Columba Livia Research Articles

Dynamics and development of interhemispheric conflict solving in pigeons

The dominance of one hemisphere for cognitive operations and decision making may be an efficient mechanism solving interhemispheric conflicts. To understand the ecological significance of the so-called metacontrol, we need better knowledge of its frequency and ontogenetic foundations. Since in pigeons, embryonic light experiences influence degree and direction of interhemispheric specialization and communication, it is conceivable that light affects metacontrol mechanisms. We therefore trained pigeons (Columba livia) with and without embryonic light stimulation in a colour discrimination task. Each eye/hemisphere learnt a different set of colours. After training, hemispheric-specific information was put into conflict and the analysis of conflict decision pattern allowed the identification of hemispheric dominance under binocular and monocular viewing conditions. A majority of pigeons displayed individual metacontrol independent of embryonic light experiences though not in the first test session. Reaction times indicate that interhemispheric mechanisms are critically involved in mediating the dominance of one hemisphere. The impact of interhemispheric components rises with increasing experience and even affects decision making under monocular seeing conditions. Overall results indicate that the hemispheres do not evaluate information independently and that interhemispheric communication in the pigeon brain is much stronger than previously thought and becomes more important with increasing experience.

Efficacy of myrrh extract against Eimeria labbeana-like experimental infection in Columba livia domestica: in vivo study

BackgroundThe Protozoan pathogen Eimeria is a significant issue in poultry production. Scientists are concerned with finding alternative strategies due to the spread of resistance against the commonly employed coccidiostats. This study examined how well myrrh extract (MyE) protected domesticated pigeons from an experimental Eimeria labbeana-like infection.MethodsFemale pigeons were divided into six groups (5 pigeons/group): Group1: control pigeon group, Group2: Non-infected and treated pigeon group with MyE (500 mg/kg). Group3: Infected and non-treated pigeon group, Group4: Infected and treated pigeon group with MyE (250 mg/kg), Group5: Infected and treated pigeon group with MyE (500 mg/kg), Group6: Infected and treated pigeon group with amprolium (1 g/L of H2O). Oral infection with 3 × 104 sporulated E. labbeana-like oocysts was used to inoculate groups (3–6). Three days after infection, groups (4–6) received daily treatment with MyE and amprolium for five days. Oocyst output was assessed on day 8 post-infection. After sacrificing the pigeons, the small intestine and blood were collected from each pigeon and processed for histological, biochemical, and oxidative damage examinations.ResultsThis study looked into the overall phenolic and flavonoid contents and MyE’s antioxidant activity. According to the data, the best dose of MyE was 500 mg/kg, which significantly decreased the output of oocysts produced (2.090 × 105 ± 1.04 × 104 oocysts/g.feces). This result has been linked to a -2.51% decrease in the pigeon’s body weight gain. The morphometric characteristics of freshly unsporulated and sporulated oocysts were obtained, and pigeons treated with MyE significantly decreased size. Furthermore, there was a significant decrease in both the number and size of the developmental stages of E. labbeana-like (i.e. meronts, gamonts, and developing oocysts) in the intestinal tissue among the MyE-treated group. MyE facilitates the disruption of intestinal homeostasis caused by E. labbeana-like infection, specifically concerning carbohydrates and proteins. Concurrent with the state of total antioxidant capacity (TAC), the antioxidant activity of MyE reduced the blood plasma levels of trace elements (Fe, Cu, Cr, Zn, and Ni).ConclusionOur findings suggest that MyE could be a useful antioxidant source and a replacement for coccidiostats in preventing and treating avian coccidiosis.

Environmental and social correlates of the plumage color polymorphism in an urban dweller, feral pigeon (Columba livia f. domestica)

We examined how urban environments affect the abundance, proportion, and diversity of plumage color morphs in feral pigeons. Five major plumage color morphs (black, blue, white, red, and mixed) were counted in sixty 25-ha plots in Poznań City (Poland). Generalized additive models were used to study the correlations among abundance, proportion of morphs, and environmental factors. Anthropogenic food sources were positively correlated with the abundance of black morphs and the proportions of black and red morphs. The blue morph abundance peaked at a moderate percentage of tall building cover, but its proportion decreased. A similar decrease was observed in the mixed plumage morphs. The abundance of blue morphs decreased, whereas the abundance of white morphs and the proportion of red morphs increased as the distance from the city center increased. The plumage color morph diversity (Simpson) index was positively correlated with food sources and hedgerow density but negatively correlated with street density. Color morph diversity in the study area may be sustained by differential responses of morphs to the environmental features of the urban environment. However, the positive correlation between the abundance of morphs indicates social attraction rather than social isolation among plumage color morphs.

