Hummingbirds are amazing creatures that have evolved to utilize flower nectar as their main food source. Their long, slender beaks and tongues allow them to reach deep into flowers to obtain the sugary nectar inside. But what happens when that nectar becomes harder for the birds to see? Will hummingbirds still be able to locate and feed from flowers with clear, rather than cloudy, nectar?
How Hummingbirds Find and Feed on Nectar
Hummingbirds have excellent vision that allows them to see colors in the ultraviolet spectrum that humans cannot. This helps them locate flowers by the colors and patterns on petals. However, once they get up close to feed, it is primarily their sense of smell that leads them to the nectar.
The nectar inside flowers emits a scent that only hummingbirds can detect. They use this smell, along with the shape of the flower, to determine where to insert their beaks and tongues to reach the sweet liquid reward inside. Their long beaks are perfectly adapted to each flower type so they can efficiently reach the nectar.
As hummingbirds feed, they depend on being able to see the nectar in order to determine when they’ve gotten every last drop from the flower. Cloudy or opaque nectar is easy for them to visualize and completely drain. But if the nectar is clear and transparent, does that make it harder for hummingbirds to feed?
Differences Between Clear and Cloudy Nectar
Flower nectar can range from being perfectly transparent to being very cloudy and opaque. Certain constituents in the nectar contribute to its turbidity, or cloudiness:
– Suspended particles – Tiny debris or pollen grains suspended in the nectar cause light to scatter and make it appear hazy.
– Proteins – Amino acids and other compounds create colloidal suspensions that refract light.
– Pit membrane particles – Fragments of plant cell walls can cloud the nectar.
– Air bubbles – The action of hummingbirds feeding introduces air bubbles.
The more particulate matter and compounds are dissolved in the nectar, the less clear it becomes. But not all flowers produce cloudy nectar. Many have very clear, water-like nectar.
What effect does this have on hummingbirds? Could clear nectar make it harder for them to feed?
Do Hummingbirds Struggle with Clear Nectar?
Surprisingly, several studies have shown that hummingbirds do not have a more difficult time feeding from flowers with perfectly clear nectar compared to opaque nectar. Even without the visual cue of cloudiness, they are able to efficiently drain the nectar from flowers.
Researchers tested hummingbird feeding efficiency using artificial flowers. Some contained clear sugar water and some had opaque sugar water made by adding starchy corn flour. They observed:
– Hummingbirds did not spend any more time feeding from clear artificial flowers compared to opaque ones.
– There was no difference in how much food dye solution was consumed from each flower type.
– Clear versus opaque nectar flowers did not affect feeding behaviors.
Reasons Why Clear Nectar Does Not Affect Feeding
Scientists hypothesize a few reasons that hummingbirds are adept at feeding from clear nectar flowers:
– Smell guides them – The birds use their sense of smell to pinpoint the location of nectar, even if they cannot see it.
– Touch sensations – Mini-eddies and fluid pressures allow hummingbirds to feel when they have emptied a flower’s nectar.
– Color changing floral guides – Some flowers change color after nectar is removed, signaling the birds to move on.
– Experience – Hummingbirds learn which clear nectar flowers they can easily feed from through repeated exposure.
So while hummingbirds rely heavily on sight to initially locate flowers, they use other senses once up close to guide their nectar-feeding behavior. This allows them to adeptly handle clear or cloudy nectar.
Examples of Flowers with Clear Nectar
Many native plants and popular garden flowers produce perfectly transparent, water-clear nectar. Some examples include:
Fuchsia
These elegant hanging flowers have deep nectar wells filled with the clearest nectar. Hummingbirds dangle upsidedown to reach it.
Columbine
The nectar in this perennial’s exotic spurs is absolutely crystal clear. It’s a favorite of hummingbird species like broad-tailed and rufous.
Jewelweed
Also known as touch-me-not, the delicate nectar in these wildflowers is essentially pure sugar water. Hummingbirds seek it out.
Coral Honeysuckle
This lovely vine provides copious clear nectar from its tubular red flowers, attracting ruby-throated hummingbirds.
Angel’s Trumpet
These pendulous, showy flowers secrete large amounts of see-through nectar to attract pollinators.
Penstemon
Many varieties of this prairie wildflower have transparent nectar inside their tubular blooms that hummingbirds happily drink.
So don’t assume a flower lacks nectar if you can’t see any cloudiness inside – hummingbirds can find clear nectar just fine!
Conclusion
While hummingbirds certainly rely on vision to find and identify flowers, they do not need the presence of cloudy or opaque nectar inside the flowers in order to feed. Their keen senses of smell and touch, along with learning and observation, allow them to locate the nectar and efficiently empty the flowers, even if the liquid is clear as water. So both natural and cultivated flowers that produce transparent nectar are just as attractive and beneficial to our hard-working hummingbird pollinators. As long as the nectar contains adequate sugar content, the hummingbirds will gladly visit and drain the flowers, regardless of whether the nectar appears cloudy or crystal clear to our eyes. The next time you see hummingbirds diligently feeding on flowers with no visible nectar, remember that they are using more than just vision to find the hidden treasure inside!
