Emberizidaebuntings, American sparrows, and relatives(Also: New World sparrows and Old World buntings)

Diversity

The family Emberizidae (sparrows, buntings and relatives) falls within the order Passeriformes (perching birds). Members of the Emberizidae family are commonly referred to as American or New World sparrows and buntings. The common name "sparrow" is actually a misnomer and is based on a superficial resemblance the members of Emberizidae have to the family Passeridae (Old World sparrows). Old World sparrows have similar size, shape and colors as New World sparrows and were mistakenly called sparrows by people arriving in the New World. New World sparrows are not actually closely related to Old World sparrows despite their name.

The classification of the family Emberizidae has been the subject of much debate (see Systematic and Taxonomic History). For this account I will use the classification found in Howard and Moore’s third edition of the Complete Checklist of the Birds of the World. Howard and Moore (2003) list 73 genera and 308 species of sparrows and buntings. The greatest diversity of Emberizids occurs in the New World where they are thought to have evolved.

On average, Emberizids are nondescript, small to medium sized, brownish birds. Many birdwatchers jokingly call them “little brown jobs”. They have a world-wide distribution and are found in a variety of different habitat types. Males and females are usually monogamous and are quite similar in appearance. Most Emberizids eat seeds and insects. (Dickinson, 2003; Dunning, 2001; Rising and Beadle, 1996; )

Geographic Range

Emberizids are found on all continents except Australia and Antarctica. However, the highest diversity of sparrows and buntings is found it the Western Hemisphere. (Dunning, 2001; Rising and Beadle, 1996; )

Habitat

Emberizids feed and nest in a wide variety of terrestrial habitats, in temperate, tropical and polar regions. They generally prefer open country and can be found in habitat from salt marshes at sea level to areas of alpine tundra at high elevation. They live in grasslands, deserts, desert scrublands, wetland and woodland edges, shrubby habitat, arctic and alpine tundra, agricultural fields, urban and suburban areas. Sparrows and buntings are almost never found in mature forest interiors; Bachman’s sparrows (Aimophila aestivalis) are the only sparrows that live in old growth forest. However, the longleaf pine forests that they inhabit are very open and are more like edge habitat than dense forest. (Dunning, 2001; Rising and Beadle, 1996; )

Physical Description

Emberizids are small to medium sized birds 10 to 24 cm in length (15 cm on average). Towhees are the largest members of the family. Males are usually larger than females. Males and females are generally similar in appearance, however, where dimorphism occurs, males are brighter than females. Longspurs, buntings, towhees and seedeaters are the groups within Emberizidae that most often show sexual dimorphism.

Emberizids have conical bills. Most members of Emberizidae are brown or gray with streaks on their breast and/or back. However, there are some exceptions; for example, snow buntings (Plectrophenax nivalis) are primarily white. Juveniles usually have streaky coloration, especially on their breast. Adults molt in the late summer/early fall and in the spring. The molt does not usually change the bird’s appearance. (Dunning, 2001; Rising and Beadle, 1996; )

  • Sexual Dimorphism
  • sexes alike
  • male larger
  • sexes colored or patterned differently
  • male more colorful

Reproduction

Most Emberizids are monogamous. However, a few are polygynous. Even among the socially monogamous species, extra-pair copulation (when birds mate with individuals other than their mate) is common. Smith’s longspurs (Calcarius pictus) are polygynandrous (promiscuous, males and females have multiple mates). Saltmarsh sharp-tailed sparrows (Ammodramus caudacutus) exhibit what is called scramble competition polygyny. In this mating system, which is common in frogs, males are not territorial and more than one male will try to mate with a single female at once. In most species, males defend breeding territories using song and by chasing intruders. (Byers, et al., 1995; Dunning, 2001; Rising and Beadle, 1996; )

Breeding in Emberizids usually takes place during the summer or rainy seasons. Breeding usually occurs during the season with the maximum abundance of invertebrates, the favored food source for parents to feed their young. Many species have more than one brood per year and will re-nest if their initial nest is lost due to depredation. Nests are built between 0 and 6 meters above the ground, however, usually on the ground or in shrubs within one meter of the ground. Sparrows and buntings usually build open cup nests (a few species build domed nests) made of grass and stems, lined with fine roots, grass and hair. Nests are not re-used year after year and take from 2 to 12 days to build (usually 3 to 4).

