Aspectos morfológicos, ultrassonográficos e radiográficos ósseos e oculares de ninhegos de garças vaqueiras (Bubulcus ibis)

Abstract

Cattle egret is a cosmopolitan species. There are few studys on the development of cattle egret´s chicks and morphology of the species. Cattle egret is a semi-altricial species that depends on its parentes for the first 50 days of life. Chicks start walking on the branches with in 14 days and leave the nest within 30 days. During this period long occurs. Studies on the presence of post hatsching ossifications centers appearance in birds are scarce. This study was realized with animals from a pelecaniform colony located in Lavras - Mg. Cattle egret´s chicks that fell from the nests were collected and radiographed . A study to determine post -hatching ossification centers appearance by staining and radiographs was conducted. Timing of post -hatching ossification centers appearance of hind limb bones, and epiphyseal plate closure w as related to paternal dependence. Cattle egret post-hatching ossification center appearance and epiphyseal plate closure occurs at an early age compared to precocial species. In 2015, there was a higher number of chicks that fell from the nests and some of them showing fibrous osteodystrophy. Also, some birds exhibit cut -blunt lesions suggesting pecks. It is suggested that in year of the study there was a lack of sufficient food and the food given for the chicks by their parents was with an inadequate composition. Between the years studied there was a difference between the beginning of the rainy season and the average monthly rainfall during the breeding period of the birds that could explain the scarcity of food or of some itens such as vertebrates. A third study was performed on the ophthalmic morphometric parameters of the cattle egret´s chicks. Macroscopy and ultrasound parameters were similar to other diurnal birds. The histology of the eyes was similar to other avian species.