Are hummingbirds nocturnal or active at night?
Hummingbirds usually feed heavily in the morning, the evening hours and begin to settle in about a half hour or so before dark. But in some locations--especially if there is artificial lighting such as porch light--hummingbirds may actually feed well into the night, usually during warmer weather. Hummingbirds do also fly at night, but this almost always happens during migration.
Hummingbirds and Sleep
When hummingbirds sleep, they go into a hibernation-like state called Torpor (pronounces TOR-per). This is really deep sleep. Their metabolism will lower to one-fifteenth (1/15) of normal. Their body temperature will drop to the point of becoming hypothermic. Their heart rate will drop to about 50 beats per minute. Their breathing will slow to the point that it looks like they have stopped breathing. By sleeping like this, hummingbirds can save up to 60% of their available energy.
A hummingbird will settle in a favorite perching place that they feel is safe. If the hummingbird is a female with a nest of baby hummingbirds that cannot care for themselves, the mother hummingbird will sit on the nest.
When hummingbirds sleep and are in the Torpor state, they have been known to hang upside-down. If you find a hummingbird that is hanging upside-down and they appear to be dead, it is actually more likely that they are just asleep. They will probably not even respond if you touched them. If at all possible, leave them alone and they will wake up when they get warmer. It takes anywhere from 20 minutes to an hour for a hummingbird to fully recover from torpor. Once they are up and about, the first order of business is food. The hummingbirds will eat 25% of their daily intake as soon as they recover from torpor.
How do hummingbirds survive cold winter nights?
Sometimes, for reasons that are not entirely clear, individual birds remain behind for the winter, and sometimes, they survive. Thus, as average seasonal temperatures increase, hummingbirds are increasingly becoming established as year-round residents outside of their traditional ranges. Anna's Hummingbird is one species whose range has expanded steadily northward as seasonal temperatures have become milder. Thus, this bird is now a common year-round resident along the northwestern coast of the United States and even into some parts of Canada.
As most people know, hummingbirds feed on flower nectar, which is a tempting "gift" of high-energy sugars provided by flowers in exchange for pollination. In addition to nectar, hummingbirds also consume large quantities of small insects, which are full of higher-energy fats as well as essential proteins. Because of their tremendous metabolic requirements, hummingbirds have voracious appetites, equivalent to the average human consuming an entire refrigerator full of food, hummingbirds eat roughly 2 to 3 times their body weight in flower nectar and tiny insects each day.
Migration During The Night
While migrating, hummingbirds generally will fly during the day and sleep at night. When the Ruby-Throated Hummingbirds are flying over the Gulf of Mexico during spring and fall migrations, there is no place to land to sleep, so it's apparent these hummingbirds must spend at least some of that time flying in the dark.