Northern Emerald-Toucanet Aulacorhynchus prasinus Like other species of Aulacorhynchus, it is primarily bright green, with a white or blue throat, and rufous . Northern Emerald-Toucanet Aulacorhynchus prasinus. Order: Piciformes; Family: Ramphastidae; Polytypic: 7 subspecies; Authors: Thomas S. Schulenberg. San Luis Potosí and Oaxaca); Aulacorhynchus prasinus warneri: Mts. of se Mexico (Sierra de Los Tuxtlas in s Veracruz); Aulacorhynchus prasinus [ virescens or.

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In spite of ongoing advances in the description and recognition of biodiversity, few genera can offer such an incongruous history as Aulacorhynchus Gould Aves: The Aulacorhynchus toucanets inhabit montane forests from Mexico to Guyana and Bolivia, and there are many allopatric taxa. Although generic limits have been generally consistent during the past century, the number of species within the genus has aulacorhyncus a matter of considerable disagreement.

In the second edition of his monograph on the Ramphastidae, Gould recognized 10 species in the genus Aulacorhamphus now Aulacorhynchus by prioritybut several taxa remained undescribed at that time. Ridgway followed this treatment. Alacorhynchus considered aulacorhynnchus of these species A. Although a new species was described in A.

Haffer followed Petersexcept that he reduced one species A. The treatment of this genus since is summarized in Table 1. The massive lumping of Peters proceeded with neither the presentation of data nor with discussion.

Careful study of one taxon, A. Presumably similar reasoning was behind Peters But subspecies, even those distinctive enough to have been considered full species for a century, can get lost in the shuffle. The AOU ; considered Middle American diversity in the genus as being just two subspecific groups of a single species, A. Renewed interest aluacorhynchus this complex Navarro et al. These latter works have recommended elevation of numerous A. There has also been heavy reliance on a single molecular marker mtDNA for species delimitation in A.

Thus, species limits in the group remain uncertain Table 1. Most disagreement has been in the A. The sexes are alike by plumage sexually monochromaticbut sexual size dimorphism is apparent in all taxa examined. In past work there has been too little discussion of the fact that different levels of differentiation occur among the subspecies of A.

All of the named forms do not represent equally differentiated populations; there are major subspecific groups of one or more described subspecies. Objectively determining what these groups are can be done by following taxonomic history, coupled as it is with a color-based clustering. Cory recognized eight species that were later lumped by Peters into A. It seems that four of these A. Two of these taxa, A. This was not uncommon: Ridgway considered that the genus had 15 species, but he was uncertain because he had only been able to examine seven of them.

The subsequent rediscovery and examination of A. These considerations reduce the number of major, color-based subspecific groups in the A. The rather pronounced differences among these aulacorhhynchus groups are illustrated in Fig. Diagnostic characters of these six groups are given in Table 2. It is these six groups that form the basis for my comparisons. They are the color-based groupings that have been recognized by students of the birds themselves.


The troubled taxonomic history of Aulacorhynchus aulxcorhynchus A. Members of the A.

Emerald Toucanet (Aulacorhynchus prasinus) – BirdLife species factsheet

Given evidence of hybridization, it is unclear how the birds themselves perceive these differences. Is this group A. Or are full species being overlooked? If, on the other hand, aulacorhyjchus, concordant morphological changes are also occurring, then perhaps the concept of ecologically similar geographic replacements, which seems broadly applicable to A.

Such morphological differences might suggest adaptive changes among groups that would make immigrants and hybrids less fit Price, My question then is simple: If substantial morphometric changes occur concurrently with dramatic color changes, then species limits should probably be reconsidered, as several have suggested Navarro et al.

Morphometrics alone are unlikely to be important components of species limits in forms like these where colors are obviously important, and this is not meant as a study of prsainus morphology varies within the group independently of color-based clustering. Geography alone can affect morphology e. In this study I will 1 test orasinus univariate differences between pairwise groups that are geographically closest to each other; 2 compare these groups in multivariate, principal component space because univariate measures can be correlated with each other ; and 3 visually examine specimens for evidence of hybridization because such evidence has been historically important in the taxonomy of the group.

Museum specimens institutions listed in Acknowledgments were visually examined and measurements of wing chord, tail, tarsometatarsus, bill, bill height, and bill width all three bill measures from anterior edge of nares were made to the nearest 0.

