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Melospiza georgiana (Latham, 1790)
Swamp Sparrow
Family: Passerellidae

Species account author: Jamie Fenneman
Introduction to the Birds

Photograph

© Greg Lavaty     (Photo ID #9212)

Map


Distribution of Melospiza georgiana in British Columbia.
(Click on the map to view a larger version.)
Source: Distribution map provided by Jamie Fenneman for E-Fauna BC

Species Information

Breeding adult
This plumage is acquired in early spring (March) and is retained until late summer or early fall (August-early September). The upperparts (back, scapulars) are rusty-buff to rusty-brown with extensive sharp black streaks, usually with the suggestion of buffy lines, or “braces,” on each side of the back. The wing feathers are brownish to blackish with rusty outer edges on the flight feathers and wing coverts, thus the wings appear extensively rusty when folded. The rump and uppertail coverts are rusty-brown with narrow blackish or dark brown streaks. The slightly rounded tail is brownish with rusty-brown outer edges to the feathers. The breast is grey or grayish-brown, the sides and flanks are extensively washed with rusty-buff, and the belly and undertail coverts are whitish. There are usually some fine, though often faint, buffy-brown streaks on the sides of the breast, sides, and flanks, and the undertail coverts are finely streaked wit dark brown. The forehead is black and the crown (extending to the centre of the nape, where it becomes blackish) is rusty, sometimes with a few narrow black streaks. These are sharply demarcated from the broad grey supercilium and sides of the neck to form a distinct cap. There is a narrow dark brown or blackish line extending from the eye to the rear of the ear coverts, and there is usually the suggestion of a narrow whitish eye-ring. The lores are pale grayish and the ear coverts are brownish-grey. The moustachial stripe is buffy-grey to whitish-buff, the narrow malar stripe is dark grey or grey-brown, and the throat and chin are whitish. The iris is dark, the conical bill is dark grey or brownish-grey with a paler horn-coloured base to the lower mandible, and the legs and feet are pinkish. Males average slightly brighter rusty on the crown than females, but these differences would only be apparent with mated pairs.

Non-breeding adult
This plumage is acquired in late summer or early fall (August-early September) and is retained through the winter and into early spring (March). It is overall similar to the breeding plumage, although it is noticeably dingier and browner overall, especially on the underparts which are washed with buff and sometimes shows faint, blurry streaks on the breast. The head pattern is similar to the breeding adult, but is buffier, with extensive black streaks on the crown that largely obscure the rusty colouration (more extensively rusty in males than females).

Juvenile
This plumage is held briefly during the summer of the first year, and is lost during the late summer (August). It is similar in overall pattern to the non-breeding plumage, but is extensively brownish or buffy and distinctly streaked. The supercilium, sides of the neck, and ear coverts are buffy-brown rather than grey, with a less distinct olive-brown supercilium and blackish or dark brown, often darker-streaked crown. The underparts are extensively buffy with brownish streaking or spotting on the breast, sides, and flanks (occasionally unmarked).

Measurements
Total Length: 14-15 cm
Mass: 15-24 g

Source: Mowbray (1997); Sibley (2000)


Biology

Identification

Breeding adults are fairly distinctive within the context of B.C. given their rusty cap, bright rusty and buffy body, gray face, and association with wetland habitats. The only other rusty-capped sparrow species occurring with regularity within the breeding range of this species is the Chipping Sparrow, but that species is easily distinguished by its bold white supercilium, prominent black eyeline, two white wing bars, and more contrasting body plumage with brownish upperparts and grayish underparts. It is also a smaller, more slender species and is associated with upland habitats. During migration, American Tree Sparrows can occur in the same areas as the Swamp Sparrow and can cause confusion due to their similar rusty cap. It is easily distinguished, however, but its prominent rusty (rather than blackish) eyeline, bicolored bill with a yellow lower mandible, dark spot in the centre of the breast, and two white wing bars.

Non-breeding adults are less distinctive than breeding-plumaged birds, and can be confused with other species in the genus Melospiza (Song and Lincoln’s Sparrows). The Song Sparrow is also extensively rusty, but is a larger and darker species with less contrasting plumage. In particular, the head pattern of Swamp Sparrow is clean and sharp, with a well-defined black-streaked rusty cap, grey eyebrow, dark eyeline, brownish ear coverts, and grey sides of the neck (head pattern much less well-defined in Song Sparrow). Furthermore, the underparts are unstreaked or faintly streaked in Swamp Sparrow, differing from the extensively dark-streaked underparts of the Song Sparrow. Lincoln’s Sparrow is a distinctly buffier species than Swamp Sparrow, with extensive crisp, fine dark streaks on the buffy breast, sides, and flanks.

