Avian Biology Research

Cryopreservation of animal germplasm is an important ex situ conservation strategy. Germplasm can be preserved at subzero temperatures and recovered in a way that allows germline development to be resumed at a later time. This strategy is routinely used for genetic improvement of dairy cattle, maintenance of lab strains of rodents and in human reproductive medication, and it contributes to genetic conservation of a growing number of wild mammalian species. Although there is an urgent need, cryoconservation of germplasm for birds is limited, partly because of skepticism with respect to the effectiveness of cryopreservation techniques. An understanding of fundamental principles of cryobiology and comparative cryobiological and physiological properties of germplasm is essential to the development and optimisation of cryopreservation protocols. In mammals, slow freezing has been used to cryopreserve gametes and embryos but the effectiveness of slow freezing is specific to the cell type and it does not protect extracellular structures. Vitrification, which is a process of solidification without crystallisation, can be used to effectively preserve multicellular structures such as gonadal tissue. In some domestic and wild avian species, the fertility produced by cryopreserved semen is sufficient for conservation but the w chromosome is lost. Avian eggs and embryos cannot be cryopreserved, but gonadal tissue can be cryopreserved and recovered by transplantation. Cryopreservation of germplasm allows ex situ conservation of avian species because it allows repopulation without the limitations of geographic isolation or reproductive longevity.

The temporal variation of bird assemblages at three sites within a wetland of the Parana River was examined. The aim was to obtain an overview of the influence of spatial heterogeneity on communities in such a variable environment as the wetlands. We recorded 1,662 individuals belonging to 139 species from 40 families. There were no significant differences between sites in richness, abundance nor diversity. Species richness in the first year was greater than during the second year. Number of resident and migrant species decreased in the second year. Community composition differed between the two years of study and was significantly different among seasons. Species were grouped into 19 trophic guilds. In this study, number of species and their abundances were not significantly different among sites; there were differences in the composition of birds among sites. Thus, the structure of the environments influenced the composition of assemblages in different areas. Guild composition remained fairly constant between years and among seasons. Geomorphological and hydrological dynamics of the river produce a heterogeneous availability of habitats and resources that affect the composition of bird assemblages. Annual and seasonal changes in meteorological variables can lead to changes in the structure and/or composition of those assemblages.

This study observed the effect of different LED light colour on the behaviour and fear responses of broilers. In experiment 1, 400 broilers were placed into eight different light treatments. In experiment 2, six different light colours with five different age groups were considered. In experiment 1, use of a red and red–yellow mixed light significantly increased walking behaviour. Consequently, sitting and standing behaviour were found to be wavelength dependent, whereby short wavelength (blue, green–blue) treated birds spent more time sitting and standing than that under long wavelength (red, red–yellow). Consistently in experiment 2, birds spent more time feeding under the green treatment than with other treatments. Walking behaviour was significantly decreased and sitting and standing behaviour was increased under the blue light. Age also influenced the behaviour of broiler: young birds were more active than older birds. In addition, ground pecking and wing stretching behaviour were influenced by the wavelength of the light. Time of day did not influence the behaviour of the broilers. Under the red and red–yellow light treatments, birds spent longer in tonic immobility. Thus, the results suggest that red and red–yellow light activated the broiler's movement and fear responses while blue and green-blue decreased the movement and they spent more time sitting.

This study sought to examine the relationship between weather and aggression in Caribbean flamingos by utilising a novel observation method. Previous research has shown evidence of increased levels of aggression during periods of warmer weather in a wide range of species including humans. We observed the captive flock of Caribbean flamingos at the Smithsonian National Zoological Park (Washington, DC, USA) by means of a web cam, and correlated the observed instances of aggression with eight different weather variables gathered via www.weather.com. Results evidenced significant positive correlations between aggression and several variables including: temperature [r (38) = 0.31, P = 0.048], “feels like” [r (38) = 0.31, P = 0.049], and UV-index [r (38) = 0.35, P = 0.025]; and a multiple linear regression (stepwise) suggested that UV-index is a significant predictor of aggressive instances, thus highlighting the relationship between such environmental factors and flamingo aggression. Evidence has been found of a relationships between UV light and aggression in other species, and the results of the present study suggest a similar relationship in flamingos. Employing webcams may allow researchers to obtain larger samples to be included in the study of aggression or to examine this and other behaviors in a wider variety of captive animals.

In general, avian species produce clutches of more than one egg. Differential investment in egg weight and hormone levels is possible and their effects on development and behaviour can be measured. Here we investigated changes in three hormones (testosterone, T; androstenedione, A₄ and progesterone, P₄) in the outer layer of yolks of infertile domestic goose eggs over the course of a laying season. There was a significant change in the concentration of all three hormones: T and P₄ increased in a linear manner across the season whilst A₄ increased until mid season and then steadily decreased. The correlation between T and P₄ (r =0.613, P < 0.001), and between T and A₄ (r = 0.746, P < 0.001) were both positive, but the relationship between A₄ and P₄, while positive was not strong (r = 0.379, P < 0.001), although still significant. The increase in P₄ over the laying season is consistent with the transition from a laying to a broody state. The increase in T is consistent with a trade-off for the seasonal decline in egg weight.

