Full text
| |
| Author(s): |
Francisco Voeroes Dénes
Total Authors: 1
|
| Document type: | Master's Dissertation |
| Press: | São Paulo. |
| Institution: | Universidade de São Paulo (USP). Instituto de Biociências (IBIOC/SB) |
| Defense date: | 2009-08-03 |
| Examining board members: |
Luis Fábio Silveira;
Marcelo Rodrigues de Carvalho;
Pedro Ferreira Develey
|
| Advisor: | Luis Fábio Silveira |
| Abstract | |
The White-collared (or Forbes) Kite Leptodon forbesi Swann, 1922 is an endemic raptor of the Centro Pernambuco, the northernmost portion of the Atlantic Forest, in Northeastern Brazil, and its taxonomic status is still a case of controversy. It is considered a valid species by Swann (1922, 1954), Teixeira et al. (1987) and del Hoyo (1994), whereas Grossman and Hamlet (1964), Brown and Amadon (1968), Blake (1977) and Sick (1994) opt to consider it a morphological variant of the widespread Grey-headed Kite L. cayanensis. The traditional diagnoses of L. forbesiare the underwing coverts, white instead of black; grey pileum; white collar; white tip of quills, mantle and scapular feathers; and a wide white band on both sides of the tail (Swann 1945; Hellmayr and Conover 1949; Pinto 1964). The present study aims to analyse and describe the morphological and morphometrical variation in L. cayanensis, and to test the validity of taxa within the complex, with a special interest in L. forbesiand its geographical distribution. 128 specimes of the genus Leptodon, from Mexico to Southern Brazil, were studied. Morphometrical data was obtained and analysed to evaluate differences between sexes, colour polymorphism in the juvenile plumage, and the subspecies described by Swann (1922) for L. cayanensis. Plumage characters were also studied to test the validity of L. forbesi. We conclude that L. cayanensis shows sexual dimorphism, the females being larger (I); that there are two, not three, coloration morphs in the juvenile plumages of L. cayanensis (II); that the subspecies described by Swann (1922) for L. cayanensis are invalid, the geographical variation in size better explained as a response to latitude module, as predicted by Bergmanns Rule (III); and that the species L. forbesi is a valid taxon, based on the coloration of underwing and leading edge coverts, white in L. forbesi and black in L. cayanensis; on the coloration of the ventral side of the rêmiges, with a contrast between dark primaries and lighter secondaries in L. forbesi; and on the collar coloration, white in L. forbesiand grey in L. cayanensis (IV). Therefore, L. forbesi constitutes another endemic and endangered species of the Centro Pernambuco, in the Brazilian Atlantic Forest. (AU) | |