sparrow

Savannah Sparrow

What is the savannah sparrow? What does it look like? Where does it live? What are its special characteristics? Why is it important in the Great Salt Lake Playa food web? Bibliography

What is the savannah sparrow (passerculus sandwichensis nevadenis)? The Savannah Sparrow found around the Great Salt Lake is a subspecies of passerculus sandwichensis named after the state of Nevada. The subspecies differ only slightly in appearance and often get their unique name from the location in which they are found. Below are the migratory maps of the species represented as a breeding distribution map and a winter distribution map. Return

Breeding Distribution Map

Winter Distribution Map

The savannah sparrow is found in most of North America. It frequents moist grassy areas in valleys, often near marshes or wetlands, and often where the waters and soils are very alkaline. It requires habitat where the ground cover of grasses, sedges, or alfalfa is dense but short. The savannah sparrow inhabits grasslands surrounding the wetland areas of the Great Salt Lake region. Nesting on the ground or in the grasses, the savannah sparrow remains somewhat hidden. Because its foraging station is on the ground this bird rarely leaves the ground for any extended period of time. It spends its time feeding on a variety of insects, spiders, and seeds. Return

The savannah sparrow's primary features are a whitish, streaked breast, and a short cleft tail which is usually notched. A grayish crown and yellow eyebrow stripes are also primary indicators of the savannah sparrow. Secondary features include brown upper parts which are streaked, as are the pale under parts. The belly and undertail are normally white and flesh colored legs are found beneath. Return

The male often establishes a territory. It sings while perched on clumps of vegitation or low fenceposts. When an intruder enters his territory he chases the intruder out while emitting a buzzing call. "During boundary disputes males may assume a face-to-face threatening posture, or they may walk together, side by side, along their common boundary" (Birds of the Great Basin p.488).
When disrupted by humans the bird will take a short flight only far enough to dive back into the grasses and be hidden from view, or it will duck and sprint through the grasses. The savannah sparrow is very difficult to spot and observe, because of his tendency to forage beneath grass, and shrubs. Return

Why is the savannah sparrow important in the Great Salt Lake Playa food web?

     On the Great Salt Lake Playa the savannah sparrow inhabits areas composed of native salt grass, alkali dropseed, and foxtail barley. Among these grasses are introduced annual weedy grasses such as cheat grass, and mouse barley.    Beneath the blades of grass drop little seeds upon which the bird forages. Also beneath these grasses one will find insects such as spiders, and grasshoppers. It is most likely that the savannah sparrow eats more insects during the nesting season in order to feed its young.
     As mentioned above, the savannah sparrow often inhabits areas where the waters and soils are very alkaline. It is difficult for trees and larger shrubs to grow in these conditions, and grasses thrive. The savannah sparrow forages on these grass seeds. Because the birds do not frequently fly long distances, they are limited to the alkaline waters near their nests to drink. "The Passerculus sandwichensis has no salt gland to deal with this alkalinity, but it uses its kidney to concentrate salt in its urine to a level 4.5 times that in its blood plasma" (Welty p.354).
     The savannah sparrow becomes food for some larger birds such as the northern harrier, and sometimes even the badger. However, much of the time they remain untouched. Because nests are often on the ground snakes are common predators for the eggs of the birds. Return

Bibliography

breeding distribution maps http://www.mbr-pwrc.usgs.gov/bbs/htm96/htmra/ra5420.html

winter distribution maps
http://www.mbr-pwrc.usgs.gov/bbs/cbcra/h5420ra.html

sparrow photograph
http://www.imperial.cc.ca.us/birds/sv-sprrw.htm

Behle, William H. 1958. The bird life of the Great Salt Lake. University of Utah Press, Salt Lake City, Ut.

Lambert, Mike. 1985. An Instant Guide to Birds, Bonanza Books, Spain.

Robbins, Chandler S., Bruun, Bertel, and Zim, Herbert S. 1983. Birds of North America, Western Publishing, New York, NY.

Ryser, Fred A. Jr. 1985. Birds of the Great Basin. University of Nevada Press, Reno, NV.

Udvardy, Miclos D.F. 1997. National Audubon Society Field Guide to North American Birds, Chanticleer Press, inc., New York, NY.

Welty, Joel C. 1980. The Life of Birds. W.B. Saunders Company. Philadelphia, PA

Wetmore, Alexander. 1976. Song and Garden Birds of North America. National Geographic Society. Chicago, Ill.

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