The quantitative anatomy of the hippocampal formation in homing pigeons and other pigeon breeds: implications for spatial cognition.

Artificial selection for specific behavioural and physical traits indomesticated animals has resulted in a wide variety of breeds. One of the most widely recognized examples of behavioural selection is the homing pigeon (Columba livia), which has undergone intense selection for fast and efficient navigation, likely resulting in significant anatomical changes to the hippocampal formation. Previous neuroanatomical comparisons between homing and other pigeon breeds yielded mixed results, but only focused on volumes. We completed a more systematic test for differences in hippocampal formation anatomy between homing and other pigeon breeds by measuring volumes, neuron numbers and neuron densities in the hippocampal formation and septum across homing pigeons and seven other breeds. Overall, we found few differences in hippocampal formation volume across breeds, but large, significant differences in neuron numbers and densities. More specifically, homing pigeons have significantly more hippocampal neurons and at higher density than most other pigeon breeds, with nearly twice as many neurons as feral pigeons. These findings suggest that neuron numbers may be animportant component of homing behaviour in homing pigeons. Our data also provide the first evidence that neuronal density can be modified by artificial selection, which has significant implications for the study of domestication and interbreed variation in anatomy and behaviour.

Use of anthropogenic landscapes in a wild Columba livia (Rock Dove) population

Abstract Despite the role of many domestic animals as model organisms, our understanding of their undomesticated conspecifics is comparatively poor. This limits our ability to infer the eco-evolutionary context of phenomena studied in the laboratory and to explore domestication. The domestic pigeon’s wild form is the Rock Dove (Columba livia). By studying 5 global positioning system–tagged wild Rock Doves in Scotland’s Outer Hebrides, we present the first individual-level assessment of undomesticated Rock Dove movements, revealing extensive use of anthropogenic habitats in both a roosting and foraging context. This association with humans provides tantalizing opportunities for research into the pre-domestication human–pigeon relationship. More generally, this work highlights the value of researching laboratory model species in nature.

Research on palatability of bait for targeted control of Brandt's vole (Lasiopodomys brandtii) in typical steppes

Chemical control is still the primary means of controlling wild rodent pests in China's grasslands; however current rodenticides are broad-spectrum and pose a risk to several other grassland ecosystems. Improving the precision of grassland rodent pest control and reducing collateral damage to non-target animals is an urgent problem. One solution to this problem is to ensure that bait choices are preferred by specific rodent. However, most studies on the development of rodenticides have neglected bait choice. We focused on Brandt's voles (Lasiopodomys brandtii), the dominant rodent species in the typical steppes of China, in this study. By measuring the percentage of feeding amount (PFA) different baits in a cafeteria setting, we sought to test the palatability of different candidate baits. We found that one of our blend baits was as popular as the wheat bait among Brandt's voles under laboratory conditions. However, our blended bait was preferred to the wheat bait when rodenticide was added. Non-target animals Columba livia, Gallus domesticus, Ovis aries, and sympatric non-target rodents feed less on blended bait than on wheat. We also used field trials to test whether baits were removed by Brandt's voles or PFA of partially consumed baits. In the wild, the removal time and PFA of Brandt's voles for the rodenticide + blend bait were better than those for the rodenticide + wheat bait. Mixing the wheat baits with bromadiolone rodenticide made poisoned baits less attractive to prey species than unpoisoned baits; however, Brandt’s voles were more likely to take the tainted baits than the unpoisoned baits when bromadiolone was added to the blends. Our results suggested that blend bait with 80 % Allium polyrhizum+ 20 % Stipa krylovii was highly palatable to Brandt's voles, did not become less palatable when poisoned with rodenticide, and was less likely to be eaten by non-target species including Columba livia, Gallus domesticus, Cricetulus barabensis, Phodopus campbelli and Ovis aries. Thus, blend bait has the potential to improve the pest management of Brandt's voles in China.

Seasonal diversity, daily use and behaviour of birds using a green roof in a Mediterranean city.

