The birds of family Ramphastidae are found in South and Central America, from central Mexico to southern Brazil, and include the large toucans, the small aracaris, and smaller toucanets.¹ Known for their large and colorful bills, this group consists of at least five genera and over 40 species.²³

 

Class: Aves

Order: Piciformes (woodpeckers, honeyguides, barbets, jacamars, puffbirds)

Family: Ramphastidae

Ramphastos: large, black toucans

Andigena: large, mountain-ranging toucans

Pteroglossus: araçaris

Aulacorhynchus: green mountain toucanets

Selenidera: lowland, forest-ranging toucanets

 

In captivity, toucans are charismatic birds that are popular in zoos and aviaries. They are occasionally kept by aviculturists or as household pets.^25,26 Toco toucans (Ramphastos toco) and sulfur-breasted or keel-billed toucans (R. sulfuratus) are commonly seen in clinical practice.²⁵ Swainson’s toucan, also known as the chestnut-mandibled toucan (Ramphastos ambiguus swainsonii) is also commonly imported. Many araçaris and toucanet species are also seen in aviculture and as pets (Kuchinski, email message to editor, Nov 3, 2021).

The International Union for Conservation of Nature (IUCN) Red List describes most free-ranging ramphastid populations as of “least concern”.¹³ Although numbers are decreasing for most species, few species are threatened with extinction.¹³

Species	IUCN Assessment
Grey-breasted mountain toucan (Andigena hypoglauca)	Near threatened
Plate-billed mountain toucan (Andigena laminirostris)	Near threatened
Saffron toucanet (Pteroglossus bailloni)	Near threatened
Yellow-throated toucan (Ramphastos ambiguus)	Near threatened
Channel-billed toucan (Ramphastos vitellinus)	Vulnerable
Red-billed toucan (Ramphastos tucanus)	Vulnerable
Yellow-ridged toucan (Ramphastos culminates)	Vulnerable
Ariel toucan (Ramphastos ariel)	Endangered
Eastern red-necked araçari (Pteroglossus bitorquatus)	Endangered

When properly cared for, toco toucans have a life expectancy of up to 25 years ^9b,10b.

Ramphastid species		Body weight (grams)1
Green aracari	Pteroglossus viridis	120-160
Ivory-billed aracari	P. azara	130-160
Curl-crested aracari	P. beauharnaisii	180-280
Crimson-rumped toucanet	Aulacorhynchus haematopygus	200-230
Black necked aracari	P. aracari	230-250
Keel-billed toucan	Ramphastos sulfuratus	280-400
Plate-billed mountain toucan	Andigena laminirostris	300-350
White-throated toucan	R. tucanus	450-600
Toco toucan	R. toco	550-800

