Abstract
The second largest of all the toucans, the Swainson's Toucan, also known as the Chestnut-rnandibled Toucan, is as attractive as it is rare in captivity. With perhaps less than 30 birds in the United States (a population size seldom exceeded) and dim prospects for future imports, lucky are those bird enthusiasts who have an opportunity to see this striking Ramphastid.
The Swainson's Toucan (Ramphastos swainsonii) is considered related to the similar Blackmandibled Toucan (R. ambigua). The differences between the two are found in the dark areas of their bicolored bills, and in the eye-skin. The Swainson's has a reddish brown or chestnut colored lower mandible, and the Black-mandibled a black lower mandible. The eye-skin in Swainson's is bright yellow to yellowish green, and yellowish green to blue in the Black-mandibled. Both have yellow upper mandibles, are otherwise colored the same, and have yelping calls (the Choco Toucan is similar to the Black-mandibled, but is decidedly smaller and has a croaking call).
The Swainson's Toucan is geographically distributed throughout the lowland forest from central Honduras south to northwestern Ecuador and as far east as northcentral Colombia, on the western slope of the Colombian Andes. The Black-mandibled Toucan is found on the eastern slope of the Colombian Andes. Throughout its range, the Swainson's is found from sea level up to 6,000 feet and is common except where its habitat has been destroyed.
Swainson's Toucans are usually encountered higher up in the canopy than other species in its range and is seen in pairs or small groups. Breeding season begins usually in April, though as early as March and adults have been observed as late as November with newly fledged young. Diet, as in all toucans, is primarily fruits, available from several dozen plant species, along with some insects and small vertebrates.
In the Swainson's Toucan, sexes are alike in appearance except for variation in bill size. The hen's bill appears shorter and stubbier. The upper mandible is yellow distally and chestnut brown below as is the entire lower mandible. The eye-skin is yellowish green, and the iris is brown. The Swainson's is essentially a large black toucan with a large lemon yellow breast, bordered by a thin red line below. The rump is white, and the vent is red. The legs are blue.
The Swainson's Toucan has been kept by various private and public collecitons in small numbers for many years. In the mid 1960s, a pair at the Los Angeles Zoo laid eggs, the first recorded laying of eggs in captivity. In the 1980s, several private breeders have had pairs produce eggs, and there have been one or more hatchings, though the young immediately disappeared, probably due to cannibalism on the part of the parents.
It was not until 1990 that the first successful rearing of a Swainson's Toucan occured. On May 6, 1990, a single pair of Swainson's laid two eggs at Walnut Acres Aviaries. Prior to the appearance of the eggs, material from the nest log had been observed on the ground just below the entrance hole. Several days there after, the parents were observed entering and leaving the nest. During this period and the entire nesting cycle to follow, the parents were quite nervous, and would leave the nest as soon as they heard the approach of their keepers.
May 22, 1991 in the early morning, the first egg hatched producing a small, prehistoric looking, naked, pink baby which was very energetic. The remaining egg appeared infertile as seen from the nest entrance. These observations were made using a flashlight and a small mirror, which readily illuminates the nest contents three feet below. By the morning of the following day, the parents had ejected and consumed the infertile egg.
The baby Swainson's grew steadily over the next 18 days. It was observed every other day via mirror and flashlight and, on the in-between days, efforts were made to overhear the faint peeping noises emanating from the nest. This strategy minimized the nest interference, which was deemed an important key to success in light of the parents' inherent shyness.
While the parents never displayed any aggressiveness to their offspring, on June 6, 1990, the young Swainson's was pulled for handrearing. There were two reasons for that intervention, the most important being the closing of escrow on the property where the birds were housed and my impending move to my new facility in Fallbrook, California. The second reason stemmed from concerns the parents might have decided to abandon their efforts, which is not an uncommon occurance with large toucan species.
On June 14th, 23 days after hatching, the baby Swainson's opened its eyes. On the 28th day, the first primary flight feathers emerged. The young bird reached a maximum weight of 436 grams on the 49th day, then gradually lost weight until it was eating completely on its own on July 22, 1990, the 61st day.
The pair of Swainson's were housed in a 10' x 20' x 8' flight, constructed of 1/ 2'' square steel tubing and 1/2" x 1" 16 gauge wire, galvanized after welding. Four feet of the rear roof area, and four feet of the rear side and the back of the cage were solid galvanized metal, the sides covered from the roof down to four feet from the ground. The lower four feet of this "sheltered" area was wire, such that the birds could see you standing behind the cage, from which area the feed and water were serviced and where the entry door was located. The aviary floor was dirt, and growing inside were a Crepe Myrtle tree on one side and dominating most of the interior was a very large, dense Pineapple Guava, in which the birds spent endless hours sitting, preening, and hopping about.
Both the nest log, constructed from a four foot piece of palm tree trunk 20" in diameter, and the feeding station were located inside the sheltered area. The feeding station was serviced from the outside, through a small door which minimized interference with the adult birds.