Pine Warbler is one of the least migratory wood-warblers, breeding from Florida north to southern Canada. Most of its breeding range and wintering range is within the Lower 48 United States, and, true to its name, it is strongly associated with pine forest.
A fascinating pattern is shown for this species by concentrating on the gaps in its breeding distribution. Pine Warblers are abundant in the pine forests of the Southeastern U.S. and breed uncommonly in northern Maine and New England, primarily in areas of Pitch Pine and Eastern White Pine. Similarly, they take advantage of Jack Pines in northern areas of Michigan and Minnesota. The Upper Midwest, however, is primarily agricultural, and forest areas there tend to be deciduous, so the species is absent as a breeder from much of Ohio, Indiana, and Illinois. This is a unique pattern among eastern breeding landbirds, since deciduous forest breeders tend to occur from northern Florida and east Texas into southern Canada (e.g., Wood Thrush) and most other pine forest breeders–like Brown-headed Nuthatch or Red-cockaded Woodpecker specialize on the southeastern pine ecosystems (Loblolly and Longleaf Pines), and do not occur in these more northerly pines (like Eastern White Pine and Jack Pine).
Note also how areas of sandy soil, which tend to be dominated by pines, show up extremely well. The New Jersey Pine Barrens (in central southern New Jersey) and Cape Cod are two bright areas that make perfect sense given this species’ habitat preference.
Below is a winter map, which shows that the northern populations of Pine Warblers withdraw to winter throughout Southeastern pine forests. During this season, they can be a little less restricted in their habitat, and may occur in flocks with Eastern Bluebirds and Chipping Sparrows in deciduous habitats, and even on grassy lawns. During this season, a few even reach the Rio Grande Valley of Texas, and now and then a few are found across the border in Mexico. there are no pines in these areas, and instead Pine Warblers use Live Oaks and often occur among flocks of other birds. Notice the faint orange blush to south Texas that is visible in the below map.