches to assemble complete mitochondrial genomes for eleven pigeons, including the extinct Ryukyu wood pigeon (Columba jouyi), the thick-billed ground dove (Alopecoenas salamonis), the spotted green pigeon (Caloenas maculata), the Rodrigues solitaire (Pezophaps solitaria), and the dodo (Raphus cucullatus). We used a Bayesian approach to infer the evolutionary relationships among 24 species of living and extinct pigeons and doves.ConclusionsOur analyses indicate that the earliest radiation of the Columbidae crown group most likely occurred during the Oligocene, with continued divergence of major clades into the Miocene, suggesting that diversification within the Columbidae occurred more recently than has been reported previously.

Pathologists and radiologists spend years acquiring and refining their medically essential visual skills, so it is of considerable interest to understand how this process actually unfolds and what image features and properties are critical for accurate diagnostic performance. Key insights into human behavioral tasks can often be obtained by using appropriate animal models. We report here that pigeons (Columba livia)-which share many visual system properties with humans-can serve as promising surrogate observers of medical images, a capability not previously documented. The birds proved to have a remarkable ability to distinguish benign from malignant human breast histopathology after training with differential food reinforcement; even more importantly, the pigeons were able to generalize what they had learned when confronted with novel image sets. The birds' histological accuracy, like that of humans, was modestly affected by the presence or absence of color as well as by degrees of image compression, but these impacts could be ameliorated with further training. Turning to radiology, the birds proved to be similarly capable of detecting cancer-relevant microcalcifications on mammogram images. However, when given a different (and for humans quite difficult) task-namely, classification of suspicious mammographic densities (masses)-the pigeons proved to be capable only of image memorization and were unable to successfully generalize when shown novel examples. The birds' successes and difficulties suggest that pigeons are well-suited to help us better understand human medical image perception, and may also prove useful in performance assessment and development of medical imaging hardware, image processing, and image analysis tools.

Pathologists and radiologists spend years acquiring and refining their medically essential visual skills, so it is of considerable interest to understand how this process actually unfolds and what image features and properties are critical for accurate diagnostic performance. Key insights into human behavioral tasks can often be obtained by using appropriate animal models. We report here that pigeons (Columba livia)-which share many visual system properties with humans-can serve as promising surrogate observers of medical images, a capability not previously documented. The birds proved to have a remarkable ability to distinguish benign from malignant human breast histopathology after training with differential food reinforcement; even more importantly, the pigeons were able to generalize what they had learned when confronted with novel image sets. The birds' histological accuracy, like that of humans, was modestly affected by the presence or absence of color as well as by degrees of image compression, but these impacts could be ameliorated with further training. Turning to radiology, the birds proved to be similarly capable of detecting cancer-relevant microcalcifications on mammogram images. However, when given a different (and for humans quite difficult) task-namely, classification of suspicious mammographic densities (masses)-the pigeons proved to be capable only of image memorization and were unable to successfully generalize when shown novel examples. The birds' successes and difficulties suggest that pigeons are well-suited to help us better understand human medical image perception, and may also prove useful in performance assessment and development of medical imaging hardware, image processing, and image analysis tools.