Urban green roofs offer environmental and social benefits and provide resources for urban wildlife; however, how birds use green roofs remains poorly studied in Mediterranean cities. Here, we develop a 1-year study in Madrid, Spain, recording the birds that use both an urban green roof and the adjacent conventional roofs throughout the four seasons. We recorded a total of 17 bird species in the area, of which 8 use the green roof surveyed. The most common species detected in both types of roofs was the feral pigeon (Columba livia), which exploited the green roof permanently, in contrast with the other species observed, which only appeared occasionally. We also found that more species visited the green roof in the central hours of the day and a higher richness of species in the spring. Moreover, we detect that most of the species were residents all year in the area and have granivorous or granivorous-omnivorous feeding habits. The main behaviour observed in the green roof was feeding, while no reproduction of any species was confirmed. We conclude that green roofs offer birds much-needed resources in metropolitan areas, promoting greener, more connected and more biodiverse cities.

Introduction of Chlamydia psittaci into a hospital area by feral pigeons

Pigeons are associated with zoonotic pathogens such as Chlamydia psittaci, the main causative agent of avian chlamydiosis, and related to psittacosis cases in humans worldwide. The aim of the present study was to investigate the occurrence of C. psittaci in feral pigeons (Columba livia) and environmental samples from places frequented by pigeons in a Brazilian hospital area. A cross-sectional study was carried out sampling feral pigeons, their droppings and nest material in a hospital area. Squares in a nearby region with a high density of pigeons were also sampled. Pigeon cloacal swabs (n=123) were collected from each bird, as well as pigeon droppings from the environment (n=77) and material from pigeon's nests (n=28). Chlamydiaceae-PCR targeting the 23S rRNA gene was used as screening. Positive samples were submitted to another PCR targeting the ompA gene of C. psittaci, followed by sequencing and phylogenetic analysis. C. psittaci was detected in 7.5% (17/228) of the samples, 7.3% (12/164) from the hospital area and 7.8% (5/64) from the squares. By sample type, 9.8% (12/123) of the pigeon cloacal swabs, 5.2% of droppings (4/77) and 3.6% of nest material (1/28) were positive for C. psittaci. All sequenced samples corresponded to C. psittaci genotype B. These results demonstrate the occurrence of C. psittaci in urban areas, with emphasis on a hospital area where immunocompromised individuals are present. Adopting a One health approach to prevent the proliferation of the pigeons, health education campaigns and specific recommendations for the hospital administration are essential. Guidance on practices such as not feeding the pigeons, avoiding contact or proximity and removing available areas for roosting and nesting, are measures that will reduce environmental contamination and risk of human exposure to C. psittaci.

Novel zoonotic Enterocytozoon and Encephalitozoon genotypes in domestic pigeons (Columba livia domestica) in Iran: Public health implications

To determine the occurrence of microsporidiosis in domestic pigeons in Iran, privately-owned pigeons presenting weight loss and diarrhea were tested through molecular and histopathological methods. Multiplex-PCR findings showed 57%, 30%, and 14% positivity for Enterocytozoon, Encephalitozoon, and mixed infection in the fecal samples, respectively. A novel Enterocytozoon bieneusi genotype, named IrnEb1, falling into zoonotic group 1 of E. bieneusi, and a novel genotype of Encephalitozoon hellem, named Irn2E, clustering as a sister taxon to genotype 2B were identified in pigeons for the first time using Sanger sequencing and phylogenetic analyses. Histopathological examination revealed the occurrence of non-suppurative enteritis, nephritis, pneumonia, hepatitis, and encephalitis associated with focal necrosis and inflammatory cell infiltration. Data shown herein present a high prevalence of microsporidiosis in pigeons in Iran. Considering that both detected microsporidian species are zoonotic parasites, these findings suggest that the infected pigeons could pose a risk to public health.

Prevalence and Pathology of Endoparasitic Infections of Rock Pigeons (Columba livia) in Taiwan

Prevalence and Pathology of Endoparasitic Infections of Rock Pigeons (Columba livia) in Taiwan

Lead Concentrations in Tissues of Pigeons (Columba livia) in the Urban Area of Comarca Lagunera, Mexico.

