Tyrant flycatcher

Tyrant flycatchers
Scissor-tailed Flycatcher
Tyrannus forficatus
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Aves
Order: Passeriformes
Suborder: Tyranni
Family: Tyrannidae
Vigors, 1825
Genera

Some 100, see text
Distribution of tyrant flycatchers

The tyrant flycatchers (Tyrannidae) are a family of passerine birds which occur throughout North and South America, but are mainly Neotropical in distribution. They are now considered the largest family of birds on Earth, with around 400 species. In every country in the Americas, except for the United States and Canada, they are the most diverse avian family. As could be expected from a family this large, the members vary greatly both in shape, patterns and colours. Some Tyrant flycatchers superficially resemble the Old World flycatchers. They are members of suborder Tyranni (suboscines) that do not have the sophisticated vocal capabilities of the songbirds.

Most, but not all, are rather plain, and many have erectile crests. As the name implies, most are insectivorous, but some will eat fruit or small vertebrates (e.g. small frogs). The smallest family members are the closely related Short-tailed Pygmy Tyrant and Black-capped Pygmy Tyrant. With a total length of a mere 6.5-6.8 cm (2.5-2.7 in) and a weight of 4-5 grams, they are the smallest passerines on earth. The largest tyrant flycatcher is the Great Shrike-Tyrant at 29 cm (11.5 in) and 88 grams (3.1 oz). A few species such as the Streamer-tailed Tyrant, Scissor-tailed Flycatcher and Fork-tailed Flycatcher have a larger total length, but this is mainly due to their very long tails.

A number of species previously included in this family are now placed in the family Tityridae (see Systematics).

Contents

Habitat and distribution

Species richness of Tyrannidae, when compared to habitat, is highly variable. The habitats of tropical lowland evergreen forest and montane evergreen forest have the highest single site species diversity while many habitats including rivers, palm forest, white sand forest, tropical deciduous forest edge, southern temperate forest, southern temperate forest edge, semi-humid/humid montane scrub, and northern temperate grassland have the lowest single species diversity. The variation between the highest and the lowest is extreme; ninety species can be found in the tropical lowland evergreen forests while the number of species that can be found in the habitats listed above typically are in the single digits. This may be due in part to the fewer niches found in certain areas and therefore fewer places for the species to occupy.

Tyrannidae specialization among habitat is very strong in tropical lowland evergreen forests and montane evergreen forests. These habitat types therefore display the greatest specialization. The counts differ by three species (tropical lowland evergreen forests have 49 endemic species and montane evergreen forests have 46 endemic species). It can be assumed that they both have similar levels of specialization.

Regionally, the Atlantic Forest has the highest species richness with the Chocó following closely behind.

Protected status

The Northern Beardless Tyrannulet (Camptostoma imberbe) and the Rose-throated Becard (Pachyramphus aglaiae) are protected under the Migratory Bird Treaty Act of 1918.[1]. Both these species are common south of the US border. The situation for a number of other species from South and Central America is far more problematic. In 2007, BirdLife International (and consequently IUCN) considered two species, the Minas Gerais Tyrannulet and Kaempfer's Tody-Tyrant critically endangered. Both are endemic to Brazil. Additional, 7 species were considered endangered and 18 species vulnerable.[1]

Systematics

There are about 400 species in 97 genera. A full list, sortable by common and binomial names is at list of tyrant flycatchers. Species in the genera Tityra, Pachyramphus, Laniocera and Xenopsaris have been placed in this family, but evidence strongly suggest they belong in Tityridae[2], where now placed by SACC.

Northern Royal Flycatcher, Onychorhynchus (coronatus) mexicanus
Eastern Wood Pewee, Contopus virens
The Great Shrike-tyrant (Agriornis lividus) is the largest species of tyrant flycatcher.
Great Kiskadee, Pitangus sulphuratus
Fork-tailed Flycatcher, Tyrannus savana
Common Tody Flycatcher, Todirostrum cinereum
Agile Tit-Tyrant, Anairetes agilis

References

  1. ↑ BirdLife International (2007). Species factsheets. Accessed 12 December 2007 available online
  2. ↑ Adopt the Family Tityridae - South American Classification Committee (2007)

External links