Dictionary T-Z - BirdForum Opus

This section is aimed at explaining the bird and biology specific vocabulary you are likely to meet in other threads in Birdforum.

This page is divided into four sections: Dictionary A-F, Dictionary G-L, Dictionary M-S and Dictionary T-Z.

T

Tarsus: see Legs and Feet

Taxon, taxa: a taxonomic unit (in principle any taxonomic unit), most often used for either a subspecies or a species. For example, when discussing Kaempfer's Woodpecker calling it "the taxon obrieni" does not make a statement as to whether Kaempfer's Woodpecker is a full species or a subspecies.

Taxonomic order: a linear order of the species of birds of the world based on a phylogenetic analysis (see Phylogeny), and therefore also based on the evolutionary relationship among the birds. Bird families that are very old are placed first, more recent additions later. The commonly used order have for a long time been based on Voous 1977¹ but some recent DNA based studies have revolutionized the order: one example of the results are that Grebes and Flamingos are each others closest relatives.

Tertials: see Wings

Tibia: see Legs and Feet

References T

1. Karel Hendrick Voous (1977). List of recent Holarctic bird species. Published for the British Ornithologists' Union by Academic Press. 85 pages.

V

Vent: see General Anatomy

Vicariance: the situation when two closely related populations get separated, for example by ice during an ice age, by water such as a river or sea, a mountain range, etc. Some theories of speciation state that vicariance is a necessary step in producing two species from populations that were one species before.

W

Whiffling: the name given to the method of rapid descent that some waterfowl use. They twist their body and wings, first one way then the other, loosing lift and forward speed in the process to very quickly descend to the water surface. When large flocks of birds engage in this manouver the result can be astounding.

World-wide checklists: for purposes of taxonomy in the Opus, the baseline was the Sibley, CG and BL Monroe. 1996¹. Opus will change if there is a consensus between Clements² and the Howard & Moore checklists³. Two additional lists are worth mentioning: the Gill & Wright list⁴ started as an attempt to address differences in names world-wide, but also includes new taxonomic reports in a very fast format, while the BirdLife international list⁵ is published as a spreadsheet regularly, but with very little information of which kind of thoughts go into the taxonomic decisions, or on who constitutes the group behind the list.

References W

1. Sibley, CG and BL Monroe. 1996. Birds of the World, on diskette, Windows version 2.0. Charles G. Sibley, Santa Rosa, CA, USA.

1. Clements, JF. 2008. The Clements Checklist of Birds of the World. 6th ed., with updates to December 2008. Ithaca: Cornell Univ. Press. ISBN 978-0801445019.

1. Dickinson, EC, ed. 2003. The Howard and Moore Complete Checklist of the Birds of the World. 3rd ed., with updates to October 2008 (Corrigenda 8). Princeton: Princeton Univ. Press. ISBN 978-0691117010

1. Gill, F, M Wright and D Donsker. 2009. IOC World Bird Names (version 2.0). Available at http://www.worldbirdnames.org/.

1. BirdLife International. 2009. The BirdLife checklist of the birds of the world, with conservation status and taxonomic sources. Version 2. Downloaded from http://www.birdlife.org/datazone/species/downloads/BirdLife_Checklist_Version_2.zip [.xls zipped 1 MB].

Z

Zygodactyl: Having two toes on each foot pointing forwards whilst the other two point backwards. The backwards pointing toes are the innermost and outermost toes. Woodpeckers and other arboreal species share this trait while Trogons have a Heterodactyl arrangement. see Legs and Feet

This page is divided into four sections: Dictionary A-F, Dictionary G-L, Dictionary M-S and Dictionary T-Z.