The Comarca Lagunera is one of Mexico's most important productive areas. Its main economic activities are livestock, agriculture, and the processing industry. A wide variety of industries emit wastes that are considered highly toxic environmental pollutants, which have strong negative impacts on public health. The objective of this work was to determine the lead concentrations present in tissues of pigeons (Columba livia) belonging to the urban area of the Comarca Lagunera, Mexico. Specimens were collected from the localities that comprise the region and the tissue extracted; the organs were dried, calcined, and diluted in an acidic HCl solution. Lead concentrations were obtained by atomic absorption spectrometry using the graphite furnace technique. The results demonstrate the presence of lead in all the tissues analyzed, with maximum concentrations of 191.14 mg/kg and minimum concentrations of 0.86 mg/kg, the area with the highest average concentration being Torreón, Coahuila (p = 0.030). The organ with the highest concentration was the bone (p = 0.000). Evidence of lead poisoning is presented in Columba livia tissues in the Comarca Lagunera, thus demonstrating the presence of this contaminant and the ability of these pigeons to function as bioindicators of environmental contamination.

Flight initiation distance differs among eumelanin‐based color morphs in feral pigeons

AbstractOrganisms facing anthropogenic activities usually exhibit phenotypic responses assumed to enhance coping with disturbance. These responses include a decreasing degree of reaction toward potentially risky situations (“behavioral tolerance”) with increasing disturbance. Though melanin is associated with many phenotypic traits, including pigmentation and behavior, the potential relationship between behavioral tolerance and melanin has never been explored. Such relationship may potentially result from either direct association between melanin and behavior (e.g., genetic correlation) or indirectly through a coloration‐dependent behavior‐modulating factor (e.g., differential predation or human preferences in cities toward color morphs). Feral pigeons (Columba livia) represent an ideal biological system to test for these hypotheses, due to their presence in cities worldwide, their considerable variation in eumelanin‐based coloration, ranging from white to black plumage, and their close proximity to humans. We measured Flight Initiation Distance (FID, classically used for behavioral tolerance assessment) of feral pigeons of 4 different eumelanin‐based color morphs in sites differing in their urbanization rate and pedestrian traffic within the restricted scale of a city center (Paris). Urbanization rate and pedestrian traffic had no effect on FID, maybe because of the small spatial scale considered. FID varied with eumelanin‐based coloration: white pigeons had lower FID (104.6 cm; i.e., higher behavioral tolerance) than darker morphs (232.3 cm for Blue bar, 184.4 cm for T‐pattern & Checker, and 181.8 cm for Spread color morphs). Though the exact underlying causes remain to be identified, we propose different possible mechanisms for this relationship that remain to be investigated in future work.

First report on the diversity of domestic pigeons (Columba livia) using plumage coloration and patterning in Saravena, Arauca, Colombia

The domestic pigeon (Columba livia Gmelin, 1789), native to Africa and Eurasia, is extensively found across Europe, Western Asia, Africa, and the Americas. The pigeon (Columba livia) was domesticated several centuries ago and holds a privileged place as a symbol of peace, love, fidelity, and ornamentation in parks. In recent decades, an increase in the populations of these pigeons has been detected. The Spanish brought Columba livia to Colombia in the 15th century. The objective of this study was to evaluate the genetic diversity of the domestic pigeon using loci related to plumage coloration and patterning in Saravena. Random sampling was conducted in six colonies between March and April 2024. Through urban visits, direct observation, and photographic records, a phenotypic classification of each of the 580 pigeons from the different flocks studied was carried out. Autosomal markers associated with coloration and plumage were analysed: Grizzle, Spread, Checker, and the sex-linked locus Ash-Red. Genetic profiles were calculated using indices: allele frequency, genetic diversity, and population structure, estimated with the PopGene 1.31 program. Diversity was assessed using the FSTAT program. The dendrogram was constructed with the MEGA X program. The marker with the highest allele frequency was Grizzle (P=0.1834), while the Spread marker had the lowest values (P=0.0300). The highest HT value was 0.3002 for the Grizzle marker, GST showed figures of 0.0360, and gene flow was 20.6; the FIS and FIT statistics reported values of 0.2779 and 0.2848, and FIT was 0.0091. Moderate genetic diversity, a deficit of heterozygotes, and an excess of homozygotes were observed, along with low interpopulation genetic differentiation and high gene flow between subpopulations. Low genetic distance values were also found between the studied subpopulations. The populations are closely related genetically, which may be due to their geographical proximity, which has favoured genetic exchange.

