Aviary design____________________________________________________________

For the best chances of breeding, privacy and the feeling of security are at least as important as aviary size. All of the on-exhibit aviaries have a solid back and ends, leaving only the front open to zoo guests. With 3 sides of the aviary solid, the birds are assured that they cannot be approached from any direction except the front. This tends to make the birds feel safe and far less threatened than if they were in an open-sided aviary. The aviaries also have mature plants and trees that further insulate the birds from clamorous attention. The keel-billed toucans are very nervous when keepers enter the aviary, but the birds accept any amount of attention from onlookers because of the natural screen provided by the foliage.

A solid-sided aviary is even more important to protect the birds from the cold winter winds. In addition, a partly solid roof can offer protection from driving, freezing rain, as well as helping to exclude pathogens that may be introduced by the feces of wild birds or mammals. The exhibits at Riverbanks have roofs that are seven-eighths solid. Even with such well constructed aviaries and the provision of heat boxes, shown below, maintaining toucans outside year-round in our climate carries a small risk. We are always aware of the weather, and constantly observe the birds for any signs of injury from frost. However, all of our birds currently look excellent, perhaps due to good nutrition; and overall, they appear far healthier and livelier outside than inside, regardless of the weather.

Heat boxes are installed in all of the outdoor toucan aviaries. It is not thought that any of the toucans actually enter the boxes, but instead, they may sit in front of the opening as the warm air emerges. Equally, the birds may stand on top of the boxes to warm their feet, the part of their body most likely to be frost damaged during the winter. The boxes are made of plywood and mounted to the back of the aviary about 8 feet above the ground. A 250 watt heat lamp is fitted inside each box. This is turned on when temperatures of less than 40 degrees Fahrenheit are predicted.




Small ramphastids: Green aracari, emerald toucanet, saffron toucanet.
An enclosure of 5' x 6' is sufficiently large for good health and breeding. As with most birds, the higher the aviary the safer the toucans feel. Our green aracaris and emerald toucanets have bred in outdoor and indoor enclosures ranging in height from 9' to 12'.

Large ramphastids: Toco toucan, keel-billed toucan, chestnut-mandibled toucan.
For short periods of time, we have kept off-spring of the larger species in modest sized aviaries measuring 7' x 10' x 12' high. Two birds can thrive in such enclosures for approximately a year until permanent accommodation is available. However, for breeding, aviaries must be considerably larger. Our keel-billed toucans breed in an aviary 21' x 10' x 12' high. The toco toucans breed in an aviary 28' x 10'x 12' high; and the chestnut-mandibled toucans have bred in an enclosure of similar dimensions. The aviaries sit on a base that is raised 2' above the public pathway. The birds' highest perches are therefore nearly 14' above the public.

Yersiniosis and aviary design:
All ramphastids appear to be highly susceptible to Yersiniosis. Also called pseudotuberculosis, the disease is spread by the feces of mice and rats, and can be extremely potent. Many aviculturists have seen their birds transformed from apparent excellent health to death, within only a few hours. The disease can be confirmed by a post-mortem examination, with yellowish-white spots on the liver similar to that of tuberculosis. Appropriate antibiotics can help affected birds, but they must be administered immediately. The rapid onset of the disease makes early detection difficult. Survivors from an afflicted aviary could benefit from prophylactic antibiotic treatment. But of course prevention is far better than a cure, and with ramphastids, the correct aviary design is the best defense against this devastating disease.

Mesh which is small enough to exclude vermin is ideal. Zoomesh is a fairly new product available in the US. It is literally a woven, stainless steel mesh that is so fine that even most insects are kept out. It is also easy to see through, especially when painted black. An important additional benefit of such fine mesh is that the toucans cannot damage their bills if they fly into it. Young birds are especially prone to hitting mesh and permanently creasing, or even snapping off, the ends of their bills. Ultimately, mice and rats will always penetrate an outdoor aviary, and overall aviary hygiene is essential.

Drainage is especially important. Rat and mouse feces can remain in a damp environment far longer than a well-drained one. The substrate in the toco aviary is sand; in the keel-billed and chestnut-mandibled toucan aviaries it is granite rock chips. In each exhibit, the substrates cover a drained, concrete floor. The floor is cleaned daily with a hose. Otherwise, every aviary remains fairly dry, especially since the roof shelters it from rain.