Animal Diversity Web

Ge­o­graphic Range

Field spar­rows are found through­out the east­ern United States from just east of the Rocky Moun­tains to the At­lantic Coast and from North Dakota to south­ern Texas in the west and New Hamp­shire to Florida in the east. They are also found in south­ern On­tario and south­ern­most Que­bec. Their breed­ing and win­ter­ing ranges over­lap sub­stan­tially and they are found year-round through­out much of their range ex­cept for the north­ern­most and south­ern­most por­tions. Some pop­u­la­tions are res­i­dent year-round while oth­ers un­der­take short mi­gra­tions. (Carey, et al., 2008)

• Biogeographic Regions
• nearctic
  • native

Habi­tat

Field spar­rows can be com­mon in pre­ferred habi­tat, but are rarely found near human habi­ta­tion, even in ap­pro­pri­ate habi­tat. They are found in open, sa­vanna-like habi­tats, such as suc­ces­sional old fields, for­est edges and open­ings, fencerows and road or rail­way cuts near open fields, and oc­ca­sional or­chards and nurs­eries. They are found only in fields with some trees or shrubs that pro­vide perches. Once suc­ce­sional habi­tats be­come over­grown with trees and shrubs, field spar­rows are no longer found there. (Carey, et al., 2008)

• Habitat Regions
• temperate
• terrestrial

• Terrestrial Biomes
• savanna or grassland

Phys­i­cal De­scrip­tion

Male field spar­rows are slightly larger than fe­males, but both sexes have sim­i­lar plumage. They are red­dish brown on their heads and back with gray, un-streaked bel­lies. They have two white wing bands, a white eye ring, and a rusty brown stripe ex­tend­ing from the eye. Their bill and legs are pink­ish, help­ing to dis­tin­guish them from other spar­rows. They might be con­fused with Worthen's spar­rows (Spizella wortheni) in south­ern New Mex­ico, but they lack the ru­fous stripe from the eye, a dif­fer­ent song, and black legs. (Carey, et al., 2008)

• Other Physical Features
• endothermic
• homoiothermic
• bilateral symmetry

• Sexual Dimorphism
• male larger

• Range mass

  11.4 to 15.7 g

  0.40 to 0.55 oz

• Range length

  12.5 to 15 cm

  4.92 to 5.91 in

Re­pro­duc­tion

Field spar­rows are monog­a­mous. Males seem to use their sim­ple songs to at­tract a mate, the fre­quency of sim­ple songs de­creases after a pair bond forms. Males ac­com­pany fe­males dur­ing nest build­ing and begin cop­u­la­tory be­hav­ior while the nest is being built. Fe­males seem to find a male mate within a few days of ar­riv­ing in their breed­ing area and re­main with their mate for a breed­ing sea­son. A small num­ber of in­di­vid­u­als mate with each other again in fol­low­ing years. Ex­tra-pair cop­u­la­tions have been ob­served. (Carey, et al., 2008)

• Mating System
• monogamous

Field spar­rows breed from April through Au­gust each year. They lay up to 4 clutches per breed­ing sea­son. Mul­ti­ple nest­ing at­tempts are typ­i­cal be­cause of high rates of nest pre­da­tion and de­ser­tion. Fledg­lings still de­pen­dent on their par­ents have been ob­served as late as Oc­to­ber. Fe­males choose a nest site and con­struct a bowl-like nest of woven grass in veg­e­ta­tion near trees and saplings. Nests early in the sea­son are built on or near the ground, but later in the sea­son, after woody veg­e­ta­tion has leafed out, they may be in the branches of shrubs or small trees. Dur­ing egg lay­ing the par­ents don't seem to pro­tect the nest. If eggs are taken by preda­tors, the par­ents will at­tempt to build a new nest else­where. Fe­males lay from 2 to 5 eggs and begin in­cu­bat­ing just be­fore the last egg is laid. Fe­males may delay in­cu­ba­tion until well after the last egg is laid if the weather is cold and wet. In­cu­ba­tion is gen­er­ally from 11 to 12 days long, but can be from 10 to 17 days. Young fledge 7 to 8 days after hatch­ing, begin to fly at 13 to 14 days after hatch­ing, and be­come in­de­pen­dent within 24 to 36 days after hatch­ing. Young are sex­u­ally ma­ture in the year fol­low­ing their hatch­ing. (Carey, et al., 2008; Na­ture­Serve Ex­plorer, 2008)

• Key Reproductive Features
• iteroparous
• seasonal breeding
• gonochoric/gonochoristic/dioecious (sexes separate)
• sexual
• oviparous

• Breeding interval

  Field sparrows breed in the warm season, attempting several clutches in each breeding season. From 2.9 to 4 clutch attempts per breeding is typical.

