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The Hyacinth Macaw Project 1996-1997
Piaui, Brasil
Heather Bowles
senior veterinary student
Virginia-Maryland Regional College of Veterinary Medicine
Reprinted fron the Proceedings of the International Aviculturists Society, January, 1997.
The Hyacinth Macaw, Anodorhynchus hyacinthinus, was at one time widely distributed through Brazil, Bolivia, and Paraguay. However, a more recent survey has estimated their total numbers to be between 2500 to 5000, in three distinct populations. These populations are located in the rainforests of Para, Brazil, in the seasonally dry, rocky valleys of northeastern Brazil (Tocantins, Piaui, Maranhao, and Bahia), and the Pantanal wetland of Brazil, Bolivia, and Paraguay. At this time the most studied population had been that one located in the Pantanal, leaving these other two to be further examined. This Hyacinth Macaw is currently considered rare to endangered, and at a definite risk of becoming extinct if the causal factors continue to operate. To this day international trade, hunting, agriculture, logging, and hydroelectric projects considerably insult their survival.
The objectives of this study were to asses the Hyacinth Macaw population and area of southern Piaui, in northeastern Brasil, collect information concerning the diet, and study the physical condition of chicks. In addition, we collect preliminary data concerning nest cavity temperature and relative humidity, nest dimensions, and nest distribution in the cliffs.
To assess the trapping situation and current population of Hyacinth Macaws in the area several ex-trappers were interviewed separately and repeatedly. Consistent reports of trapping an average of 80-100 Hyacinth Macaws per year were obtained. This included chicks as well as reproducing adults. Approximately 70% of the nests were exploited, the remaining 30% were reported as inaccessible to humans. The current numbers were difficult to assess accurately as I worked in a small area as compared to the reported habitat for these birds.
Hyacinth Macaws were found to consume several fruits which were abundant in the area. The types of fruits and time of peak numbers and availability are as follows:
Fruit Time of Year Available Peak Season Portion Consumed
Chule* year round Sept - Feb nut & mesocarpus
Pia Caba year round Feb - July nut & mesocarpus
Buruti year round Oct - Feb ripened fruit: oily substance, just beneath outer surface
green fruit: nut & mesocarpus
Tucun year round Oct - Dec nut & mesocarpus
Sapucaia July - Dec nut & mesocarpus
Clay from cliffs and inside nest cavities
*Chule(pronounced catolay) was by far the most abundant during my study.
Data regarding the physical condition and body measurements was collected from 11 Hyacinth Macaw chicks from 9 nests. This was done by performing thorough physical exams, assigning a body condition score using a body condition score chart designed by Kaytee Products, Inc., and measuring the wingspan, body length, and chest circumference of each bird. The average body condition score was a 3.5/6. This is very good as compared to many Hyacinth Macaw chicks in captivity in the United States. The chicks were found to be well hydrated, and feather quality of most birds was found to excellent, with no evidence of stress bars nor retained feather sheaths. Most birds were found to have full crops, filled with chunks of food of a hard consistency. Two nests studied contained two chicks. These chicks were somewhat thinner, with an average body condition score of 2.5/6, and a few stress bars were found in the feathers of each chick. This may represent a certain level of stress in raising two chicks at one time.
It was determined that further studies would indeed be possible in this area as much information is needed regarding Hyacinth Macaws. Future studies that would be useful would be an extended reproductive study from incubation to weaning with regard to chick condition, weight, and mortality, as well as, nest cavity temperature and relative humidity. It would also be beneficial to assess current numbers in the area of southern Piaui.
Heather Bowles, DVM, DABVP