Domestic Pigeons Research Articles

Pathological and molecular identification of Mycobacterium avium infection in a loft of domestic pigeons (Columba livia var. domestica) from India.

Mycobacterium avium is a zoonotic pathogen associated with a wide range of pulmonary and extrapulmonary manifestations in a range of host species like humans, animals, and birds. The disease is more common in the avian population, and opportunistic infections have been reported in immune-compromised or debilitated animals and humans. This study reports the pathological and molecular identification of Mycobacterium avium causing avian mycobacteriosis in a loft of domestic pigeons (Columba livia var. domestica). Out of 30 pigeons aged 2-3 years, ten adult racing pigeons revealed a severe chronic and debilitating disease followed by death. The clinical signs included chronic emaciation, dullness, ruffled feathers, lameness, and greenish, watery diarrhea. Post-mortem examination of birds revealed multifocal gray- to yellow-colored raised nodules in the liver parenchyma, spleen, lungs, intestines, bone marrow, and joints. Avian mycobacteriosis was suspected based on the tissue impression smears stained by Ziehl-Neelsen staining. Histopathological examination also revealed multifocal granulomatous lesions in affected organs, which is characteristic of avian mycobacteriosis. The PCR analysis based on 16S rRNA, IS1245, and IS901 regions suggested the presence of Mycobacterium avium infection belonging to either subspecies avium or sylvaticum. This is the first detailed report of avian mycobacteriosis in pigeons from India, warranting a strict surveillance program to identify the carrier status of these microorganisms in the pigeons, which may prove a fatal zoonotic infection in humans.

Association of variants and expression levels of MYOD1 gene with carcass and muscle characteristic traits in domestic pigeons

This study was to investigate the correlations of myogenic differentiation 1 (MYOD1) gene polymorphisms with carcass traits and its expression with breast muscle development in pigeons. Four SNPs were found in the pigeon MYOD1 gene. Correlation analysis showed that individuals with AA genotype at both SNPs g.2967A > G (p < .01) and g.3044G > A (p < .05) have significantly higher live weight (LW), carcass weight (CW), semi-eviscerated weight (SEW), eviscerated weight (EW) and breast muscle weight (BMW). Moreover, the two SNPs also had the same significant effects on MYOD1 mRNA expression levels in breast muscle of pigeons, ie, the AA genotype showed higher MYOD1 mRNA expression levels. The diameter and cross-section area of muscle fibers continuously increased from 0w to 4w (p < .05), accompanied with the increasing expression of MYOD1 gene, while the density decreased (p < .05) dramatically from 0w to 1w and continuously fell over in the next few weeks (p > .05). What’s more, the expression level of MYOD1 gene was positively correlated with a diameter (r = 0.937, p < .05) and cross-sectional area (r = 0.956, p < .01) of myofiber, and negatively correlated with density (r = −0.769, p < .01). The results showed that individuals with AA genotype at both SNPs g.2967A > G and g.3044G > A have showed higher carcass traits (LW, CW, SEW, EW, and BMW) and higher MYOD1 mRNA expression level in breast muscle than AB and BB genotypes. Moreover, the expression level of MYOD1 gene was closely correlated with muscle characteristic traits, indicating variants of MYOD1 gene was closely related to muscle development and could be a potential candidate gene in marker-assisted selection of pigeons.

The domestic pigeon (Columba livia) and its association with self-perceived respiratory and skin morbidity in a neighborhood of Bogotá

With their food and shelter seeking habits, pigeons are often found in places where humans are present. However, these shared spaces can host public health risks for the transmission of zoonoses. Therefore, we sought to explore the existing relationship between the presence of domestic pigeons (Columba livia) and self-perceived respiratory and skin morbidity in individuals in a neighborhood of Bogotá, Colombia. We conducted a cross-sectional neighborhood survey from February to May, 2014. Random and probabilistic sampling based on a list of dwellings was conducted. All of the dwellings in the neighborhood, as well as all the inhabitants at home during the survey, were included. A univariate and bivariate descriptive analysis was carried out, to establish statistical relationships based on use of the chi-square test and prevalence ratios. Also, a negative binomial regression model was used to determine the relationship between some pigeon exposures and the number of self-perceived symptoms. Respiratory and skin self-perceived symptoms were surveyed, along with the conditions in the dwellings and the presence of pigeons and their droppings. Altogether, 27.4% of those surveyed reported pigeon droppings within their dwellings or outside of them, and 33.1% stated they had experienced contact with pigeon droppings. The presence of sick pigeons around the houses was associated with self-reported headaches, rhinorrhoea and sneezing. Similarly, droppings inside dwellings were associated with a range of self-reported symptoms, such as fever, dry cough and sneezing. The self-perception of respiratory and skin symptoms, and their association with the presence of pigeons may indicate that zoonotic transmission of pathogens has occurred in the respondents, despite the limitations of the study. Contact with domestic Columba livia pigeons or their droppings has previously been identified as a transmission route for zoonotic microorganisms.

