Hummingbirds are one of the primary pollinators of flowers around the world. Their small size allows them to access the nectar hidden deep within flowers that other larger animals cannot. In the process of slurping up this nectar, hummingbirds get covered in pollen which they then carry to other flowers, pollinating them. But what exactly do hummingbirds do with all that pollen they collect?
Do Hummingbirds Eat Pollen?
While hummingbirds primarily eat nectar, they do sometimes consume small amounts of pollen as they move between flowers. Pollen contains proteins and other nutrients that are beneficial to hummingbirds. However, pollen alone does not provide enough nutritional value to sustain a hummingbird. They rely heavily on the carbohydrate-rich nectar for most of their caloric needs.
When hummingbirds collect nectar from flowers, they get pollen all over their beaks, heads and throats. As they move to the next flower, some of this pollen inevitably ends up getting ingested. The pollen provides extra protein and boosts the nutritional value of the nectar-based diet. Female hummingbirds especially benefit from the extra nutrition when developing eggs.
That being said, pollen is not a significant part of a hummingbird’s diet. They have evolved to live off the sugars in nectar. Too much pollen can even be problematic by coating the hummingbird’s feeding apparatus and reducing their ability to feed on nectar efficiently. The small amount of pollen they ingest is more of a supplemental bonus rather than a dietary staple.
Do Hummingbirds Use Pollen to Make Nests?
In addition to accidentally eating traces of pollen, hummingbirds also intentionally collect pollen to use in making their tiny nests. The nest is where the female hummingbird lays and incubates her eggs and raises her chicks.
The body of the nest is made of plant down, cobwebs, lichen and moss. This gives the structure padding and insulation. Hummingbirds then create a layer of ‘nest glue’ on the outside made from tree sap and chewed plant fibers. This keeps the nest held together and attached securely to branches.
Finally, hummingbirds coat the entire nest with a layer of pollen. They gather pollen by rubbing their heads on flowers loaded with it. The pollen forms a protective outer coating over the nest materials. It acts as a form of insect and fungal repellent to keep parasites away from the eggs and chicks.
In addition to keeping pests away, the pollen also helps camouflage the nest by masking the white plant down. A pollen coating makes the nest blend in with its surroundings, helping keep it hidden from predators.
So in summary, yes, hummingbirds intentionally gather pollen during the nest building process to help protect and conceal the nest.
Do Male and Female Hummingbirds Collect Pollen Differently?
There are some differences between how male and female hummingbirds interact with flowers and collect pollen.
Male hummingbirds do not participate in nest building. Their purpose is to mate with females and provide some minimal parenting to chicks once hatched. As a result, males do not have as much use for gathered pollen.
Females, on the other hand, require a lot of pollen to construct her nest. She has to visit many more flowers over a shorter period of time to scrape off the pollen. This concentrated effort leads to females having much higher pollen loads on their bodies.
There are a couple other reasons female hummingbirds carry more pollen:
- Females spend more time probing flowers for nectar to get adequate nutrition for developing eggs. This increased foraging leads to increased pollen coverage.
- Females have multiple brooding periods over the course of a breeding season. This means building multiple pollen-coated nests.
- Females doing the brooding are stuck in the nest for long periods of time. They cannot groom off pollen like males can while perching.
These factors contribute to females generally having a much higher pollen load compared to males throughout the breeding season.
How Does Hummingbird Pollen Collection and Transfer Lead to Pollination?
Hummingbirds serve as an important pollination vector for many flowering plant species. As they move from flower to flower feeding on nectar, they transfer pollen between the plants, facilitating cross-pollination and reproduction.
The pollination process works as follows:
- The hummingbird feeds from a flower using its long bill to reach the nectar. As it does so, pollen grains from the flower’s anthers get stuck all over the hummingbird’s head, bill, throat and body.
- When the hummingbird finishes feeding, it flies off in search of another flower source. The pollen that got stuck to its body comes along for the ride.
- The hummingbird feeds from the next flower, transferring some of the pollen from the previous flower onto the pistil of the new flower.
- Any pollen transferred to the pistil then travels down the stigma to fertilize the ovules.
- Seeds develop, allowing the fertilized plant to reproduce.
This sequence of flower to hummingbird to flower pollen transfer is crucial for continuing the genetic diversity and viability of many tropical plant species. Up to 30% of tropical flowering plants rely on pollination services from hummingbirds.
Certain adaptations make this pollination partnership work:
- Bright red tubular flowers perfectly match a hummingbird’s long, slender bill while providing a high nectar reward.
- Anthers are located in spots likely to dust a feeding hummingbird’s head in pollen.
