Macaws are noted for being long lived. Estimates of their life span have reached 60 years or longer. Actually, little documented evidence of their life span exists in the literature. With this in mind, a study of the known ages of the birds in residence at Parrot Jungle, Miami, Florida, was undertaken to provide some documented data on this topic.
Parrot Jungle was founded in 1936 as a tourist attraction. Free flying parrots and macaws were the leading attraction. Birds were allowed to breed freely and a facility was constructed for those birds that did breed. Many of the birds hatched at Parrot Jungle have remained there a11 of their lives, making tracking age possible.
To document the aging in these birds, 57 birds known or estimated to be 25 years or older were examined for three years. Of these, 26 were captive-bred and ranged from 25 to 52 years of age. Thirty-one were wild-caught and had been residents of Parrot Jungle for over 20 years.
The oldest bird at Parrot Jungle was recently euthanized due to severe seizure activity. This was one of the original birds imported in 1936, and was at least 57 years old. This bird, however, had been blind and had a chronic neurologic disorder for many years. The first baby hatched at Parrot Jungle is still in residence and is known to be 52 years old. His sibling died at age 49. Seven captive-bred birds are known to be between 41 and 48 years old. All have cataracts that have obscured or reduced vision. All show degenerative diseases associated with advanced age.
Macaws show physical degeneration progressing with age, becoming evident at about the time their reproductive potential is exceeded. In this study group, Macaws produced offspring between approximately four and 35 years of age.
While age changes were variable as to age and onset, in general, muscle wasting and weight loss was evident in most individuals after about 40 years of age. Some of this muscle deterioration could be attributed to lack of exercise. Typically, older birds, who had been free-flying would resort to walking or resting in a familiar location for most of the day.
Posture changes were not dramatic, however, joint stiffness is evident in many birds over 40 years of age. Spotty depigmentation of the feet was common, and aged Blue & Gold and Green-winged Macaws often showed thinning of the facial feathers. Feather pigmentation was largely unaffected, although feather condition and lustre declined in birds in their mid to late forties.
A large number of disease processes associated with advancing age were evident in these older birds, including eye changes (cataracts, etc.), stroke, chronic heart disease, liver disease, kidney disease, etc. Macaws are long lived and have few natural predators. They reproduce for many years and provide parental care for their young for at least four months, making multiple clutches in the wild unlikely unless of clutch loss. Reports indicate they may not breed every year, or may often rear only a single chick. Theoretically, species, which have a low reproductive rate, can maintain their population in the wild if they have a long reproductive life span.
Wednesday 17th February 2021
Native trees planted on burned pasture land
Neiva Guedes recently visited the imposing mountain range in the centre of the Pantanal and discovered some of the burned pasture land had been replaced with native trees such as manduvi, acuri and bocaiuvia. She reported this with some photograph ... Read More »
" Naturam expellas furca, tamen usque recurret "
( If you drive out nature with a pitchfork, she will soon find a way back)
Horace (65-8 BC)