Ramphastos ambiguus

Geographic Range

Yellow-throated toucans ( Ramphastos ambiguus ) are a native and endemic species to the Neotropics with a geographical range spreading from Central America to the northwestern countries of South America. Based on subspecies, this range varies from southeastern areas of Honduras to some stretches as far south as Peru, including countries such as Nicaragua, Costa Rica, Panama, Ecuador, and Columbia, as well as isolated occasions in northwestern Venezuela. However, yellow-throated toucans are not found widespread throughout each country, and sometimes found only in isolated patches.

• Biogeographic Regions
• neotropical neotropical
  • native native

Habitat

Yellow-throated toucans occupy many primary forested habitats, but mostly wet, tropical forests, gallery forests near wetlands, and lowland evergreen forests. These canopy birds also live in a large range of elevations between 100 m and 2670 m depending on the subspecies and location. Some subspecies like R. a. swainsonii are found in lowlands and lower mountain slopes around elevations of 1000 m and below. Other subspecies such as R. a. abbreviates and R. a. ambiguus can be found more in elevations above 1000 m.

Yellow-throated toucans dwell among canopies and avoid most open areas; however, they can also be found along forest edges. Forest edges and old-secondary forests habitats play a role in foraging for this species. Some of the tree species they are found in include peach palm ( Bactris gasipaes ), and fruiting tree like Casearia corymbose , Euterpe edulis , and Virola bicuhyba .

• Habitat Regions
• tropical tropical

• Terrestrial Biomes
• forest forest
• rainforest rainforest

Physical Description

The yellow-throated toucan's name alone is what gives away its most distinguishing feature. With a bright yellow plumage on the face and chest, along with a long, bi-colored bill, this species stands out. Plumage on the upperparts of the back and wings are a black, with a white patch on the rump and black tips on the upper tail feathers. The undertail coverts are a dark red color. There is no known difference between males and females for feather pigment. As one of the largest toucan species, yellow-throated toucans can also be easily recognized by size. The average weight for males and females ranges between 599 g and 746 g, with the male tending to be slightly larger than the females. Varying by subspecies yellow-throated toucans’ bill length (chord) ranges between 129 mm and 198 mm. The upper mandible appears half yellow on top and most distal from the body, and black towards the bottom and more proximal to the body. The lower mandible is generally a black or a chestnut color; this is found in different subspecies.

Some morphologically similar members of the Ramphastidae family include the keel-billed toucan, ( Ramphastos sulfuratus ) and the choco toucan ( Ramphastos brevis ). These two species often overlap in the same range and habitat as yellow-throated toucans. They can be distinguished however, by bill color and markings as well as by voice. Yellow-throated toucans are again larger, with a longer and broader bill. Another distinct characteristic found is that the yellow-throated toucan has a dark red colored tint on the chest under its bright yellow chest/throat, and red plumage under its tail feathers.

Not much difference had been seen in juveniles morphologically speaking, except bill length to body ratio. It takes several months for the bill to fully grow.

• Other Physical Features
• endothermic endothermic
• bilateral symmetry bilateral symmetry

• Sexual Dimorphism
• male larger

Reproduction

Not many studies are available on yellow-throated toucans’ breeding, however what is known mainly applies to the subspecies R. a. swainsonii . According to Short and Horne (2001), breeding seasons will vary depending on the specific location the species is found and quantity of food available. Breeding has been recorded between March and June in Costa Rica, December and May in Ecuador, and January and July in Panama and Columbia. Yellow-throated toucans are thought to be monogamous and form long-term bonds, however this area needs more data and studies completed.

It is noted that males sing on perches throughout the year to draw attention of females. Also, it is commonly hypothesized that the colorful and oversized beak on yellow-throated toucans may add to selection benefits in mating choice and drawing attention. However, there is no known correlation between beak coloration and length with successful mating and reproduction. Along with singing behaviors, observations show that mates will allopreen and perform courtship feeding- where the male will feed the female, often regurgitated fruit. This is a common mating ritual among all toucan species. Another mating ritual that occurs called fruit tossing is seen in other toucan species like the ‘toco toucan ( Ramphastos toco )’ and is initiated between males and females. This courtship behavior could be a possible behavior seen with yellow-throated toucans as well. Other mating behaviors may include male territorial behaviors and guarding of fruit trees while the female feeds.

