The length of time hummingbirds stay in Michigan is determined by the annual migratory cycle of the Ruby-throated Hummingbird (Archilochus colubris). This species is the only one that breeds reliably in the state. Their residency is a period of intense activity, encompassing territory establishment, breeding, and preparation for their journey south.
The Arrival and Summer Stay
Ruby-throated Hummingbirds begin arriving in Michigan from late April to early May. Arrival starts in the southern Lower Peninsula and progresses northward, following the spring bloom of nectar sources. The earliest arrivals are adult males, who precede the females by about a week to establish breeding territories.
Once established, their summer stay is dedicated to breeding and raising young. Females construct tiny nests and raise one to two broods of young, a process that takes place throughout May, June, and July. This period of residency ensures the next generation is ready for the upcoming migration, fueled by the state’s abundant summer nectar and insect resources.
The Departure and Migration Trigger
The length of their stay is determined by an internal biological clock, with departure spanning from late August through September. The first birds to depart are generally the adult males, who begin their southward journey in late summer after their parental duties are complete. Females and the young birds hatched that summer follow the main migration wave later in September.
The primary trigger for migration is photoperiodism, the shortening of daylight hours each day. This predictable environmental change signals the time to depart, overriding variables like temperature. Leading up to migration, hummingbirds enter hyperphagia, or excessive feeding, to accumulate a dense layer of fat. This fat reserve is necessary for the long-distance flight, which often includes a remarkable 500 to 600-mile non-stop flight across the Gulf of Mexico.
Their ultimate destination is their wintering ground in southern Mexico and Central America, a journey of thousands of miles. The accumulated fat nearly doubles the bird’s body weight, providing the energy needed for this trip. While most individuals are gone by the end of September, some late travelers, often females or young birds, may linger into early October.
Supporting Hummingbirds During Their Residency
Supporting these travelers involves feeding and habitat management timed to their migratory schedule. Place feeders outdoors a few weeks before their anticipated spring arrival to provide energy when natural nectar sources are scarce. The proper nectar solution is a simple 1:4 mixture of one part plain white table sugar dissolved into four parts water, which mimics natural flower nectar.
Change the solution every few days, or daily in hot weather, and thoroughly clean the feeder with hot water to prevent mold or fermentation. Habitat support through native flowering plants is also important, providing both nectar and the small insects hummingbirds rely on for protein. Plants like wild columbine, bee balm, and jewelweed ensure a consistent food supply.
A common concern is that keeping feeders up in the fall prevents migration, but this is a misconception; the urge to migrate is triggered by daylight hours, not food availability. It is helpful to leave feeders up well into the fall, even after the main wave has passed, to provide sustenance for late-migrating individuals. Feeders can be removed entirely once a week has passed with no hummingbird sightings.