Juvenile Melospiza are particularly difficult to distinguish, and juvenile Swamp and Lincoln’s Sparrows are extremely similar. Juvenile Lincoln’s Sparrow is distinguished primarily by the brownish to buffy-grey, finely black-streaked crown which differs from the unstreaked brownish or blackish crown of juvenile Swamp Sparrow. Additionally, the lining of the upper mandible of juvenile Lincoln’s Sparrow is grey, whereas in Swamp Sparrow it is yellow (although this feature would be difficult to determine under normal viewing conditions). Juvenile Song Sparrows are easily distinguished from juvenile Swamp Sparrows by their larger size, longer tail, and noticeably heavier bill.
Vocalizations

The male’s song is a somewhat musical, slow series of trilled notes that are often doubled so as to sound like two differently-pitched notes given at the same time: weet-weet-weet-weet-weet-weet or chinga-chinga-chinga-chinga-chinga. The song is two to three seconds in length and often fades towards the end. It is reminiscent of the songs of several other species within the same region (Dark-eyed Junco, Chipping Sparrow, Palm Warbler) but tends to be slower and more musical, with the distinctive double-toned characteristic that is lacking in these other species. The most commonly heard call throughout the year is a sharp, loud, hard chink that is similar to the call of the White-throated Sparrow but not as metallic. Males occasionally give a high, buzzy zeet or zhrew call during territorial disputes throughout the year, both with conspecifics as well as other sparrow species. This call is very similar to one of the calls of the Lincoln’s Sparrow, but is somewhat coarser and more level in tone.

Source: Mowbray (1997); Sibley (2000)

Bird calls (and videos) from Cornell's Lab of Ornithology
Breeding Ecology

Courtship
Males establish breeding territories immediately after arrival on the breeding grounds so that when females arrive several weeks later these territories are fully established. Pair formation occurs 1-2 weeks after the arrival of the females. Males establish territories through song, usually singing from exposed perches within the territory. Males also perform a “song flight,” during which the song is given during a short upward flight and while fluttering downward to land on the same perch. The female solicits copulation by perching on a conspicuous perch, crouching, fluttering her wings, and giving soft mewing calls. Some males mate with more than one female during the breeding season.

Nest
Nest construction takes 2-7 days and is completed entirely by the female, although the male may bring nesting material to the female to contribute to the building process. The nest is a bulky (8-15 cm wide, 4-11 cm high) cup of coarse, dry grasses, sedges, leaves, and rootlets and is lined with fine grasses, plant down, hair, and rootlets. It is placed in low vegetation above or near water (rarely on the ground) and is usually well concealed by surrounding vegetation. It is rarely placed higher than 30 cm above the ground or water.

Eggs
Clutches of (1) 4-5 (6) smooth, slightly glossy eggs are laid in June and are incubated for 12-14 days by the female alone The eggs are pale green or bluish-green with reddish-brown or purplish-red scrawls, splotches, and spots and background markings of pale grey or lilac; markings are usually concentrated near the larger end of the egg. This species is double-brooded. In B.C., eggs can be found from early June to mid-July. Brown-headed Cowbird parasitism is infrequent in this species but has been observed in B.C.

Young
The young remain in the nest for 9-13 days following hatching and are able to fly weakly at approximately 2 weeks of age. Nestlings are altricial and downy, with pink skin and blackish-brown down (some white on the undersides). The mouth is reddish-orange and the gape flanges are pale yellow. The fledglings are tended by both parents for up to 15 days after leaving the nest, after which time they become independent. Nestlings and dependent fledglings are present in B.C. between mid-June and late July.

Source: Baicich and Harrison (1997); Mowbray (1997); Campbell et al. (2001)
Foraging Ecology

This species feeds on a variety of seeds and fleshy fruits throughout the year, although these food sources are much more important in the diet during migration and winter than during the breeding season. During the breeding season, the Swamp Sparrow feeds primarily on adult and larval insects and other invertebrates, including damselflies, beetles, ants, and bees. Aquatic invertebrates are also taken in the winter when available, and this species is much more insectivorous than other similar sparrows (e.g., Song Sparrow). It prefers to forage on wet ground throughout the year, often wading into shallow water in search of invertebrate prey. It also forages at low levels in woody and marsh vegetation, and occasionally visits bird feeders. This species does not typically form flocks, unlike several other sparrows, but individuals regularly associate with mixed-species aggregations of sparrows during migration and winter.

