The Prothonotary Warbler (Protonotaria citrea) also referred to as the “Golden Swamp Warbler” is a small vibrantly colored songbird. The prothonotary warbler or PROW, belongs to the wood warbler family. PROWs are a large bodied warbler with a large pointed black bill and black legs. Males have a vividly yellow-orange head and neck. Their backs are olive-green, with a yellow chest and belly, blue-grey wings with black tips on the under parts, and white undertail coverts. Females are less vibrant over all, when compared to males.
Historically, Prothonotary warblers were a typical summer resident and breeding bird; found in forested swamps and riparian habitat in throughout the western part of Kentucky and reaching as far up the Ohio River as Louisville (Mengel 1965). Over the last four decades the species population has been in decline at about 1% per year (Sauer 2014). The Prothonotary Warbler has been listed as a Species of Greatest Conservation Need in the Kentucky State Wildlife Action Plan
, as well as the U.S. Fish and Wildlife Service Birds of Conservation Concern (USFWS 2008). Suitable nesting habitat has been lost to the draining and clearing of bottomland forests, mostly for agricultural purposes, leaving less than 25% of the original bottomland forest across the entire southeast (Harris 1984). Additionally, the destruction of critical wintering habitat in Central and South America has increased considerably since 1996 (Spalding 2010).
Prothonotary warblers are Neotropical migrants and have a strong association with forested wetlands throughout their range.
These warblers spend the winter months in the mangrove swamps and wet lowland forests of the Caribbean, and in Central and South America. They are a fairly early spring migrant, beginning to arrive back in Kentucky in early April. During the summer, PROWs breed in flooded bottomland forest, along rivers, streams, lakes, sloughs and swamps throughout the southeastern United States. Prothonotarys are the only cavity-nesting warbler in the southeast, and like to nest in cavities that are over or near standing or slow moving water. PROWs are secondary cavity nesters, meaning they use preexisting cavities instead of excavating their own nests. Egg laying occurs in May; however, PROWs will occasionally produce a second brood in June- July. PROWs will typically being their fall migration in September, with rare occurrences of PROWs as late as early October.
Due to habitat loss, the availability of suitable nest sites is a considerable limiting factor for prothonotary warblers in Kentucky. In an attempt to increase nest site availability and productivity, the Kentucky Department of Fish and Wildlife Resources (KDFWR) has placed nest boxes at many locations on public land throughout the state. In 2016, KDFWR partnered with the Central Kentucky Audubon Society to construct 100 nest boxes to provide supplemental nesting habitat for the warblers on Wildlife Management Areas.
KDFWR's prothonotary warbler nest box design can be found here
. The design was modeled after the prothonotary warbler box design of the Wisconsin Division of Natural Resources. Private landowners and land managers can help support Prothonotary Warblers by leaving standing snags where it is safe to do so and by installing nest boxes in forested swamps and riparian areas. Nest boxes should be installed by April 1st. Boxes should also be cleaned out once the birds have left for fall migration (November – February).
Harris, L. D., R. Sullivan, and L. Badger. 1984. Bottomland hardwoods: valuable, vanishing, vulnerable. Univ. of Florida School of Forest Resources and Conservation technical report. Tallahassee, Florida.
Mengel, R.M., 1965. The Birds of Kentucky. American Ornithologists' Union. Ornithological Monographs, (3), pp.459-461.Sauer, J. R., J. E. Hines, J. E. Fallon, K. L. Pardieck, D. J. Ziolkowski, Jr., and W. A. Link. 2014. The North American Breeding Bird Survey, Results and Analysis 1966 - 2013. Version 01.30.2015 USGS Patuxent Wildlife Research Center, Laurel, MD.
Spalding, M., M. Kainuma, and L. Collins. 2010. World Atlas of Mangroves. Earthscan from Routledge, London, UK.
U.S. Fish and Wildlife Service. 2008. Birds of Conservation Concern 2008. United States Department of Interior, Fish and Wildlife Service, Division of Migratory Bird Management, Arlington, Virginia. 85 pp.