Yellow-faced Grassquit
Encyclopedia
The Yellow-faced Grassquit (Tiaris olivaceus) is a passerine
bird
from the Central America
n tropics
and surrounding regions. It was formerly alled with the American sparrow
s and placed in the Emberizidae
; actually, however, it is one of the tholospizan "finch
es" which are specialized tanager
s (Thraupidae). As such, it is closely related to the famous Darwin's finches
.
s. It is 3.9-4.2 in (10-10.7 cm) long and weighs about 0.28-0.35 oz (8-10 g), depending on subspecies
. The adult male has an olive-green back, and its face and breast are black apart from a bright yellow throat, supercilia
, and lower eyelid spot. The rest of the underparts are greyish olive. The beak
and eyes are dark, the legs are grey.
The adult female is slightly smaller on average than the male. It is dull olive-green above and paler grey below, and may have some dark breast smudges. The yellow face pattern is much weaker and duller, and may be almost invisible. The lower part of the beak is dark horn-colored. Young birds are colored essentially like the adult female, but duller and greyer. Young males begin to acquire full adult plumage in their first year.
The Yellow-faced Grassquit has a weak buzzing trilled ttttt-tee call. The song is a varying series of high thin rapid trills. Given for a prolonged time, it is melodious, yet subdued, and often only heard from a short distance away.
to northern Ecuador
and northwestern Venezuela
, and also on the Greater Antilles
and nearby islands (e.g. the Cayman Islands, and Jamaica). It is not a migratory bird but moves about outside the breeding season; vagrants have been recorded in the United States
. It has been introduced to Hawaiʻi.
The Yellow-faced Grassquit is a common to abundant resident in lowlands and foothills up to 7,500 ft (2,300 m) altitude in semi-open areas such as roadsides, pasture, weedy fields and low scrub. It avoids dry grassland and other very low growth, but will readily utilize neglected gardens where lawn
grass has grown high. It is a fairly sociable bird, sometimes forming loose flocks with other tanager
s (such as seedeater
s) and emberizid
s that share its lifestyle, and occasionally adult males will come together to perch in a shrub and sing.
This species feeds mainly on grass
seeds, but also takes other seeds, berries and some insect
s. Food is typically plucked from the inflorescence
s directly, or gathered from the ground. Animal prey is hunted among foliage in a New World warbler
-like fashion.
The main breeding season is in the summer months, but perhaps except for February to April birds may nest at all times of the year. This species sometimes forms loose nesting colonies. During courtship, the male vibrates his wings as he sings his subdued song, sitting only 1-2 in (a few cm) away so the female can properly hear him. The roughly globular nest, built by the female, is made of grass and weed stems compacted into a thick mass, and lined with pieces of grass inflorescences and bast
fiber. It has a side entrance and is placed usually less than 1 ft (30 cm) above the ground, often among grass or weeds on a road or river embankment
. Occasionally, the species nests in shrubs up to 5 ft (1.5 m) above the ground. The clutch
is two or three, rarely four, brown-speckled white eggs. They are incubated by the female alone for 12–14 days to hatching.
This bird is not rare and widely distributed; it is thus classified a Species of Least Concern
by the IUCN. It seems to benefit from deforestation
, increasing in numbers and expanding its range; for example, it is only since 1997 known from the eastern Andean
slope of Meta Department
in Colombia
.
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...
from the 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...
n tropics
Tropics
The tropics is a region of the Earth surrounding the Equator. It is limited in latitude by the Tropic of Cancer in the northern hemisphere at approximately N and the Tropic of Capricorn in the southern hemisphere at S; these latitudes correspond to the axial tilt of the Earth...
and surrounding regions. It was formerly alled with the American sparrow
American sparrow
American sparrows are a group of mainly New World passerine birds, forming part of the family Emberizidae. American sparrows are seed-eating birds with conical bills, brown or gray in color, and many species have distinctive head patterns....
s and placed in the Emberizidae
Emberizidae
The Emberizidae are a large family of passerine birds. They are seed-eating birds with a distinctively shaped bill.In Europe, most species are called buntings. In North America, most of the species in this family are known as sparrows, but these birds are not closely related to the sparrows, the...