Wing tip length of longest primary to first secondary was also measured to the nearest 0. Although Navarro et al. Morphometric geographic variation within these six major subspecific groups was not examined, because that is not related to the hypothesis being tested, i. However, the effects of geography upon the data are examined after the main questions posed are addressed.

Aulacorhynchus prasinus has four prasinuswarneri, virescens, volcaniusA. Color differences formed the basis for the majority of characters used to describe all of these named subspecies, with size being mentioned in addition to color in just three of 14 cases.

Within-group variation is accounted for in the standard statistical manner e. Immature individuals were not measured. I examined and measured specimens of the six major subspecific groups of A. Morphometric data exhibited male-biased sexual size dimorphism Table 3so all analyses were performed separately for each sex. Univariate mensural characteristics Table 3 were visually examined to determine whether it was warranted to apply statistical testing for differences.

This was done to reduce the overall number of tests made, which enhances the power of individual tests when applying multiple-test corrections. No statistical tests were done on mass due to small sample sizesand tests were applied in a pairwise manner between groups most proximate to each other except for A. While false discoveries will accrue with multiple testing, determining whether there are differences at the individual test level is very important for a study of this type.

I report both aspects uncorrected and correctedbecause future investigators of subsets of these taxa should focus on characteristics that differ between them and not be distracted by the additional statistical gyrations that I needed to perform to reduce table-wide error when making so many tests 60 tests for Table 4 and 24 for Table 5. Significant univariate mensural differences were found among the six groups in both sexes Tables 3 and 4.


The number of significant differences was highest when A. After multiple-test correction which only affected A.

I included a pairwise comparison between A. Intermediate levels of univariate differences occurred between A. Wingtip, bill width, and tarsometatarsus showed the fewest significant differences between groups, whereas wing chord and tail lengths showed the most Table 4. A pronounced large-small-large pattern was revealed among A.

The characteristics exhibiting significant differences between taxon pairs varied among pairs and, in most cases, between sexes Table 4. In other words, significant mensural differences were decidedly inconsistent between groups.

Morphometric relationships between groups within sexes were further explored using principal components analyses PCA. Two analyses were performed.

For each sex, all individuals of all groups were run through a single analysis, and the first two principal components PC1 and PC2 were extracted from the variance—covariance matrix of the log-transformed data.

PC1 and PC2 explained For each of the two sex-specific analyses, principal components scores were generated for each individual on PC1 and PC2, and these individual scores were then compared between the major subspecific groups using t aaulacorhynchus. These tests were done to determine whether, on a multivariate basis, morphometric differences between taxon pairs were as heterogeneous as suggested by univariate analyses Tables 3 and 4.

Results suggest that they were; again, differences between groups varied in an unpredicatable manner between the sexes and between the two independent multivariate dimensions PC1 and PC2; Table 5. Of the multivariate pairwise comparisons, only A. These results may reflect the small sample size in A. After multiple-test correction, contrasts within the South American forms aulacorhynchhus last three aulacorhhynchus in Table 5 yielded no significant differences at the table-wide level. The major, color-based subspecific groups of A.

Thus, geography has a small but significant influence in 5 of the 11 differences denoted in Table 5perhaps contributing to the higher significance levels found in females there.

Because members of the genus are known to wander rather widely during the nonbreeding season, the opportunity for gene flow does exist between these largely allopatrically breeding groups. Among the six major subgroups I examined there are theoretically five pairwise instances of possible gene flow between any two of the groups, particularly across some of the narrower zones of separation, A.

Note that closest approach distances are not accurate in Fig. An example of a hybrid A. A a pure A. Download full-size image DOI: Specimens were examined carefully for phenotypic evidence i. Four specimens representing possible F 1 hybrids due to intermediacy of praasinus were found; one from La Libertad, Utcubamba 25 OctoberD.

Emerald toucanet

Watkins, AMNH, and All four specimens show obvious intergradation between these two taxa, particularly in bill coloration see Fig. In addition, there are another five specimens that seem to show evidence of intergradation to a lesser degree, two females that are phenotypically mostly A. These latter three birds are from three localities: Divisoria, Cordillera Azul, Dept. Huanuco 17 AugustJ. Ayacucho 6 MayJ. Loreto 14 AugJ.