Hummingbirds, with their iridescent plumage and rapid wingbeats, are a source of fascination for many. These tiny birds undertake remarkable journeys, bringing a burst of energy and color to the landscapes they visit. Understanding their movements, particularly their return to Iowa, reveals intricate connections between wildlife and environmental cues.
Annual Migration Patterns
The Ruby-throated Hummingbird is the primary species observed in Iowa, undertaking an annual migration. These birds begin to arrive in Iowa in mid-April, with male hummingbirds often appearing about two weeks before the females. Their presence peaks throughout the summer months as they establish breeding territories and raise their young.
As summer transitions to fall, Ruby-throated Hummingbirds depart south from late August through September. Some individuals may linger until early October, especially if warmer weather persists. Their wintering grounds extend across Mexico, Central America, and South America. During migration, they fly individually, often following established routes that include a non-stop, 500-mile flight across the Gulf of Mexico.
Environmental Influences on Migration
Hummingbirds navigate their migratory journeys guided by changes in daylight hours and their internal biological rhythms. These cues act as signals, signaling preparation for long flights. While their internal clocks dictate the general timing of migration, other environmental factors can influence the precise dates of arrival and departure.
Weather patterns, such as warm fronts or cold snaps, affect their migratory progress. The availability of food sources, including nectar-producing flowers and insects, impacts their journey, as hummingbirds must build significant fat reserves to fuel their flights. Warmer winter temperatures have been linked to earlier northward migrations for some species.
Creating a Welcoming Habitat
Attracting hummingbirds involves providing reliable food sources and suitable environments. Nectar feeders offer a supplemental food source and should contain a solution of one part white cane sugar dissolved in four parts hot water, cooled before use. Avoid adding red dye, honey, artificial sweeteners, or other ingredients to the solution.
Feeder hygiene: they should be cleaned at least weekly, or every three days in warmer temperatures, using warm water or a diluted vinegar solution to prevent fermentation. Placing feeders out by mid-April ensures they are ready for the first arrivals, and leaving them up until early October, or two weeks after the last sighting, can support late migrants. Planting native flowers that produce nectar is another effective way to draw hummingbirds. They are drawn to red, orange, and pink tubular flowers, such as Bee Balm, Cardinal Flower, Trumpet Vine, and Salvia. Hummingbirds also consume small insects for protein, making a naturalized yard beneficial.