Musculoskeletal	The feet of these birds are zygodactyl, with digits 2 and 3 facing forward and digits 1 and 4 directed back.16 The tail vertebrae are modified so that birds are capable of rotating their tails forwards to touch their heads. This is a common sleeping position.23
Gastrointestinal	The large bill consists of spongy bone protected by a thin wall of keratin, the rhamphotheca.10,21 The bill is serrated, highly vascular and extremely sensitive. The internal beak is supported by bony struts, but the beak is also very lightweight and can be easily injured (see common medical conditions below).23 Many functions have been proposed for these magnificent bills, including foraging, courtship, aggression, and thermoregulation.23,24 The thin, delicate tongue features laminated sides and a brush-like tip. Some ramphastids will rattle the tongue against their bill to produce a characteristic rattling sound. Ramphastids do not have a crop or cecum.3,23 Some toucans possess an elongated gall bladder.15 Ramphastids produce voluminous, wet fecal droppings. In fact, the droppings frequently look like undigested food, particularly fruit (Cubas and Kuchinski, email messages to editor, Nov 3, 2021). A survey of normal cloacal flora in toucans and aracari found Gram-negative bacteria (E. coli, Klebsiella spp., Enterobacter spp.) as well as Gram-positive cocci (Staphylococcus spp., Streptococcus spp.) (Cornelissen 1991)
Respiratory	Ramphastids have a ventral deviation of the trachea at the thoracic inlet which can be appreciated radiographically (select lateral radiograph image left to enlarge).6,23
Integumentary	Adult birds lack down feathers 16, although powder down has been described in toucans.20 The apterylae, or the space between feather tracts, can be quite large making venipuncture relatively easy. Plumage color may become faded in captive birds due to inadequate dietary carotenoids (Cubas, email message to editor, Oct 18, 2021).
Reproductive	Most ramphastids, including the keel-billed toucan, have melanistic or colored gonads.25 The vast majority of captive ramphastids are kept as aviary birds in breeding situations.25 Toucans are cavity-nesting birds. Some species take over the nests of woodpeckers, while others, especially the larger species, use their bills to make a hole and hollow out decaying limbs of trees. Both sexes share incubation and rearing duties.23 The general convention in captive toucans is to provide a hollowed-out section of palm log to facilitate breeding. Some breeders have been successful with conventional plywood nest boxes, especially when they have been modified to include an external bark tile covering with cork over the entrance hole to allow the birds to “hollow it out”. Captive birds may be parent reared but are also often hand reared.23 See Behavior for additional information.
Pediatrics	Eggs per clutch in toucans, toucanets: 2 to 4 23 Incubation period in toucans, toucanets: 15-16 days23 When compared to toucans, toucanet and araçari offspring have higher survival rates, averaging 80% (Dislich 2014). Causes of chick mortality include infanticide by parents, stomach impaction, and bacterial disease (Dislich 2014). Neonates usually have a hypotarsal pad (or heel pad) on their hocks, that they use to rest on the ground, rather than standing on two feet while in the nest. These pads atrophy as birds mature.6,23 Chicks leave the nest at 6-7 weeks of age and begin eating on their own at 10-12 weeks of age (Dislich 2014).23 See Diet for information on hand feeding.
Sexual dimorphism	Most ramphastids are phenotypically monomorphic 23, although male birds tend to have a larger beak than females.4,25 Measurement of the upper bill from the origination with the facial skin to the tip may also be helpful in determining sex. In mature toco toucans, it has been suggested that birds with upper bill length <15.5 cm are usually females but if the length exceeds 16 cm the bird is usually a male.25 DNA sexing and endoscopy are the most reliable methods of sex determination in monomorphic species. Sexually dimorphic birds include lowland toucanets of genus Selenidera and two of the araçaris, P. viridis and P. inscriptus (lettered araçaris).23,25

Ramphastids are primarily frugivores, although they are opportunists and will also eat insects and small birds or reptiles.²³ Free-ranging ramphastids play a crucial ecological role in the dispersal of the seeds of fruit trees. Ramphastids consume a variety of fruits and seeds, such as fruits of Ficus, guava, and palm trees (Euterpe spp.) as well as chili pepper ^10b.

In captivity, ramphastids should be offered diced, mixed fruit. Toucans especially enjoy colorful fruits, such as papaya and berries.¹⁴ They will also readily consume bananas and a variety of melons.¹⁴ Due to the high risk of iron storage disease in these birds, the diet should be iron restricted. Avoid citrus fruits, tomatoes, and pineapple, as these contain high levels of citric acid and ascorbic acid, which increase iron absorption.^14,23

Ramphastids also require a source of high protein not available in fruit.¹⁴ Offer a nutritionally complete, formulated toucan pellet with low iron (< 150 ppm). The total iron content of the diet should ideally be less than 40 ppm (20-60 ppm). There is some debate about the best dietary iron levels for optimal reproductive performance (Kuchinski, email message to editor, Nov 3, 2021), however dietary iron is generally limited except when raising chicks, which need animal protein for growth.²³

Fresh water should always be available, however ramphastids generally do not consume large quantities of water. Instead they obtain most of their daily fluid requirements from fruit.^14,25

When compared to psittacine birds, hand feeding time is prolonged due to the absence of a crop.^{22b, 23} For instance, it can take up to 30 minutes to feed a 2-3 week old bird.^22b Commercial hand feeding formulas developed for psittacine birds can be used in toucans; this diet can be supplemented with fruit.^22b,23