Objective: to determine the presence of parasites andenterobacteria that are relevant to public health among feralpopulations of Columba livia inhabiting urban areas of theEnvigado municipality, Colombia. Methodology: a descriptivecross-sectional, prospective study in which 40 pigeons weretaken from six different areas. The feathers were assessedto determine ectoparasitic infestation. Likewise, coanal andcloacae swab was conducted and blood samples were takenfrom the axillar veins. Direct examination of feces with salineand iodine solution was performed, the flotation techniquewas used and the Ziehl-Neelsen staining tests were conducted.Haemoparasites were diagnosed with the thick smear method,Wright and Hemacolor® staining. The API 20e® systemwas used for enterobacteria. Descriptive statistic procedureswere carried out along with a correlation analysis betweenhaemoparasites and ectoparasites. Results: Escherichia coli(95%), Haemoproteus spp. (73%), Columbicola columbae(64%), oocysts compatible with Eimeria spp. (55%),Pseudolynchia canariensis (52%), Trichomona spp. (40%),Capillaria spp. (28%), Menopon gallinae (24%), Ascaridiaspp. (8%), and a case of Enterobacter cloacae. Additionally,the presence of Ornithonyssus bursa was detected in the nestsof some of the birds sampled in this study. Discussion: In spiteof the reports of sparse cases of infection in humans found inthe literature, the microorganisms isolated in this study havea low risk of transmission in humans. However, they maybecome a veterinary public health problem since they are apotential source of infection for the urban wildlife with whichthey share water, food and refuge. Conclusion: The mostimportant percentage was that of oocysts compatible withEimeria spp (55%) and enterobacteria such as E. coli (95%).The presence of Ornithonyssus bursa in the nests evidences apotentially zoonotic pathogen responsible for dermatologicallesions in humans., Objetivo: diagnosticar la presencia de parásitos y enterobacterias de importancia en Salud Pública en poblaciones ferales de Columba livia en zonas urbanas del municipio de Envigado, Colombia. Metodología: Estudio descriptivo transversal prospectivo con cuarenta palomas en seis lugares diferentes. Se evaluó plumaje para determinar ectoparásitos, hisopado coanal y cloacal, y muestra de sangre de la vena axilar. Se realizó examen directo con solución salina y yodada; técnica de flotación y tinción de Ziehl-Neelsen. El diagnóstico de hemoparásitos se efectuó mediante método de gota gruesa, coloración de Wright y tinción Hemacolor®. Se utilizó API 20e® para Enterobacterias. Se realizó estadística descriptiva y análisis de correlación entre hemoparásitos y ectoparásitos. Resultados: Escherichia coli (95%), Haemoproteus spp. (73%), Columbicola columbae (64%), ooquistes compatibles con Eimeria spp. (55%), Pseudolynchia canariensis (52%), Trichomona spp. (40%), Capillaria spp. (28%), Menopon gallinae (24%), Ascaridia spp. (8%), y un caso de Enterobacter cloacae. Se identificó la presencia de Ornithonyssus bursa en nidos de algunas de las aves muestreadas. Discusión: Aunque se han presentado reportes de casos eventuales de ellos en personas dentro de la revisión de literatura, los microorganismos aislados tienen un bajo riesgo de transmisión en humanos; sin embargo pueden convertirse en un problema de salud pública veterinaria al ser potenciales fuentes de infección a la fauna silvestre urbana con quienes comparten albergue, fuentes de agua y alimento. Conclusión: El mayor porcentaje fue ooquistes compatibles con Eimeria spp (55%) y enterobacterias como E. coli (95%). Ornithonyssus bursa en las palomeras evidencia la presencia de un patógeno potencialmente zoonótico, causante de lesiones dérmicas en humanos.

De types of modellen van de Engelse kropper en van de Engelse dwergkropper zijn gelijk. Het verschil zit in de afmetingen. De dwerg of pigmy is ongeveer 2/3 van z’n grote broer. Hierbij moet men wel goed bedenken dat een Engelse kropper vrijwel nooit te groot kan zijn en een Engelse dwergkropper vrijwel nooit te klein.

In de meeuwengroep treffen we een groot scala van rassen aan die één gezamenlijk raskenmerk bezitten: zij dragen allen een stropdas, oftewel: een jabot. In verscheidene landen vinden we dit raskenmerk ook terug in de naam van het ras. We zien op tentoonstellingen meeuwen van groot tot klein, met (kogel-) en ronde tot hoekige koppen met vele kleuren en tekeningvariëteiten en afkomstig uit vele -en verre- landen. We blijven hier dicht bij huis en zetten de Antwerpse smierel in de schijnwerper, een attractief ras uit België.

Na een tentoonstellingsverbod van bijna twee maanden kon de Noordshow als eerste grote show gelukkig weer haar poorten openen. De verhuizing vanuit Zuid Laren naar Assen is naar mijn menig een grote vooruitgang. Een mooie grote en ruime hal met goed licht en alle dieren bij elkaar was erg gezellig.

Al eeuwen voor de opkomst van de oosterse beschavingen is de wilde Rotsduif huisdier geworden. De mens zelf hoefde daar weinig moeite voor te doen, want de dieren raakten snel aan de mens gewend, werden steeds tammer en vonden in de menselijke nederzettingen voldoende voedsel en ideale nestgelegenheden.

Op bezoek bij Geert de Vries in Goutum, nog volop actief als keurmeester en fokker van Oosterse meeuwen, die hij inmiddels 60 jaar ononderbroken op zijn hok heeft.

