iris billed toucan o piquiverde toucan (Ramphastos Sulfuratus), is a playful little social bird found mainly in Central and South America. It is the smallest of all toucans. Its beak is one of the most colorful in the world of birds, hence its name. We must not confuse it with the common toucan, since it has many variations that we will see below.

We can appreciate the beautiful beak of the iris-billed toucan, its greatest feature

We can appreciate the beautiful beak of the iris-billed toucan, its greatest feature

Features

The adult is mostly black in color with a yellow bib covering the throat and chest. The sexes are similar in color but the male is larger. Males measure an average of 55 cm long, females an average of 52 cm. Keel-billed toucans are similar in plumage, but smaller than the chestnut-jawed toucans (Ramphastos ambiguus swainsonii).

Similar species

The Ramphastos toucan species are similar to each other in their primarily black plumage, large bill, and light-colored throat (white or yellow). Of those with yellow throats, only the "chestnut-jawed toucan" (Ramphastos ambiguus swainsonii) overlaps geographically with the keel-billed toucan (R. sulfuratus). Both species have plumage and coloration patterns similar to orbital skin. However, the keel-billed toucan is smaller and has a distinctive coloring, which explains the alternative name, rainbow-billed toucan.

Detailed description

Adults: SULFUR billed brevicarinatus: The color pattern is similar in both sexes. The crown and rear neck are black, the latter heavily washed with garnet; the upper part of the tail cover is white; the remainder of the upper surface includes glossy greenish-black wings and tail. The underside of the tail coat is red (basal black) and the rest of the underparts are slightly greenish-black. The malar and auricular regions, the throat, the upper chest, and the small spot between the eye and the nostril are bright yellow. The convex lower margin of the yellow breast has a broad curved band, 5-12 mm wide, of bright red color.

Chick: Similar to adults but more opaque; the red on the chest and under the coverts of the tail is decidedly more opaque, the black feathers on the body are opaque brownish black, those on the belly with a red tip; less garnet on the nape feathers. The red chest band is more diffuse over the black lower chest.

Young

An incomplete formative molt ("post-juvenile") begins within a month after flying, and involves all body plumage except the remiges and rectrices. All feathers change in the first basic molt.

In all subsequent years, there is only one basic annual molt. In Panama, this occurs after nesting (February-May). The variation occurs at the exact moment of molting, some still molting during the last of August.

The method and order of molting is regular, beginning in the proximal primaries and almost immediately afterwards in the plumage of the body, first on the head, and then on the various tracts over the whole body.

The primaries molt out in regular sequence, the main top coverages in the same order, but several places ahead of their respective primaries. The main lower coverages were lost around the same time as the primaries. The secondaries begin to molt at the same time, when the fifth or sixth primary is lost. The secondaries proceed inward. The tertiary molt is completed before the secondary ones because they are fewer in number.

Tail shedding is almost unique among birds, starting from the outside and continuing to the central feathers. This molt begins simultaneously with the molt of the second primary and is usually completed by the time the sixth primary is molted. The upper and lower coverts of the tail molt at the same time as the tail, in no particular order. The moult of the remiges and rectrices is usually very symmetrical; the corresponding feathers on both sides are lost at exactly the same time.

There is no natal molt. The chick is well covered when they begin flight (about XNUMX days).

Bare parts

Adult

The iris is olive yellow to green in color; greenish yellow bare orbital skin around eye to lemon yellow on top and back.

The beak is light greenish yellow along the culmen turning into yellow green towards the tomia and the basal third of the mandible; quarter terminal of the maroon beak. The lateral wedge-shaped area in the thomial half of the maxilla is orange; the rest of the jaw is pale cerulean blue. The bill is basally marginalized by a clearly defined black line about two millimeters wide.

Tarsus and toes pale gray-blue, turning pale green on upper tarsus; black claws.

Chick (until moult of juvenile plumage)

Pale gray iris, lime green; yellow orbital skin (bright green-yellow around nostrils), pale blue under eye.

Maxillary apple green centrally to olive yellow on culm. The anterior part turns yellow-green centrally to yellow at the top; wedge-shaped lateral area is light orange, turning into; the terminal quarter of the bill is light red.

The jaw is green, with a light gray-blue color on the front and green on the base.

At the base of the bill, unlike the adult, there is no clearly defined black line, but a broader blackish area almost ten millimeters wide. This becomes more restricted at the end of the juvenile period. Its beak has no serrations.

Behavior

Among five categories of behavior, toucans in Mexico were observed to spend approximately the same amount of time upright and in search of food (35% to 40%); calls, grooming, and social interaction (movement by another bird or direct contact between birds) each occupied 10% or less of the birds' activity.

The flight of the iris-billed toucan is slow and undulating, consisting of rapid wing beats (six to ten), then a glide with the bird's beak extending forward and plunging downward as if pulling the rest of the bird. Its legs are traced forward in flight.

Flight distances are typically short, outdoors through streams or small clearings. They can travel in small groups of up to a dozen individuals. This appears to be uncoordinated, with one bird after another, lagging along a single row.

Although Van tyne (1929) y Skutch (1971) describe the iris-billed toucan as weak fliers, Wetmore (1968) argue that this is a misconception and that they can easily travel between distant ridges.

Toucans are very playful, they gather in small groups of 6 to 22 chasing each other from branch to branch, playing 'ball', one throwing a fruit in the air and the other catching it.

The iris-billed toucan is a very sociable bird.

The iris-billed toucan is a very sociable bird.

Habitat

It tends to live around tropical, subtropical, and lowland forests. Usually lives in groups. Nests in natural tree holes, or made by woodpeckers, mainly in the treetops and often with other members of the family. While sleeping in the tree hole, it sleeps with its beak and tail tucked under its body to make room for other family members. It is a social bird and is rarely seen alone.

