Birds that live in Pennsylvania during the summer migrate south for the winter to find warmer temperatures and more abundant food sources. Different bird species take different migration routes and end up in different wintering grounds, depending on their needs and capabilities.
Why do Pennsylvania birds migrate?
Birds migrate because the habitats and resources they depend on are not available year-round in Pennsylvania. During winter, food becomes scarce as insects die off or hibernate, and snow and ice covers natural sources of seeds and berries. The cold temperatures and freezing rain make it difficult for birds to maintain their body heat and survive extended periods of sub-freezing weather.
Migrating allows birds to find areas with adequate food, unfrozen water sources, and hospitable climates during the winter months. The majority of Pennsylvania’s summer birds, including species like the ruby-throated hummingbird, barn swallow, Baltimore oriole, and scarlet tanager, migrate south in the fall to overwinter in warmer regions.
When do birds migrate from Pennsylvania?
Most birds migrate from Pennsylvania in the fall between the months of August and November. The timing depends on the species:
- Early migrants like hummingbirds, swifts, and flycatchers leave as early as July and August.
- Warblers, vireos, and tanagers migrate in September.
- Sparrows, hawks, and finches pass through in October.
- Stragglers like robins and juncos may stay until November.
Spring migration happens in the reverse order, from February through May, as birds return to Pennsylvania to take advantage of the surge of insects, plants, and warmer temperatures.
What routes do migrating birds from Pennsylvania take?
There are four main flyways, or migration routes, used by Eastern North American birds:
- The Atlantic Flyway follows the Atlantic coastline south.
- The Mississippi Flyway follows the Mississippi River valley south.
- The Central Flyway crosses the Great Plains and Mississippi Delta.
- The Pacific Flyway follows the West Coast.
Birds that breed in Pennsylvania primarily take the Atlantic and Mississippi flyways. These flyways funnel birds southward where they spread out across the southern United States, Caribbean islands, Mexico, Central America, and northern South America.
Atlantic Flyway
Many Pennsylvania birds take the Atlantic Flyway, which concentrates east of the Appalachian Mountains. Spring migrants will stopover to rest and feed in places like the coastal wetlands of Delaware Bay and the forests of the Appalachians before fanning out to breeding grounds across the state.
In fall, these birds trace the Atlantic coastline south, passing over or stopping in states like Virginia, North Carolina, South Carolina, Georgia, and Florida. Some cross the Caribbean to winter in Mexico, Central America, or northwestern South America.
Examples of Pennsylvania birds that primarily use the Atlantic Flyway include:
- Tree swallow
- Chimney swift
- Wood thrush
- Black-throated blue warbler
- Scarlet tanager
- Rose-breasted grosbeak
- Baltimore oriole
- Gray catbird
Mississippi Flyway
Birds in western Pennsylvania often take the Mississippi Flyway along the Appalachian Mountain corridor down through the Appalachians and along the Mississippi River basin. Spring migrants may stopover along large rivers and wetland areas.
In fall, these birds follow the Mississippi River south through Louisiana and continue on to wintering grounds in Texas, Mexico’s Gulf coast, and the Caribbean. Species like shorebirds may travel as far as South America.
Some Pennsylvania birds that use the Mississippi Flyway are:
- Mallard
- Blue-winged teal
- Green heron
- Spotted sandpiper
- Willow flycatcher
- Cliff swallow
- Veery
- Red-eyed vireo
- Northern parula
- Magnolia warbler
- Yellow-breasted chat
Where do different Pennsylvania bird species spend the winter?
The wintering grounds used by migrating Pennsylvania birds span a broad range based on species needs and capabilities. Some remain relatively close along the southern U.S. while others travel thousands of miles into South America.
Backyard species
Some common backyard birds like tufted titmouse, Carolina chickadee, downy woodpecker, white-breasted nuthatch, and Carolina wren do not migrate far from Pennsylvania. They may move slightly south within the Mid-Atlantic region or the southern U.S., but do not make long migrations.
Species like the dark-eyed junco and white-throated sparrow migrate from northern areas into Pennsylvania for the winter. They take shelter in backyards, thickets, and woodlands throughout the state alongside resident species.
Short-distance migrants
Many songbirds migrate relatively short distances down the Atlantic coast or to the southern U.S. They winter in areas like:
- Southeastern Coastal Plain from North Carolina to northern Florida
- Gulf Coast region from eastern Texas to the Florida panhandle
- Southern tip of Florida
Short-distance migrants include species like:
- Ruby-crowned kinglet
- Hermit thrush
- Orange-crowned warbler
- Palm warbler
- Chipping sparrow
- Field sparrow
- Dark-eyed junco
Long-distance migrants
Many neo-tropical songbirds complete long-distance migrations down through Mexico, Central America, and into South America. They winter in tropical habitats like:
- Caribbean islands
- Coastal regions of Central America
- Andes Mountains
- Amazon River Basin
Notable long-distance migrants from Pennsylvania include:
- Ruby-throated hummingbird
- Barn swallow
- Wood thrush
- Scarlet tanager
- Rose-breasted grosbeak
- Baltimore oriole
Waterfowl and shorebirds
Waterfowl like ducks and geese migrating down the Atlantic and Mississippi flyways often winter in wetlands, estuaries, lakes, and agricultural fields across the southern U.S. coastline. Some travel to Mexico, Central America, or even South America.
