Incubação de ovos e criação de filhotes de guará (Eudocimus ruber) no parque Mangal das Garças: uma ferramenta para a conservação da espécie

Abstract

The population of scarlet ibis is considered to be extinct in several regions. Captive breeding techniques are complementary tools for species conservation. The objectives were to develop a feeding protocol and an ambient environment for the rearing of scarlet ibis chicks, to intensify reproduction in captivity and increase the number of ibises in the colony, describe the developmental stages of chicks and develop growth estimation equations. The chicks were fed with three diets: Diet C (commercial feed), S (commercial ration and shrimp) and F (commercial ration and fish). The body condition and weight were taken daily, and the body measurements every seven days. The mortality rate under Diet C was 100%, and 0% under Diets S and F. The mean body weight and bones lengths were higher with Diet F and the mean length of the unpigmented portion of the beak did not differ among the diets (P<0.05). Diet F had higher nutritional contents. Rearing was artificial during year I and natural during year II at one of the areas of the park. The limbs development and body condition were evaluated daily, and the weight every seven days during artificial rearing. The mortality rate was lower and the number of births and survival rate were higher during artificial rearing. All of the young exhibited weight gain (P<0.05), good body condition and no dystrophies were observed. The development stages of chicks and the weight were monitored daily, and the measurements of the beak and bones were taken every seven days. The eyes opened on day 4.73±0.12, the nestlings moved within the nest on day 6.31±0.18 and left the nest on day 15.3±0.68. The means weight and measurements of the bones increased (P<0.05). The means of beak despigmentation decreased (P<0.05). The beak pigmentation started on day 7º and on day 35º was completely pigmented. The correlation between all parameters and the determination coefficients of regression equations were high. Diet F was found to be best for the artificial rearing. The artificial rearing protocol provided an adequate environment and feeding, intensified the reproduction and increased the number of scarlet ibises. Growth estimation equations were developed to assess the chicks growth and was possible to describe the developmental stages. Beak pigmentation was found to be a useful parameter for estimating the age.