Ze zeggen dat een duif van gerst eten het geel krijgt. Ook wordt er beweerd dat gerst kropontstekingen veroorzaakt bij duiven. Dit artikel gaat over de zin en de onzin die in duivenland de ronde doet, kleine stukjes, waarover ik niet een groot artikel zou schrijven.

Vitaal, slim, eigenwijs en goedvliegend. Dat is de Balear kropper in een notendop. Het Spaanse kropperras verovert de harten van een groeiend aantal Nederlandse duivenliefhebbers, niet zo gek, want het is een leuk ras. Zelf heb ik ze sinds anderhalf jaar en ik ga ze steeds meer waarderen.

Mei 2015, goed geslapen, ontbeten, mooi weer, radiobericht: de duiven van de westenlijn (Clermont in Frankrijk) worden gelost vanaf 7.30 uur. Het wordt blijkbaar een eivolle echte duivendag, want ik ga op hokbezoek bij een absolute grootmeester in de aanverwante sierduivensport.

Binnen de wereld van de sierduiven is de Lahore één van de meest opvallende verschijningen. Niet vanwege een opvallende bouw of een uitgesproken groot of regelmatig voetstuk, niets van dat alles. Nee, het is de uitgesproken tekening die de Lahore tot zo’n bijzondere verschijning maakt, waarbij de fraaie kleuren deze indruk nog versterken.

Via het plaatsje Barchem rijd je over de Lochemse Berg, Lochem binnen. Natuurlijk is deze berg niet de ‘Kwaremont’ of de ‘muur van Gerardsbergen,’ maar er woont wel een bewoner die afkomstig is uit het Vlaamse land, Peter Goossens, geboren en getogen in Vlaanderen. Hoe komt zo’n ‘plezant manneke’ in het noordoosten van de Achterhoek terecht. Het is een heel verhaal, maar dat doet Peter ons dadelijk wel uit de doeken.

De Luzerner kleurduiven komen uit de regio (deelstaat/kanton) Luzern, centraal gelegen in Zwitserland. Het type van Luzerner kleurduiven, ook van de Luzerner goudkraag, wijkt af van het voor kleurduiven gangbare type, maar het zijn ‘echte’ kleurduiven, met veel aandacht voor kleur, tekening en vleugelpatroon. De Luzerner goudkraag is in drie kleurslagen erkend.

De Franse Bagadet. Hoekig, grof, zwaar bespierd en toch zo elegant, een ras dat we niet veel zien op onze shows, maar altijd met enkele trouwe aanhangers in beeld gebleven. De Wrat en Kipduivenclub is trots en zuinig op deze aanhangers en geeft dit prachtige ras de plaats die het verdient.

Kleurduif in optima forma. Figuur zonder toeters en bellen, gemakkelijk te houden, goede ouders, goede vliegers en redelijk vertrouwelijk te krijgen door hen te wennen aan de nabije aanwezigheid van de fokker.

Het seizoen is al enkele weken van start en de duiven van de eigen combinatie (Snijder-Mulder) stonden voor het eerst op weduwschap. Dat was wel te merken, want ze kwamen al een stuk beter. De thermometer haalt nog geen 10 graden als de duiven vertrekken met nogal wat noord in de wind. Als de temperaturen zo tegenvallen dient het eten te worden aangepast voor de duiven. We brengen wat meer ‘warmte’ in het voer, dus wat extra mais erbij voor een betere verzadiging. Moeten de duiven nu ook extra vitamines hebben?

De Nederlandse hoogvlieger is van oorsprong een vliegduif die gehouden werd op de Amsterdamse duivenkasten. Het ras kon uitstekend vliegen en zo rond het midden van de vorige eeuw waren er zelfs mensen die d.m.v. kruisingen b.v. met postduiven de vliegcapaciteiten nog aanzienlijk opvoerden en de duiven met een sierduivenuiterlijk in een soort semipostduiven onderhandse vliegwedstrijden meegaven. Dit was een tijd erg populair en men noemde dat, -in tegenstelling tot de postduiven-, de opgooierij. Die onderhandse wedstrijden hielden van toch wel flinke afstanden.

