Avian Biology Research

Somatic cells in mammalian semen can be a potential source of nuclei for nuclear transfer to produce cloned animals. Somatic cells recovered from avian semen could also provide a source of cells for use in chimera formation or cloning of threatened and endangered birds. This type of assisted reproductive technology is especially important when a genetically unique animal has died and the only viable genetic material available is semen cryopreserved for artificial insemination and in vitro fertilization purposes. The usefulness of somatic cells obtained from fresh and frozen mammalian semen for nuclear transfer has already been evaluated, but still remains to be accomplished for avian semen. A non-invasive, or minimally invasive, technique to conserve avian genetic diversity via somatic cell collection from fresh avian semen, to our knowledge, has not been described. The present study investigated the use of fresh semen samples from domestic chickens (Gallus domesticus) (n = 7), i.e., white leghorn (n = 4) and silkie chickens (n = 3), as a source of somatic cells, specifically fibroblast-like cells and epithelial cells, for cytological analysis and somatic cell gene banking. Ultimately, somatic cell culture was successful for two of six selected samples (33.3%), with two of four white leghorn semen samples yielding cell cultures compared to 0 of 2 silkie chicken semen samples. Further research may include applying this technique to other avian species or address the effects of cryopreservation on the viability and DNA integrity of somatic cells derived in this manner.

The ecological diversity and distribution of ectoparasites on Greater Flamingo chicks (Phoenicopterus roseus) were investigated in Algeria at two distinct sites: Ezzemoul (Hauts Plateaux) and Safioune (Sahara) at the end of the breeding seasons of 2009 and 2011. Results from the first records for the Greater Flamingo in North Africa, indicate that they were infested by the following louse species: Colpocephalum heterosoma Piaget and Triniton femoratum Piaget (Menoponidae); Anaticola phoenicopteri (Coinde) and Anatoecus pygaspis Nitzsch (Philopteridae). These data support the hypothesis of a connectivity of the Greater Flamingo metapopulation across the Mediterranean region. The results also suggest that there was a spatial segregation in the distribution of the various louse species across distinct body parts of their hosts. Adaptive explanations for this niche partitioning are suggested.

Demoiselle Cranes (Anthropoides virgo) migrate through Pakistan between their breeding and wintering grounds. We undertook macro and micro-analyses of 16 gizzards and 35 faecal samples of this elegant bird during its stopovers in the Lakki Marwat area of Khyber Pakhtunkhwa Province, Pakistan. Analysis of 16 gizzards and 16 faecal samples of spring season showed that the bird was predominantly vegetarian and fed on cultivated crops (viz: wheat, sorghum, chickpea, Egyptian clover and garlic) and wild flora (viz: wild onion, beard grass and bur clover). Similarly, analysis of 19 faecal samples collected during the autumn revealed the presence of cultivated crops (viz: chickpea, mustard and spinach) and wild plant species (viz: wild onion, bur clover, salt cedar, beard grass and alkali seep weed). The Demoiselle Crane supplemented its diet with animal matters (ranging from 3 to 20%) derived from invertebrates belonging to Phylum Arthropoda (Order Pauropodina and Order Plecoptera) and vertebrate species i.e. tadpoles, Mus spp. and nestlings of birds. In addition, large quantities of grit composed of small stones and quartz crystals were found in the gizzards and faecal samples. This study provides information on the important flora and fauna that contribute to the diet of migratory Demoiselle Cranes. This aids strategies to conserve and protect the natural habitats from intensive anthropogenic use and livestock grazing, and helps to sustain and enhance numbers of this avian species.

