Hummingbirds are seasonal guests in Northern Michigan, known for their iridescent plumage and aerial agility. These tiny birds bring vibrancy to gardens, leading to questions about their eventual departure. As seasons change, they prepare for their journey.
Typical Departure Timeline
Ruby-throated hummingbirds, the most common species found in Michigan, typically begin their southbound migration from Northern Michigan starting in late August. This departure is a gradual process that unfolds over several weeks. Adult males are generally the first to initiate this journey, often leaving as early as mid-July, though peak departure for males from Michigan occurs in August.
Females and juveniles follow later, usually in early and mid-September, ensuring they have sufficient time to build up fat reserves after the breeding season. By mid-September, most hummingbirds have departed from the state, heading towards their wintering grounds in southern Mexico and Central America. However, the exact timing can vary slightly each year depending on local weather conditions and environmental factors.
Why Hummingbirds Migrate
Hummingbirds undertake migrations due to environmental and biological cues. A key driver is the changing photoperiod, or decreasing daylight hours as summer transitions to fall. This light reduction triggers hormonal changes, prompting an innate urge to migrate south. Simultaneously, their primary food sources—nectar from flowering plants and small insects—begin to diminish. Even with some flowers present, the decline in nectar and insect populations signals insufficient local food for their high metabolic demands. This combination of decreasing daylight, dwindling food, and inherited instinct guides them toward warmer climates where food remains abundant.
Observing Late Departures
Despite the typical departure timeline, it is not unusual to observe hummingbirds lingering in Northern Michigan later into the fall. Some individuals, particularly young birds or those still accumulating fat reserves, may remain into late September or even early October. These late travelers are often making their first migration and might be slightly behind the main migratory wave.
Continuing to provide sugar-water feeders during this period can be beneficial, offering a readily available energy source for these stragglers. Feeders do not prevent hummingbirds from migrating; their instinct is driven by changes in daylight, not food availability. Leaving feeders accessible provides a valuable resource for any birds still passing through, aiding their preparation for the demanding journey.