Family Parulidae

     There are about 116 species of wood warblers found in North and South America.  Because of the bright coloration and the variety of songs produced by the birds of this family, they are a very popular group of birds among bird watchers.  Warblers feed primarily on insects and many also prey on spiders.  Some also feed on seeds (such as yellow rumped warblers and yellow throated warblers) and berries (blackpoll warblers).  In the autumn when insects are less abundant, warblers may include more fruit and nectar in their diet.

    In the past 30 years, the populations of many birds which migrate to the tropics have been decreasing, including the numbers of warblers.  The loss of habitat has impacted them in a variety of ways.  Because of increased development in their summer grounds of North America, each year there are fewer and fewer breeding pairs that can be supported.  The rapid deforestation of forests in Central and South America results in smaller areas which can support their populations in winter.  The loss of habitat along their migration routes results in greater mortality during migration because there are fewer rest stops and less food to support them along the way.  In the United States, the fragmentation of their original habitat also the creates additional “edge” regions of existing habitat where birds are more vulnerable to nest parasitism by cowbirds as well as to predation by feral cats. 

    A number of warbler species can hybridize, such as the blue winged and golden winged warblers, Nashville warbler and American redstart, blue winged and Kentucky warblers, and Northern parula and yellow-throated warblers (Garrett, 1997).