In human and animals, it has been reported that Cd was linked with a number of health problems including marked damage of testes and fertility reduction. As for the sensitivity of fowl testes to Cd the results published so far differ from those reported in mammalian species. In this experiment, the effect of Cd with and without Se on spermatogenesis and semen quality in the rooster was studied after dietary Cd uptake. Cadmium (Cd) as Cd chloride (CdCl₂) and Se (Se) as sodium selenite (Na₂SeO₃) were added to the feed at dosages: group 0 – control, group 1 – 20 mg kg⁻¹ Cd, group 2 – 30 mg kg⁻¹ Cd + 4 mg kg⁻¹ Se. The cocks were exposed to Cd for 8 weeks. The structure of seminiferous tubules and boundary tissue, volume of semen, motility, concentration of spermatozoa and total sperm count were evaluated. In groups with 20 mg kg⁻¹ Cd, the disarrangement of germinal epithelium, diminution of spermiocytes, detachment and presence of developing cells in the lumen of seminiferous tubules was observed. Analysis of the semen showed a significant decrease of volume of semen, the total sperm count and motility of spermatozoa (P < 0.05). In the group with 30 mg kg⁻¹ Cd and Se supplementation, seminiferous tubules displayed all the developing spermatogenic cells. Local disarrangement and accumulation of germ cells in the luminal space was observed. In semen, a significant increase of volume of semen, motility and total sperm count (P < 0.05) was observed. A beneficial effect of Se on the development of spermatogenic cells and on semen quality was observed.

Four groups of broiler chicken hybrid (Ross 308) eggs were incubated under different temperature and light conditions to assess the effects of both variables on musculature development. During the incubation, the first group was the control and the eggs were incubated at a temperature of 37.8 °C without light, the second group was exposed to increased temperature, while the third group was exposed to monochromatic green light. The fourth group of eggs was incubated under simultaneously changed temperature (according to the regime of the second group) and light (according to the regime of the third group) conditions. Tissue samples from the breast muscle (M. pectoralis superficialis) were taken on embryonic days 9, 12, 15, 19 and 20, as well as on days 1, 3, 7, 14, 21 and 42 after hatching. Histological preparations were used to assess muscle cell diameter, connective tissue volume density, and the nucleocytoplasmic ratio of muscle cells. Our findings indicate that thermal and light manipulations during incubation increase diameter and decrease nucleocytoplasmic ratio in postnatal skeletal muscle cells. No differences were found among groups with regard to connective tissue volume density. These results can be explained by the influence of thermal and light manipulations during incubation on prolonged myoblast proliferation, as well as on the greater postnatal development of skeletal muscle cells.

Captive parrots (Psittaciformes) commonly engage in “feather-damaging behaviour” (FDB) that suggests compromised welfare. Susceptibilities to FDB have been suggested, but not empirically demonstrated, to vary across the > 200 species kept in captivity. Other demographic risk factors have been proposed for particular species – but neither confirmed nor generalised across Psittaciformes. In this preliminary study, we analysed data from a previously-conducted survey of pet owners: among 538 companion parrots representing 10 non-domesticated, non-hybrid species (n ≥ 17/species), FDB prevalence was 15.8% overall. We tested whether individual FDB status was predicted by four previously-suggested demographic risk factors: species, sex, age, or hatch origin. Available (limited) data on husbandry were assessed as potential confounding variables and controlled for as appropriate. Species identity was a predictor of FDB status (P = 0.047), even after controlling for all other variables tested; however, in light of multiple statistical testing, this effect cannot be considered robust until it is replicated. The strongest predictors of FDB status were age (P = 0.001; with odds of positive FDB status lower in juveniles versus adolescents or adults [P ≤ 0.036]), and sex (P = 0.006; with odds of FDB lower in individuals of unknown, versus known, sex [P ≤ 0.037]). These findings need to be replicated with data that allow better statistical controls for systematic differences in housing. However, they do provide preliminary empirical evidence for within-species risk factors (suggesting new, testable hypotheses about the etiology of parrot FDB); and for intrinsic, cross-species differences in FDB susceptibility (providing a rationale for future study of the biological factors that might underpin any such taxonomic differences).

