If you paddle through the hardwood swamps of Delmarva in the spring, take your binoculars and field guide with you. Keep your eyes open for a small, golden flash darting among the low-lying branches along the creek. Occasionally, the little flash will perch on a branch above the dark water, and you will be rewarded with a glimpse of one of the most beautiful birds of the shore's springtime swamp - the prothonotary warbler.

This diminutive yellow bird spends the winter months in tropical mangrove swamps and lowland woods. It migrates north early in the spring to spend the nesting season in wet woods and along the borders of rivers, lakes and ponds of the eastern United States. By late August, the prothonotary is again heading south for the tropics.

Males establish territories by loud singing and rambunctious displays that include chasing and fighting other males. The prothonotary is unique among warblers with its habit of nesting in tree holes rather than out in the open. After the male has attracted a female, she will build the nest in a tree cavity, often a woodpecker hole, usually 5-10 feet above the water. The nest is filled deep with moss, leaves and bark, and three to eight creamy pink eggs are laid. Both parents assist in feeding the baby birds. Fledglings leave the nest after 10 days, and the young can even swim to a low branch if they fall in the water. Some prothonotary pairs produce two broods each nesting season.

Prothonotary warblers feed on aquatic insects, ants, caterpillars, and spiders, as well as freshwater snails and some seeds. They actively pursue their prey by searching the foliage of the forest, peeping under loose bark, and hopping about on floating logs and debris.

With the clearing of bottomland forests for timber and the draining of swamps for agriculture, the prothonotary warbler population has declined. In its remaining habitat, it is still a fairly common summer resident. In addition to habitat loss, the prothonotary is also affected by the nesting habits of the brown-headed cowbird (Molothrus- ater). Cowbirds lay their eggs in warbler nests, and the parent warblers will then raise the young cowbirds as if they were their own. Forest fragmentation is the biggest factor in cow bird parasitism.

The name "prothonotary" refers to medieval scribes in the Catholic Church, who wore golden hoods as part of their ceremonial dress. The prothonotary's highest reported breeding density is in Worcester County where it can reach 40 nests per 100 acres along the Pocomoke River and Nassawango Creek.