Shorebirds that breed in Pennsylvania, like plovers, sandpipers, snipes, and terns, migrate to coastal wetlands and mudflats along the U.S. coast of the Atlantic Ocean and Gulf of Mexico. Many travel as far south as northern South America.
Major wintering areas for Pennsylvania migratory birds
Here is an overview of some of the most important wintering regions used by birds migrating from Pennsylvania:
| Area | Description | Example Species |
|---|---|---|
| Southeastern U.S. | Coastal areas and inland wetlands from NC to FL | Ruby-crowned kinglet, hermit thrush, American woodcock, field sparrow |
| Gulf Coast | Coastal regions from FL to TX | Orange-crowned warbler, palm warbler, Nelson’s sparrow, dunlin |
| Florida | Southern tip and Everglades region | Blackpoll warbler, ovenbird, American redstart, bobolink |
| Caribbean Islands | Cuba, Jamaica, Hispaniola, Puerto Rico | Black-throated blue warbler, American redstart, prairie warbler, indigo bunting |
| Mexico | Yucatan Peninsula, lowlands along Gulf and Pacific coasts | Magnolia warbler, Canada warbler, summer tanager, rose-breasted grosbeak |
| Central America | Lowlands from Panama to Belize | Scarlet tanager, Baltimore oriole, wood thrush, barn swallow |
| South America | Caribbean coast, Amazon basin, Andes mountains | Ruby-throated hummingbird, blue-winged warbler, solitary sandpiper, bobolink |
Threats faced by migrating birds
Migrating birds face many threats and challenges throughout their annual journeys. Some major hazards include:
- Habitat loss – Loss of critical stopover habitats needed to rest and refuel, especially coastal wetlands and forests along migration routes
- Extreme weather – Storms, high winds, cold snaps, heat waves, and flooding can be deadly during migration
- Predators – Hawks, falcons, owls, gulls, shrikes, and other predators prey on migrants throughout their journeys
- Collisions – Window strikes, vehicles, communications towers, and other structures kill huge numbers of migrating birds every year
- Light pollution – Artificial light can disrupt navigation and cause fatal building collisions during nocturnal migration
- Hunting – Legal and illegal hunting adds pressure, especially on waterfowl and shorebirds along migration routes
Conserving stopover habitats, reducing collisions, and mitigating climate change are crucial for protecting migratory bird populations that visit Pennsylvania.
Tracking bird migration
Ornithologists have learned much about bird migration through methods like bird banding and attaching transmitters. Now, new technologies are providing additional insights into migratory timing, routes, habitats, and threats.
Tracking technology
Geo-locators and satellite tags allow researchers to remotely track individual bird movements and map out migration pathways and wintering grounds. Stable isotope analysis of feathers can reveal migration origins and destinations. Genetic analyses also shed light on migratory connectivity between breeding and wintering populations.
Weather surveillance radar
Networks of weather radar stations can detect concentrations of migrating birds. This helps determine the timing, altitudes, and density of migratory movements on a continental scale.
Citizen science data
Online data platforms like eBird collect millions of bird sightings submitted by citizen scientists. This massive dataset demonstrates migration timing and routes based on first arrival dates across latitudes.
Acoustic monitoring
Automated audio recorders can capture the night flight calls of migrating songbirds. Large sensor networks can then trace the timing, direction, and composition of migration traffic.
How to help migrating birds from Pennsylvania
Here are some ways individuals and communities can support migratory birds that breed in Pennsylvania:
- Provide habitat for migrants through backyard native plantings, green roofs, bird-friendly yards, and urban greenspaces.
- Make windows visible to birds using decals, screens, or external treatments to prevent collisions.
- Keep outdoor lighting to a minimum and point lights down to reduce disorientation.
- Supply food and clean water before and during spring/fall migration.
- Report early arriving or late departing species to online databases used to track migration timing.
- Support conservation organizations focused on research, education, habitat protection, and policy related to migratory birds.
Conclusion
Each year, millions of songbirds, waterfowl, raptors, and shorebirds migrate along major flyways between Pennsylvania and wintering grounds to the south. Their epic journeys are driven by seasonal changes and the search for abundant food, water, and shelter. Though migration is an awe-inspiring phenomenon, many threats imperil migratory birds along their routes. Conservation measures focused on habitat protection, collision reduction, climate change mitigation, and community engagement can help protect species that connect ecosystems across continents through persistence, adaptability, and resilience.