Source: Mowbray (1997)

Habitat


True to its name, the Swamp Sparrow is usually associated with moist to wet habitats throughout the year. During the breeding season, this species is found in a variety of low elevation wetlands such as wooded swamps, shrub-swamps, cattail marshes, bogs, fens, ditches, sloughs, beaver ponds, lakeshores, wet meadows, and streamside thickets. It commonly nests near the ecotone between grassy meadows and adjacent shrub thickets (willows, alder, scrub birch etc.), or where scattered shrubby vegetation occurs in otherwise grassy or sedgy wetlands. It is less tied to wetlands during migration, when it can also be found in overgrown fields, weedy roadsides, brambles, upland thickets, and grassy meadows, although it still tends to gravitate towards water. Wintering birds occur in a wide range of low elevation wetland habitats with emergent vegetation such as marshes, ditches, streamside thickets, and sloughs, and many wintering birds on the south coast occur in coastal estuaries and brackish marshes.

Source: Mowbray (1997); Campbell et al. (2001)

Distribution

Global Range

Breeds across northern and eastern North America, from B.C. east to Newfoundland and south to Iowa, Ohio, West Virginia, and New Jersey. Most birds winter throughout the eastern United States, from southern Ontario and New England south to the Florida and the Gulf Coast, westwards to the Great Plains, Texas, and New Mexico. Smaller numbers winter in western North America, including southern Arizona and along the Pacific coast from southwestern B.C. to California. Wintering populations are also widespread in central and northeastern Mexico.
BC Distribution

Breeding
Fairly common, although often local, in northeastern B.C. east of the Rocky Mountains, particularly in the Peace River and Fort Nelson lowlands; uncommon throughout the Liard River valley south of the Yukon border. Uncommon and local in central B.C. west of the Rocky Mountains, from Mackenzie south to the Quesnel area and west to the Bulkley Valley as well as south along the Rocky Mountain Trench to the Robson Valley. Recently discovered breeding in small numbers in the Revelstoke area of the southeastern interior.

Winter
Rare to very uncommon, and highly local, in winter on the south coast, including southeast Vancouver Island (Sooke north to Nanaimo, very rarely to Campbell River) and the Lower Mainland; most frequent in the lower Fraser Valley and in the Victoria, Duncan, and Port Alberni areas of Vancouver Island. Very rare on western Vancouver Island and in the Okanagan Valley of the south-central interior, and casual elsewhere across the southern interior in winter.

Migration and Vagrancy
Uncommon spring and fall migrant in northeastern B.C. (east of the Rocky Mountains) and across the central interior. Very rare to locally rare spring and fall migrant in southern B.C., including areas on the south coast as well as across the southern interior. Small numbers of spring migrants occur across southern portions of the province through April and into early May, with substantially larger numbers arriving on the breeding grounds in central and northern B.C. in late April and early May. Peak spring movements in central and northeastern B.C. are in mid-May. Fall migrants begin departing the breeding grounds in mid-August and have left the region by late September or early October (rarely lingering into late October). Peak fall movements across northern and central B.C. are in September. Fall migrants in southern B.C. are recorded primarily between mid-September and November (rarely in late August or early September), with wintering birds lingering into December and beyond. It is an accidental fall vagrant to the Queen Charlotte Islands.

Source: Campbell et al. (2001)

Conservation

Population and Conservation Status

Breeding populations in B.C. and across Canada are secure and not considered threatened, with some local populations (e.g., Alberta) increasing. Some declines have been noted in the eastern United States, particularly in populations breeding in coastal salt and brackish marshes. Breeding populations in B.C. have apparently increased somewhat over the past century, but wintering populations (especially on the south coast) have increased dramatically. The first few records of this species on the south coast were in the late 1960s and early 1970s, but by the 1990s it had become a regular, albeit scarce, migrant and winter visitor in the area. It now winters regularly in small numbers on southern Vancouver Island and the Lower Mainland.

Source: Mowbray (1997); Campbell et al. (2001)

Taxonomy


Three subspecies of Melospiza georgiana are currently recognized, although only one (M.g.ericrypta Oberholser) occurs in British Columbia. This subspecies differs marginally from the nominate subspecies of eastern North America in its slightly paler and greyer plumage, but these two subspecies are unlikely to be identifiable in the field.

Source: Mowbray (1997)

Status Information

Origin StatusProvincial StatusBC List
(Red Blue List)		COSEWIC
NativeS4S5YellowNot Listed



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