Ramphastos Sulfuratus Research Articles

MORPHOMETRIC TRAITS AND THEIR ASSOCIATION WITH SEX IN THE KEEL-BILLED TOUCAN RAMPHASTOS SULFURATUS

Sexing monomorphic birds is essential for reproduction in conservation programs. In ramphastids (toucans) species, males have longer beaks than females, making beak morphometry potentially useful for sexing. In this study, we measured the following traits: curved beak length, total culmen length, straight beak length, curved and straight length of the ventral line of the gnathotheca, beak width, lateral area of the rhinotheca, and cloacal opening in 44 Keel-billed Toucans, as well as previously reported morphometric data from 17 additional individuals. Measurements were obtained using two methods (manual and image processing software), and the reliability between the two methods was assessed using the intraclass correlation coefficient (ICC). Individuals of unknown sex were sexed via PCR tests. The ICC showed poor reliability between the two measurement methods, so we only used manual measurements for comparisons between the sexes. We used GLMMs to determine whether the morphometric traits we measured could be used to determine sex in keel-billed toucans. In addition, we evaluated GLMMs to determine which morphometric trait was the strongest predictor of sex in this species. Beak length was longer in adult males than in females. The GLMMs indicated that beak traits associated with sex in this species are beak curved length, beak straight length, straight length of the ventral line of the gnathotheca, and total culmen length. The straight length of the ventral line of the gnathotheca was the strongest predictor of sex in the Keel-billed Toucan. Unlike previous research, the development of GLMMs allows us to determine the probability of a toucan’s sex based on continuous variables, facilitating sexing and allowing us to evaluate the reliability of the estimation of the sexing of each toucan. This method is an alternative for situations where other sexing methodologies cannot be performed.

Development of genetic markers for reproductive management of toucans.

Retention of genetic diversity in successive generations is key to successful ex situ programs and will become increasingly important to restore wild populations of threatened animals. When animal genealogy is partly unknown or gaps exist in studbook records, the application of molecular resources facilitates informed breeding. Here, we apply molecular resources to an ex situ breeding population of toucans (Ramphastidae), a bird family zoos commonly maintain. Toucans face population declines from illegal poaching and habitat degradation. We developed novel microsatellite markers using blood samples from 15 Keel-billed Toucans (Ramphastos sulfuratus Lesson 1830). Parentage of two individuals was known a priori, but possible sibship among 13 putative founders-including the parents-was unknown. We compared available avian heterologous and novel microsatellite markers to recover known relationships and reconstruct sibship. Eight of 61 heterologous markers amplified consistently and were polymorphic, but less so than the 18 novel markers. Known sibship (and three sibling pairs whose relatedness was unknown a priori) and paternity-though not maternity except in one case-were well-recovered using both likelihood and pairwise relatedness methods, when incorporating novel but not heterologous markers. Zoo researchers seeking microsatellite primer sets for their breeding toucan populations will likely benefit from our heterologous markers, which can be leveraged both to assess relatedness and select breeding pairs. We recommend that zoo biologists rely on species-specific primers and not optimize heterologous primers for toucan species without molecular resources. We conclude with a brief discussion of modern genotyping methods of interest to zoo researchers.

Onto the sense of smell in macaws, amazons and toucans: can they use volatile cues of fruits to make foraging decisions?

Over the past decades, empirical evidence has been accumulated indicating that olfactory information plays a fundamental role in bird life history. Nonetheless, many aspects of avian olfaction remain poorly understood. Our purpose was to broaden the knowledge about the importance of the sense of smell in some neglected bird groups: psittaciformes and ramphastids, and to compare how the response varied between the species. Because of the lack of information about the use of chemical cues for locating food in fruit-eating species, we also aimed to delve into this question. We conducted a 3-choice (water/vinegar/papaya and banana juice) scent test in 5 Costa Rican native species: scarlet macaw (Ara macao), red-lored amazon (Amazona autumnalis), yellow-naped amazon (Amazona auropalliata), keel-billed toucan (Ramphastos sulfuratus), and yellow-throated toucan (Ramphastos ambiguus). Results revealed that macaws and toucans allocated significantly more time to interacting with the fruit scent container, indicating that these species can perceive the volatile chemicals emitted by ripe fruits and that they can use this information to make foraging decisions. However, amazons did not dedicate more time to interact with the fruit treatment. Our research provides the first evidence of the ability to exploit chemical volatile cues in macaws and toucans.