Distribution of virulence-associated genes, antibiotic resistance and phylogenetic groups in Escherichia coli isolated from domestic and racing pigeons.

Despite a lot of information about virulence and resistance of Escherichia coli (E. coli) in poultry, very limited data are currently available on its occurrence in pigeon isolates, although this poses a threat to human and animal health. Therefore, this study was conducted to explore the phylogenetic classification, antibiotic sensitivity, and virulence factors in E. coli isolated from cloacal swabs of domestic pigeons bred for meat (n = 47) and racing pigeons (n = 44). The most frequent phylogroup in racing pigeons was E (36, 82.00%), unlike domestic pigeons (B2- 19, 40.00%). The most abundant iron uptake system in both groups of bird was feoB (racing = 40, 90.90%; domestic = 44, 93.61%). The presence of ibeA (52, 57.10%) and kpsMTII (46, 50.50%) genes was detected in more than half of all strains belonging exclusively to phylogroups B2, D, E, F, clade I. Antibiotic resistance was higher in racing pigeons. All racing pigeon isolates were resistant to tetracycline and trimethoprim + sulphonamide. Resistance to ciprofloxacin was determined in three isolates (6.38%) of domestic and 33 isolates (75%) of racing pigeons. Aminoglycosides and β-lactamases resistance were also recorded. One of the important detected phenotypic mechanisms of resistance occurring in isolates from racing pigeons was AGL AAC(6´)I. Our study confirms that healthy pigeons are a reservoir of antibiotic-resistant E. coli containing an arsenal of virulence factors, thus capable of potentially causing infection. Pigeons with the option to fly to multiple places can transfer virulent and resistant bacteria. Direct contact with pigeons and their faeces and the contamination of water and food pose a threat of infection to humans and other animal species.

Trichomonas gallinae, Prevalence and Histopathology in Domestic Pigeons in Sadat ‎District, Egypt

Trichomonas gallinae, Prevalence and Histopathology in Domestic Pigeons in Sadat ‎District, Egypt

Fatal Sarcocystis calchasi hepatitis in a captive Indian ringneck parakeet (Psittacula krameri manillensis)

An adult Indian ringneck parakeet (Psittacula krameri manillensis) from an outdoor aviary in Sacramento, California was found dead on the nest box. Postmortem examination showed firm, enlarged, yellow‑tinged liver and splenomegaly. Multifocal to coalescing, acute necrosis with macrophages, lymphocytes, plasma cells, and periportal ductular reaction were seen on liver histology with extra- and intracellular schizonts and merozoites. A few schizonts and lymphohistiocytic inflammation were seen in the spleen. Toxoplasma gondii, Sarcocystis neurona, S. falcatula and Neospora caninum were ruled out by immunohistochemistry. PCR of the liver for Sarcocystis spp. Based on the positive amplification/PCR of ITS1 segment and sequencing of 28S rRNA fragment, S. calchasi was confirmed. The splanchnic presentation of S. calchasi in this parakeet resembles the acute infection described experimentally in domestic pigeons (Columba livia f. domestica) and cockatiels (Nymphicus hollandicus). Since large populations of red-tailed hawks (Buteo jamaicensis) and Cooper's hawk (Accipiter cooperi), the likely definitive hosts of S. calchasi in North America, inhabit the Sacramento area, their presence near outdoor aviaries may account for the source of S. calchasi infective sporocysts.

