Hummingbirds are migratory birds known for their small size, rapid wingbeats, and vibrant plumage. North Carolina serves as a significant stopover and breeding ground for the Ruby-throated hummingbird, the most common species in the eastern United States. These birds undertake annual journeys, connecting their breeding territories with distant wintering grounds.
Departure from North Carolina
Ruby-throated hummingbirds typically begin their southward migration from North Carolina in late summer and early fall. Many birds that breed in North Carolina start their journey as early as late July or August, continuing through September. Peak departure periods often occur in September, with most hummingbirds having left the state by early to mid-September. However, hummingbirds from further north continue to pass through North Carolina into October, making it possible to observe them later in the fall.
Observers might notice increased activity at feeders during this time, as hummingbirds consume large amounts of nectar and insects to build up fat reserves for their journey. These fat stores are important, as they can represent 25-40% of their body weight, providing the energy for sustained flight. Males generally migrate first, followed by females about 10-14 days later.
Arrival in North Carolina
Hummingbirds return to North Carolina in the spring, signaling the start of their breeding season. Ruby-throated hummingbirds typically begin arriving in the state as early as late March. By early April, sightings become more widespread, and the bulk of the birds are present by mid-April.
Their arrival coincides with the blooming of early spring flowers, providing nectar sources after their journey from wintering grounds in southern Mexico and Central America. Some individuals may even be spotted by the end of March, particularly in the southern parts of the state. The spring migration is a solitary journey for each bird to reach their breeding grounds.
Factors Influencing Migration
Hummingbird migration is influenced by biological programming and environmental cues. A primary trigger is the changing photoperiod, or the decreasing length of daylight hours as summer transitions to fall. This internal signal prompts hormonal changes within the birds, initiating their migratory preparations.
Environmental factors such as dropping temperatures and the diminishing availability of food sources, including nectar from flowers and insects, play an important role. As autumn advances, many plants enter their dormant stage, reducing flower and insect populations. Hummingbirds respond to these cues by intensely feeding to accumulate the fat reserves needed for their journey. Climate change is also influencing migration patterns, with altered temperatures affecting flower blooming times and potentially causing a mismatch with hummingbird arrival.
Supporting Hummingbirds During Migration
Individuals in North Carolina can provide support to hummingbirds during their migratory periods. Maintaining clean feeders is important, as sugar water spoils quickly, especially in warmer temperatures. Feeders should be cleaned every few days, or more frequently in hot weather, using hot water and a brush, and a bleach solution monthly. Leaving feeders up does not prevent hummingbirds from migrating, as their migration is driven by internal cues.
Planting native, nectar-rich flowers offers a natural food source. Suitable plants for North Carolina include:
- Red Buckeye
- Bee Balm
- Cardinal Flower
- Coral Honeysuckle
- Cross Vine
- Trumpet Creeper
Avoiding herbicides and pesticides in yards is also important, as these chemicals can harm the insects hummingbirds rely on for protein.