Northern Beardless Tyrannulet
Encyclopedia
The Northern Beardless Tyrannulet, Camptostoma imberbe, is a small passerine
bird
in the tyrant flycatcher
family. It breeds from southeasternmost Arizona
and Texas
of the United States
through Mexico
and Central America
to northwestern Costa Rica
.
This species is found in light forests, cultivation and gardens with trees. The domed nest is made of plant fibre or leaves with a side entrance. The nest is placed by a tree fork. The typical clutch is two white eggs, which are marked with rufous and lilac mostly at the larger end. Incubation by the female is 14-15 days to hatching, with another 17 days to fledging.
The Northern Beardless Tyrannulet is 10.2 cm (4 in) long, and weighs 7.5 g (0.26455471578834 oz). The head is dark brown with an erectile crest and pale supercilium
. The upperparts are grey-green becoming paler on the rump. The wings are brown with yellow feather-edging and two whitish wing bars. The tail is brown, the throat grey, the breast yellowish, and the abdomen yellow. The bill is pinkish.
Sexes are similar, and this species always appears not as bright, especially with regard to the wing bars, as the closely related Southern Beardless Tyrannulet
, C. obsoletum, with which it was once considered conspecific. However, the two forms overlap without interbreeding in Costa Rica.
Northern Beardless Tyrannulets are active birds, feeding in a vireo
or warbler-like
fashion on insect
s, spider
s and berries
. The call is a loud whistled Fleeeeeerrr, sometimes broken up as a fleeer-it, or a flee-flee-flee-flee. In courtship, or when alarmed, the crests are raised, the tail flicked, and an excited call is made.
Passerine
A passerine is a bird of the order Passeriformes, which includes more than half of all bird species. Sometimes known as perching birds or, less accurately, as songbirds, the passerines form one of the most diverse terrestrial vertebrate orders: with over 5,000 identified species, it has roughly...
bird
Bird
Birds are feathered, winged, bipedal, endothermic , egg-laying, vertebrate animals. Around 10,000 living species and 188 families makes them the most speciose class of tetrapod vertebrates. They inhabit ecosystems across the globe, from the Arctic to the Antarctic. Extant birds range in size from...
in the tyrant flycatcher
Tyrant flycatcher
The tyrant flycatchers are a family of passerine birds which occur throughout North and South America. They are considered the largest family of birds on Earth, with more than 400 species. They are the most diverse avian family in every country in the Americas, except for the United States and...
family. It breeds from southeasternmost Arizona
Arizona
Arizona ; is a state located in the southwestern region of the United States. It is also part of the western United States and the mountain west. The capital and largest city is Phoenix...
and Texas
Texas
Texas is the second largest U.S. state by both area and population, and the largest state by area in the contiguous United States.The name, based on the Caddo word "Tejas" meaning "friends" or "allies", was applied by the Spanish to the Caddo themselves and to the region of their settlement in...
of the United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
through Mexico
Mexico
The United Mexican States , commonly known as Mexico , is a federal constitutional republic in North America. It is bordered on the north by the United States; on the south and west by the Pacific Ocean; on the southeast by Guatemala, Belize, and the Caribbean Sea; and on the east by the Gulf of...
and Central America
Central America
Central America is the central geographic region of the Americas. It is the southernmost, isthmian portion of the North American continent, which connects with South America on the southeast. When considered part of the unified continental model, it is considered a subcontinent...
to northwestern Costa Rica
Costa Rica
Costa Rica , officially the Republic of Costa Rica is a multilingual, multiethnic and multicultural country in Central America, bordered by Nicaragua to the north, Panama to the southeast, the Pacific Ocean to the west and the Caribbean Sea to the east....
.
This species is found in light forests, cultivation and gardens with trees. The domed nest is made of plant fibre or leaves with a side entrance. The nest is placed by a tree fork. The typical clutch is two white eggs, which are marked with rufous and lilac mostly at the larger end. Incubation by the female is 14-15 days to hatching, with another 17 days to fledging.
The Northern Beardless Tyrannulet is 10.2 cm (4 in) long, and weighs 7.5 g (0.26455471578834 oz). The head is dark brown with an erectile crest and pale supercilium
Supercilium
The supercilium is a plumage feature found on the heads of some bird species. It is a stripe which runs from the base of the bird's beak above its eye, finishing somewhere towards the rear of the bird's head. Also known as an "eyebrow", it is distinct from the eyestripe, which is a line which runs...
. The upperparts are grey-green becoming paler on the rump. The wings are brown with yellow feather-edging and two whitish wing bars. The tail is brown, the throat grey, the breast yellowish, and the abdomen yellow. The bill is pinkish.
Sexes are similar, and this species always appears not as bright, especially with regard to the wing bars, as the closely related Southern Beardless Tyrannulet
Southern Beardless Tyrannulet
The Southern Beardless Tyrannulet, Camptostoma obsoletum, is a small passerine bird in the tyrant flycatcher family. It breeds from Costa Rica through South America south to Paraguay, Bolivia, and Argentina.-Description:...
, C. obsoletum, with which it was once considered conspecific. However, the two forms overlap without interbreeding in Costa Rica.
Northern Beardless Tyrannulets are active birds, feeding in a vireo
Vireo
The vireos are a group of small to medium-sized passerine birds restricted to the New World. They are typically dull-plumaged and greenish in color, the smaller species resembling wood warblers apart from their heavier bills...
or warbler-like
Warbler
There are a number of Passeriformes called "warblers". They are not particularly closely related, but share some characteristics, such as being fairly small, vocal and insectivorous....
fashion on insect
Insect
Insects are a class of living creatures within the arthropods that have a chitinous exoskeleton, a three-part body , three pairs of jointed legs, compound eyes, and two antennae...
s, spider
Spider
Spiders are air-breathing arthropods that have eight legs, and chelicerae with fangs that inject venom. They are the largest order of arachnids and rank seventh in total species diversity among all other groups of organisms...
s and berries
Berry
The botanical definition of a berry is a fleshy fruit produced from a single ovary. Grapes are an example. The berry is the most common type of fleshy fruit in which the entire ovary wall ripens into an edible pericarp. They may have one or more carpels with a thin covering and fleshy interiors....
. The call is a loud whistled Fleeeeeerrr, sometimes broken up as a fleeer-it, or a flee-flee-flee-flee. In courtship, or when alarmed, the crests are raised, the tail flicked, and an excited call is made.
External Links
- Northern Beardless-Tyrannulet Images http://tsuru-bird.net/image.htm Copyright 2009 Monte M. Taylor