Hummingbirds are known for their iridescent plumage and remarkable aerial agility. These tiny birds, the smallest in the world, can hover in place and dart with incredible speed. In Upstate New York, the Ruby-throated Hummingbird is the primary migratory species, often seen flitting among flowers. Their presence throughout the summer months culminates in an annual journey.
Typical Departure Timeline
As late summer transitions into early fall, Ruby-throated Hummingbirds in Upstate New York begin their southward journey. Most birds leave around late August and early September. Peak migration occurs during the first half of September (August 23 to September 15), though some stragglers may be seen towards the end of September, especially those from farther north.
Adult males initiate their migration earlier than females and juveniles, sometimes as early as mid-July, though the main departure period remains consistent for the species. The exact timing can vary slightly from year to year, influenced by environmental conditions. This departure marks the end of their breeding season in the temperate north, prompting their need to seek warmer climates.
Environmental Cues for Migration
Hummingbird migration is driven by environmental signals. A primary trigger is the change in daylight hours. As days shorten in late summer and early fall, diminishing light levels prompt hormonal shifts within the birds, signaling it is time to migrate.
Alongside the changing photoperiod, a decrease in food sources also contributes to their migratory urge. As temperatures cool, nectar-producing flowers become less abundant, and insect populations, which are a part of their diet, decline. In preparation for the energy demands of migration, hummingbirds undergo a physiological change, doubling their body weight (from approximately 3 grams to over 6 grams) by accumulating fat reserves.
The Long Journey South
From Upstate New York, Ruby-throated Hummingbirds undertake a long journey spanning thousands of miles to reach their wintering grounds. Their destinations are the warmer regions of Central America and parts of Mexico. Most winter from southern Mexico southward across Central America to Panama, with smaller numbers in the West Indies.
This migration includes a non-stop flight of up to 500 miles across the Gulf of Mexico, a feat that can take approximately 22 hours and requires endurance from such a small bird. While some individuals brave the open water, others may follow an overland route through Mexico. The entire migratory journey can last about two weeks, with birds making stops along the way to feed, rest, and replenish their energy reserves.