The presence of hummingbirds is a welcome sign of summer across Indiana, and the Ruby-throated Hummingbird is the only species that breeds regularly in the state. These tiny, jewel-toned birds rely on a steady supply of nectar from natural sources and backyard feeders to fuel their incredibly high metabolism. As summer ends, many people enjoy the increased activity at their feeders as the birds prepare for their long journey south. A common concern arises regarding the best time to stop feeding these visitors, with many wondering if leaving a feeder up too late will interfere with their natural migration cycle. Understanding the biological triggers for their departure provides the definitive answer to when the feeding season in Indiana should truly end.
Understanding Indiana’s Hummingbird Migration
The migration of the Ruby-throated Hummingbird is a feat of nature, with individuals traveling thousands of miles to wintering grounds in southern Mexico and Central America. The primary trigger for their southbound journey is not a lack of food but the change in photoperiod. This environmental change initiates hormonal shifts within the birds, signaling that it is time to depart.
The majority of adult males begin their solitary migration first, often leaving Indiana as early as late July or August after their breeding duties are complete. Females and juvenile birds follow shortly after, with the peak of the southward movement occurring throughout late August and the first two weeks of September. The birds begin a period of hyperphagia, or excessive feeding, to build up the necessary fat reserves for their journey. Hummingbirds can gain 25 to 40% of their body weight in preparation for their long flight, including a non-stop crossing of the Gulf of Mexico.
The Crucial Timeline for Feeder Removal
While the bulk of the hummingbird population departs Indiana by mid-September, maintaining feeders well into the fall supports late travelers. The official migration window for Ruby-throated Hummingbirds in the state can extend through late October. These later sightings often involve juvenile birds or individuals migrating from farther north who need to refuel.
The most practical guideline is to keep feeders clean and filled for at least two weeks after the last hummingbird sighting. Waiting this extended period provides necessary sustenance for any stragglers or late-hatching juveniles. The sugar solution must be changed every few days, even if the feeder is not actively being used, to prevent spoilage and mold growth.
Dispelling the Migration Delay Myth
The misconception that leaving food available will cause hummingbirds to delay or skip their migration is common. Providing nectar does not interfere with the birds’ ingrained seasonal instincts. The urge to migrate is a complex biological response driven by the shortening day length.
Hummingbirds are programmed to leave when their internal clock tells them to, regardless of a full feeder. A readily available nectar source is purely beneficial, as it allows the birds to efficiently gain the fat reserves they need. Removing a feeder prematurely could remove a life-saving fueling station for a bird that is already behind schedule or is passing through from a northern territory. Continuing to offer the 4:1 sugar-water solution throughout the late fall supports their natural preparation process.
Preparing Feeders for Storage
Once the two-week observation period has passed without a single hummingbird sighting, it is time to clean and store the feeders for the winter. Begin by thoroughly emptying any remaining sugar water and disassembling the feeder completely.
Scrub all parts using hot water and a bottle brush to remove residual nectar and film. For sanitation, soaking the components in a solution of one part white vinegar to four parts water for 15 minutes is an effective method. Rinse every piece with clean water to remove all traces of the vinegar solution. Allow the feeder parts to air-dry completely before reassembling and storing them in a cool, dry place until the next spring migration.