Distribution

The iris-billed toucan is found in lush and secondary tropical lowland forests from southern Mexico, where it is the only large toucan, from south through Central America to northern Colombia and the extreme northwest of Venezuela. Over much of its range, it overlaps with the "Chestnut-jawed Toucan" (Ramphastos ambiguus swainsonii).

Food

The Iris-billed toucan is mostly frugivores, they eat fruits and tree seeds such as Cercropia (green spiked fruits) and Inga and Protium. In Belize, toucans consumed fruits of the fig tree, the trumpet tree, the copal, the wild cherry and the breadnut. They frequented the trumpet and the fig tree almost twice as much as the other types of trees.

A small flock of eight to ten toucans will fly towards a particular tree in the early morning. They lag one or two at a time. The individual toucans will then move with long bouncing jumps towards the outermost branch that will support their weight. It will stay in this position, holding on to the branch and extending the wing in all directions to grab the fruit.

Predators

The iris-billed toucan is most vulnerable when nesting and is targeted by mammals, snakes, hawks, and eagles. For example, they are the most abundant prey for the osprey (Spizaetus tyrannus).

Reproduction

We are going to comment step by step on the reproduction of the iris-billed toucan.

Breeding season

The iris-billed toucan breeds from March to June in Costa Rica and in April in Panama. In Panama, this is the dry season.

Toucans raise a single young and probably remain mated throughout the year. They return to the same nest the following breeding season as long as the previous one was successful. Toucans acquire a nest up to 6 weeks before laying their eggs. Because the number of suitable natural tree cavities is small compared to the toucan population, this can occur to ensure that the pair have a safe place to nest when the time is right.

Nests

In natural cavities, 6 meters high, in trees such as Inga, Hura, Pentaclethra macroloba and Cupania. The open hole of the cavity is small. Although toucans begin to nest long before they lay eggs, they do not use the cavity as a resting place.

Toucans clean the cavity, leaving only a few chips to line the nest. They also bring small green leaves (up to two and a half inches long) to the nest almost every day. When the leaves dry they are frequently brought back. These can work as insect repellants (as in falcon nests).

The nest is a mosaic of seeds and bones of various sizes, shapes and colors that result from the habit of toucans to slaughter the bones of the fruits that form their food. As a result, the young are raised in a nest with a "cobblestone" lining of fruit pits the size of large marbles.

Clutch size and eggs

A female toucan lays between 1 and 4 eggs, one egg per day. The eggs are rounded with one end slightly more pointed than the other. They are dull white and sculpted with irregular grooves that run the length of the egg, being more prominent at the large end. At the small end of the egg they become less distinctive or disappear entirely. The yolk is a deep orange color.

Parental care

Incubation begins after all the eggs are laid. Both parents are involved. Sessions last from four minutes to nearly two hours, with one pair observed keeping their eggs covered for about 70% of an 11-hour period. The total length of incubation time is unknown. In smaller toucans, for example the emerald toucan (Aulacorhynchus prasinus), the incubation lasts 16 days.

Feeding of the iris-billed toucan chicks and the removal of fecal matter is performed by both parents. In one observation, the day brood was abandoned early, but a single parent spent the night with the chicks for most, if not all, of their nest stay.

The young are born at approximately 45 days.

Youth development

Details are from Van tyne (1929) y Skutch (1971). Two experts on the iris-billed toucan.

  • In hatching: Pink skin is bare and eyes are tightly closed. The lower jaw of the short bill is slightly longer than the upper jaw. Around each heel joint is a pad, a ring of light-colored projections. The nest continuously emits a screeching hum.
  • In its first minutes: The young bird constantly repeats a low chirping note.
  • Day 4: The pattern of the feather areas of the body is visible and the ten tail feathers become a row of small spikes one or two millimeters long.
  • Day 10: Still naked, the skin is pinkish at first, turning to a golden hue within a few hours. Its two jaws (the upper and lower) are the same length.
  • Day 14: Still naked but all feather tracts well marked. The rudiments of the rectrices are slightly longer, and a darkening in the wings is caused by the buds of the flight feathers. The eyes are still closed.
  • Day 15: Wing feathers emerge and then grow rapidly.
  • Day 17: The eyes are partially open. The rudiments of the body feathers are visible as dark spots under the pinkish skin. The screeching vocalizations of the buzz sometimes escalate to a loud scream.
  • Day 18: The chicks began to flap their wings vigorously.
  • Day 19: Secondary feathers begin rapid growth.
  • Day 20: The contour feathers extend all over the body except for the head, go through the skin and begin to grow rapidly. The eyes began to open. The voices of the chickens abruptly change from an almost constant buzz to a "wraa, wraa."
  • Day 23: The tail feathers began to grow rapidly.
  • Day 24: The remigres and the upper coats of the secondary feathers begin to unfold.
  • Day 30: The eyes are wide open. Remiges and coverts expand rapidly from the ends of their pods. The body is still largely bare, the dorsal feathers protruding from the ends of its short sheaths. There is a pin-feather ridge along the top of the head, but the rest of the head is quite bare.
  • Day 33: Feathers are coming out rapidly all over the body, including the red feathers at the bottom of the throat.
  • Day 37: The chicken is fully feathered.
  • Day 47: They leave the nest.
An iris-billed toucan chick.

An iris-billed toucan chick.

State of conservation

Although numbers for the iris toucan may be declining, the IUCN Red List status of the iris toucan is assessed as Least Concern (LC) due to the large population size and wide range of distribution.

Effects of human activity on populations

Populations are in decline due to habitat loss, and hunting and trapping as pets. On the other hand, elevation ranges are expanding upward in response to climate change.

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