- Hummingbirds hover and lick nectar using a figure-8 pattern that maximizes pollen transfer.
- Hummingbirds have no pollen-collecting body hair so pollen only sticks where it can be delivered to other flowers.
This co-evolution makes hummingbirds the ideal pollinator for ornamental plants such as lilies, fuchsias, penstemons, columbines, mimulus and coral bells.
Do Hummingbirds Help Pollinate Food Crops?
In addition to pretty flowers, hummingbirds also pollinate several food crops important for human nutrition. Hummingbirds have been observed pollinating vanilla, cocoa, tomatoes, peppers, bananas, avocados and more.
One study in California found that hummingbird pollination increased Yields of a local tomato variety by over 20%. Chile farmers also report better fruit set when hummingbirds are abundant to pollinate the chili pepper flowers.
So while they may be best known for their role in pollinating ornamental flowers, hummingbirds also provide an economically important ecosystem service by boosting yields of essential food crops as well.
Pollination of Specific Food Crops
Cocoa – Theobroma cacao flowers rely on tiny midge flies and hummingbirds to transfer pollen between flowers on the cocoa trees. Hummingbirds such as the violet-eared hummingbird in South America are important pollinators that help with the initial fruit set.
Vanilla – Vanilla vines produce yellow-green flowers with nectar only accessible by hummingbird beaks. Hummingbirds vibrant the flowers to release the pollen. Hand pollination must be used on vanilla orchards without hummingbirds.
Bananas – Banana flowers have purple bracts that attract hummingbirds. Nectar-feeding hummingbirds transfer pollen between banana flowers on the same plant and between separate banana plants as they move around.
Tomatoes – Small wild tomatoes relied on hummingbird pollination. Modern greenhouse tomatoes are often hand pollinated but outdoor tomato plants still benefit from hummingbird transfer of pollen between flowers.
Chili Peppers – Chili plants do not produce much nectar but their pendulant red or purple flowers attract hummingbirds. The hummingbirds facilitate cross-pollination between pepper plants which improves fruit production.
How Do Pesticides Affect Hummingbirds and Pollination?
Pesticide use poses a major threat to hummingbird populations. Insects are one common target of insecticide sprays. Since hummingbirds rely heavily on insects as a food source, especially when feeding chicks, insect decline can harm hummingbird reproduction and survival.
Herbicides and fungicides also reduce availability of nectar-producing flowers that hummingbirds depend on.
On top of reducing food supplies, certain chemicals are directly toxic to hummingbirds:
- Neonicotinoid insecticides can cause disorientation and death in very small amounts.
- Glyphosate herbicides may be linked to developmental issues.
- Chlorpyrifos has been correlated with impaired hummingbird reproduction.
In addition to posing health risks, pesticides can interfere with hummingbird pollination benefits. One study showed hummingbird pollination of tomatoes increased fruit weight by over 50% compared to pesticide dependent pollination. Pesticides reduce insect pollinators and thereby increase reliance on less consistent wind or self-pollination.
Maintaining hummingbird biodiversity through organic farming practices maximizes their pollination ecosystem services. Providing diverse nectar plant habitat around crops attracts the hummingbird populations needed to improve yields.
Ways to Support Hummingbirds and Pollination
Here are some tips for attracting hummingbirds to your yard so you can benefit from their amazing pollination services:
- Plant a variety of bright, tubular, nectar-rich flowers
- Avoid pesticide use
- Provide a clean water source
- Supplement with feeders especially in winter
- Include perches where they can rest between flower visits
Consider cultivating some pollinator-friendly food crops as well like tomatoes, peppers, berries and fruit trees. Growing your own food helps reduce reliance on commercial crops heavily treated with pesticides harmful to pollinators like hummingbirds.
This mutually beneficial relationship allows us to enjoy the beauty of hummingbirds whirring about the garden while they enhance production of our vegetables and fruits.
Conclusion
Hummingbirds play a vital ecological role by transferring pollen between flowering plants. As they slurp nectar through their long bills, pollen sticks to their heads and bodies, hitching rides from bloom to bloom. Female hummingbirds in particular accumulate large pollen loads while gathering it to construct their ingenious nests.
The pollen tagging along with hungry, energetic hummingbirds enables the fertilization and reproduction of many tropical ornamental and food crops. Attracting these master pollinators can increase garden yields and productivity. Supporting native plants and reducing pesticide usage helps sustain healthy hummingbird and pollinator communities.
So next time you see a pollen-dusted hummingbird buzzing between flowers, remember it is actively facilitating the growth of the surrounding ecosystem. Those delicate-looking fliers are actually tough, resilient workers putting in overtime to fill the world with fruit and flowers.