De ogen zijn de spiegel van de ziel, zo schreef Leonardo Da Vinci en hij had waarschijnlijk in zekere zin gelijk, omdat de twinkeling in iemands ogen soms kan verraden wat er in hem of haar omgaat. Sommige postduivenliefhebbers nemen dit echter veel serieuzer en beweren dat zij aan het oog van een duif kunnen zien of het een potentiële kampioen is. Of het ook een kampioen wordt ligt aan andere factoren, zo beweert men. Daarom kunnen we waarschijnlijk nooit vaststellen of de zogenaamde ‘eye-sign’ theorie ook werkelijk klopt. Wat we wel zeker weten is dat bepaalde oogkleuren op een eenvoudige overerving zijn gebaseerd. De fijnere kleurnuances echter kunnen we vaak niet verklaren en hebben waarschijnlijk meer met de leefomgeving en gezondheidstoestand van het betreffende dier van doen.

The Pacific Coast band-tailed pigeon (Patagioenas fasciata monilis) is a migratory game bird of North America that is at risk for population decline. Epidemics of avian trichomonosis caused by upper digestive tract infection with Trichomonas spp. protozoa in these and other doves and pigeons of the United States are sporadic, but can involve tens of thousands of birds in a single event. Herein, we analyze the role of trichomonosis in band-tailed pigeon mortality and relate spatial, temporal and demographic patterns of parasite transmission to the genetic background of the infecting organism. Infections were most common in adult birds and prevalence was high in band-tailed pigeons sampled at mortality events (96%) and rehabilitation centers (36%) compared to those that were hunter-killed (11%) or live-caught (4%). During non-epidemic periods, animals were primarily infected with T. gallinae Fe-hydrogenase subtype A2, and were less often infected with either T. gallinae subtype A1 (the British finch epidemic strain), T. stableri n. sp. (a T. vaginalis-like species), or Tritrichomonas blagburni n. sp.-like organisms. Birds sampled during multiple epidemics in California were only infected with T. gallinae subtype A2 and T. stableri. The non-clonal etiology of avian trichomonosis outbreaks in band-tailed pigeons and the risk of spill-over to raptor and passerine species highlights the need for additional studies that clarify the host range and evolutionary relationships between strains of Trichomonas spp. in regions of trichomonosis endemicity.

Many studies investigating cue competition have focused on the blocking effect. We investigated the blocking effect with pigeons using a landmark-based spatial search task in both a touchscreen preparation (Exp. 1a) and an automated remote environmental navigation apparatus (Exp. 1b). In Phase 1, two landmarks (LMs: A and Z) appeared on separate trials as colored circles among a row of eight (touchscreen) or six (ARENA) identical response units. Subjects were rewarded for pecking at a target response unit to the right of LM A and to the left of an extraneous LM, Z. During the blocking trials in Phase 2, LM X was presented in compound with a second LM (A) that had been previously trained. On control trials, LM Y was presented in compound with LM B and a target in the same manner as in the trials of AX, except that neither landmark had previously been trained with the target. All subjects were then tested with separate trials of A, X, B, and Y. Testing revealed poor spatial control by X relative to A and Y. We report the first evidence for a spatial-blocking effect in pigeons and additional support for associative effects (e.g., blocking) occurring under similar conditions (e.g., training sessions, spatial relationships, etc.) in 3-D and 2-D search tasks.

Trichomonas gallinae is a ubiquitous flagellated protozoan parasite, and the most common etiologic agent of epidemic trichomonosis in columbid and passerine species. In this study, free-ranging Pacific Coast band-tailed pigeons (Patagioenas fasciata monilis) in California (USA) were found to be infected with trichomonad protozoa that were genetically and morphologically distinct from T. gallinae. In microscopic analysis, protozoa were significantly smaller in length and width than T. gallinae and were bimodal in morphology. Phylogenetic analysis of the ITS1/5.8S/ITS2, rpb1, and hydrogenosomal Fe-hydrogenase regions revealed that the protozoan shares an ancestor with Trichomonas vaginalis, the sexually-transmitted agent of trichomoniasis in humans. Clinical and pathologic features of infected birds were similar to infections with T. gallinae. Evidence presented here strongly support taxonomical distinction of this parasite, which we hereby name Trichomonas stableri n. sp. This work contributes to a growing body of evidence that T. gallinae is not the sole etiologic agent of avian trichomonosis, and that the incorporation of molecular tools is critical in the investigation of infectious causes of mortality in birds.