Ramphastids are very active birds that should be housed in large, lightly planted aviaries that allow them to move around enclosures by hopping from branch to branch.^9,14,23 Ramphastids also require ample space.²³ Large toucans should be housed in aviaries 4 m wide, 7-8 m deep, and 2-3 m high.^9,14 It is also important that some visual security be provided. ^9,14

Although most ramphastids are relatively cold-tolerant, these birds can be sensitive to frostbite in temperate climates. Some species, such as the toco toucan, have been reported to be particularly susceptible to frostbite in winter.²⁵ These birds should be brought inside during the colder months in temperate climates.²³

Although some of the larger toucans, and to a lesser extent the larger araçaris like the chestnut-eared (P. castanotis), can be noisy, these birds are far quieter than most psittacine birds.

Ramphastids enjoy bathing and should be provided large water receptacles.¹⁴

Sanitation and vermin control are also important (see Infectious Diseases and yersiniosis below). Elevate food dishes off of the ground, ideally on freestanding structures.²³

Toucans are social birds that often spend their time in flocks of dozens. Pairs may split off for breeding but return to flocks with their offspring.

Toucans are also territorial birds.²³ Mate aggression, fights between males, and interspecies aggression are common.¹⁰ Reproductively active birds are particularly territorial. During the breeding season, males caged next to each other without the presence of a visual barrier may injure their beaks by engaging in beak jousting.¹⁰

Many captive parent birds will reject their young in response to stressors, such as inspection of the nest log. Therefore some breeders place a camera in the nest box to minimize both the need for inspections and parental stress (Kuchinski, email message to editor, Nov 3, 2021).

Manual restraint

Ramphastids can be aggressive and can inflict painful injuries to handlers. Use a towel to remove birds from the cage. Manual restraint can involve holding the bill, taking care not to obstruct the nares, which are located at the base of the upper bill.¹⁰ The beak is easily damaged if too much side-to-side pressure is applied.¹²

Netting is also theoretically possible, but realistically quite challenging. Ramphastids can be remarkably quick putting birds at significant risk for injury during capture.

Chemical restraint

Inhalant anesthetic induction of a toco toucan using a small human pediatric mask placed over the nares at the base of the bill has been described ¹², alternatively a mask can be constructed from a cylindrical plastic bottle, like a soda bottle, to accommodate the long beak.^10,12,23 To reduce mechanical dead space the mask should be the exact size of the beak.¹⁰  The beak of the smaller araçaris and toucanets fit into a large dog mask.

Endotracheal intubation is a relatively simple procedure in ramphastids. The small, filamentous tongue makes the glottis easy to visualize.¹⁰

Iron storage disease

Iron storage disease is the most famous clinical condition of ramphastids.^6,7,22,23 It is important to make the distinction between hemosiderosis and hemochromatosis, the former being a potentially physiological presence of iron in the tissues which does not result in inflammation, the latter being a pathological condition which results in cellular derangements.

More research is needed, however it is thought that high levels of dietary iron is an important predisposing factor. Free-ranging ramphastids typically eat diets that are low in iron and have potentially evolved to retain iron very effectively.² Diets should be limited to 20-60 ppm of iron, although they may be slightly higher during the breeding season when chicks are being reared. A lack of tannins in the diet has also been theorized as a possible risk factor for excess absorption of iron in the intestines. It is thought that wild birds consume water from cavities in trees that have been leached with tannins from plants. Ascorbic acid increases the bioavailability of iron and diets containing citrus fruits may also predispose to iron storage disease. Stress has also been suggested as a contributing factor.^6,7,22,23

Clinical signs include lethargy, anorexia, abdominal distension, ascites, dyspnea, neurological signs, and sudden death. Liver biopsy is the diagnostic test of choice. Liver enzymes and bile acids may be elevated on biochemistry analysis. The use of MRI to measure the iron content of the liver has shown promise in other species and may have a place in avian medicine for diagnosis and monitoring of this condition. Treatment is with weekly phlebotomy of 1% of body weight. The use of iron chelators such as deferoxamine (100 mg/kg q24h SQ) or deferiprone (50 mg/kg q12h PO) for 30 days has also shown positive results.^6,7,22,23  Intestinal iron absorption can also be reduced by adding tannin-rich items, such as black tea, and phytates ^10b. Supportive care and symptomatic treatment is also indicated.^6,7,22,23