Productive performance and Nutritional of domesticated pigeons. Present status and future concerns

Productive performance and Nutritional of domesticated pigeons. Present status and future concerns

The microbiota in feces of domestic pigeons in Seoul, Korea

In Korea, feral pigeons pose significant public health risks because they carry various zoonotic pathogens. Human population density is a significant factor in zoonotic disease events. Seoul is one of the largest cities by population density among developed countries and where most of the homeless population in Korea exists. We designed this study to compare the microbiota of pigeon feces by regional characteristics and the presence of homeless individuals. Therefore, this study used 16S rRNA amplicon sequencing to detect possible pathogenic microbes and assess the current risk of zoonosis in Seoul, South Korea. Pigeon fecal samples (n = 144) obtained from 19 public sites (86 and 58 fecal samples from regions in and outside Seoul, respectively) were examined. Potentially pathogenic bacteria were also detected in the fecal samples; Campylobacter spp. was found in 19 samples from 13 regions, Listeriaceae was found in seven samples, and Chlamydia spp. was found in three samples from two regions. Principal coordinates analysis and permutational multivariate analysis of variance revealed a significant difference in bacterial composition between the regions in Seoul (n = 86) and outside Seoul (n = 58) and between the regions with (n = 81) and without (n = 63) homeless individuals. Overall, this study identified various potentially pathogenic microorganisms in pigeon feces at public sites in South Korea. Moreover, this study demonstrates that the microbial composition was influenced by regional characteristics and homelessness. Taken together, this study provides important information for public health strategic planning and disease control.

Preparing and Presenting a Pigeon Skeleton for Gross Anatomical Study Using Boiling Maceration Method: A Quick and Effective Method

The study’s main objective was to prepare and display the pigeon skeleton using a practical and effective approach. Two matured domestic pigeons (Columba livia), aged 8 months old were purchased from local market, Gazipur sadar, Bangladesh for this purpose. This experiment was carried out in the department of Anatomy and Histology, Faculty of Veterinary Medicine and Animal Science in Bangabandhu Sheikh Mujibur Rahman Agricultural University, Gazipur, Bangladesh, in January 2021. The birds were first killed by being injected with MgSO4 directly into the hearts. After dead, they were peeled using a knife. 3% soda water solution was used to boil peeled animals for two hours. Having cooling, the bony samples were cleaned and dipped into 10% solution of bleaching water for 1 hour to avoid further growth of microorganism following washed by tap water. After drying in the sun for eight hours, the skeletal pieces were fully articulated for the skeletal frame. The whole processes were taken 2 days (33 hours). The boiling maceration method for preparation of skeleton is very effective because restrain the chance of losing small bones, requires less expenditure, time and labor. It is also visible that the bone’s original color was preserved. Extracted bones were divided into two parts, axial and appendicular skeleton. Axial skeleton comprises the bones of skull, vertebrae such as-cervical, thoracic, lumbar and sacral vertebrae (fused to form synsacrum) and coccygeal vertebrae or caudal vertebrae then ribs, costal cartilages and breast bone or keel bone. In contrast, the appendicular skeleton comprises the forelimb or wing bone like scapula, coracoid, clavicle, humerus, radius-ulna and manus. On the otherhand hindlimb or pelvic limb comprises of pelvic girdle, femur, tibio-fibula and feet bone (metatarsal and digits). In adult pigeon no developed tarsal bone. Therefore, this is the most efficient way for quickly preparing and presenting skeleton for use in studies of the avian skeletal system.

Survey and Prevalence of Lice Infestation the Pigeons (Columba livia domestica) in Kurdistan Region-Iraq

Many parasite species may damage domestic pigeons, which are from the most essential birds for human populations in every corner of the world. Ectoparasites can be found in almost every bird. Birds can be impacted by a number of health problems, but parasitic illnesses play a crucial role influence. They are a significant source of disease infection and transmission. Although domestic pigeon lice are not known to spread any avian infections, they are hazardous to young birds in particular and typically accompany poor poultry health that is due to other factors. where a lot of lice could keep you up at night. They consume their bodily fluids, such as blood, and feathers. Since lice have a chewing mouthpart and feed on dry skin scales, scab tissues, and feather parts in addition to irritating the host's skin and sucking blood, the effects of louse parasitism on birds are frequently severe and include stunted growth and susceptibility to other infections. From October 2017 to July 2018, 200 domestic pigeons were checked for pigeons chewing lice. Three urban locations were chosen at random for each of the three main governorates in the study area—Duhok, Erbil, and Sulaymaniyah. Hands were picked clean of lice; Samples were kept in 96 percent ethanol-filled tubes before being examined and identified under a dissecting microscope. In the current study, 48% (96/200) of domestic pigeons were infected with one or more lice and three species of lice were recorded and identified by morphological characteristics: Companulatus compare, Columbicola columbae, and Hohorostilla lata.