Outbreaks of Acute Necrotic Enteritis and Haemolytic Crisis and Renal Disease Associated with Clostridium perfringens in Captive Toucans (Ramphastos spp)

Four toco toucans (Ramphastos toco), one channel-billed toucan (Ramphastos vitellinus) and one white-throated toucan (Ramphastos tucanus) died in two disease outbreaks in the same aviary in 2011 and 2016. Post-mortem examination revealed diffuse necrotic enteritis (NE) as the cause of death of five of these six birds. Clostridium perfringens was identified by culture and real-time multiplex PCR for C. perfringens α-, β-, ε- and ι-toxin genes in ligated intestine of one toucan from each outbreak. At another aviary, two keel-billed toucans (Ramphastos sulfuratus) died peracutely from severe haemolytic crisis with haemoglobinaemic nephrosis and cholestasis and acute tubulointerstitial nephritis. Mild NE was present in these birds and C. perfringens was demonstrated in liver by bacterial culture and real-time multiplex PCR for C. perfringens α-, β-, ε- and ι-toxin genes. To the authors' knowledge, this is the first description of outbreaks of NE associated with C. perfringens in captive toucans. Although haemolytic crisis has been reported in humans with C. perfringens type A septicaemia and hepatic abscesses, this presentation appears not to have been described in C. perfringens infections in toucans or other avian species. The factors causing C. perfringens proliferation and disease in the toucans were not identified. PCR for C. perfringens NetB toxin and enterotoxin genes performed retrospectively on one of the C. perfringens isolates from the second outbreak and on paraffin-embedded tissues from one dead toucan from the first outbreak was negative. With the current C. perfringens toxin typing scheme, C. perfringens type A was identified in the first two outbreaks.

An Unusual Aberrant Colored Keel-billed Toucan (Ramphastos sulfuratus, Ramphastidae) in Northern Costa Rica

Although plumage color aberrations are common in birds, they often are difficult or even impossible to properly identify in the field. Even though some of these aberrations are common, including progressive greying, leucism, and albinism, there is confusion among the mechanisms responsible for each of the color aberrations. Other color abnormalities, such as dilution and ino, are found or reported less frequently. The Keel-billed Toucan (Ramphastos sulfuratus; Piciformes: Ramphastidae) is predominantly black, red under the tail coverts, and the feathers above the tail that are white colored. It has a yellow bib covering the throat and chest with a red band countering it, and the skin of the face is chartreuse. The Keel-billed Toucan is most notable for its massive, multicolored bill that makes up to a third of its length. Here we report a genetic-based melanin deficiency producing an unusual coloration in the Keel-billed Toucan. An individual observed at Pital, San Carlos, in the lowlands of northern Costa Rica in October, 2020 lacked melanin, but retained carotenoids. As most parts of the plumage normally have both melanin and carotenoids, the yellow becomes visible where the black is now absent, such as the ventral feathers. We discuss possible explanations for this unusual coloration.

A Quantitative Method for Evaluating Contemporary Cultural Uses of Birds: A Case Study from Mexico

This study evaluates the relationship between people and birds in Mexico, a country where high cultural and biological diversity are reflected in the close associations between people and natural resources, recorded since pre-Hispanic times. It systematically reviews 1041 records of cultural use of wild birds in Mexico published between 1996–2017 and analyzes patterns of contemporary use of avifauna. It classifies information for 252 birds by grouping uses of species and families into 11 categories and quantifies overall use with a Cultural Value Index (CVI). The data show that birds have a high cultural value as food, pets, and for medicinal uses (312, 235, and 119 records, respectively), particularly in the state of Chiapas. Large edible birds had the highest CVIs and included Plain chachalacas (Ortalis vetula; 9.72), Black-bellied whistling-ducks (Dendrocygna autumnali; 6.65), Crested guams (Penelope purpurascens; 6.25), and Great currasows (Crax rubra; 6.23), with the Cracidae family recorded as favored gamebirds. Conspicuous, brightly-colored birds had high CVIs, including Keel-billed toucans (Ramphastos sulfuratus; 6.50), Red-lored amazons, (Amazona autumnalis; 6.03), and allied species, which were traded or kept as pets despite legal protection. The high CVIs of Barn owls (Tyto alba; 5.45) were related to medicinal uses, and Mourning doves (Zenaida macroura; 5.69) were mainly used as gamebirds. Wild bird populations face increasing pressure from habitat loss and overexploitation. We propose that evaluating the ethnological significance of wildlife with indices like CVIs can quantify the distinctive needs of rural communities, which when combined with information on conservation status can develop more sustainable species management plans.

