Ocular Ultrasonography and Biometry in the Cinereous Vulture (Aegypius monachus).

To establish reference standards for ocular ultrasound and biometry, 24 cinereous vultures (Aegypius monachus) (45 eyes) underwent B-mode and A-mode ultrasonographic examination using a 12.5-MHz probe. The vultures were manually restrained without sedation, and the eyes were topically anesthetized. Biometry was performed in the sagittal plane for axial length of the globe (AGL), anterior chamber depth (ACD), lens thickness (LT), and vitreous chamber depth (VCD). Biometry of the pecten oculi (LP) was measured on images of transversal scan at 9 hours. Biometric findings were as follows: AGL=27.74 ± 0.77 mm, ACD=3.73 ± 0.62 mm, LT=5.41 ± 0.18 mm, VCD=18.60 ± 0.58 mm, and LP=10.21 ± 1.19 mm. No correlation was found between body weight and AGL. Right and left globe sizes were not significantly different, but AGL and VCD were significantly longer (P < .05) in male than in female vultures. Including diagnostic protocols such as ocular ultrasound may improve the ophthalmologic care of endangered raptors injured by blunt trauma, when opacities of the ocular media prevent examination of the internal ocular structures.

Ocular Histomorphometry of Free-Living Common Kestrels ( Falco tinnunculus).

We evaluated the histomorphometry of the eye structures (cornea, retina, choroid, and sclera) of 13 adult free-living common kestrels ( Falco tinnunculus). Birds included in the study were euthanatized because of severe trauma from a motor vehicle injury. The eyes were enucleated immediately after euthanasia, fixed in 10% buffered formalin, and decalcified. The right eyes were cut vertically (dorsoventrally) and the left eyes cut horizontally (temporonasally). Tissues were processed, stained with hematoxylin and eosin, and evaluated by an image analysis software. The thicknesses of the diverse corneal layers were measured at 3 points; 2 at the peripheral region (A and C) and one at the central region (B). The thicknesses of the retina, choroid, and sclera were evaluated at 6 different positions. Measurements of the left and right eyes of the male and female birds were compared. The median thicknesses of the cornea at the peripheral points were 210.78 (A) and 197.79 (C) µm, and 129 µm at the central point (B). The thickness of the cornea did not differ significantly between males and females or between right or left eyes. The mean thicknesses of the retina, choroid, and sclera were 91.13, 20.74, and 92.8 µm, respectively. The thickness of the choroid and sclera did not differ significantly between the sexes or between the right and left eyeballs. The retinas of the females were significantly thicker than those of males at the points in the fundus of the eyeball, near the insertion of the pecten (optical nerves).

The arteries root from the aortic arch in the sparrowhawk (Accipiter nisus, Falconiformes: Accipitridae) / La raíz de las arterias desde el arco aórtico en el gavilán (Accipiter nisus, Falconiformes: Accipitridae)

This study was aimed at determining the morphology of the aortic arch in the sparrowhawk. For this purpose, arteries near the heart of six sparrowhawks were assessed. Latex injection method was applied to the three materials and barium sulphate solution was injected into the aorta for angiography in three other materials. It was observed that two major arteries arose from aortic arch in the sparrowhawk: the left brachiocephalic trunk and the right brachiocephalic trunk. These trunks were contiguous arteries but separately originated from the aorta. The brachiocephalic trunks were divided into the common carotid and subclavian arteries after their origins. First, the common carotid arteries are given off by the brachiocephalic trunks. The common carotid artery was giving off esophagotracheobronchial artery and vertebral trunk. Vertebral trunk was locating under the brachial plexus. The subclavian artery was continuations of the brachiocephalic trunk and it was bifurcating to the axillar artery and the pectoral trunk just from its own beginning. The axillary artery passed the brachial plexus crosswise from above, and reached to the wing. The sternoclavicular artery stemmed from ventral aspect of the begining of the axillary artery. The thickest branch of the subclavian artery was the pectoral trunk, which was branched the cranial external thoracic artery, the caudal external thoracic artery, the dorsal thoracic artery, and the internal thoracic artery. It is hoped that the results of this morphological study will contribute to the species specific anatomical data in the birds.