Modulation of Immunity, Antioxidant Status, Performance, Blood Hematology, and Intestinal Histomorphometry in Response to Dietary Inclusion of Origanum majorana in Domestic Pigeons’ Diet

This experiment was conducted to evaluate the effect of adding Origanum majorana (OM) powder to domestic pigeon diets on growth performance, feeding and drinking behaviour, blood hematology, blood biochemical parameters, blood inflammatory and oxidative markers, carcass characteristics, the weights of lymphoid organs, and and intestinal cecal, and bursa of Fabricius histology. A random distribution of fifty-four unsexed pigeon squabs (30 days old, average body weight; 321 g ± 7.5) into three groups was done. The first group was fed the grower basal diet without adding OM powder, while OM powder was added at levels of 0.5 and 1% to the basal diets of the second and third groups, respectively. The changes in growth performance parameters and feeding and drinking behavior under OM powder's effect were insignificant. However, the lymphoid organs (spleen and thymus) significantly increased in weight (p < 0.05) in the OM-fed groups. Moreover, blood examination showed positive responses to OM powder in terms of blood cell counts (RBCs andWBCs), and the values of hemoglobin, hematocrit, mean corpuscular volume, lymphocyte numbers, levels of globulin, and glutathione peroxidase enzyme were significantly increased. The numbers of heterophils, the ratio of heterophil to lymphocyte, malondialdehyde levels were reduced (p < 0.05). Histomorphometry examination revealed increases in intestinal villi height, cecal thickness, and bursal follicle area and number. These results indicated that adding OM powder to the pigeon diet may improve their immunity, increase their antioxidant status, and correct some hematological disorders.

Molecular identification and antiprotozoal activity of silver nanoparticles on viability of Cryptosporidium parvum isolated from pigeons, pigeon fanciers and water

Cryptosporidium is a protozoan that causes acute gastroenteritis, abdominal pain, and diarrhea in many vertebrate species, including humans, animals and birds. A number of studies have reported the occurrence of Cryptosporidium in domestic pigeons. Thus, this study aimed to identify Cryptosporidium spp. in samples collected from domestic pigeons, pigeon fanciers, and drinking water, as well as to investigate the antiprotozoal activity of biosynthesized silver nanoparticles (AgNPs) on the viability of isolated Cryptosporidium parvum (C. parvum). Samples were collected from domestic pigeons (n = 150), pigeon fanciers (n = 50), and drinking water (n = 50) and examined for the presence of Cryptosporidium spp. using microscopic and molecular techniques. The antiprotozoal activity of AgNPs was then assessed both in vitro and in vivo. Cryptosporidium spp. was identified in 16.4% of all examined samples, with C. parvum identified in 5.6%. The highest frequency of isolation was from domestic pigeon, rather than from pigeon fanciers or drinking water. In domestic pigeons, there was a significant association between Cryptosporidium spp. positivity and pigeon's age, droppings consistency, housing, hygienic and heath conditions. However, Cryptosporidium spp. positivity was only significantly associated with pigeon fanciers' gender and heath condition. The viability of C. parvum oocysts was reduced using AgNPs at various concentrations and storage times in a descending manner. In an in vitro study, the highest reduction in C. parvum count was observed at the AgNPs concentration of 1000 µg/mL after a 24 h contact time, followed by the AgNPs concentration of 500 µg/mL after a 24 h contact time. However, after a 48 h contact time, a complete reduction was observed at both 1000 and 500 µg/mL concentrations. Overall, the count and viability of C. parvum decreased with increasing the AgNPs concentration and contact times in both the in vitro and in vivo studies. Furthermore, the C. parvum oocyst destruction was time-dependent and increased with increasing the contact time at various AgNPs concentrations.