Infectious diseases

Ramphastids are known to be especially sensitive to yersiniosis (Yersinia pseudotuberculosis). This disease is usually spread by rodents entering enclosures and a strict rodent exclusion protocol is particularly important where these birds are kept.¹⁸

Bacterial septicemia has often been reported in ramphastids, caused by a variety of species including Coxiella spp., Bacteroides spp., Mycobacteria spp., Escherichia coli and Salmonella spp.²³

Capillariosis is common and a significant cause of mortality in captive toucans.^10,23 Clinical findings may include lethargy, dehydration, and emaciation.²³ Many birds will ingest their droppings, which can be an issue when trying to control parasite loads within aviaries (Kuchinski, email message to editor, Nov 3, 2021).

Damage to the beak

The beak is very lightweight and can be easily injured.²⁵ Beak injuries occur most frequently in young birds that are learning to fly or that have been recently introduced into a new flight.²⁵ The beak also tends to be softer and more susceptible to injury in juvenile birds.²³

Urgent care of beak injury involves control of hemorrhage. Apply pressure for a few minutes with a gauze pad moistened with an antiseptic solution. Remove debris and gently clean, then thoroughly dry the wound.¹⁰ Take care not to introduce liquid or debris into the spongy bone, which can carry contaminants to deeper parts of the beak or sinuses.¹⁰ Apply water-soluble antibiotic ointments to the wound and tape gauze dressings over the defect.¹⁰ Replace dressings every 24 hours until hemorrhage and infection are controlled.¹⁰ Parenteral antibiotics are often indicated. Biocompatible cellulose membrane or other dressings can be used to treat open wounds and fractures in the beak.

Beak repair techniques using dental adhesive systems, orthognathic correction with molds, surgeries and beak prosthesis can be employed in toucans ^10c. Both natural and artificial beak prostheses have been used to restore function in birds with traumatic beak deficits. Natural beak prostheses may be alloplastic (from the same species) or heteroplastic (from a different species).^9,11

Diabetes

Diabetes mellitus has been reported in keel-billed and toco toucans. As in other species, weight loss, polyuria, polydipsia, and polyphagia may all be seen. Hyperglycemia and glycosuria are usually appreciable with diagnostic investigation. Initial treatment with PZI or NPH insulin has been successful, followed by long-term insulin treatment on a daily or every other day basis. Dietary modification may also be a consideration. ^17,23

Diabetes may be associated with iron storage disease, since iron deposits may be seen in the pancreas as well as the liver ^9b (Cubas, email message to editor, Oct 18, 2021).

Metabolic bone disease

Nutritional secondary hyperparathyroidism is reported commonly in young birds fed a calcium-deficient diet.²³ Chicks may refuse to eat formulated diet in preference to tastier fruit.²³,²⁵ The beak may become soft and rubbery, or the pelvic limbs may be bent or bowed. In some cases, trauma from flying into aviary walls with underlying metabolic bone disease issue can result in fracture of the bill tip. Recommended dietary modifications include increasing calcium levels along with supplementation of calcium or vitamin D3. Provision of an UVB bird lamp is also likely to be beneficial for birds that are housed indoors.

Other reported conditions

• Foreign body ingestion may be seen in ramphastids due to the curious nature of these birds.²⁵ Foreign bodies, such as sticks or large insects, can also be fed to chicks by parent birds (Kuchinski, email message to editor, Nov 3, 2021).
• Herpesvirus infection causing necrotizing hepatitis and sudden death was reported in a toucan, species unknown. The etiologic agent was thought to be distinct from psittacine herpesvirus (Pacheco’s disease).⁵
• An outbreak of ulcerative enteritis caused by Clostridium colinum caused sudden death in a group of young toucans ^24b.
• Chlamydia psittaci has been demonstrated in toucans, however these birds do not seem as predisposed to developing clinical disease as other species, such as psittacine birds.¹⁹
• Candidiasis has also been reported in ramphastids, especially in young, hand fed birds.²³ Other fungal diseases, such as aspergillosis, have also been described.²³