Hummingbird moths, also known as hawk moths, are a group of insects that resemble hummingbirds in their appearance and behavior. Like hummingbirds, these moths have the ability to hover in midair and feed on flower nectar while beating their wings rapidly. This gives them their common name of “hummingbird moth”. But unlike hummingbirds which are active during the day, many species of hummingbird moths are most active at dawn and dusk or even at night.
Feeding
Hummingbird moths need to eat frequently to fuel their high-energy lifestyle. They mainly feed on nectar from flowers using their long proboscis which works like a straw. Some species prefer certain flowers over others based on factors like nectar quantity and quality. During the day, hummingbird moths will visit a wide variety of blooms to obtain enough food to sustain their high metabolism. This includes flowers from plants like:
- Petunias
- Honeysuckles
- Columbines
- Lilies
- Rhododendrons
- Lilacs
- Foxgloves
In addition to nectar, adult hummingbird moths gain nutrients from pollen they collect as they move between flowers. They have specially adapted hairy bodies and legs that allow them to carry pollen from one blossom to another. This helps pollinate the plants in exchange for the nectar meal.
Resting and Sheltering
During the warmer daylight hours, hummingbird moths will periodically stop to rest their flight muscles and regulate their body temperature. They may perch under leaves, branches or eaves, often selects shady spots to prevent overheating. Their coloring and camouflage allows them to disappear against trees and foliage at rest stops. Some species may flap their wings slowly or shiver to lower their temperature if needed.
Hummingbird moths tend to be most active on warmer, sunny days so they can raise their body temperature high enough for sustained hovering flight. On excessively hot or rainy days, they may spend more time resting in sheltered areas. Having access to shade also protects them from predators while they refuel and take cover.
Reproduction and Lifecycle
In the daytime, male hummingbird moths will aggressively defend territory around plants that are preferred food sources for females. They also perform elaborate courtship displays during the day where they hover in front of the female to present themselves. If she approves, mating occurs in midair and then the female lays her eggs one at a time on host plants.
Hummingbird moth eggs are very small and often blend in with leaves and stems of host plants. After 3-10 days, caterpillars emerge and immediately start feeding. They spend 2-6 weeks voraciously eating leaves of host plants before forming a pupa. The pupal stage lasts 1-3 weeks depending on species and climate. Adult moths then emerge and the lifecycle repeats.
Some species go through multiple generations per year while others only complete one generation annually. The number of generations is influenced by regional climate patterns. Hummingbird moths overwinter as pupae underground or in plant debris before emerging as adults in spring or early summer when flowers bloom.
Typical Lifecycle Stages:
- Egg – Laid singly on host plants, incubates 3-10 days
- Caterpillar – Feeds on leaves 2-6 weeks, goes through 5-6 instars
- Pupa – Formed on plants, leaf litter or underground; dormant stage lasts 1-3 weeks
- Adult – Emerges to mate, feed on nectar and pollinate flowers; life span around 4-6 weeks for most species
Migration
The ruby-throated hummingbird is the only hummingbird species that migrates, traveling between Central America and the Eastern United States each year. However, some species of hummingbird moths also migrate long distances.
For example, the hawkmoth Manduca sexta undertakes a multigenerational annual journey up to 3000 miles between Central America and the Northern U.S. and Canada. Northern populations cannot overwinter so they must continually recolonize more southern areas. Other examples of migratory hummingbird moth species include:
- Hyles lineata – White-lined sphinx moth
- Hemaris thysbe – Hummingbird clearwing moth
- Hyles gallii – Bedstraw hawk moth
It is still unclear how moths orient themselves and navigate during migration. Potential mechanisms include using the earth’s magnetic field, visual landmarks, and circadian rhythms. The timing and routes of migrations are believed to be hardwired behaviors passed down genetically.
| Species | Migration Route |
|---|---|
| Manduca sexta | Central America to Northern U.S. and Southern Canada |
| Hyles lineata | Northern Mexico to Canada |
| Hemaris thysbe | Southern U.S. to Northern U.S. and Southern Canada |
Behavioral Adaptations
Hummingbird moths display some interesting adaptations and behaviors to aid their survival:
Camouflage
Most species are cryptically colored to blend in against bark, foliage and flowers at rest. This helps conceal them from predators.
Mimicry
Their resemblance to hummingbirds may protect them by fooling predators into thinking they are distasteful or dangerous.
Swift Flight
Their rapid, darting flight makes them hard to catch and track visually by predators.
Nectar Robbing
Some species pierce flowers at the base rather than pollinate properly. This allows them to steal nectar without benefiting the plant.
Heat Control
They can raise and lower their body temperature rapidly via shivering and altering blood circulation in their thorax.
Sound Production
Caterpillars of some species make chirping or squeaking sounds by rubbing body parts together or vibrating.
Interactions with Other Species
Hummingbird moths establish diverse relationships with different organisms during their daily activities:
Plants
As pollinators, they transfer pollen between flowers as they feed on nectar. This makes them very important for pollinating wildflowers and some agricultural crops.
Predators
They are preyed upon by birds, bats, insects, spiders and other predators. Their camouflage, speed and maneuverability help them avoid capture.
Parasitoids
Some parasitoid wasp species lay eggs on hummingbird moth caterpillars. The wasp larvae then consume the caterpillar host.
Symbiosis
A species of stink bug (Cercopeus chrysorrhoeus) feeds on moth eggs and caterpillars but also benefits the moths by protecting eggs from other parasites.
Threats and Declines
Several factors have contributed to declines in some hummingbird moth populations:
- Pesticide use – Can poison adults and caterpillars
- Habitat loss – Reduces feeding and breeding areas
- Light pollution – Disrupts navigation and feeding behaviors
- Invasive plant species – Replace native host plants
- Climate change – Seasonal timing mismatches disrupt breeding
Providing suitable gardens, meadows and woodland habitats can help offset these threats by creating pollinator-friendly spaces. Avoiding pesticide use and excessive outdoor lighting near vegetation may also support hummingbird moth populations. Tracking moth migration patterns and adjusting conservation strategies can counter climate change impacts.
Conclusion
While many hummingbird moth species tend to be most active around dawn and dusk, they display a diverse array of behaviors and adaptations during daylight hours. Feeding on nectar from favored flowers provides the energy they require for hovering flight. Periodic resting allows them to regulate body temperature and avoid overheating. Males defend plant territories that will attract females. Some species even migrate long distances similar to ruby-throated hummingbirds. Maintaining suitable habitats and resources will help hummingbird moth populations thrive during their complex daytime activities.
