Hummingbirds, with their iridescent feathers and rapid wingbeats, are captivating visitors to Virginia’s landscapes during the warmer months. These tiny birds are not year-round residents of the state; instead, they undertake remarkable migratory journeys. Understanding their patterns of movement helps appreciate their incredible endurance and the natural cues that guide them.
Typical Departure Schedule
Ruby-throated hummingbirds, the most common species in Virginia, typically begin their southward migration in late summer and early fall. The main exodus from Virginia generally occurs from late August through September. Adult males are often the first to leave. Females and younger hummingbirds usually follow a few weeks later, after the nesting season concludes.
Most birds depart by early October, though some stragglers might be observed until mid-October. The migration period can extend, ensuring that late-migrating individuals have access to resources for their demanding journey. These tiny travelers embark on a solo journey.
Why Hummingbirds Migrate from Virginia
The primary drivers for hummingbird migration from Virginia are environmental changes that signal the onset of colder seasons. Decreasing daylight hours serve as a key trigger for their migratory instinct, rather than solely temperature drops or food scarcity.
A decline in available food sources, such as nectar from flowers and insects, also contributes to their decision to migrate. As temperatures fall, the abundance of flowering plants and the insect populations they rely on diminish significantly in Virginia. This scarcity necessitates a move to regions like Mexico and Central America, where food remains plentiful year-round. Migrating south allows them to find consistent food resources, reducing competition they might face in tropical wintering grounds.
Preparing for the Journey
Before embarking on migratory flight, hummingbirds undergo changes. They enter a phase known as hyperphagia, an intense feeding period where they consume amounts of nectar and insects. This increased intake allows them to build up substantial fat reserves, which serve as their primary fuel source for the long journey.
A hummingbird can nearly double its body weight, gaining between 25% to 50% of its normal mass, often from about 3 grams to over 6 grams. This stored fat is highly energy-rich and provides more than twice the energy per gram compared to carbohydrates or protein. The fat reserves can fuel non-stop flights of several hundred miles, with some Ruby-throated hummingbirds capable of crossing the Gulf of Mexico, a 500-mile journey, without needing to refuel. During this preparatory phase, they may also become more territorial around food sources, ensuring they acquire enough energy for migration.
Assisting Hummingbirds Before They Leave
Supporting hummingbirds during their pre-migratory period helps their demanding journey. Keeping feeders clean and filled with a sugar-water solution (one part white sugar to four parts water, or one part sugar to three parts water during migration) provides an available energy source. Avoid red dyes or commercial nectars with additives, as these can be detrimental to the birds’ health. Feeders should be cleaned every few days, or daily in hot weather, to prevent bacterial growth.
A common misconception is that keeping feeders up will prevent hummingbirds from migrating; however, their departure is triggered by changes in daylight, not food availability. Continuing to offer feeders, even into late fall, can provide crucial energy for late migrants or stragglers passing through Virginia. Planting late-blooming, nectar-rich native flowers like cardinal flower, wild bergamot, swamp milkweed, and pineapple sage also offers natural food sources. Minimizing pesticide use in your yard helps ensure a supply of tiny insects, which are an important protein source for hummingbirds.