Hummingbirds are captivating and acrobatic birds that grace many gardens during warmer months. These tiny, iridescent creatures are known for their incredible migratory journeys. Their annual appearance and disappearance are part of a natural cycle, driven by environmental cues. Understanding these patterns helps predict their seasonal movements.
When Hummingbirds Typically Depart
Hummingbirds generally begin their southward migration in late summer, with most departing between late August and early October. Ruby-throated hummingbirds, common in eastern North America, typically start their fall journey in late August or September. Similarly, Rufous hummingbirds, found in western North America, may begin their southward movement as early as July, traveling down the Rocky Mountains. The exact timing can vary by species and geographic location, with northern populations usually leaving earlier.
Adult male hummingbirds are often the first to leave their breeding grounds, sometimes as early as July, followed by adult females and then juveniles. This staggered departure may ensure less competition for diminishing food sources. Most hummingbirds embark on journeys spanning hundreds or thousands of miles to their wintering grounds in Mexico and Central America.
Key Factors Influencing Departure
The primary signal for hummingbird migration is the change in daylight hours, known as photoperiod. As summer wanes and days become shorter, these subtle changes in light intensity instinctively trigger physiological responses. This internal clock prompts them to prepare for their arduous journey, regardless of local weather conditions.
Another significant factor influencing their departure is the decline in food availability. As temperatures drop in late summer and early fall, natural nectar sources from flowering plants become less abundant. Insect populations, which provide essential protein for hummingbirds, also decrease. These environmental cues work together, signaling to the hummingbirds that it is time to build up fat reserves for the extensive flight ahead. Hummingbirds can gain 25-40% of their body weight before migration to fuel their journey.
Supporting Hummingbirds Before Migration
Providing a consistent food source can greatly assist hummingbirds as they prepare for migration. Continuing to offer sugar water in feeders is beneficial, as it provides essential energy without delaying their natural migratory instincts. Feeders should be cleaned every few days, or daily in warm weather, using a solution of one part white sugar to four parts water. This helps prevent the growth of mold and bacteria that can harm the birds.
Planting late-blooming, nectar-rich flowers offers natural sustenance. Options like salvias, such as Mexican bush sage and Texas sage, provide abundant nectar into the fall. Other beneficial plants that extend food availability include:
- Bee balm
- Cardinal flower
- Honeysuckle
- Penstemon
Avoiding the use of pesticides is important. These chemicals can contaminate nectar and reduce insect populations, negatively impacting hummingbirds’ energy levels and navigation.
Common Reasons for Unexpected Departures
Sometimes, hummingbirds may seem to disappear earlier than anticipated, which can be perplexing for observers. One common reason is individual variation in migration timing. Not all hummingbirds leave at the exact same moment; adult males typically depart first, followed by females and then juveniles.
Local food source depletion can also lead to an early departure from a specific area. Even if the general migration has not yet begun, a garden’s flowers might have faded, or a feeder might have been neglected or become contaminated, causing birds to seek sustenance elsewhere. While less common, consistent disturbances or the presence of predators might also prompt hummingbirds to relocate to a safer area. Some birds may also engage in short, local movements to find more abundant food sources before embarking on their full, long-distance migration.