If your hummingbird feeder empties quickly overnight, it may cause speculation that hummingbirds can be seen eating in the dark.
However, typically other creatures will eat the sweet nectar at night, and it is not hummingbirds.
Hummingbirds don’t see well in the dark and are rarely active at that time. They sleep at night in a state of torpor. Hummingbirds have excellent day vision to find colorful food sources. Most species of hummingbirds migrate during the day, resting at night. An exception is the ruby-throated hummingbird, which migrates at night, relying more heavily on migratory instincts rather than vision.
Read on to learn more about the activities of hummingbirds in the dark and in the light.
Learn more about the unique color vision that hummingbirds possess and how it is essential to their survival.
Hummingbird Sight: Dark Vs. Light
Hummingbirds exhibit different behaviors at night than they do during the day.
In The Dark
It is rare and uncommon to see a hummingbird flying in the dark.
Not only does the cooler nighttime temperature pose a risk to the hummingbird’s survival, but these birds also rely on light to find colorful food sources.
They cannot see colors in the dark unless it is warm enough, and there is a source of natural moonlight or artificial light that illuminates the area.
Even then, it is unlikely that a hummingbird will be seen, since it needs to rest daily.
If a hummingbird feeder seems to be emptying overnight, hummingbirds are typically not the culprit. Other creatures such as insects, bats, raccoons, and bears seek out sweet food sources.
At this time, the hummingbird’s heart, metabolism, and respiration rates slow down. This allows the hummingbird to conserve energy and survive colder overnight temperatures.
In The Light
Hummingbirds are active during the day, making them diurnal birds. They rely on sunlight to clue them in on when to wake up and eat and when to sleep.
The light of the day also gives the hummingbird the ability to see a wide range of colors.
As dawn approaches, hummingbirds begin to wake up from their state of torpor. Sunlight triggers a hormonal response in the hummingbird to wake it up, called corticosterone.
As soon as it wakes up, the hummingbird will begin feeding vigorously.
In torpor, the hummingbird’s body temperature is up to 50 degrees lower than its normal temperature of 104°F to 108°F. Feeding upon waking helps to bring its body temperature back up to the normal range.
Most species of hummingbirds migrate during the day, stopping for rest and nutrition as needed.
However, ruby-throated hummingbirds (Archilochus colubris) migrate over 500 miles over the Gulf of Mexico, with no place to stop. This trip can take up to 20 hours to complete.
Before migrating, hummingbirds eat more than usual, gaining 25% to 40% more of their body weight to have enough energy to travel long distances.
Hummingbirds migrate individually, but use instincts to find their way, despite poor night vision.
Birds have a pineal (light-sensitive gland) in their brains that respond to the number of hours of sunlight (photoperiod). This activates hormones in the bird to begin migration.
Hummingbirds do not sing like songbirds and as they fly fast, they rely on vision to locate food sources, navigate terrain, and find mates.
Hummingbirds’ eyesight is an essential sense for their survival.
They can see all colors, including ultraviolet ones because they have four color cones (tetrahedral) in their eyes (whereas people only have 3).
In particular, hummingbirds are drawn to red, orange, and yellow nectar sources, which tend to have a higher sugar content than other flowers.
Hummingbirds thus learn that certain colors represent more food.
Male hummingbirds are colorful showing off iridescent feathers. This structural coloration reacts to sunlight, showing a variety of wavelengths of light. This colorful plumage attracts the females.
The four cones in the hummingbird’s eye allow it to see additional colors such as ultraviolets (nonspectral colors) in green, red, yellow, and purple.
This video discusses the research that has taken place to learn about the vision of hummingbirds:
Hummingbirds cannot see in the dark.
At night, it is cooler and they go into a hibernation-like state called torpor. This allows the bird to conserve energy for the following day and to survive the cooler temperatures overnight.
Unlike other species of hummingbird, the ruby-throated species will migrate at night, but relies on instincts to find its way, rather than vision.
Hummingbirds have 4 cones in their eyes that allow them to see non-spectral colors in ultraviolet hues. This gives them the ability to find colors associated with higher sugar content (such as red and orange) as well as mates.
Learn More About Hummingbirds:
- Where & How Do Hummingbirds Sleep?
- Can Hummingbirds Fly In The Rain?
- Can Hummingbirds Fly Backwards?
- Do Hummingbirds Have Predators?
- Can Hummingbirds Eat Honey?