This is a question that has intrigued people for centuries. The answer isn’t as simple as you might think — not only because of all those vibrant blues and oranges, but also due to how each color affects different species of hummers in specific ways. Hummingbird scientists haven’t quite nailed down an exact explanation yet, although they do know some things about this topic.
For instance, we can safely assume that reds, yellows and greens aren’t really attractive to them, since these colors don’t exist on most hummingbird feathers (see How Birds See Color). We’ll take a look at why other colors may be more or less desirable later in this article. First, let’s talk about where hummingbirds get their bright clothing from.
Colors That Attracting Hummingbirds
Scientists have learned a great deal about the attraction hummingbirds feel toward certain colors. Hummingbirds generally enjoy shades of purple, violet, pink, lavender and light blue. Certain types of ultraviolet radiation excite photoreceptors located in the birds’ eyes.
Photoreceptor sensitivity varies greatly among individuals, but researchers believe this trait influences whether hummingbirds respond positively to particular colors. Researchers have found that hummingbirds become very excited when presented with images of violet objects, including flowers. Since hummingbirds cannot produce violet light themselves, they must depend entirely on reflected sunlight for reproduction purposes.
Violet reflects well against dark backgrounds, so hummingbirds see it as a sign of good health. It stimulates production of hormones related to egg development, growth and survival. Violet reflects particularly strongly against black, which helps protect hummingbirds from heat produced by their own bodies.
Related: How to Attract Hummingbirds
Another reason that violet attracts hummingbirds is that this wavelength of light corresponds to the peak absorption spectrum of melanin. Melanin is pigment responsible for the shine of hummingbird feathers. Finally, violet signals a safe environment, indicating low levels of toxins and parasites.
Other studies indicate that hummingbirds prefer lighter tones, such as pinks and purples, because they reflect best in these ranges. Light reflection increases when wavelengths shift closer to the shorter side of the electromagnetic scale.
Short waves create brighter contrasts compared to long waves. Therefore, the intensity of reflected light increases when shorter wave lengths interact with darker surfaces. Because hummingbirds eat mainly nectar, they spend much time basking in sunlight. Hummingbirds absorb a significant amount of excess solar radiation, causing tissue damage and eventual death.
Exposing hummingbirds to intense direct sunlight causes physiological changes associated with sunburn. Longer wavelengths cause greater harm to hummingbirds, whose tissues contain higher concentrations of chlorophyll, which absorbs shortwave photons. Chlorophyll fluoresces brilliantly when exposed to strong light, giving hummingbirds a shimmery glow.
Colorful Hummingbird Courtships
In addition to having gorgeous coloring, hummingbirds possess extraordinary behaviors that fascinate humans worldwide. One such behavior involves courtship displays. Most hummingbirds engage in mating rituals and territorial disputes, sometimes even fighting one another.
Female hummingbirds tend to mate exclusively with members of their own sex. However, if two unrelated male hummingbirds happen to come across a female who doesn’t recognize either of them, she could end up being tricked into pairing up with one of them. This sort of event actually happens fairly frequently among some types of hummingbirds.
A male Anna’s hummingbird, for example, may sneak up behind a female he thinks belongs to his territory. He then grabs her with his claws and tries to convince her to stay with him. Afterward, the pair flies away together until they find somewhere secluded. Once they settle down, he fertilizes her eggs, ensuring her success in producing baby hummingbirds.
Male hummingbirds fight for dominance using song and dance. Their songs consist of short notes separated by pauses lasting between 0.1 seconds and 1 second. Songs last anywhere from three minutes to more than 20 minutes, depending on the species.
Male hummingbirds sing loudly in order to communicate with potential rivals and attract females. Song spurs competition among males, allowing them to show off their skills and assert control over territories. There are distinct differences between the various species of hummingbirds based solely on their vocalizations.
Blue-throated sliders, green martins and rufous pronghorn ants mimic the sounds made by tropical hummingbirds. Yellow-bellied sapsuckers imitate northern cardinals, wagtails and meadowlarks. Northern harvesters mimic orioles and mockingbirds. And brown dacrids create a buzzing noise.