Many studies investigating cue competition have focused on the blocking effect. We investigated the blocking effect with pigeons using a landmark-based spatial search task in both a touchscreen preparation (Exp. 1a) and an automated remote environmental navigation apparatus (Exp. 1b). In Phase 1, two landmarks (LMs: A and Z) appeared on separate trials as colored circles among a row of eight (touchscreen) or six (ARENA) identical response units. Subjects were rewarded for pecking at a target response unit to the right of LM A and to the left of an extraneous LM, Z. During the blocking trials in Phase 2, LM X was presented in compound with a second LM (A) that had been previously trained. On control trials, LM Y was presented in compound with LM B and a target in the same manner as in the trials of AX, except that neither landmark had previously been trained with the target. All subjects were then tested with separate trials of A, X, B, and Y. Testing revealed poor spatial control by X relative to A and Y. We report the first evidence for a spatial-blocking effect in pigeons and additional support for associative effects (e.g., blocking) occurring under similar conditions (e.g., training sessions, spatial relationships, etc.) in 3-D and 2-D search tasks.

The Pacific Coast band-tailed pigeon (Patagioenas fasciata monilis) is a migratory game bird of North America that is at risk for population decline. Epidemics of avian trichomonosis caused by upper digestive tract infection with Trichomonas spp. protozoa in these and other doves and pigeons of the United States are sporadic, but can involve tens of thousands of birds in a single event. Herein, we analyze the role of trichomonosis in band-tailed pigeon mortality and relate spatial, temporal and demographic patterns of parasite transmission to the genetic background of the infecting organism. Infections were most common in adult birds and prevalence was high in band-tailed pigeons sampled at mortality events (96%) and rehabilitation centers (36%) compared to those that were hunter-killed (11%) or live-caught (4%). During non-epidemic periods, animals were primarily infected with T. gallinae Fe-hydrogenase subtype A2, and were less often infected with either T. gallinae subtype A1 (the British finch epidemic strain), T. stableri n. sp. (a T. vaginalis-like species), or Tritrichomonas blagburni n. sp.-like organisms. Birds sampled during multiple epidemics in California were only infected with T. gallinae subtype A2 and T. stableri. The non-clonal etiology of avian trichomonosis outbreaks in band-tailed pigeons and the risk of spill-over to raptor and passerine species highlights the need for additional studies that clarify the host range and evolutionary relationships between strains of Trichomonas spp. in regions of trichomonosis endemicity.

Trichomonas gallinae is a ubiquitous flagellated protozoan parasite, and the most common etiologic agent of epidemic trichomonosis in columbid and passerine species. In this study, free-ranging Pacific Coast band-tailed pigeons (Patagioenas fasciata monilis) in California (USA) were found to be infected with trichomonad protozoa that were genetically and morphologically distinct from T. gallinae. In microscopic analysis, protozoa were significantly smaller in length and width than T. gallinae and were bimodal in morphology. Phylogenetic analysis of the ITS1/5.8S/ITS2, rpb1, and hydrogenosomal Fe-hydrogenase regions revealed that the protozoan shares an ancestor with Trichomonas vaginalis, the sexually-transmitted agent of trichomoniasis in humans. Clinical and pathologic features of infected birds were similar to infections with T. gallinae. Evidence presented here strongly support taxonomical distinction of this parasite, which we hereby name Trichomonas stableri n. sp. This work contributes to a growing body of evidence that T. gallinae is not the sole etiologic agent of avian trichomonosis, and that the incorporation of molecular tools is critical in the investigation of infectious causes of mortality in birds.

The geographic origins of breeds and the genetic basis of variation within the widely distributed and phenotypically diverse domestic rock pigeon (Columba livia) remain largely unknown. We generated a rock pigeon reference genome and additional genome sequences representing domestic and feral populations. We found evidence for the origins of major breed groups in the Middle East and contributions from a racing breed to North American feral populations. We identified the gene EphB2 as a strong candidate for the derived head crest phenotype shared by numerous breeds, an important trait in mate selection in many avian species. We also found evidence that this trait evolved just once and spread throughout the species, and that the crest originates early in development by the localized molecular reversal of feather bud polarity.

Portret van Jan Kastelein, fokker van Oud-Hollandse meeuwen en roodschild en geelschild duiven.

Het vrij laten vliegen van sierduiven is geen vanzelfsprekendheid meer. Steeds meer fokkers voorzien hun duivenhokken van volières.