28-3-2017 VILLA LAPAS, COSTA RICA - NORTHERN WATERTHRUSH (Parkesia noveboracensis)

The northern waterthrush (Parkesia noveboracensis) is a species of ground-feeding migratory New World warbler of the genus Parkesia. It breeds in the northern part of North America in Canada and the northern United States including Alaska, and winters in Central America, the West Indies and Florida, as well as in Venezuela, Colombia, and Ecuador. It is a rare vagrant to other South American countries and to western Europe. Its closest relative is the Louisiana waterthrush.

On the wintering grounds in Puerto Rico, northern waterthrushes leave daytime foraging areas and fly up to 2 km (1.2 mi) to nighttime roosts. The roosts are often located in red mangrove habitats. Northern waterthrushes winter in 4 main habitats in Puerto Rico: white mangrove, red mangrove, black mangrove, and scrub. Males, which are larger and migrate earlier in spring, prefer to winter in white mangrove, and are able to maintain or gain weight through the winter. Females winter in the other drier and less food-rich habitats. During the non-breeding period, northern waterthrushes are site-faithful and tend to be solitary.

Waterthrushes wintering in red and black mangrove can maintain body weight through the winter but lose weight in scrub. Another determinant in body mass increase in the wintering grounds is moisture.

Northern waterthrush territories are distributed across both upland and riparian habitats, but have limited occupation of harvested areas. Crowding into riparian buffer zones adjacent to harvested areas have more difficulty foraging compared to those in untouched areas.

 

The breeding habitat of the northern waterthrush is wet woodlands near water. It nests in a stump or among tree roots where it lays three to six eggs, cream- or buff-colored, with brown and gray spots. These eggs are laid in a cup nest constructed of leaves, bark strips, and rootlets.

The northern waterthrush is a terrestrial ground feeder, eating insects, spiders, mollusks (such as snails), worms, and crustaceans found amongst leaf litter, as well as minnows, found by wading through water.