• Mating System
• monogamous monogamous
• cooperative breeder cooperative breeder

The reproductive processes and cycles remain understudied. It is believed that the yellow-throated toucan clutch size is between two and three eggs, however egg and incubation information remain undescribed to our knowledge. Further knowledge on the physiological development of this species’ young would be helpful and provide a comparison to other bird species. Nesting takes place in hollowed tree cavities due to wood rot, as yellow-throated toucans are not capable of excavating themselves like other bird species. However, the length for nestling period is not known. In other toucan species, the nestling period ranges between 40 and 60 days, as seen in Araçari toucans.

• Key Reproductive Features
• iteroparous iteroparous
• year-round breeding year-round breeding
• gonochoric/gonochoristic/dioecious (sexes separate)
• sexual sexual
• oviparous oviparous

Details of parental care in the yellow-throated toucan are understudied, which is mainly due to the high elevation where breeding, nesting and weaning care occurs. It is believed however that dual parental care occurs, and the main role of the male is protection of the nesting area.

• Parental Investment
• altricial altricial

Lifespan/Longevity

There are no known current records of longevity and life history for yellow-throated toucans. Further knowledge on matters such as age at first breeding, survivorship, and population regulation also could be an area for future research.

Behavior

Yellow-throated toucans are a diurnal and social species. Yellow-throated toucans are also arboreal. Their flight occurs with rapid and shallow wingbeats, followed by gliding from tree to tree, and do not travel long distances. However, they will travel further distances for foraging and mating. Regardless of primarily traveling alone, this social bird can still be found in small groups or pairs. Spending much of its time in tree canopies, the most recorded behaviors seen include foraging by hopping branch to branch, preening or other comfort behaviors, and vocal communications.

Yellow-throated toucans are very vocal and perform frequent calling from high perches in the canopy of trees. They often are heard in pairs or echo calls in chorus around dusk and dawn. As described by Stiles and Skutch (1989), calling is done with the head thrown upward with the first note and lowered with each following note.

Other behaviors seen in yellow-throated toucans would be frequent self-maintenance, including sleeping, preening, and scratching or rubbing. Though, due to their extremely large beaks, allopreening is more common and less limiting. Toucans are known for their unusual sleeping style, as they tuck their beak behind their back and under raised tail feathers; this is displayed also in yellow-throated toucans. The abnormal sleeping style is not well studied, but it is hypothesized that in most toucan species the beak acts to regulate heat distribution and as a transient thermal radiator, along with other functions, thus this sleeping position may help regulate heat while sleeping.

This species generally forages in pairs or even small flocks. They have also been observed in larger flocks of mixed species where food is abundant. Along with this, cooperative and specialized social hunting is believed to be another behavior demonstrated in yellow-throated toucans. In a study by Mindell and Black (1984) they describe two toucans working together to capture prey, a lizard ( Dactyloa frenata ).

• Key Behaviors
• arboreal arboreal
• flies
• glides
• diurnal diurnal
• motile motile
• territorial territorial
• social social

Communication and Perception

Communication for yellow-throated toucans primarily occurs through vocalizations. They are known for a loud yelping call that has been described as "KEEU de-deh de-deh". This call is widely distinguishable compared to other species in the Ramphastidae family. As noted in many studies, locals describe the call as “Díos te dé te dé”, which means “God give you” in Spanish. Yellow-throated toucans’ call are often heard in early morning and evening chorus and echoed throughout the canopies. The meaning behind the call is believed to be associated in mating, warning, feeding, and territorial displays, however the functional significant of the call is still unknown and understudied. Toucan species in general, including this species, are often observed calling in synchrony. This may convey information on an individual’s reproductive status as seen by Coulson (1966), that high frequency synchronous calling may be characteristic of a strong pair bond, which is often viewed as a precondition for successful mating.