Urban Pigeons as Reservoirs of Critical Pathogens: Improved protocol for sequencing pigeon faeces in disease monitoring

The spread of pathogens by animals is a serious issue around the world that causes a severe threat to human health. Feral pigeons (Columba livia forma domestica) that live in urban areas are zoonotic carriers of various pathogens that can be transmitted to humans by faecal contamination. This study aimed to detect the presence of bacterial, viral, and specifically fungal pathogens in pigeon faeces based on the World Health Organization's (WHO) priority pathogen list published in 2022. Fresh faecal samples were collected at Uppsala, Central Station, and Svandammen, the pigeons' most relevant gathering spots and feeding sites. Genomic DNA was directly extracted from these samples, and ScilifeLab performed High throughput sequencing through Oxford Nanopore Technologies(ONT) (PromethION). Metagenomic analysis revealed that most of the critically prioritized viral and bacterial pathogens listed by WHO were present in pigeon faeces. Regarding fungal pathogens, which were the main objective of this study, samples from both studied locations contained all critical, high and, medium-important fungal pathogens published in the WHO list, such as Aspergillus fumigatus, Candida albicans, Candida auris, Cryptococcus neoformans, Nakaseomyces glabratus, Candida tropicalis, and Cryptococcus gattii. These fungal pathogens pose the risk of invasive fungal diseases and severe infections in low-immunity individuals and vulnerable populations. The findings indicate the importance of conducting further research to comprehensively understand potential exposure to feral pigeons. Furthermore, keeping pigeons away from sensitive areas, such as hospitals, and implementing measures to control pigeon populations can significantly decrease the spread of pathogens.

Evidence for a general cognitive structure in pigeons (Columba livia)

A well replicated result in humans is that performance, whether good or bad, is consistent across a wide variety of cognitive tasks. Factor analysis extracts one factor that can account for approximately half of the variance in performance. This factor is termed g and almost all cognitive tasks positively load onto this factor. While some neurobiological correlates of g have been identified in humans, causal experiments are only feasible in animals. When mice and some avian species are assessed with cognitive test batteries, performance positively correlates, and the first component extracted has similar properties to g. There are some limitations to the species tested thus far, including comparability in the cognitive domains assessed. The pigeon is an ideal subject to overcome these issues since pigeons, humans, and other primates are frequently given similar tasks and many neural correlates of performance have been identified in the pigeon. We created a test battery that assessed different domains, including associative learning, memory, cognitive flexibility, and reaction time. When all tasks were included, there was evidence for a two-component structure that was influenced by subjects’ age. When the reaction time task was excluded, there was a g-like component. The implications for these results when constructing future test batteries and comparing across species are discussed.

Differences in paradoxical choice between pigeons (Columba livia) and rats (Rattus norvegicus): The problem of cue trackability.

Organisms are believed to attempt to maximize their net energy intake while foraging. The paradoxical choice task shows that they may instead prefer to obtain information rather than primary reward when the outcome is uncertain. That is, they prefer stimuli that consistently predict food or no food (informative option), to stimuli that inconsistently predict both food and no food in larger amounts (noninformative option). This task also seems to indicate that some species (like pigeons, Columba livia, and starlings, Sturnus vulgaris) are more prone to choose the informative option, while other species (like rats, Rattus norvegicus, and humans, Homo sapiens) tend to favor reward procurement through the noninformative option. There is empirical evidence for and against this view. However, an analysis of the literature suggests that species differences in paradoxical choice might be less pronounced than often believed. We argue that pigeons and rats are usually not tested under conditions that are motivationally equivalent for both species-in particular, the opportunities to track consistent stimulus-food pairings are less often met in the rat studies than in the pigeon studies. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Serial pattern learning: Pigeons (Columba livia) prefer an improving schedule over an initially easier fixed ratio schedule.

Serial pattern learning describes behavior in which a subject anticipates not only the time and effort needed for the next reinforcer but also the pattern of time and effort to reinforcers after the first. Chandel et al. (2021) found that pigeons left a progressive (increasing ratio) schedule earlier than would have been optimal. They argued that the pigeons anticipated the harder-to-obtain reinforcers beyond the next one. In the present experiments, pigeons were trained on a progressive schedule for which each reinforcer was successively easier to obtain. However, the initial choice was between a fixed ratio schedule (FR23) for which a reinforcer was easier to obtain than the first reinforcer on the improving progressive schedule (32 pecks). Delayed discounting theory suggests that the pigeons would prefer the FR23 because more immediate reinforcers should be preferred, whereas serial pattern learning suggests that the progressive schedule might be preferred because easier-to-obtain reinforcers would follow the initially harder 32 pecks. In Experiment 1, a preference for the fixed ratio schedule was not found, however, in Experiment 2, when the two alternatives were equated for the number of reinforcers that could be obtained on each trial, a significant preference for the improving progressive schedule was found. The results of Experiment 2 were consistent with the serial pattern learning hypothesis. The pigeons did not choose the more immediate reinforcer associated with fixed ratio alternative. Rather, they showed a preference for the improving progressive schedule for which later reinforcers would be easier to obtain. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Crossed effects of helminth infection and lead exposure on fitness: An experimental study in feral pigeons (Columba livia).