Application potential of chicken DNA chip in domestic pigeon species – Preliminary results

Introducing the SNP technology to pigeon breeding will enhance the competitiveness of a sector that produces one of the healthiest and best quality meats. The present study aimed to test the applicability of the Illumina Chicken_50K_CobbCons array on 24 domestic pigeon individuals from the Mirthys hybrids and Racing pigeon breeds. A total of 53,313 SNPs were genotyped. Principal component analysis shows a significant overlap between the two groups. The chip performed poorly in this data set, with a call rate per sample of 0.474 (49%). The low call rate was likely due to an increase in the evolutionary distance. A total of 356 SNPs were retained after a relatively strict quality control. We have demonstrated that it is technically feasible to use a chicken microarray chip on pigeon samples. Presumably, with a larger sample size and by assigning phenotypic data, efficiency would be improved, allowing more thorough analyses, such as genome-wide association studies.

A computer vision framework for quantification of feather growth patterns.

Feather growth patterns are important anatomical phenotypes for investigating the underlying genomic regulation of skin and epidermal appendage development. However, characterization of feather growth patterns previously relied on manual examination and visual inspection, which are both subjective and practically prohibitive for large sample sizes. Here, we report a new high-throughput technique to quantify the location and spatial extent of reversed feathers that comprise head crests in domestic pigeons. Phenotypic variation in pigeon feather growth patterns were rendered by computed tomography (CT) scans as point clouds. We then developed machine learning based, feature extraction techniques to isolate the feathers, and map the growth patterns on the skin in a quantitative, automated, and non-invasive way. Results from five test animals were in excellent agreement with "ground truth" results obtained via visual inspection, which demonstrates the viability of this method for quantification of feather growth patterns. Our findings underscore the potential and increasingly indispensable role of modern computer vision and machine learning techniques at the interface of organismal biology and genetics.

A Comparison of Feathers and Oral Swab Samples as DNA Sources for Molecular Sexing in Companion Birds.

The early age determinism of the sex in case of monomorphic birds is very important, because most companion birds have no distinct sexual dimorphic traits. Molecular genetic sexing was proved to be one of the most accurate sex determinations in monomorphic birds. The aim of this study was to compare the results obtained by PCR performed on isolate genomic DNA from paired samples of feathers and oral swabs collected from the same individuals. Samples of oral swabs (n = 101) and feathers (n = 74) were collected from 101 companion birds from four different species (Columba livia domestica, Psittacula krameri, Neophema splendida and Agapornis spp.). The PCR was performed for the amplification of the CHD1W and CHD1Z genes in females and the CHD1Z gene in males. The overall PCR success rate of sex determination was significantly higher from oral swabs than from feathers. The PCR success rate from oral swabs was higher in juveniles and from feathers was significantly higher in adults. The similarity between the oral swab and feathers was obtained in 78.38% of the birds. Oral swabs proved to be a more reliable sample for genetic sex determination in the species tested in this study.

Description of Sarcocystis platyrhynchosi n. sp. (Apicomplexa: Sarcocystidae) from domestic ducks Anas platyrhynchos (Anseriformes: Anatidae) in China