The objective of this study was to determine the effects of formic acid on egg production, egg weight, feed conversion ratio, egg quality and immunity in commercial layer reared during the hot season. In this study, 360 Hy-Line W-98 commercial White Leghorn, 68-week old hens were randomly assigned into four groups. The first group (control) continued receiving normal drinking water and other three groups consumed drinking water containing formic acid at levels of 0.5, 1.0 and 1.5 mL L⁻¹. The results showed that the laying hens that consumed drinking water with formic acid had greater egg production, egg weight and egg mass than the control. Similarly, feed conversion improved with the administration of formic acid in water. Haugh units, egg shell thickness and egg grading from hens consuming acidified water containing 1.0 or 1.5 mL L⁻¹ were significantly greater than those from the control group. Formic acid had no effect on yolk colour. In addition, the geometric means HI titres against Newcastle disease of birds consuming water containing formic acid were higher on all sampling days than those consuming water without acid. This study showed that formic acid at levels of 1.0 or 1.5 mL L⁻¹ positively influences egg production, egg weight, shell quality, egg grading and enhances the immunity in older commercial layers during the hot season.

Mycoplasma synoviae (M. synoviae) is an important avian and extracellular pathogen which causes great economic losses in poultry industry. We have performed a phylogenetic analysis of M. synoviae isolates derived from commercial chicken farms in Iran based on 16S rRNA gene. Partial sequences of 16S rRNA genes obtained from 19 isolates of central region of Iran were amplified by PCR in 207bp fragment, then sequenced and next compared with the 16S rRNA gene of M. synoviae sequences that were available in GeneBank. Sequences were aligned using the ClustalW method, the UPGMA algorithm was used to create the phylogenetic tree. Phylogenetic analysis of these sequences demonstrated that all 19 M. synoviae isolated from Iran were most closely related to sequences of M. synoviae from Brazil. Variations, polymorphisms, and differences between nucleotides of all isolates were observed. The results of this study suggest that the close relationship, different molecular structure and heterogeneity among M. synoviae isolated may be explained by the transmission of mutations and variations between countries due to trading or to the stabilisation of spontaneous mutations because of regional conditions.

The viability and hatchability of Houbara bustard (Chlamydotis undulata) embryos were investigated in a surrogate (chicken) albumen and eggshell system. Egg yolk including embryos were separated from freshly laid Houbara bustard eggs, and cultured in albumen from chicken and Houbara, respectively. The viability of Houbara embryos after day 4 in the same sized chicken eggshell was 76.9% and 61.1% in chicken and Houbara albumen, respectively. The entire content (egg yolk with embryo and the surrogate albumen) were then transferred on day 4 into an eggshell of a larger double yolk chicken egg, and incubated for a further 19 days. On day 14, the viability of Houbara embryo in the surrogate Houbara and chicken albumen were 27.3%, and 57.1%, respectively. Two Houbara chicks hatched successfully from the chicken albumen (7.7%), while one hatched from the Houbara albumen (5.6%). The results showed that Houbara embryo could develop to hatching in chicken albumen and eggshell. This technology will provide a tool to hatch damaged eggs as well as soft-shelled egg of endangered wild birds.

Ducks exhibit sexual dimorphism in vocal anatomy. Asymmetrical ossification of the syrinx (bulla syringealis) is discernable at about 10 days of age in male Pekin duck (Anas platyrhynchos domestica) embryos, but information is lacking on the early development of the bulla in wild ducks. To evaluate the reliability of this characteristic for sexing developing embryos, we examined the syrinx of dead embryos and compared results with molecular sexing techniques in high arctic nesting Common Eiders (Somateria mollissima). Embryos 8 days or older were accurately (100%) sexed based on the presence/absence of a bulla, 2 days earlier than Pekin duck. The use of the tracheal bulla can be a valuable technique when sex identification of embryos or young ducklings is required.

The red-legged partridge (Alectoris rufa) is normally found in the Iberian Peninsula, southern France and some points of northern Italy and southern England. A number of factors have drastically reduced the number of wild red-legged partridges in these areas. It is necessary to know their genetic situation and to identify different populations and species. Microsatellite markers are very effective genetic markers. In order to identify microsatellite markers in this species to gain genetic knowledge of their populations, DNA was cleaved partially with AluI and ligated in plasmid pSMART; this was inserted in Escherichia coli to obtain a whole genome library. This library was screened by amplifying with the polymerase chain reaction and then sequencing the A. rufa DNA in plasmids isolated from colonies selected at random. Some of the sequenced PCR products were found to contain possible microsatellite sequences and two of these were used to characterise four different species of Alectoris. One of these sequences (GTTTT) was always found to be repeated three times but the number of repeats of the second one (AG) was found to vary between species. Therefore, the (AG)n microsatellite may be a good candidate to distinguish between species of the genre Alectoris.