Along with their signature call, yellow-throated toucans also create grunting noises and rattles, but are often used in a more aggressive manner. The yellow-throated toucan also communicates non-verbally using its two notched outer primaries to create a wing-rustling noise. With most bird species including yellow-throated toucans, perception of their environment occurs through auditory, chemical, tactile, and visual stimuli. However, no significant studies have been performed to further knowledge on this topic.

• Communication Channels
• visual visual
• acoustic acoustic

• Other Communication Modes
• duets duets
• choruses choruses

• Perception Channels
• visual visual
• tactile tactile
• acoustic acoustic
• chemical chemical

Food Habits

Yellow-throated toucans are primarily frugivores like most toucans, eating nuts, roots, seeds, and mostly fruit from trees. Most information recorded on yellow-throated toucans’ diet is for the subspecies R. a. swainsonii . Some of the primary food sources for this species includes fruit from fruiting tress. Genera such as g. Beilschmiedia , g. Casearia , g. Cecropia , g. Didymopanax , g. Faramea , g. Virola , g. Protium , g. Hampea, and g. Trophis are all examples of the large variety of trees that supply resources for yellow-throated toucans. Some species including V. sebifera and C. corymbose are vital food sources for these birds. Both provide important fruits that yellow-throated toucans’ diet rely on during seasons/spans of limited resources and fruiting trees available.

Other forms of food that yellow-throated toucans eat include invertebrates like insects, also lizards, frogs, and snakes. Yellow-throated toucans additionally are nest predators and have been recorded raiding nests of species like ‘tropical kingbirds ( Tyrannus melancholicus )’, and ‘boat-billed flycatchers ( Megarynchus pitangua )’. Although it seems that this species has a large varying diet, the degree these frugivores prey on other animals is usually unknown. In a study by Remsen et al. (1993), the food content in the stomach was analyzed for multiple toucan species, and it was found that in yellow-throated toucans, the primary contents were from fruit.

• Primary Diet
• carnivore carnivore
  • eats terrestrial vertebrates
  • eats eggs
  • insectivore insectivore
  • eats non-insect arthropods
• herbivore herbivore
  • frugivore frugivore
  • granivore granivore
• omnivore omnivore

• Animal Foods
• eggs
• insects
• terrestrial non-insect arthropods

• Plant Foods
• roots and tubers
• seeds, grains, and nuts
• fruit

Predation

Little is known about any predatory challenges yellow-throated toucans may face. They are among one of the largest toucan species and are predatorial themselves. It is believed that most other species avoid confronting or challenging yellow-throated toucans when predation of other species’ nests occurs. This may arise due to the intimidating size of beak seen on this species, but no studies support this hypothesis.

Ecosystem Roles

Yellow-throated toucans have been found to be especially important and vital when it comes to seed dispersion. As a frugivore species, they are as said by Sekercioglu (2006), genetic linkers that carry genetic material from one plant to another or to habitats that are suitable for regeneration. Yellow-throated toucans are one of many species which allows for seeds to be dispersed in a wide geographical range. Along with other large frugivore species, they have been shown to hold a certain resilience for seed dispersal in human-impacted landscapes or fragmented forests. According to Markl et al. (2012), rates of dispersion are not greatly affected by fragmentation, but more significant factors like logging and hunting disrupted rates of seed-dispersion for this species. Yellow-throated toucans’ role in tropical ecosystems overall is believed to play a component in increasing biodiversity in heavily impacted deforested areas. However, more research would help outline the effectiveness and essentiality for this species.

• Ecosystem Impact
• disperses seeds

Economic Importance for Humans: Positive

As seen in other toucan species, yellow-throated toucans play a big economic role in Neotropical forest ranges. They are important as a food resource and valued for colorful feathers used in local crafts. Yellow-throated toucans are also no exception to pet trade. Although not much information has been recorded for this species specifically, other toucans such as the toco toucan ( R. toco ) have documented accounts for pet trade. According to CITES (2020) around 200 toco toucans per year have been legally exported from Guyana since 1997. Paraguay had also exported 132 birds in 2002.