Characterization of aortic and brachiocephalic filariasis by Filarioidea sp (Nematoda:Spirurida:Filarioidea) in Mexican ramphastids.

The manuscript presented herein documents the findings of filaria nematodes in 5 keel-billed toucans, and one emerald toucanet, originated from 2 private aviaries in Mexico City during two years. The birds displayed ruffled feathers, depression, inability to perch, convulsions, and sudden death. Furthermore, thickened wall of the aortic and brachiocephalic arteries, with connective tissue proliferation and chondroid metaplasia were observed. Molecular characterization matched Filarioidea sp (Nematoda: Spirurida: Filarioidea). To the authors’ knowledge, this is the first documented report of filariae Filarioidea sp. causing mortality in ramphastids in Mexico. This manuscript may contribute to expand current knowledge of filariasis and the health risks and livability of wild birds.

Keel-billed Toucans (Ramphastos sulfuratus) on the ground in a tropical forest restoration experiment

ABSTRACT Motion-activated cameras captured images of 2 Keel-billed Toucans (Ramphastos sulfuratus) on and near the ground in two 900 m2 experimental forest restoration plots located in the Los Tuxt...

Germinación de semillas de Ficus insipida (Moraceae) defecadas por tucanes (Ramphastos sulfuratus) y monos araña (Ateles geoffroyi)

To test the null hypothesis that two vertebrate fructivores, toucans (Ramphastos sulfuratus) and spider monkeys (Ateles geoffroyi), are equally specialized in germinating Ficus insipida seeds after these have passed through their digestive tracts, we fed fruits to captive individuals. We extracted seeds from feces and placed them on filter paper in petri dishes under controled light, temperature and humidity. Control seeds had not passed through a digestive tract. We found that a greater proportion of seeds from A. geofroyi (65%) germinated (R. sulfuratus: 4%). The germinative value was also greater in seeds from monkey feces (rate=13.76; toucan 0.046; control group 0.172). If, despite individual variability of seeds and dispersers, future studies continue to show that A. geoffroyi favors germination more (maybe because of a longer digestion time), this would indicate that diet specialization is not necessarily related to dispersal efficiency.

Información adicional sobre la avifauna de Hidalgo, México

Reportamos cinco especies de aves no registradas previamente en el estado de Hidalgo: gavilán zancón (Geranospiza caerulescens), gallineta morada (Porphyrio martinica), tucán pico canoa(Ramphastos sulfuratus), titira pico negro (Tityra inquisitor) y tordo arrocero (Dolichonyx oryzivorus).Ratificamos la presencia de la anhinga americana (Anhinga anhinga), del hormiguero-cholino escamoso(Grallaria guatimalensis) y del mirlo-acuático norteamericano (Cinclus mexicanus), que sólo contaban con un registro para Hidalgo.

Isolation of Toxoplasma gondii from the Keel-Billed Toucan (Ramphastos sulfuratus) From Costa Rica

Pectoral muscles from a captive keel-billed toucan (Ramphastos sulfuratus) from Costa Rica were fed to a Toxoplasma gondii-free cat, and the cat shed oocysts. Laboratory mice fed these oocysts developed antibodies to T. gondii in their sera and T. gondii tissue cysts in their brains. The DNA extracted from the brains of infected mice was characterized using 10 polymerase chain reaction-restricted fragment length polymorphic markers (SAG1, SAG2, SAG3, BTUB, GRA6, c22-8, c29-2, L358, PK1, and Apico). The isolate designated TgRsCrl was found to be non-clonal with Type I, II, and III alleles at different loci. This is the first isolation of T. gondii from this host.