BackgroundLimited data are currently available on protozoan parasites of the genus Sarcocystis that infect their avian hosts within the order Anseriformes (waterfowl). To date, no Sarcocystis species has been recorded in ducks in China.MethodsLeg muscles were sampled from 26 domestic ducks (Anas platyrhynchos) in China in 2021. Morphological characteristics of sarcocysts detected in the muscle tissue were described using light microscopy (LM) and transmission electron microscopy (TEM). Genomic DNA was extracted from single sarcocysts obtained from different ducks, and three genetic markers, 18S ribosomal DNA (18S rDNA), 28S ribosomal DNA (28S rDNA) and mitochondrial (mt) cytochrome oxidase subunit 1 (cox1), were amplified and cloned for sequence analyses.ResultsSarcocysts were observed by LM in only three of the 28 samples (10.7%). These sarcocysts had a thick cyst wall with numerous brush-like villar protrusions (vps) of 3.8–4.3 μm in length (n = 30) on the cyst surface. TEM observation showed that the sarcocysts had lanceolated vps. Each vps narrowed in the stalk and contained a bundle of microtubules that extended into the ground substance. Comparisons of the new sequences with those deposited in GenBank showed that the most similar sequences were those of Sarcocystishalieti in the great cormorant Phalacrocorax carbo and European starling Sturnus vulgaris, and Sarcocystis calchasi in the domestic pigeon (Columba livia) at the 18S rDNA (99.1% identity); Sarcocystiswenzeli from the domestic chicken Gallus gallus at the 28S rDNA (95.9–96.0% identity); and Sarcocystis speeri from the opossum at the mtcox1 (98.2% identity). The new 18S rDNA, 28S rDNA and mitochondrial cox1 sequences shared up to 99.0%, 95.6% and 97.7% identity, respectively, with those of Sarcocystis spp. obtained from Anseriformes avian hosts. Phylogenetic analysis inferred from the sequences of the three genetic markers placed the organism within a group of Sarcocystis spp. obtained from avian or carnivorous intermediate hosts and avian, marsupial or carnivorous definitive hosts. Based on the morphological observation and molecular analyses, the organism found in the Chinese domestic ducks was regarded as a new species and named Sarcocystis platyrhynchosi n. sp.ConclusionsBased on morphology and sequence analyses, the microcysts diagnosed in the domestic ducks examined in this study were named as a new species. This is the first record of Sarcocystis spp. from waterfowl in China. Sarcocysts of similar morphology occur frequently in different Anseriformes birds, and the relationships among these species need to be further clarified in future studies using more molecular markers.Graphical

Morphological, molecular, and histopathological studies on Hadjelia truncata from Columba livia domestica and its role as an environmental biological indicator.

Pigeons are a cosmopolitan group of birds with abundant and large populations associated with human activities. This study focused on determining parasitic infections within domestic pigeons (Columba livia domestica). Forty-eight pigeons were examined for infections, of which 29.16% were infected with a nematode parasite, identified as Hadjelia truncata (Habronematidae), under the koilin layer of their gizzards. The population of nematodes in infected gizzards did not exceed 20 adult worms. DNA from the gizzard worms was extracted and subjected to PCR using primers that amplify the partial 18S rDNA and cytochrome C oxidase subunit I (COX I) regions. Identification of this parasite based on microscopic study revealed the presence of trilobed lips with cephalic papillae and amphidial pores, as well as other characteristic features. In males, spicules were unequal with the presence of six pedunculated pairs of caudal papillae (4 pre- and 2 post-anal) and a tail surrounded with caudal ala. In females, the vulva was a rounded aperture located in front of the posterior end of the esophagus and uteri, which was filled with numerous embryonated eggs. DNA Sequences from partial 18S rDNA were homologous to sequences obtained from H. truncata in GenBank with a high percentage of identity. DNA sequences from mitochondrial gene COX I, however, were unique, and they were the first sequenced for H. truncata, since no sequences for this taxon were previously available in GenBank. Histopathological examination revealed enlargement of infected gizzards in comparison to non-infected ones, with the presence of necrosis and interstitial infiltration in the koilin layer. Concentrations of heavy metals (Fe, Cu, Zn, Cd, Cr, and Co) were measured using inductivity-coupled plasma in tissues (liver, muscles, and gizzards) from infected and non-infected pigeons as well as their parasites. Results showed different affinities of metals to tissues. Recovered parasites can minimize element concentration from their pigeon tissues. In Saudi Arabia, this study was considered the first report identifying pigeon nematodes and evaluating of the effects of their pathogenicity on the animals' welfare, as well as their application as a useful tool for monitoring environmental pollution.

Antibiotic resistance of Escherichia coli and Salmonella spp isolated from domestic pigeons in Ardabil,Iran