Females lay 3 to 5 eggs on average. Eggs are white, bluish or tan with very few spots to a lot of spotting. They measure between 17 by 13 mm to 25 by 19 mm. Females incubate the eggs and may be fed occasionally by their mates during this period. Incubation lasts 11 to 14 days and the eggs hatch synchronously. Young are fed primarily insects by both parents and usually fledge between 9 to 12 days after hatching. If the nest is disturbed, chicks will fledge earlier. Young reach sexual maturity in one year. (Byers, et al., 1995; Dunning, 2001; Rising and Beadle, 1996; )

Females incubate the eggs and may be fed occasionally by their mates during this period. Incubation lasts 11 to 14 days and the eggs hatch synchronously. Young are altricial and are fed primarily insects by both parents. Chicks usually fledge between 9 to 12 days after hatching. If the nest is disturbed, chicks will fledge earlier. Young receive parental care for 21 to 35 days after hatching. Males often take a greater part in raising fledglings than females so that females can begin a second brood. (Byers, et al., 1995; Dunning, 2001; Rising and Beadle, 1996; )

Lifespan/Longevity

The oldest recorded sparrow was 13 years and 4 months old. Adult annual survival is usually around 60 percent. Like most small birds, Emberizids probably live on average only two to five years. (Dunning, 2001; Gill, 1995; )

Behavior

Male Emberizids are usually territorial during the breeding season and gregarious in winter. Males arrive at the breeding grounds in spring and set up territories before the females arrive. They defend their territories using song and by chasing intruders.

A few species of Emberizids are migratory, but most are permanent residents or make only short-distance migrations or nomadic wanderings. Species that breed at high elevations will often move to lower elevations during winter.

Most Emberizids are diurnal. Many sparrows and buntings form feeding flocks, some flocks consist of a single species; some are mixed. Dominance hierarchies exist within the flocks; older individuals are dominant over younger individuals, individuals with brighter coloration are dominant over others who are duller, and larger individuals are dominant over smaller individuals. (Byers, et al., 1995; Dunning, 2001; Rising and Beadle, 1996; )

Communication and Perception

Female Emberizids rarely sing. Males sing to attract females and to defend territories against other males. Some species have simple songs (chip notes linked together) and others have more complex or melodic songs. Males often sing from prominent perches within their territories, some also sing while in flight. Male and female pairs often have a call that they use to communicate with each other and with their offspring. Emberizids also give alarm calls when threatened. (Dunning, 2001; Rising and Beadle, 1996; )

Food Habits

Emberizids are typically omnivorous (both insectivorous and grainivorous). They primarily eat seeds during the winter and insects during the summer. Their choice of prey usually consists of whatever insects are most common and easiest to catch. Some species, such as song sparrows (Melospiza melodia), that live in coastal areas, feed on mollusks and crustaceans.

Many species will specialize on certain types of seeds; small beaked sparrows eat small seeds, large beaked sparrows eat large seeds. Bill size and shape are adaptations that reflect the birds' food type. Emberizids forage by scratching at the ground looking for insects and seeds, pulling them off of vegetation, picking them off the ground, or gleaning insects from vegetation. Some species can get most of the water they need from insects and seeds and do not need additional water. (Anderson, 2003; Dunning, 2001; Rising and Beadle, 1996; )