Among the cellular pathways conferring protection against oxidative stress, a key role is played by heat-shock proteins, especially HSP70. It has been proposed that blue egg colouration in certain birds, which is related to the deposition of the pigment biliverdin, should be related to basic antioxidant processes in the laying female given the strong antioxidant role of biliverdin. If HSP70 levels express antioxidant defences a higher allocation of the pigment to the clutch could induce a higher response by other components of the antioxidant system like HSP70. In a field study of a breeding population of pied flycatchers Ficedula hypoleuca, a species laying blue-green eggs, we measured spectrometrically the colouration of all eggs and collected blood samples of incubating females one week after clutch completion. We estimated female condition, plasma antioxidant capacity and level of HSP70 in blood cells. HSP70 level was positively related to plasma antioxidant capacity indicating that HSP70 is involved in responses to oxidative stress. Variation in HSP70 level was in good part explained by mean egg blue-green chroma of the clutch when controlling for plasma antioxidant capacity. Results suggest that intensity of eggshell blue colouration in this population is related to a basic system involved in protection against oxidative stress.

We present the first case of angioinvasive pulmonary aspergillosis caused by Aspergillus fumigatus in a Himalayan Griffon vulture (Gyps himalayensis). We describe in detail the clinical, gross, histopathological and mycological findings. Clinical signs of weakness, emaciation, dyspnea, incoordination, and inability to fly were observed in this bird before succumbing to the illness, despite supportive care. Grossly, several yellowish circumscribed, raised, miliary nodules were observed on the surface of lungs, air sac membranes, trachea, pericardium, aorta, pulmonary artery and kidneys. Histologically, granulomatous pneumonia and airsacculitis, and angioinvasion of fungal hyphae were noticed. Aspergillus fumigatus organism was isolated from the lungs and air sacs of the bird. This seems to be the first report of angioinvasive pulmonary aspergillosis in birds of prey, and a rare finding in avian species.

The nest is a key element of avian reproductive fitness. It provides the developmental environment for the embryo and nestling thereby affecting their quality and survival. Nests are often constructed by the male and nest quality, elaboration, and ornamentation vary among males in a species. Therefore, male nest-building behaviour is likely under sexual selection and females may use male nest-building behaviour and nest features as cues in mate choice and their own reproductive investment. We tested this hypothesis in European starlings (Sturnus vulgaris). Male starlings present green plants to females during their courtship display and furbish their nests with variable quantities of fresh green plants. The highest frequency of plant incorporation into the nest occurs during pair formation and oogenesis. We determined nest composition and measured yolk testosterone concentrations in eggs. Yolk testosterone concentrations were positively correlated with the amount of green plant material in nests. Because males use green nest material in courtship and green nest material positively affects nestlings’ development, we suggest that female European starlings use male nest-building effort, ritualised courtship display of green plants, and nest characteristics in mate choice, and adjust yolk testosterone levels in the eggs to the quality of the nest to optimise offspring growth.

Group D rotavirus (RVD) is one of the evolving viral causes of acute gastroenteritis in avian species all over the world but its frequency in Indian poultry is not known. We report here the first sequence-confirmed RVD infection in 1–2 week old broiler chicks from northern India. Initial confirmation of type D rotavirus was done using polyacrylamide gel electrophoresis and VP6 gene based reverse-transcriptase-PCR (RT-PCR) for group D rotavirus, which produced a specific 742 bp amplicon in positive cases. The intestinal contents which showed presence of group D rotavirus strain were designated as RVD/Avian/India/PTN-14/2012/ GXP[X] and RVD/Avian/India/UKD-48/2012/GXP[X]. The comparative sequence analysis based on partial VP6 gene of type D rotavirus Indian strains revealed higher homology with the VP6 genes of the avian group D rotaviruses from Brazil, Germany, Netherlands, Bangladesh and UK, both at the nucleotide (87.2–89.6%) and amino acid (98.7–99.5%) levels. These two Indian avian RVD isolates clustered together, away from other Asian group D isolates from Bangladesh. The analysis of group specific VP6 protein showed amino acid changes at only two positions i.e. 228 and 384 when compared to the reference group D rotavirus strain (GenBank accession number: GU733448) confirming conserved nature of this protein. This seems to be the first sequence-confirmed detection of group D avian rotavirus in broiler chicks from India. The findings emphasise the importance of this virus in enteric infections of Indian poultry flocks. The study also emphasises the need for intensifying the epidemiological surveillance for group D rotaviruses in the near future.