Regional scale effects of human density and forest disturbance on large-bodied vertebrates throughout the Yucatán Peninsula, Mexico

The occupancy probability of 35 large-bodied bird and mammal species was examined in relation to patch- and landscape-scale habitat and disturbance variables in 147 forest patches distributed throughout the Mexican Yucatán Peninsula. Occupancy was assessed on the basis of interviews with local informants. The most important predictors of vertebrate species richness, composition, and patch occupancy were human population density and the extent and quality of forest cover. Most forest species responded positively to forest extent, while felids in particular were sensitive to human population density. However, the effects of human density on patch occupancy operated at extremely local scales. Effects were stronger at a smaller grain size, offering optimistic prospects for conservation strategies that incorporate human population effects. Three arboreal frugivores ( Ateles geoffroyi, Alouatta pigra, and Ramphastos sulfuratus) were strongly associated with total basal area of trees bearing fleshy fruits. The degree of hunting pressure was not related to human population density, and affected the occupancy probability of three game species, two of which ( Mazama spp., Crax rubra) are among the most preferred prey across the Yucatán Peninsula. Levels of patch occupancy across this region varied considerably among species, and were best explained by body size and degree of forest habitat specificity, large-bodied species and habitat specialists being the most vulnerable. This study provides a quantitative assessment of the conservation potential of large vertebrates in Mesoamerica and identifies disturbance-sensitive species. This can inform regional-scale conservation planning at a time when low deforestation in parts of the Yucatán Peninsula still provides a narrow window of conservation opportunity given the rapid human population growth.

In vitro culture, serologic and molecular analysis of Acanthamoeba isolated from the liver of a keel-billed toucan ( Ramphastos sulfuratus)

Members of the genus Acanthamoeba are usually free-living amebae and are found in a variety of ecological niches including soil, fresh and brackish water, dust in air, filters of heating, ventilating, and air conditioning units, swimming pools and hot tubs, etc. Occasionally, they are also known to cause central nervous system infections in humans and other animals. We isolated into culture an amoeba from the liver tissue of a keel-billed toucan and identified it as Acanthamoeba sp. based on culture characteristics and immunofluorescent analysis. Further, we characterized the cultured amoeba and also the amoeba in the liver tissue as Acanthamoeba, genotype T4, by sequencing a diagnostic region of the nuclear small subunit ribosomal RNA gene.

Torquatoides trogoni n. sp. and Excisa ramphastina n. sp. (Nematoda: Habronematoidea: Habronematidae) in birds from the area de Conservacion Guanacaste, Costa Rica.

Two new species of habronematid nematodes are described in birds from the Area de Conservacion Guanacaste, Costa Rica. Torquatoides trogoni n. sp., in Trogon massena, can be distinguished from T. torquata, T. bengalensis, and T. crotophaga in lacking lateral alae. Among species lacking lateral alae, the new species differs from T. balanocephala in having 14 versus 8-10 cephalic cuticular plaques, 21-22 versus 13-17 pairs of preanal papillae, and a beak-shaped versus U-shaped gubernaculum. The new species differs from T. singhi in body length, in having 21-22 versus 10 pairs of precloacal papillae, longer spicules, and larger eggs. The new species differs from T. crotophaga, the only other species known from Central America, in lacking lateral alae, and having 14 versus 6 cephalic cuticular plaques, 21-22 versus 17 pairs of precloacal and 3 versus 2 pairs of postcloacal papillae, and a gubernaculum. Excisa ramphastina n. sp., in Ramphastos sulfuratus, can be distinguished from E. excisa, E. biloba, E. buckleyi, E. dentifera, and E. khalili in having 1 lateral ala versus none, cervical papillae anterior versus posterior to the nerve ring, and asymmetrical caudal alae. Excisa ramphastina is similar to E. curvata in having cervical papillae anterior to the nerve ring but differs in having 1 lateral ala versus none, asymmetrical caudal alae, an average spicule ratio of 1:4.4 versus 1:3.3, and 4 versus 2 pairs of sessile papillae. The new species differs from E. columbi in having 1 versus 2 lateral alae, in the length of the spicules, in having a different spicule ratio, and in the numbers of sessile papillae.

