Last Updated on by Catherine Tobsing
Budgerigars, also called budgies or parakeets, are small, colorful parrots that lots of people keep as pets. They come in many different colors, but in the wild, they are usually green and yellow with black markings.
Scientists have always been interested in how these birds pick a mate (a boyfriend or girlfriend) and whether their bright colors have anything to do with it.
But did you know that budgies can see colors that humans can’t? They can see ultraviolet (UV) light, which is invisible to us. This special vision lets them see patterns and colors on each other’s feathers that we can’t see at all! Scientists wanted to know if these secret colors help budgies choose who they want to be with.
What is Ultraviolet Light?
Ultraviolet light (UV) is a type of light that is beyond the violet color in the rainbow. Humans can’t see it, but some animals, like birds, bees, and some fish, can. UV light can make some things glow, a process called fluorescence.
For example, if you’ve ever seen a white shirt glow under a blacklight at a party, that’s fluorescence!
Budgies have feathers that reflect UV light, and some of their yellow feathers even glow under UV light. Scientists wondered if these glowing and reflective feathers help budgies pick a mate.
The Big Experiment
To figure this out, scientists did a bunch of experiments with wild-type (natural-colored) budgerigars. They wanted to see if the birds cared about UV colors when choosing a mate.
Here’s what they did:
- Changing the Light: They used special filters to block UV light or to let it through. This way, they could make some budgies look normal to other budgies, and make others look dull or less colorful (at least in UV).
- Watching the Birds: They put female budgies in cages where they could see two male budgies at once—one with UV colors showing and one without. Then they watched which male the female spent more time near.
- Testing Fluorescence: They also tested if making the yellow feathers glow more (using UV light to make them fluorescent) made the males more attractive.
What Did They Find Out?
The results were really interesting!
Female budgies liked males with UV-reflecting feathers. When a male’s feathers reflected UV light, the females spent more time near him. This means that UV colors are important for attracting a mate. It’s like having a secret “handsome” or “pretty” sign that only other budgies can see.
Fluorescence didn’t matter much.
Making the yellow feathers glow more under UV light didn’t make the males more attractive to the females. So, just glowing under UV light wasn’t enough to impress the girls.
It’s about color, not brightness.
The females weren’t just picking the brightest males; they were picking the ones whose colors looked better in UV, which changes the way their feathers look.
Boys didn’t care as much.
When the scientists did similar tests with male budgies looking at females, the UV colors didn’t seem to matter as much. The boys didn’t show a strong preference for UV-reflecting girls.
No effect on friendships.
The UV colors didn’t matter when birds were just picking friends of the same sex. It was only important for choosing a mate.
Why Does This Matter?
This study tells us that budgerigars use their special UV vision to choose who they want to date or marry. The UV colors act like a secret code that helps them decide who’s the best mate. The more UV a male reflects, the more likely a female will pick him.
But the glowing, fluorescent feathers don’t seem to matter much for attracting a mate. The scientists think that maybe fluorescence has some other purpose, like helping budgies tell each other apart or helping them blend in with their surroundings, but it’s not important for romance.
What Else Do We Know About UV Vision in Birds?
Budgies aren’t the only birds that can see UV light. Lots of birds have this superpower! For example, some birds use UV colors to find food (because some berries and seeds reflect UV light), and others use it to show off to mates. In some bird species, the males and females look the same to us, but under UV light, they look totally different! This helps them find the right partner.
Birds can see UV light because they have an extra type of color-detecting cell (called a cone) in their eyes. Humans have three types of cones (red, green, and blue), but birds have four (red, green, blue, and UV). This means their world is much more colorful than ours!
Feathered factoid: Falcons have a 5th cone that changes the sky’s contrast to help better illuminate flying prey .
Why Don’t Humans See UV?
Our eyes have a lens that blocks UV light, probably to protect us from damage. But birds’ eyes let UV in, so they can see a whole extra set of colors.
Some people with special eye conditions or who have had their eye lenses removed can actually see a bit of UV light, but most of us can’t.
So, What Did We Learn?
- Budgies use UV colors on their feathers to help pick a mate.
- Females especially like males with lots of UV reflection.
- Glowing (fluorescent) feathers don’t make a difference for romance.
- UV colors don’t matter for making friends, just for finding a boyfriend or girlfriend.
- Birds see a world full of colors that humans can’t even imagine!
This research helps us understand not just budgies, but also how lots of animals use colors and signals that are invisible to us. It’s like there’s a whole secret world of color out there, and birds are living in it every day!
Written and edited by Mitch Rezman and the Windy City Parrot content team.
Sources:
https://www.jstor.org/stable/3068090
https://research-information.bris.ac.uk/en/publications/ultraviolet-vision-fluorescence-and-mate-choice-in-a-parrot-the-b
https://onlinelibrary.wiley.com/doi/10.1046/j.0179-1613.2003.00936.x
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