When courting, male hummingbirds perform elaborate dances to display their strength and status. Many of these moves involve head bobbing and spinning movements. Sometimes, males put their tails straight up in the air before swinging back and forth. Other times, they flap their wings rapidly or hover in midair.
During courtship maneuvers, hummingbirds often move toward one another slowly with heads held high. To impress young women, males may follow one another closely and circle around them repeatedly. All of these actions draw attention to the males’ brightly colored bodies, which serve as advertisements to prospective partners. On occasion, male hummingbirds chase after females as they try to escape.
Although scientists don’t fully understand why hummingbirds prefer particular colors, it’s clear that there are definite preferences. Let’s see what colors make up a typical hummingbird wardrobe.
Blue-breasted nuthatches feed primarily on flower buds and blossoms while nesting, building nests, incubating eggs and caring for fledglings. Like many other birds, nuthatches build their homes out of mud, grass and twigs. Nests range from flat platforms attached to tree branches to conical structures rising 2 feet to 4 feet (0.6 meters to 1.2 meters) above ground level. Nest sites vary considerably, ranging from open areas to dense thickets.
Hummingbirds Body and Wings
The beautiful iridescent plumage of many hummingbird species gives us our first clue as to which colors appeal to them. Plumage refers to both the visible characteristics of a bird and its outer covering, usually called the skin or epidermis. In terms of coloring, the term “plumage” specifically means the pigment-filled feather barbs that make up the top part of a hummingbird wing.
These pigmented cells give the wings their vivid appearance and enable the hummingbird flight mechanism. When viewed through binoculars or telescopes, hummingbird wings appear solid black; however, under magnification, the true beauty reveals itself. Each individual cell looks like a miniature jewel box and contains several layers of colored feathers within its protective casing. If you’ve ever seen hummingbird wings up close, then you understand just how intricate their design is.
Like human hair, hummingbird feathers grow continuously throughout life. New feathers replace old ones right after molting. As new feathers emerge, older ones fall off naturally. With each molt, the size and shape of the previous year’s feathers change slightly. Some of the larger feathers on the outside of the wing curve downward near their tips, while others form longer filaments known as remiges (or retrices) that stick out further below.
Remiges provide stability during flight by holding onto air currents. Hummingbirds use their remiges to soar above trees and power themselves into rapid ascent without falling from the sky. They also rely heavily upon a special type of gliding mechanism called counter-current airflow propulsion (CCAPP), which allows hummingbirds to fly fast enough to break the sound barrier.
CCAPP works much like skydivers’ parachutes, except instead of slowing your descent once you jump out of an airplane, CCAPP slows the flow of air around your body to help increase speed. Scientists still haven’t figured out exactly how the hummingbird achieves this effect, but they’re studying it closely in hopes of applying similar principles to future aircraft designs [Source: Ostroff].
While there are lots of colorful creatures flying around today, hummingbirds stand apart thanks to their striking appearances and unique habits. Read on to learn more about how these amazing birds attract mates.
A male ruby-crowned kinglet resembles a smaller version of a hummingbird. It has reddish orange plumage over white underneath. Its bill is yellow, and its legs are blue. Females lack any kind of crowning markings. Males court females by chasing them with their bills while singing sweetly. While doing this, males will often vibrate their tail feathers.
It takes a lot of energy for hummingbirds to maintain a large population. Hummingbirds need plenty of food every day, which requires vast expanses of habitat suited for feeding. Larger colonies of hummingbirds often inhabit forests rather than isolated locations.
A study conducted in 2006 showed that small populations of wild indigo buntings live in patches of forest containing no more than 15 acres (6 hectares) combined. Although deforestation poses a threat to local biodiversity, it may benefit native hummingbirds if it creates room for expansion.
Even though urban centers house fewer varieties of hummingbirds, cities offer refuge from predators and cold weather. Cities also allow easy access to water sources, making them ideal places to nestle and feed. Native habitats, on the other hand, require a little extra work to reach natural resources.