• Breeding season

  Breeding occurs throughout much of the warm season, with eggs laid from April through August.

• Range eggs per season

  2 to 5

• Range time to hatching

  10 to 17 days

• Average time to hatching

  11-12 days

• Range fledging age

  7 to 8 days

• Range time to independence

  24 to 36 days

• Average age at sexual or reproductive maturity (female)

  1 years

• Average age at sexual or reproductive maturity (male)

  1 years

Fe­males in­cu­bate eggs and brood hatch­lings, spend­ing about 70% of their time on the nest. Males will oc­ca­sion­ally feed in­cu­bat­ing fe­males. Males and fe­males feed hatch­lings ap­prox­i­mately equally. Young are al­tri­cial at hatch­ing and mostly naked. They de­velop gray downy plumage, their eyes open at 4 days old, and they can stand by about 5 days old. Par­ents con­tinue to feed their young through the hatch­ling phase and into the post-fledg­ing pe­riod; they feed and pro­tect young for 26 to 34 days after hatch­ing, about 17 to 28 days after fledg­ing. Males can take over feed­ing of fledg­lings if the fe­male be­gins to con­struct an­other nest to begin a sub­se­quent brood. (Carey, et al., 2008)

• Parental Investment
• altricial
• pre-fertilization
  • provisioning
  • protecting
    • female
• pre-hatching/birth
  • provisioning
    • female
  • protecting
    • female
• pre-weaning/fledging
  • provisioning
    • male
    • female
  • protecting
    • male
    • female
• pre-independence
  • provisioning
    • male
    • female
  • protecting
    • male
    • female

Lifes­pan/Longevity

Max­i­mum recorded age in the wild is 8 years 9 months, based on band­ing records. An­nual male sur­vivor­ship is es­ti­mated at 53% and an­nual fe­male sur­vivor­ship at 36%. Win­ter range con­di­tions may re­sult in higher mor­tal­ity. Ap­prox­i­mately 50% of fledg­lings are thought to die be­fore the fall of their hatch year. (Carey, et al., 2008)

• Average lifespan
  Status: wild

  8.75 years

Be­hav­ior

Field spar­rows are found in ter­ri­to­r­ial, mated pairs dur­ing the breed­ing sea­son and in small flocks dur­ing the win­ter and mi­gra­tion. Breed­ing ter­ri­to­ries are es­tab­lished with song and per­haps some male-male ag­gres­sion, but field spar­rows are gen­er­ally re­ported to be non-ag­gres­sive. They for­age mainly on the ground, hop­ping along to dis­cover seeds, and sleep on perches in woody veg­e­ta­tion. Some pop­u­la­tions un­der­take small mi­gra­tions but other pop­u­la­tions re­main res­i­dent year-round. (Carey, et al., 2008)

• Key Behaviors
• flies
• diurnal
• motile
• migratory
• sedentary
• solitary
• territorial
• social

Home Range

Breed­ing ter­ri­tory sizes were es­ti­mated at an av­er­age 0.76 ha (range 0.31 to 1.62 ha) in one pop­u­la­tion. (Carey, et al., 2008)

Com­mu­ni­ca­tion and Per­cep­tion

Field spar­rows are rec­og­nized by their dis­tinc­tive, pretty song, con­sist­ing of soft whis­tles that ac­cel­er­ate to­wards a trill. Males use songs to ad­ver­tise ter­ri­to­ries dur­ing the breed­ing sea­son. Young field spar­rows learn songs from their par­ents. Field spar­rows also have a reper­toire of other calls, in­clud­ing a for­ag­ing note ("seep"), courtship calls, trill calls used in ter­ri­to­r­ial de­fense and courtship, cricket calls used by fe­males at the nest, chip calls given in the pres­ence of a threat, and "zeeee" or "eeeee" calls used with threats. (Carey, et al., 2008)

• Communication Channels
• acoustic

• Perception Channels
• visual
• tactile
• acoustic
• chemical

Food Habits

Field spar­rows take seeds, pri­mar­ily grass seeds, through­out the year. Grass seeds make up less than 50% of their diet in the sum­mer, but more than 90% in the win­ter. In the sum­mer, breed­ing sea­son they also take adult and lar­val in­sects and spi­ders. They for­age on the ground, most often near some form of veg­e­ta­tive cover. In the breed­ing sea­son field spar­rows for­age on their own or with a mate, but they form small for­ag­ing flocks in win­ter. They take fallen seeds or land on grass stems and push them to the ground, where they re­move the seeds. They use perches to briefly scan for in­sect prey. (Carey, et al., 2008; Na­ture­Serve Ex­plorer, 2008)