As a prevalent species within its range, yellow-throated toucans also allow probability for ecotourism for many people not local to this range. Many places like National Parks boast of wild toucans that fly freely for tourists and even interact with people for food.

• Positive Impacts
• pet trade pet trade
• food food
• body parts are source of valuable material
• ecotourism ecotourism

Economic Importance for Humans: Negative

There are no known adverse effects of Ramphastos ambiguus on humans.

Conservation Status

The yellow-throated toucan is listed as a near threatened species with a decreasing population according to the IUCN Red List of Threatened Species (2016). Yellow-throated toucans are resilient to ecosystem disturbances and deforestation, but habitat loss affects them, nonetheless. With habitat fragmentation, surveys have shown a decrease of yellow-throated toucan populations. Because this species is also considered weak at flying, as fragmentation intensifies, further isolation of this species means less access to nutritional resources and a less diversified selection in mating, leading to the overall population decline.

Not much is known about any conservation efforts in place, and no known action recovery plans are in place. There are conservation sites though, where the yellow-throated toucan is found and plentiful. Guevara et al. (2010) found that yellow-throated toucans were prevalent in Lower Sangay National Park in Morona-Santiago, Ecuador. This area indirectly benefits this species and is an example for how some of these parks can contribute to conserving this species in the future.

Hunting is another possible threat for yellow-throated toucans, which are considered a meat source in some areas. Many toucan species are affected by hunting and pet trade, however no detailed information on this problem and how it affects yellow-throated toucan populations is available.

Additional Links

Encyclopedia of Life

Contributors

Brianna Lilly (author), Northern Michigan University, Alec Lindsay (editor), Northern Michigan University, Tanya Dewey (editor), University of Michigan-Ann Arbor.

References

Beletsky, L. 1998. Costa Rica: The Ecotraveller's Wildlife Guide . San Diego, CA: San Diego: Academic Press.

BirdLife International, 2016. "Ramphastos ambiguus" (On-line). IUCN Red List. Accessed February 12, 2020 at https://www.iucnredlist.org/species/22727999/94967701 .

Clayton, D., P. Cotgreave. 1994. Behavior. Comparative Analysis of Time Spent Grooming by Birds in Relation to Parasite Load , 131 (3-4): 171-187.

Coulson, J. 1966. Journal of Animal Ecology. The Influence of the Pair-Bond and Age on Breeding Biology of the Kittiwake Gull Rissa tridactyla , 35 (2): 269-279.

Garcia, D., D. Martinez. 2012. Proceedings of the Royal Society B: Biological Science. Species Richness Matters for the Quality of Ecosystem Services: A Test Using Seed Dispersal by Frugivorous Birds , 279 (1740): 3106-3113. Accessed March 17, 2020 at https://royalsocietypublishing.org/doi/full/10.1098/rspb.2012.0175 .

Granizo, T., C. Pacheco, M. Ribadeneira, M. Guerrero, L. Suarez. 2002. Libro rojo de las aves del Ecuador. . Quito, Ecuador: SIMBIOE. Accessed April 17, 2020 at chrome-extension://gphandlahdpffmccakmbngmbjnjiiahp/https://biblio.flacsoandes.edu.ec/catalog/resGet.php?resId=56484 .

Guevara, E., R. Gualotuña, T. Santander, J. Guevara, V. Ortiz. 2010. CheckList. Birds, ower Sangay National Park, Morona-Santiago, Ecuador , 6: 319.

Haffer, J. 1974. Avian Speciation in Tropical South America with a Systematic Survey of Toucans (Ramphastidae) and Jacamars (Galbulidae) . Cambridge, MA: Publications of the Nuttall Ornithological Club.

Hilty, S., W. Brown. 1986. A Guide to the Birds of Columbia . Princeton, NJ: Princeton University Press.

Hilty, S. 2003. Birds of Venezuela . Princeton, NJ: Princeton University Press.

Howe, H. 1977. Bird Activity and Seed Dispersal of a Tropical Wet Forest Tree. Ecology , 58 (3): 539-550.

Kattan, G., H. Alvarez-Lopez, M. Giraldo. 1994. Forest Frangmentation and Bird Extinctions: San Antonio Eighty Years Later. Conservation Biology , 8 (1): 138-146.