Domestic pigeons are in close contact with humans and other birds in urban areas. As a carrier of Escherichia coli and Salmonella spp, these birds can play a significant role in spreading and transmitting these pathogens to humans and industrial poultry. The aim of this study was to isolate Escherichia coli and Salmonella spp from the cloacal of the domestic pigeons in Ardabil, northwest of Iran and determine their antibiotic resistance. For this purpose, 130 swab samples were prepared from healthy household pigeons in different parts of Ardabil city. After cultivation and isolation of E.coli and Salmonella spp in selected media, their colonies were identified by biochemical methods such as EMB, TSI, SIM, MR-VP, indole and urea. Antibiotic resistance of the isolates were determined according to the standard method of disc diffusion. Out of 130 samples, 23 cases (17.69%) of E.coli and 7 cases (5.38%) of Salmonella spp were isolated. Antibiotic resistance test on E.coli showed that tetracycline and sulfadiazine + trimethoprim had the highest resistance with 86.95% and 82.60%, respectively. While enrofloxacin and gentamicin showed the lowest resistance with 21.73% and 17.39%, respectively. In Salmonella spp isolates, the highest resistance to tetracycline (100%) and sulfadiazine + trimethoprim (85.71%) and the lowest resistance to co-amoxiclav (14.28%) and florphenicol (14.28%) were observed. All isolates of E.coli and Salmonella spp were sensitive to ciprofloxacin. The results of the present study indicate the presence of E.coli and Salmonella spp contamination in Ardebil urban pigeons,and also have significant resistance to some antibiotics. The implementation of strict health programs and the principled use of antibiotics in pigeons seem necessary to prevent the transmission of contamination and the spread of antibiotic resistant strains to other poultry and human.

Gap selection and steering during obstacle avoidance in pigeons.

The ability of birds to fly through cluttered environments has inspired biologists interested in understanding its underlying mechanisms, and engineers interested in applying its underpinning principles. To analyse this problem empirically, we break it down into two distinct, but related, questions: How do birds select which gaps to aim for? And how do they steer through them? We answered these questions using a combined experimental and modelling approach, in which we released pigeons (Columbia livia domestica) inside a large hall with an open exit separated from the release point by a curtain creating two vertical gaps - one of which was obstructed by an obstacle. We tracked the birds using a high-speed motion capture system, and found that their gap choice seemed to be biased by their intrinsic handedness, rather than determined by extrinsic cues such as the size of the gap or its alignment with the destination. We modelled the pigeons' steering behaviour algorithmically by simulating their flight trajectories under a set of six candidate guidance laws, including those used previously to model target-oriented flight behaviours in birds. We found that their flights were best modelled by delayed proportional navigation commanding turning in proportion to the angular rate of the line-of-sight from the pigeon to the midpoint of the gap. Our results are consistent with this being a two-phase behaviour, in which the pigeon heads forward from the release point before steering towards the midpoint of whichever gap it chooses to aim for under closed-loop guidance. Our findings have implications for the sensorimotor mechanisms that underlie clutter negotiation in birds, uniting this with other kinds of target-oriented behaviours including aerial pursuit.

Natural infection with Toxoplasma gondii, Neospora caninum and Sarcocystis species in domestic pigeons (Columba livia domestica) in Iran

Pigeons are common birds around the world and may act as intermediate hosts of the tissue cyst-forming apicomplexan parasites Toxoplasma gondii, Neospora caninum and Sacrocystis spp. This study aimed to provide an overview on the prevalence of and exposure to these parasites in Iranian domestic rock pigeon (Columba livia domestica) through molecular, serological and histopathological examination. Blood and tissue samples (i.e., brain, heart, gizzard, neck, thigh, and pectoral muscles) were taken from 100 pigeons. Sera were screened by agglutination tests for detection of anti- T. gondii and N. caninum antibodies, genomic DNA from tissue samples were assessed by respective species-specific PCRs, and histopathological examination of tissues was carried out. A seroprevalence of 45 % to anti-T. gondii and 35 % to anti-N. caninum IgG was recorded. PCR detected T. gondii DNA in 28 pigeons. Sacrocystis spp. was detected in one animal, but sequencing of the 28 S rRNA gene product did not reveal the identity of the species. Histopathology revealed myocarditis, myositis, and gliosis in the heart, skeletal muscles, and brain, respectively. No Sarcocystis tissue-cysts were detected, but T. gondii tissue cyst-like structures in the brain (i.e., 4 %) and heart (i.e., 3 %) were found by histology. Data reported herein demonstrate that pigeons from Iran are infected with tissue cyst-forming apicomplexans, particularly T. gondii. Since domestic pigeons are in close contact with human populations, and consumption of their meat and egg is popular in different societies, control strategies for minimizing the risk of infection in both pigeons and humans are suggested.