Predation

Known predators include hawks (family Accipitridae), falcons (family Falconidae), owls (family Strigidae) and numerous mammals (class Mammalia, including house cats (Felis silvestris), raccoons (Procyon lotor), foxes (family Canidae) and weasels (family Mustelidae)). Sparrows and buntings often forage near cover so they can flee if a predator approaches. They also forage in flocks, a behavior that allows for increased vigilance and reduces the chance that any one bird will be caught. As with almost all ground nesting birds, nest predation is common among Emberizids. (Anderson, 2003; birdnature.com, 2002; Dunning, 2001; )

Ecosystem Roles

Emberizids are important members of their ecosystem. Because of their food habits, they likely have a regulatory influence on insect populations, and they are an important food source for their predators. They also have an influence on the reproduction of the plants whose seeds they eat. In addition, Emberizids are hosts for brown-headed cowbirds (Molothrus ater), a parasitic species of bird that lays its eggs in the nests of other bird species.

  • Ecosystem Impact
  • disperses seeds

Economic Importance for Humans: Positive

Sparrows and buntings are common visitors to bird feeders and many species are sought out by avid birdwatchers. Also, as insectivores they eat insects that might be crop pests (for example, crickets (order Orthoptera), beetles (order Coleoptera), caterpillars (order Lepidoptera) and ants (order Hymenoptera)). Some Emberizids are also kept as pets.

Economic Importance for Humans: Negative

Because they are seed eaters, sparrows and buntings can often be crop pests. They feed on lettuce, broccoli, sugar beats, alfalfa, grains, fruit trees, flower seedlings and grass seed, among other things. They have a negative economic impact since farmers and others spend a lot of time and energy trying to keep the birds out. (Clark and Hygnstrom, 1994)

  • Negative Impacts
  • crop pest

Conservation Status

Many populations of Emberizids are declining. Habitat loss and fragmentation are main threats. Habitat is being lost due to urbanization, and as forest succession reduces the size and number of grasslands and old fields. Over-grazing, cowbird parasitism, trapping for the cage-bird trade and house cats also pose threats to many species.

The IUCN lists a number of species as critically endangered, endangered or vulnerable. CITES also lists a few Emberizids under appendix II and III. Most migratory species in the United States are protected by the US Migratory Bird Treaty Act and the US ESA lists two subspecies as endangered (Cape Sable seaside sparrow (Ammodramus maritimus mirabilis) and Florida grasshopper sparrow (Ammodramus savannarum floridanus)) and one as threatened (San Clement sage sparrow (Amphizpiza belli clementeae)). ("UNEP-WCMC Species Database: CITES-Listed Species", 2003; Dunning, 2001; IUCN, 2002; Rising and Beadle, 1996; ; Threatened and Endangered Species System, 2003; U.S. Fish and Wildlife Service, date unknown)

  • IUCN Red List [Link]
    Not Evaluated

Contributors

Alaine Camfield (author), Animal Diversity Web.

Kari Kirschbaum (editor), Animal Diversity Web.

Glossary

Ethiopian

living in sub-Saharan Africa (south of 30 degrees north) and Madagascar.

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Nearctic

living in the Nearctic biogeographic province, the northern part of the New World. This includes Greenland, the Canadian Arctic islands, and all of the North American as far south as the highlands of central Mexico.

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Neotropical

living in the southern part of the New World. In other words, Central and South America.

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Palearctic

living in the northern part of the Old World. In otherwords, Europe and Asia and northern Africa.