Living organisms are exposed to multiple environmental factors that can affect their fitness. The negative effects of these simultaneous stressors can be additive or can interact in negative synergistic or antagonistic ways to affect the health of exposed individuals. Parasites can accumulate pollutants in their own tissues and have been shown to increase the tolerance of their hosts to different pollutants (antagonistic interaction between parasites and pollutants). Through an experimental approach, we tested the existence of combined antagonistic effects between intestinal parasites and lead exposure on urban feral pigeons (Columba livia) which are known to be exposed to trace metal pollution and harbour a wide variety of internal and external parasites. We experimentally exposed wild feral pigeons in captivity to two treatments: an anthelmintic treatment to eliminate intestinal nematode parasites; an exposure to lead for a period of 6 months. We tested the effects of these crossed treatments on several components of fitness: immunocompetence, reproduction, and body mass. Our findings suggest that the overall effects of lead exposure, either alone or in combination with the presence of intestinal parasites (without anthelmintic treatment) were negative, through either additive or synergistic means. Our results reveal the existence of negative combined effects between pollutant exposure and intestinal parasites, highlighting the importance of accounting for multiple stress factors when studying the effects of exposure to pollutants and/or other environmental stressors on the fitness of organisms.

Influence of rotation speed and frequency on the decision of Columba livia domestica (homing pigeon) to cross the rotor-swept area of paper blades mimicking a wind turbine

Abstract To reduce bird collisions with wind turbines, automatic detection systems have been developed to slow the blades down when a bird is approaching. We experimentally tested whether blade rotational speed (i.e., number of rotations per min) and frequency (i.e., number of times a blade passes a point per min) affected the decision time (i.e., time to take-off), path choice (i.e., the position in the aviary), and decision to cross the rotor-swept area in Columba livia domestica (rock dove [domestic variety]; aka homing pigeon; hereafter, pigeon). We used a homemade device with paper blades, mimicking the movement of wind turbine blades. We adjusted the paper blade dimensions and achromatic contrast with the background to match the visual capabilities of pigeons, increasing the probability of detection. Pigeons were less likely to cross the rotor-swept area at higher speeds and frequencies, independent of their decision time. When pigeons crossed the rotor-swept area (43 out of 160 trials), 63% collided with the blades, regardless of blade speed or frequency. Pigeons chose to avoid the rotor-swept area after they had travel half the distance to the wind turbine. Pigeons were not better able to avoid the rotor-swept area when blades were rotating at low speed and/or frequency and often collided with the blades. Thus, slowing blades to a low rotational speed may not reduce collisions with some species and a complete turbine shutdown may be necessary. The feasibility and economic costs of regular complete shutdowns after the deceleration triggered by the automatic detection systems need further investigation.

Antitumor effect of the Newcastle disease virus strain NDV/Altai/pigeon/777/2010 on a model of solid Lewis carcinoma

Aim. To evaluate the efficacy of intratumoral administrations of the Newcastle disease virus strain NDV/Altai/pigeon/777/2010, to compare progression of the tumor nodes after virotherapy and to analyse pathomorphological changes in the tumor tissue in vitro and in vivo. Single intratumoral injections of the mesogenic strain of Newcastle disease virus NDV/Altai/pigeon/777/2010, isolated from a rock dove in Siberia, were done into outbred mice of the C57Bl/6 line into solid nodes of Lewis lung carcinoma that were grafted subcutaneously. Then the dynamics of tumor growth and pathomorphological changes in the tumor tissue were assessed and analyzed.It was shown that single intratumoral injections into immunocompetent C57Bl/6 mice with the mesogenic strain of Newcastle disease virus NDV/Altai/pigeon/777/2010 led to an increase in peculiar pathomorphological changes in the tumor tissue of subcutaneously grafted Lewis lung carcinoma and to a decrease in tumor growth compared to the control group of mice in vivo. A direct cytotoxic effect of the NDV strain on the Vero E6 cell line in vitro was noted.The results of this study indicate that the NDV strain NDV/Altai/pigeon/777/2010 has antitumor properties. This may enable clinical trials to prove its effectiveness as an antitumor drug.