Factors Influencing Movement Patterns of Keel‐Billed Toucans in a Fragmented Tropical Landscape in Southern Mexico

Abstract:Various factors influence animal movements in fragmented landscapes, and determining these factors is key to understanding ecological processes at a landscape scale. My goals were (1) to determine what factors influence movements of Keel‐billed Toucans ( Ramphastos sulfuratus ) in a fragmented landscape in southern Mexico and (2) to use this information to predict how movement patterns might change if the landscape was altered. I developed a cost‐distance geographic information system model that adjusts Euclidean distances by a cost of moving through a certain habitat type. Cost was based on habitat preferences exhibited by toucans. I then used this model to predict how movements might be affected by removal of isolated trees and living fences from the pasture matrix and by removal of forest remnants. Toucans moved more frequently between remnants separated by a low cost‐distance value. There was a cost‐distance threshold beyond which movements between remnants were rare. Below this threshold, fruit abundance influenced toucan movements but remnant area was not influential in that toucans did not preferentially move to large patches. Remnants close to various other remnants were more frequently visited by toucans, indicating that landscape connectivity influences toucan movements. Toucans incurred a 10–30% cost increase when moving in computer‐simulated landscapes, indicating that changes in forest cover or configuration of habitats may negatively affect toucan populations, assuming that increased cost has a fitness consequence. Cost‐distance modeling has been relatively unexplored and may be a valuable tool for determining how the configuration of a landscape impedes or facilitates animal movements.

Habitat Selection and Activity Budgets of Keel-Billed Toucans at the Landscape Level

AbstractLandscape-level behavioral information is needed to understand factors that underlie animal distributions in disturbed habitats. I examined habitat use and activity budgets of Keel-billed Toucans (Ramphastos sulfuratus) in a pasture-dominated landscape in Los Tuxtlas, Mexico. The objectives were to compare habitat selection at two scales, and to describe activity budgets of toucans with an emphasis on how behavior varied by habitat type. Six toucans were followed between January and July 1998 for a total of 349 hr. I noted behavior, bird location, and habitat type. At one spatial scale, birds' individual movement area was a nonrandom portion of the overall study area. When time spent in habitats by individual toucans was compared to habitat available in individual movement areas, habitat selection was also nonrandom. Forest remnants were preferred at both scales. Toucans spent approximately equal time foraging and perching (35–40%). Calling, preening, and social interactions each occupied 10% or less of the birds' activity budgets. All activities occurred in similar proportions in all habitat types, suggesting that different habitats provide many of the same resources. Combining individual patterns of habitat selection with activity budgets yields a better understanding of factors that allow populations to persist in disturbed landscapes.Selección de Hábitat y Asignación de Actividades del Tucán Ramphastos sulfuratus a Escala de PaisajeResumen. Se requieren estudios de comportamiento enfocados a la escala de paisaje para comprender los factores que afectan la distribución de los organismos en hábitats perturbados. Se examinó el uso de hábitat y asignación de actividades del tucán Ramphastos sulfuratus en paisajes dominados por pastizales en Los Tuxtlas, México. Los objetivos fueron comparar la selección de hábitat a dos escalas espaciales y describir la asignación de actividades de los tucanes poniendo énfasis en cómo el comportamiento es afectado por el tipo de hábitat. Seis tucanes fueron seguidos entre enero y julio de 1998 por un total de 349 hr. Registré el comportamiento, la posición del ave, y el tipo de hábitat. A una de las escalas espaciales consideradas, el area individual de movimiento de las aves representó una porción no azarosa del area total de estudio. Cuando el tiempo consumido por individuo en un hábitat determinado fue comparado con el hábitat disponible en las áreas individuales de movimiento, la selección de hábitat difirió de una selección al azar. Los remanentes de selva fueron preferidos a ambas escalas. Los tucanes consumieron aproximadamente el mismo tiempo forrajeando y posados (35–40%). Los llamadas, así como las interacciones sociales ocuparon 10% o menos de la asignación de actividades de las aves. Todas las actividades se llevaron a cabo en proporciones similares en todos los tipos de hábitat. La combinación de patrones individuales de selección de hábitat con la asignación de actividades proporciona una mejor comprensión de los factores que permiten la subsistencia de poblaciones en hábitats perturbados.