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acoustic

uses sound to communicate

agricultural

living in landscapes dominated by human agriculture.

altricial

young are born in a relatively underdeveloped state; they are unable to feed or care for themselves or locomote independently for a period of time after birth/hatching. In birds, naked and helpless after hatching.

arboreal

Referring to an animal that lives in trees; tree-climbing.

bilateral symmetry

having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.

carnivore

an animal that mainly eats meat

chemical

uses smells or other chemicals to communicate

coastal

the nearshore aquatic habitats near a coast, or shoreline.

desert or dunes

in deserts low (less than 30 cm per year) and unpredictable rainfall results in landscapes dominated by plants and animals adapted to aridity. Vegetation is typically sparse, though spectacular blooms may occur following rain. Deserts can be cold or warm and daily temperates typically fluctuate. In dune areas vegetation is also sparse and conditions are dry. This is because sand does not hold water well so little is available to plants. In dunes near seas and oceans this is compounded by the influence of salt in the air and soil. Salt limits the ability of plants to take up water through their roots.

diurnal
  1. active during the day, 2. lasting for one day.
dominance hierarchies

ranking system or pecking order among members of a long-term social group, where dominance status affects access to resources or mates

ecotourism

humans benefit economically by promoting tourism that focuses on the appreciation of natural areas or animals. Ecotourism implies that there are existing programs that profit from the appreciation of natural areas or animals.

endothermic

animals that use metabolically generated heat to regulate body temperature independently of ambient temperature. Endothermy is a synapomorphy of the Mammalia, although it may have arisen in a (now extinct) synapsid ancestor; the fossil record does not distinguish these possibilities. Convergent in birds.

female parental care

parental care is carried out by females

fertilization

union of egg and spermatozoan

forest

forest biomes are dominated by trees, otherwise forest biomes can vary widely in amount of precipitation and seasonality.

granivore

an animal that mainly eats seeds

herbivore

An animal that eats mainly plants or parts of plants.

holarctic

a distribution that more or less circles the Arctic, so occurring in both the Nearctic and Palearctic biogeographic regions.

World Map

Found in northern North America and northern Europe or Asia.

insectivore

An animal that eats mainly insects or spiders.

internal fertilization

fertilization takes place within the female's body

introduced

referring to animal species that have been transported to and established populations in regions outside of their natural range, usually through human action.

iteroparous

offspring are produced in more than one group (litters, clutches, etc.) and across multiple seasons (or other periods hospitable to reproduction). Iteroparous animals must, by definition, survive over multiple seasons (or periodic condition changes).

male parental care

parental care is carried out by males

marsh

marshes are wetland areas often dominated by grasses and reeds.

migratory

makes seasonal movements between breeding and wintering grounds

monogamous

Having one mate at a time.

motile

having the capacity to move from one place to another.

mountains

This terrestrial biome includes summits of high mountains, either without vegetation or covered by low, tundra-like vegetation.

native range

the area in which the animal is naturally found, the region in which it is endemic.

nomadic

generally wanders from place to place, usually within a well-defined range.

oceanic islands

islands that are not part of continental shelf areas, they are not, and have never been, connected to a continental land mass, most typically these are volcanic islands.

omnivore

an animal that mainly eats all kinds of things, including plants and animals

oriental

found in the oriental region of the world. In other words, India and southeast Asia.

World Map

oviparous

reproduction in which eggs are released by the female; development of offspring occurs outside the mother's body.

pet trade

the business of buying and selling animals for people to keep in their homes as pets.

polar

the regions of the earth that surround the north and south poles, from the north pole to 60 degrees north and from the south pole to 60 degrees south.

polyandrous

Referring to a mating system in which a female mates with several males during one breeding season (compare polygynous).

polygynandrous

the kind of polygamy in which a female pairs with several males, each of which also pairs with several different females.

polygynous

having more than one female as a mate at one time

scrub forest

scrub forests develop in areas that experience dry seasons.

seasonal breeding

breeding is confined to a particular season

sedentary

remains in the same area

sexual

reproduction that includes combining the genetic contribution of two individuals, a male and a female

social

associates with others of its species; forms social groups.

suburban

living in residential areas on the outskirts of large cities or towns.

tactile

uses touch to communicate

temperate

that region of the Earth between 23.5 degrees North and 60 degrees North (between the Tropic of Cancer and the Arctic Circle) and between 23.5 degrees South and 60 degrees South (between the Tropic of Capricorn and the Antarctic Circle).