• Primary Diet
• herbivore
  • granivore

• Animal Foods
• insects
• terrestrial non-insect arthropods

• Plant Foods
• seeds, grains, and nuts

Pre­da­tion

Ob­served preda­tors of eggs and nestlings in­clude chip­munks (Tamias stria­tus) and many species of snakes (Pan­therophis ob­so­le­tus, Col­u­ber con­stric­tor, Lam­pro­peltis, Thamnophis sir­talis, Lam­pro­peltis cal­li­gaster). The most com­mon preda­tors recorded are black rat snakes (Pan­therophis ob­so­le­tus). Likely preda­tors in­clude red foxes (Vulpes vulpes), grey foxes (Uro­cyon ci­neoar­gen­teus), weasels (Mustela), mink (Neo­vi­son vison), skunks (Mephi­tis mephi­tis), rac­coons (Pro­cyon lotor), and opos­sums (Didel­phis vir­gini­anus). Field spar­rows use a "chip" call to alert oth­ers to a threat. They will use a bro­ken-wing dis­play to dis­tract preda­tors from their nest. (Carey, et al., 2008)

• Anti-predator Adaptations
• cryptic

• Known Predators

  • black rat snakes (Pantherophis obsoletus)
  • chipmunks (Tamias striatus)
  • blue racers (Coluber constrictor)
  • milk snakes (Lampropeltis)
  • garter snakes (Thamnophis sirtalis)
  • prairie kingsnakes (Lampropeltis calligaster)
  • red foxes (Vulpes vulpes)
  • grey foxes (Urocyon cineoargenteus)
  • weasels (Mustela)
  • mink (Neovison vison)
  • skunks (Mephitis mephitis)
  • raccoons (Procyon lotor)
  • Virginia opossums (Didelphis virginianus)

Ecosys­tem Roles

Many kinds of ec­topar­a­sites are found on field spar­rows, in­clud­ing feather mites. They are also in­fected by Plas­mod­ium species. Field spar­rows are im­por­tant preda­tors of grass seeds in their sa­vanna and edge habi­tats. Nests are par­a­sitized by brown-headed cow­birds (Molothrus ater), al­though fre­quency varies re­gion­ally. Most par­a­sitized nests are de­serted by the fe­male. If a field spar­row nest is suc­cess­fully par­a­sitized by brown-headed cow­birds, their over­all nest­ing suc­cess is greatly re­duced and few of the cow­bird nestlings are suc­cess­fully raised. (Carey, et al., 2008)

Eco­nomic Im­por­tance for Hu­mans: Pos­i­tive

There are no di­rect pos­i­tive im­pacts of field spar­rows on hu­mans. They are an in­ter­est­ing mem­ber of the na­tive, North Amer­i­can bird fauna and are ap­pre­ci­ated for their song. (Carey, et al., 2008)

Eco­nomic Im­por­tance for Hu­mans: Neg­a­tive

There are no ad­verse ef­fects of field spar­rows on hu­mans.

Con­ser­va­tion Sta­tus

Field spar­rows are sen­si­tive to habi­tat dis­tur­bance and have fairly nar­row habi­tat pref­er­ences. They are not found in areas with human habi­ta­tions, which are ex­pand­ing cur­rently. Avail­able habi­tat may in­crease in areas with re­cent for­est cut­ting, or de­crease in areas with pre­dom­i­nantly suc­ces­sional habi­tats, which be­come in­ap­pro­pri­ate for field spar­rows as they grow. Pop­u­la­tions have ex­pe­ri­enced de­clines across their range, but field spar­rows are wide­spread and fairly com­mon where habi­tat is ap­pro­pri­ate, so they are not con­sid­ered threat­ened cur­rently. How­ever, pop­u­la­tions in Col­orado are con­sid­ered crit­i­cally im­per­iled and pop­u­la­tions in New Hamp­shire, Mass­a­chu­sets, Maine, Que­bec, and the Cana­dian mar­itime provinces are con­sid­ered vul­ner­a­ble. (Carey, et al., 2008; Na­ture­Serve Ex­plorer, 2008)

• IUCN Red List

  Least Concern
  More information

• IUCN Red List

  Least Concern
  More information

• US Migratory Bird Act

  Protected

• US Federal List

  No special status

• CITES

  No special status

• State of Michigan List

  No special status

Con­trib­u­tors

Tanya Dewey (au­thor), An­i­mal Di­ver­sity Web.

Ref­er­ences

Carey, M., D. Burhans, D. Nel­son. 2008. Spizella pusilla. Birds of North Amer­ica, 103: 1-20. Ac­cessed March 27, 2009 at http://​bna.​birds.​cornell.​edu/​bna/​species/​103.

Na­ture­Serve Ex­plorer, 2008. "Spizella pusilla" (On-line). Na­ture­Serve Ex­plorer. Ac­cessed March 27, 2009 at http://​www.​natureserve.​org/​explorer/​servlet/​NatureServe?​searchName=Spizella%20pusilla.