Kricher, J. 1999. A Neotropical Companion: An Introduction to the Animals, Plants and Ecosystems of the New World Tropics . Princeton, NJ: Princeton University Press.

Markl, J., M. Schleuning, P. Forget, P. Jordano, J. Lambert, A. Traveset. 2012. Meta-Analysis of the Effects of Human Disturbance on Seed Disperal by Animals. Conservation Biology , 26 (6): 1072-1081.

Mindell, D., H. Black. 1984. Combined-Effort Hunting by a Pair of Chestnut-Mandibled Toucans. The Wilson Bulletin , 96 (2): 319-321. Accessed March 21, 2020 at www.jstor.org/stable/4161932 .

Moreira, J., P. Riba-Hernandez, J. Lobo. 2017. Toucans (Ramphastos ambiguus) Facilitate Resilience Against Seed Dispersal Limitation to a Large-Seeded Tree (Virola surinamensis) in a Human-Modified Landscape. Biotropica , 49 (4): 502-510.

Patané, J., J. Weckstein, A. Aleixo, J. Bates. 2009. Evolutionary History of Ramphastos Toucans: Molecular Phylogenetics, Temporal Diversification, and Biogeography.. Molecular Phylogenetics and Evolution , 53: 923-934.

Remsen, J., M. Hyde, A. Chapman. 1993. The Diets of Neotropical Trogons, Motmots, Barbets and Toucans. The Condor , 95 (1): 178-192.

Rice, A., J. Weckstein, J. Engel. 2020. "Birds of the World" (On-line). Yellow-throated Toucan. Accessed February 10, 2020 at https://birdsoftheworld.org/bow/species/bkmtou1/cur/introduction .

Rother, D., M. Pizo, P. Jordano. 2015. Variation in Seed Dispersal Effectiveness: The Redundancy of Consequences in Diversified Tropical Frugivore Assemblages. Oikos , 125 (3): 336-342.

Schulenberg, T., D. Stotz, L. Rico. 2006. "Distribution Maps of the Birds of Peru" (On-line). Environment, Culture & Conservation. Accessed March 12, 2020 at http://fm2.fieldmuseum.org/uw_test/birdsofperu on 01/29/20 .

Sekercioglu, C. 2006. Increasing Awareness of Avian Ecological Function. Trends in Ecology & Evolution , 21 (8): 464-471.

Short, L., J. Horne. 2001. Toucans, Barbets, and Honeyguides: Ramphastidae, Capitonidae, and Indicatoridae . New York, NY: Oxford University Press.

Short, L., J. Horne. 2002. Family Ramphastidae. Pp. 220-272 in Handbook of the Birds of the World , Vol. 7. Barcelona, Spain: Lynx Edicions.

Skutch, A. 1979. Aves de Costa Rica . Costa Rica, San Jose: Editorial Costa Rica.

Skutch, A. 1958. Roosting and Nesting of Aracari Toucans. The Condor , 60 (4): 201-219.

Stiles, F., A. Diamond, T. Lovejoy. 1985. Conservation of Tropical Forest Birds . Great Britain: Editorial Kings College, Cambridge, International Council for Bird Preservation.

Stiles, F., A. Skutch. 1989. Guide to the Birds of Costa Rica . Ithaca, NY: Comstock, Cornell University Press.

Strahl, S., A. Grajal. 1991. Conservation of Large Frugivores and the Management of Neotropical Protected Areas. Oryx , 25 (1): 50-55.

Tattersall, G., D. Andrade, A. Abe. 2009. Heat Exchange from the Toucan Bill Reveals a Controllable Vascular Thermal Radiator. Science , 325 (5939): 468-470.

Vincent, M. 2007. The Preliminary Studies of Wild Toco Toucans (Ramphastos toco)- A Keeper's Experience in the Field. Ratel , 34 (3): 8.

Weckstein, J. 2005. Molecular Phylogenetics of the Ramphastos Toucans: Implications for the Evolution of Morphology, Vocalizations, and Coloration. The Auk , 122 (4): 1191-1209.