; actually, however, it is one of the tholospizan "finch
Finch
The true finches are passerine birds in the family Fringillidae. They are predominantly seed-eating songbirds. Most are native to the Northern Hemisphere, but one subfamily is endemic to the Neotropics, one to the Hawaiian Islands, and one subfamily – monotypic at genus level – is found...
es" which are specialized tanager
Tanager
The tanagers comprise the bird family Thraupidae, in the order Passeriformes. The family has an American distribution.There were traditionally about 240 species of tanagers, but the taxonomic treatment of this family's members is currently in a state of flux...
s (Thraupidae). As such, it is closely related to the famous Darwin's finches
Darwin's finches
Darwin's finches are a group of 14 or 15 species of passerine birds. It is still not clear which bird family they belong to, but they are not related to the true finches. They were first collected by Charles Darwin on the Galápagos Islands during the second voyage of the Beagle...
.
Description
It is a small bird with a conical bill, sharper than that of the related seedeaterSeedeater
The seedeaters are a form taxon of seed-eating passerine birds with a distinctively conical bill.Most are Central and South American birds that were formerly placed in the American sparrow family , but are now known to be tanagers closely related to Darwins finches...
s. It is 3.9-4.2 in (10-10.7 cm) long and weighs about 0.28-0.35 oz (8-10 g), depending on subspecies
Subspecies
Subspecies in biological classification, is either a taxonomic rank subordinate to species, ora taxonomic unit in that rank . A subspecies cannot be recognized in isolation: a species will either be recognized as having no subspecies at all or two or more, never just one...
. The adult male has an olive-green back, and its face and breast are black apart from a bright yellow throat, supercilia
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...
, and lower eyelid spot. The rest of the underparts are greyish olive. The beak
Beak
The beak, bill or rostrum is an external anatomical structure of birds which is used for eating and for grooming, manipulating objects, killing prey, fighting, probing for food, courtship and feeding young...
and eyes are dark, the legs are grey.
The adult female is slightly smaller on average than the male. It is dull olive-green above and paler grey below, and may have some dark breast smudges. The yellow face pattern is much weaker and duller, and may be almost invisible. The lower part of the beak is dark horn-colored. Young birds are colored essentially like the adult female, but duller and greyer. Young males begin to acquire full adult plumage in their first year.
The Yellow-faced Grassquit has a weak buzzing trilled ttttt-tee call. The song is a varying series of high thin rapid trills. Given for a prolonged time, it is melodious, yet subdued, and often only heard from a short distance away.
Distribution and ecology
It breeds from central MexicoMexico
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...
to northern Ecuador
Ecuador
Ecuador , officially the Republic of Ecuador is a representative democratic republic in South America, bordered by Colombia on the north, Peru on the east and south, and by the Pacific Ocean to the west. It is one of only two countries in South America, along with Chile, that do not have a border...
and northwestern Venezuela
Venezuela
Venezuela , officially called the Bolivarian Republic of Venezuela , is a tropical country on the northern coast of South America. It borders Colombia to the west, Guyana to the east, and Brazil to the south...
, and also on the Greater Antilles
Greater Antilles
The Greater Antilles are one of three island groups in the Caribbean. Comprising Cuba, Jamaica, Hispaniola , and Puerto Rico, the Greater Antilles constitute almost 90% of the land mass of the entire West Indies.-Greater Antilles in context :The islands of the Caribbean Sea, collectively known as...
and nearby islands (e.g. the Cayman Islands, and Jamaica). It is not a migratory bird but moves about outside the breeding season; vagrants have been recorded in the United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
. It has been introduced to Hawaiʻi.
The Yellow-faced Grassquit is a common to abundant resident in lowlands and foothills up to 7,500 ft (2,300 m) altitude in semi-open areas such as roadsides, pasture, weedy fields and low scrub. It avoids dry grassland and other very low growth, but will readily utilize neglected gardens where lawn
Lawn
A lawn is an area of aesthetic and recreational land planted with grasses or other durable plants, which usually are maintained at a low and consistent height. Low ornamental meadows in natural landscaping styles are a contemporary option of a lawn...
grass has grown high. It is a fairly sociable bird, sometimes forming loose flocks with other tanager
Tanager
The tanagers comprise the bird family Thraupidae, in the order Passeriformes. The family has an American distribution.There were traditionally about 240 species of tanagers, but the taxonomic treatment of this family's members is currently in a state of flux...
s (such as seedeater
Seedeater
The seedeaters are a form taxon of seed-eating passerine birds with a distinctively conical bill.Most are Central and South American birds that were formerly placed in the American sparrow family , but are now known to be tanagers closely related to Darwins finches...
s) and emberizid
Emberizidae
The Emberizidae are a large family of passerine birds. They are seed-eating birds with a distinctively shaped bill.In Europe, most species are called buntings. In North America, most of the species in this family are known as sparrows, but these birds are not closely related to the sparrows, the...
s that share its lifestyle, and occasionally adult males will come together to perch in a shrub and sing.