El objetivo fue determinar la morfología del arco aórtico en el gavilán. Para este fin, se evaluaron las arterias próximas al corazón de seis gavilanes. En tres aves se inyectó una solución de látex, mientras que en las tres restantes se inyectó a través de la aorta sulfato de bario para someterlas luego a un estudio por angiografía. Se observó el origen de dos arterias principales del arco aórtico del gavilán: el tronco braquiocefálico izquierdo y el tronco braquiocefálico derecho. Estos troncos se presentaron como arterias contiguas, pero que se originaron por separado de la aorta. Los troncos supraaórticos se dividieron después de su origen en las arterias carótida común y subclavia. Las arterias carótidas comunes se emiten a partir de los troncos supraaórticos. La arteria carótida común emitió una arteria esófago-traqueobronquial y el tronco vertebral. El tronco vertebral se localizó por debajo del plexo braquial. La arteria subclavia se continuó a partir del tronco braquiocefálico y se bifurcó en arteria axilar y tronco de las arterias pectorales justo desde su propio inicio. La arteria axilar cruzó el plexo braquial transversalmente desde arriba, y llegó al ala. La arteria esternoclavicular derivó de la cara ventral del inicio de la arteria axilar. La rama más gruesa de la arteria subclavia fue el tronco de las arterias pectorales, que se ramificó en arteria torácica externa craneal, arteria torácica externa caudal, arteria torácica dorsal, y la arteria torácica interna. Se espera que los resultados de este estudio morfológico sean una contribución para aportar datos anatómicos específicos en esta especie de aves.

Evaluation of Cardiac Size in the Common Kestrel ( Falco tinnunculus ) Based on Radiographic Measurements.

The common kestrel ( Falco tinnunculus ) is a common raptor found worldwide. To establish reference intervals for cardiac size by radiography, 14 adult common kestrels were evaluated clinically and with radiographs (lateral and ventrodorsal views). The cardiac width, thoracic width, distance between third and fourth ribs, synsacrum width, coracoid width, and distance between clavicle bones were measured on ventrodorsal radiographs. The ratio between cardiac width and the other 5 indices was calculated. Results showed a significant, positive correlation between the cardiac width and thoracic width and between cardiac width and coracoid width. The values and ratios of this study can be used as reference intervals for cardiac size evaluated radiographically in the common kestrel for diagnosis of the cardiomegaly in this bird.

Observations on the right ovary of birds of prey: a histological and immunohistochemical study.

In most avian species, only the left ovary and oviduct are developed in the adult bird. Right ovaries and oviducts usually do not mature further after hatching and remain only rudimentary. However, occurrence of a functional right ovary is frequently found in several species of birds of prey. In this study, we investigated the occurrence of the right ovaries and their morphology in these bird species. Four examined wild bird species possessed a right ovary: long-eared owl, common buzzard, sparrow hawk and goshawk. We used histological and immunohistochemical techniques to evaluate structural differences of the gonads and tried to correlate the findings with folliculogenesis and endocrine functions. The right ovaries showed different sizes and shapes. Cytoskeletal elements (tubulin and vimentin) and α-smooth muscle actin have been detected in different structures of the right ovaries, but their staining intensity was weaker compared with the left ovary. This shows that also the right ovary is mechanically able to ovulate. We could also demonstrate the expression of oestrogen receptor α and progesterone receptor in the right ovaries, which indicates that also the right ovary can respond to steroid hormone stimuli. We assume that the expression of steroid hormone receptors in the presumptive gonad is still sufficient to mediate the development of a right ovary in the studied species. We conclude that the expression of steroid hormone receptors in the right ovary is involved in its post-natal development. The histological and immunohistochemical data also imply that in the right ovary, folliculogenesis and ovulation can occur.

Aging related changes of retina and optic nerve of Uromastyx aegyptia and Falco tinnunculus.