terrestrial

Living on the ground.

territorial

defends an area within the home range, occupied by a single animals or group of animals of the same species and held through overt defense, display, or advertisement

tropical

the region of the earth that surrounds the equator, from 23.5 degrees north to 23.5 degrees south.

tropical savanna and grassland

A terrestrial biome. Savannas are grasslands with scattered individual trees that do not form a closed canopy. Extensive savannas are found in parts of subtropical and tropical Africa and South America, and in Australia.

savanna

A grassland with scattered trees or scattered clumps of trees, a type of community intermediate between grassland and forest. See also Tropical savanna and grassland biome.

temperate grassland

A terrestrial biome found in temperate latitudes (>23.5? N or S latitude). Vegetation is made up mostly of grasses, the height and species diversity of which depend largely on the amount of moisture available. Fire and grazing are important in the long-term maintenance of grasslands.

tundra

A terrestrial biome with low, shrubby or mat-like vegetation found at extremely high latitudes or elevations, near the limit of plant growth. Soils usually subject to permafrost. Plant diversity is typically low and the growing season is short.

urban

living in cities and large towns, landscapes dominated by human structures and activity.

visual

uses sight to communicate

References

2003. "UNEP-WCMC Species Database: CITES-Listed Species" (On-line). Accessed February 10, 2004 at http://www.cites.org/eng/resources/species.html.

Anderson, B. 2003. "Sparrows" (On-line). Alaska Department of Fish and Game. Accessed February 10, 2004 at http://www.adfg.state.ak.us/pubs/notebook/bird/sparrows.php.

Beadle, D., J. Rising. 2002. Sparrows of the United States and Canada, The Photographic Guide. San Diego: Academic Press.

Byers, C., J. Curson, U. Olsson. 1995. Sparrows and Buntings, A Guide to the Sparrows and Buntings of North America and the World. Boston: Houghton Mifflin Company.

Carson, R., G. Spicer. 2003. A phylogenetic analysis of the emberizid sparrows based on three mitochondrial genes. Molecular Phylogenetics and Evolution, 29: 43-57.

Clark, J., S. Hygnstrom. 1994. "Wildlife Management - Crowned Sparrows (PDF)" (On-line). Accessed February 10, 2004 at http://www.wildlifemanagement.info/birds.htm.

Dickinson, E. 2003. The Howard and Moore Complete Checklist of Birds of the World, 3rd edition. London: Christopher Helm.

Dunning, J. 2001. New World Sparrows. Pp. 516-535 in C Elphick, J Dunning, D Sibley, eds. The Sibly Guide to Bird Life and Behavior. New York: Alfred A. Knopf.

Gill, F. 1995. Ornithology, Second Edition. New York: W.H. Freeman and Company.

IUCN, 2002. "The IUCN Red List of Threatened Species" (On-line). Accessed February 10, 2004 at http://www.redlist.org/.

Klicka, J., K. Johnson, S. Lanyon. 2000. New World nine-primaried oscine relationships: constructing a mitochondrial DNA framework. The Auk, 117(2): 321-336.

Rising, J., D. Beadle. 1996. A Guide to the Identification and Natural History of the Sparrows of the United States and Canada. San Diego: Academic Press.

Threatened and Endangered Species System, 2003. "U.S. Listed Vertebrate Animal Species Report by Taoxonomic Group" (On-line). Accessed February 10, 2004 at http://ecos.fws.gov/tess_public/TESSWebpageVipListed?code=V&listings=0#B.

U.S. Fish and Wildlife Service, date unknown. "Birds Protected by the Migratory Bird Treaty Act" (On-line). Accessed February 10, 2004 at http://migratorybirds.fws.gov/intrnltr/mbta/mbtintro.html.

birdnature.com, 2002. "Predators to Birds" (On-line). Accessed February 10, 2004 at http://www.birdnature.com/predators.html.