This species feeds mainly on grass
Grass
Grasses, or more technically graminoids, are monocotyledonous, usually herbaceous plants with narrow leaves growing from the base. They include the "true grasses", of the Poaceae family, as well as the sedges and the rushes . The true grasses include cereals, bamboo and the grasses of lawns ...
seeds, but also takes other seeds, berries and some 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. Food is typically plucked from the inflorescence
Inflorescence
An inflorescence is a group or cluster of flowers arranged on a stem that is composed of a main branch or a complicated arrangement of branches. Strictly, it is the part of the shoot of seed plants where flowers are formed and which is accordingly modified...
s directly, or gathered from the ground. Animal prey is hunted among foliage in a New World warbler
New World warbler
The New World warblers or wood-warblers are a group of small, often colorful, passerine birds restricted to the New World. They are not related to the Old World warblers or the Australian warblers....
-like fashion.
The main breeding season is in the summer months, but perhaps except for February to April birds may nest at all times of the year. This species sometimes forms loose nesting colonies. During courtship, the male vibrates his wings as he sings his subdued song, sitting only 1-2 in (a few cm) away so the female can properly hear him. The roughly globular nest, built by the female, is made of grass and weed stems compacted into a thick mass, and lined with pieces of grass inflorescences and bast
Bast
Bast may refer to:* Bast a slang term used as reference to the word Bastard* Bast, or Bastet, a goddess in Ancient Egyptian mythology* Bast fibre, a type of plant fiber* Bast, Afghanistan...
fiber. It has a side entrance and is placed usually less than 1 ft (30 cm) above the ground, often among grass or weeds on a road or river embankment
Embankment (transportation)
To keep a road or railway line straight or flat, and where the comparative cost or practicality of alternate solutions is prohibitive, the land over which the road or rail line will travel is built up to form an embankment. An embankment is therefore in some sense the opposite of a cutting, and...
. Occasionally, the species nests in shrubs up to 5 ft (1.5 m) above the ground. The clutch
Clutch (eggs)
A clutch of eggs refers to all the eggs produced by birds or reptiles, often at a single time, particularly those laid in a nest.In birds, destruction of a clutch by predators, , results in double-clutching...
is two or three, rarely four, brown-speckled white eggs. They are incubated by the female alone for 12–14 days to hatching.
This bird is not rare and widely distributed; it is thus classified a Species of Least Concern
Least Concern
Least Concern is an IUCN category assigned to extant taxon or lower taxa which have been evaluated but do not qualify for any other category. As such they do not qualify as threatened, Near Threatened, or Conservation Dependent...
by the IUCN. It seems to benefit from deforestation
Deforestation
Deforestation is the removal of a forest or stand of trees where the land is thereafter converted to a nonforest use. Examples of deforestation include conversion of forestland to farms, ranches, or urban use....
, increasing in numbers and expanding its range; for example, it is only since 1997 known from the eastern Andean
Andes
The Andes is the world's longest continental mountain range. It is a continual range of highlands along the western coast of South America. This range is about long, about to wide , and of an average height of about .Along its length, the Andes is split into several ranges, which are separated...
slope of Meta Department
Meta Department
Meta is a department of Colombia. It is close to the geographic center of the country, to the east of the Andean mountains. A large portion of the department, which is also crossed by the Meta River, is covered by a grassland plain known as the Llanos. Its capital is Villavicencio...
in Colombia
Colombia
Colombia, officially the Republic of Colombia , is a unitary constitutional republic comprising thirty-two departments. The country is located in northwestern South America, bordered to the east by Venezuela and Brazil; to the south by Ecuador and Peru; to the north by the Caribbean Sea; to the...
.