Geography/Habitat:
Nelson’s Sparrow, (Ammospiza nelsoni) is a relatively uncommon and somewhat secretive inhabitant of coastal saltwater and brackish marshes. Closely related to and once grouped with the Saltmarsh Sparrow as a single species, (known as the Sharp Tailed Sparrow until 1995), it was first described by J. Allen in 1875 .When defined as a species in 1995, it was named after EW Nelson, and American naturalist. The Nelson’s Sparrow is migratory and breeds in the Central Northern US and Canada. It winters mainly around the Gulf Coast but hybridization with the Saltmarsh Sparrow is common and may be found along the Atlantic Coast as far North as Delaware. Note there are 3 recognized subspecies, one of which winters on the Pacific Coast, (Northern California).
Typically found in brackish marshes but nests in wet grasslands and in freshwater marshes when breeding. On migration often found in damp, weedy fields. Nelson’s Sparrows typically nest close to the ground and build a nest of dry grass and sticks, supported by reeds. They are often found in loose nesting colonies and appear non territorial but do display and sing frequently. They lay 3 to 8 light greenish eggs which are incubated by the female for 11 days.
Food is typically insect based and in Summer is almost exclusively insect larvae. The Nelson’s Sparrow often runs along the ground and will feed there, sometimes even probing in soft mud. In Winter its food supply will also include plants and seeds if insects are scarce.
Outside of the breeding season this species is very secretive and its presence is often determined by its raspy trilling song or a sharp repeated chip.
Identification:
A relatively small sparrow with a largely buffy orange face, gray crown with black stripe on either side and a gray cheek. Dark post ocular stripe and a weak light-colored eye ring. The bill is small, cone shaped, and pink to gray in color. Upperparts are typically buffy with brown and black streaks while the underparts are white with the upper chest and flanks more buffy and streaked with brown. The tail is noticeably very short.
Interesting Facts:
· A group of sparrows have many collective names including a crew, a meinie, a quarrel and a ubiquity.
· The total population is estimated at 500,000 but this is likely very approximate as Nelson’s Sparrows are very difficult to count due to their secretive behavior.
· It is estimated that Nelson’s and Saltmarsh Sparrows diverged only recently during the last ice age, (11 thousand years ago).
· Both sexes are extremely promiscuous during the breeding season and many nests have multiple parents tending the young.
· The oldest recorded individual was 10 years old.