Mineral Content of Food Items Commonly Ingested by Keel-Billed Toucans (Ramphastos sulfuratus)

This study reports the content of iron and selected minerals from food items commonly ingested by keel-billed toucans (Ramphastos sulfuratus) in their native habitat in Belize, Central America. These same minerals were analyzed and compared with those found in a commercially prepared diet that was formulated to be low in iron. Seven of the food items collected from the wild had a total iron content ≤ 50 μg/g, whereas the remaining food items were ≤150 μg/g (except for 1 plant item). In contrast, the low-iron diet contained 210 μg/g of iron on a dry-matter basis. This study suggests that iron overload from feeding a commercial diet may contribute to the development of iron storage (disease) in captive toucans and other iron-sensitive species.

Habitat Selection and Activity Budgets of Keel-Billed Toucans at the Landscape Level

Abstract Landscape-level behavioral information is needed to understand factors that underlie animal distributions in disturbed habitats. I examined habitat use and activity budgets of Keel-billed Toucans (Ramphastos sulfuratus) in a pasture-dominated landscape in Los Tuxtlas, Mexico. The objectives were to compare habitat selection at two scales, and to describe activity budgets of toucans with an emphasis on how behavior varied by habitat type. Six toucans were followed between January and July 1998 for a total of 349 hr. I noted behavior, bird location, and habitat type. At one spatial scale, birds' individual movement area was a nonrandom portion of the overall study area. When time spent in habitats by individual toucans was compared to habitat available in individual movement areas, habitat selection was also nonrandom. Forest remnants were preferred at both scales. Toucans spent approximately equal time foraging and perching (35–40%). Calling, preening, and social interactions each occupied 10% or ...

Genetic structure in a population of a tropical tree Ocotea tenera (Lauraceae): influence of avian seed dispersal.

We studied the influence of avian seed dispersal on the structuring of genetic diversity in a population of a tropical tree, Ocotea tenera (Lauraceae). The seeds of O. tenera are principally dispersed by four, relatively specialized, fruit-eating bird species (emerald toucanets, keel-billed toucans, resplendent quetzals, and three-wattled bellbirds). We found high genetic diversity within the overall population and significant, nonrandom structuring of that diversity among subpopulations. Subpopulations contained members of several sibling groups, and most saplings within subpopulations were shown not to be the progeny of adult trees within the same subpopulation. Our data indicate that O. tenera subpopulations are founded with several seeds from few maternal families, and that this mode of establishment is an important determinant of population genetic architecture.

Early Consequences of Seed Dispersal for a Neotropical Tree (Virola surinamensis)

We examined the effects of distance from a fruiting conspecific, light environment, and initial seed size on survivorship using Virola surinamensis seeds and seedlings placed in concentric rings around fruiting Virola trees. Insects and mammals killed 99.2% of seeds and seedlings between fruit drop and exhaustion of parental endosperm at 12 wk after germination. During this time, survival was not influenced by either seed size or light environment, but up to a 44—fold advantage accrued to seeds dropped 45 m from a fruiting tree as compared with those underneath Virola crowns. Seeds that germinated under and near fruiting Virola trees suffered disproportionate attack from a curculionid weevil (Conotrachelus sp. nov.). Both large initial seed size and favorable light environments (assessed by canopy photographs) enhanced seedling vigor at 18 wk of age. Among those seedlings that escaped predation beyond the exhaustion of parental seed stores, a difference of as little as 1% in the amount of canopy open overhead distinguished seedlings with three leaves (3.5% open) from those with two leaves (2.3% open). Our results demonstrate clear advantages to local seed dispersal for a tree the rainforest canopy. They further suggest that dispersal of seeds >20m by large birds, such as guans (Penelope purpurascens) and toucans (Ramphastos sulfuratus and R. swainsonii), is more favorable for seedling survival than that of the smaller trogons (Trogon massena) and motmots (Baryphthengus martii), which regurgitate seeds under or near the tree crown.