Bronzed Cowbird
Encyclopedia
The Bronzed Cowbird Molothrus aeneus, is a small icterid
.
It breeds from the southern U.S. state
s of California
, Arizona
, New Mexico
, Texas
, and Louisiana
south through Central America
to Panama
. An isolated population on the Caribbean coast of Colombia
is sometimes treated as a separate species, the Bronze-brown Cowbird (M. armenti).
The male Bronzed Cowbird is 20 cm long and weighs 68 g, with green-bronze glossed black plumage and red eyes. The female is 18.5 cm long and weighs 56 g. She is duller black above and browner below. Young birds are like the female but have grey feather fringes.
Like all cowbirds, this bird
is a brood parasite
: it lays its egg
s in the nests of other birds. The young cowbird is fed by the host parents at the expense of their own young. Hosts include Prevost's Ground-Sparrow
and Yellow-throated Brush Finch.
Icterid
The Icterids are a group of small to medium-sized, often colorful passerine birds restricted to the New World. Most species have black as a predominant plumage color, often enlivened by yellow, orange or red. The family is extremely varied in size, shape, behavior and coloration...
.
It breeds from the southern U.S. state
U.S. state
A U.S. state is any one of the 50 federated states of the United States of America that share sovereignty with the federal government. Because of this shared sovereignty, an American is a citizen both of the federal entity and of his or her state of domicile. Four states use the official title of...
s of California
California
California is a state located on the West Coast of the United States. It is by far the most populous U.S. state, and the third-largest by land area...
, 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...
, New Mexico
New Mexico
New Mexico is a state located in the southwest and western regions of the United States. New Mexico is also usually considered one of the Mountain States. With a population density of 16 per square mile, New Mexico is the sixth-most sparsely inhabited U.S...
, 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...
, and Louisiana
Louisiana
Louisiana is a state located in the southern region of the United States of America. Its capital is Baton Rouge and largest city is New Orleans. Louisiana is the only state in the U.S. with political subdivisions termed parishes, which are local governments equivalent to counties...
south through 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 Panama
Panama
Panama , officially the Republic of Panama , is the southernmost country of Central America. Situated on the isthmus connecting North and South America, it is bordered by Costa Rica to the northwest, Colombia to the southeast, the Caribbean Sea to the north and the Pacific Ocean to the south. The...
. An isolated population on the Caribbean coast of 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...
is sometimes treated as a separate species, the Bronze-brown Cowbird (M. armenti).
The male Bronzed Cowbird is 20 cm long and weighs 68 g, with green-bronze glossed black plumage and red eyes. The female is 18.5 cm long and weighs 56 g. She is duller black above and browner below. Young birds are like the female but have grey feather fringes.
Like all cowbirds, this 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...
is a brood parasite
Brood parasite
Brood parasites are organisms that use the strategy of brood parasitism, a kind of kleptoparasitism found among birds, fish or insects, involving the manipulation and use of host individuals either of the same or different species to raise the young of the brood-parasite...
: it lays its egg
Egg (biology)
An egg is an organic vessel in which an embryo first begins to develop. In most birds, reptiles, insects, molluscs, fish, and monotremes, an egg is the zygote, resulting from fertilization of the ovum, which is expelled from the body and permitted to develop outside the body until the developing...
s in the nests of other birds. The young cowbird is fed by the host parents at the expense of their own young. Hosts include Prevost's Ground-Sparrow
Prevost's Ground-Sparrow
Prevost's Ground-Sparrow Melozone biarcuatum, also known as the White-faced Ground-Sparrow, is an American sparrow.-Etymology:Its English name commemorates French naturalist Florent Prévost. The isolated Costa Rican form may be a separate species, Cabanis's Ground-Sparrow Prevost's Ground-Sparrow...
and Yellow-throated Brush Finch.
Further reading
- Lowther, P. E. 1995. Bronzed Cowbird (Molothrus aeneus). In The Birds of North America, No. 144 (A. Poole and F. Gill, eds.). The Academy of Natural Sciences, Philadelphia, and The American Ornithologists’ Union, Washington, D.C.
External links
- Bronzed Cowbird videos on the Internet Bird Collection
- Bronzed Cowbird photo gallery VIREO