Aging is a biological phenomenon that involves gradual degradation of the structure and function of the retina and optic nerve. To our knowledge, little is known about the aging-related ocular cell loss in avian (Falco tinnunculus) and reptilian species (Uromastyx aegyptia). A selected 90 animals of pup, middle, and old age U. aegyptia (reptilian) and F. tinnunculus (avian) were used. The retinae and optic nerves were investigated by light and transmission electron microscopy (TEM) and assessments of neurotransmitters, antioxidant enzymes (catalase, superoxide dismustase and glutathione s transferase), caspase-3 and -7, malonadialdhyde, and DNA fragmentation. Light and TEM observations of the senile specimens revealed apparent deterioration of retinal cell layers, especially the pigmented epithelium and photoreceptor outer segments. Their inclusions of melanin were replaced by lipofuscins. Also, vacuolar degeneration and demyelination of the optic nerve axons were detected. Concomitantly, there was a marked increase of oxidative stress involved reduction of neurotransmitters and antioxidant enzymes and an increase of lipid peroxidation, caspase-3 and -7, subG0/G1 apoptosis, and P53. We conclude that aging showed an inverse relationship with the neurotransmitters and antioxidant enzymes and a linear relationship of caspases, malondialdhyde, DNA apoptosis, and P53 markers of cell death. These markers reflected the retinal cytological alterations and lipofuscin accumulation within inner segments.

Variation at phenological candidate genes correlates with timing of dispersal and plumage morph in a sedentary bird of prey.

Polymorphic genes involved in the conserved molecular signalling of circadian and circannual clocks may play important roles in governing the timing of breeding and dispersal and thereby affect fitness in vertebrates. However, relatively few studies have explored associations between phenological candidate genes and behaviour, and these are somewhat biased towards particular taxonomic groups such as passerine birds and salmonid fish. Consequently, we assayed microsatellite polymorphisms within the exonic and 3' untranslated regions of the regulatory genes CLOCK, NPAS2, ADCYAP1 and CREB1 in the common buzzard (Buteo buteo), a polymorphic raptor species with three plumage morphs that differ in key life history traits including lifetime reproductive success. In contrast to studies of passerines, CLOCK poly-glutamine (poly-Q) was found to be monomorphic in 976 common buzzard nestlings as well as in three other Buteo species. Moreover, none of the candidate genes were significantly associated with fledging dates, although intermediately melanized females were found to lay earlier on average than light or dark morph individuals, and their offspring carried longer ADCYAP1 alleles. In contrast, all three candidate genes explained significant variation in one or more measures of juvenile buzzard dispersal (resighting probability, timing of dispersal and distance dispersed). Our findings contribute towards a broader body of work on the adaptive significance of CLOCK polymorphism, while also building upon previous studies that have documented links between ADCYAP1 variability and the timing of migration.

A comparative study on the histological structure of the spleen in the ostrich (Struthio camelus), the kestrel (Falco tinnunculus) and the osprey (Pandion haliaetus).

The spleen structurally and functionally belongs to the hematopoietic organs and is also an important component of the reticuloendothelial system, which is known to play a major role in host defense. The histological structure of the spleen was investigated in the ostrich, a non-flying bird, the kestrel, a raptor, and the osprey, a fish-eating bird of prey (fish eagle). For this purpose, Mallory's modified triple stain, methyl green-pyronin and silver stain were used. Germinal centers were not present in the spleen of the osprey. In the spleen of the kestrel, penicillar arterioles and the surrounding lymphoid tissue were markedly dense. Compared to the other two birds, the red and white pulps were clearly distinguishable in the spleen of the ostrich.

Radiographic evaluation of cardiac size in four Falconiform species.

To establish reference values for the cardiac size during radiographic examination in 4 species of Falconiformes used for falconry, lateral and ventrodorsal radiographs were examined from healthy birds of 4 species: Harris' hawks (Parabuteo unicinctus) (n = 48), peregrine falcons (Falco peregrinus) (n = 35), saker falcons (Falco cherrug) (n = 19), and lanner falcons (Falco biarmicus) (n = 13). On the lateral view, ratios between the length of the heart from base to apex and total length of the carina were calculated. On the ventrodorsal view, ratios between the width of the heart at its widest point and the distance between the ribs at the same level and between the width of the coracoid immediately caudal to the humeral articular surface in the shoulder joint and width of the heart and the distance between the ribs were calculated. No differences were found between species in the ratio of length of the heart/length of the carina. The ratios of width of the heart/distance between ribs and width of the heart/coracoid width differed between hawks and falcons but did not differ between the 3 falcon species.