Hummingbirds are captivating residents and visitors in New Mexico, known for their agile flight and preference for nectar. New Mexico hosts 17 documented species, with seven commonly observed by enthusiasts.
Seasonal Departure from New Mexico
Hummingbirds typically begin their southward migration from New Mexico in late summer and early fall. The precise timing can vary by species and geographic location within the state. For instance, Rufous hummingbirds, known for their extensive migrations, may start moving south as early as July, often traversing the Rocky Mountains. Other species, such as Black-chinned and Broad-tailed hummingbirds, tend to depart later, some lingering until late November.
Their departure is primarily triggered by the shortening of daylight hours, rather than a direct response to cooler temperatures or diminishing food sources. While decreasing temperatures and reduced flower availability can play a role, these are secondary to the internal clock regulated by photoperiod. Hummingbirds are adapted to endure some cold, especially if food remains accessible.
The Science of Hummingbird Migration
Hummingbird migration is an innate journey to escape colder temperatures and seek abundant food sources in warmer wintering grounds. This instinct is known as zugunruhe. Most North American hummingbirds, including those from New Mexico, undertake journeys to wintering grounds in Mexico and Central America, with some Rufous hummingbirds traveling as far south as Acapulco.
These birds embark on solitary flights, typically during the day, covering thousands of miles. Rufous hummingbirds can travel up to 4,000 miles each way. To fuel these demanding journeys, hummingbirds engage in hyperphagia, a pre-migration feeding frenzy where they significantly increase their food intake. This allows them to accumulate fat reserves, often gaining 25-40% of their body weight, which serves as their primary energy source. They also utilize torpor, a temporary hibernation-like state, to conserve energy, particularly during chilly nights.
Preparing for Their Journey South
Supporting hummingbirds before their southward journey is important. Maintaining clean hummingbird feeders with fresh nectar is important, even as their numbers might appear to dwindle. These feeders provide energy for late-season migrants and those building fat reserves. It is advisable not to remove feeders too early, as stragglers and late migrants still rely on these accessible food sources.
Some hummingbird species, such as Anna’s and Costa’s hummingbirds, may remain in New Mexico throughout the winter, adapting to cooler temperatures. For these resident birds, keeping feeders available year-round can provide a consistent food supply. Planting native flowering plants is another effective way to offer natural nectar sources, which complement artificial feeders and contribute to a healthier ecosystem. Placing multiple feeders can also help reduce territorial aggression, especially from species like the Rufous hummingbird.
Their Return to New Mexico
Hummingbirds complete their annual migratory cycle by returning to New Mexico in late spring, typically during April and May. The timing of their return, much like their departure, is influenced by environmental cues, particularly the increasing daylight hours. Different species arrive at slightly different times.
Black-chinned and Broad-tailed hummingbirds are often among the earlier arrivals, appearing in early March. Rufous hummingbirds, having completed their longer migration, usually arrive in mid-June. The earliest northward movements from their wintering grounds in Mexico and Central America can begin in late February, with the majority occurring in March.