Hummingbird Hawk Moth: Hong Kong's Most Curious Case of Convergent Evolution
Contents
- 2023 Hummingbird Hawk Moth Sighting
- Why Do They Look Like Hummingbirds?
- How to Identify A Hummingbird Hawk Moth
- Hummingbird Hawk Moth Life Cycle and Behavior
- Where and When to See Hummingbird Hawk Moths
Hummingbird Hawk Moth Sighting in 2023
The first time I ever spotted a hummingbird hawk moth (Macroglossum stellatarum) was up on Castle Peak back in 2022. I remember sitting at the summit, looking down over Tuen Mun and marveling at the view.
A gentle buzzing sounded nearby, and drawn by a sense of curiosity, I turned to see what the source of the noise might be. To my surprise, I saw a tiny hummingbird! The buzzing sound came from the speed of its flapping wings as it flitted between the vibrant flowers, looking for nectar to feast on.
Its long tongue emerged a few times to sample the delights of the local flora before it zoomed off.
Excited by this discovery, I Googled whether hummingbirds existed in Hong Kong. Upon finding out that they didn't I did some digging and learnt about the hummingbird hawk moth, making it my mission to photograph one with my terrible phone camera until that dream finally came true in 2023 in Victoria Park!
Why Does the Hummingbird Hawk Moth Look Like a Hummingbird?
Are hummingbird hawk moths some type of distant cousin to hummingbirds? Do they disguise themselves as hummingbirds to ward off predators? Are they able to scare off potential rival insects by mimicking a bird?
In actuality, hummingbird hawk moths have nothing to do with hummingbirds and only look like them because of a phenomenon known as convergent evolution.
Convergent evolution is a natural process where unrelated species develop similar traits independently because they face similar challenges or live in comparable environments. These similar traits, called analogous structures, don't arise from common ancestry but rather because the species need to accomplish similar things to survive and thrive.
In the case of hummingbird hawk moths and hummingbirds, although one is an insect and the other a bird, both have evolved to hover in mid-air while feeding on nectar from flowers. This ability requires rapid wing movement and specialized feeding structures—like the moth’s long proboscis and the bird’s long tongue and sharp peak.
How to Identify A Hummingbird Hawk Moth (What Do They Look Like?)
Well, the most obvious way to identify them is if you think you've spotted a tiny hummingbird in flight! When at rest, hummingbird hawk moths blend into their environment exceptionally well and look far more like moths than birds.
Key Identification Markers:
- Wingspan about 40-58 mm
- Forewings: grayish-brown with darker crosslines
- Hindwings: bright orange with black edges, visible in flight
- Body: robust, grayish, with black-and-white checkered pattern near the tail
- Long coiled proboscis about as long as the body, used for feeding on nectar
- Rapid wing beats (~85 times per second), producing a humming sound
- Flight: hovers like a hummingbird while feeding on tubular flowers
- Diurnal: active during the day, especially in bright sunshine, dawn, and dusk
- Often mistaken for a hummingbird because of its flight style and feeding behavior
Hummingbird Hawk Moth Life Cycle and Behavior
The hummingbird hawk moth undergoes a four-stage life cycle typical of other moths and butterflies: egg, larva (caterpillar), pupa, and adult. Females secrete a pheromone from their abdomens to attract males. After mating, they can lay up to 200 eggs on the underside of host plant leaves. These eggs hatch within one to two weeks, depending on temperature.
In warmer regions, there can be multiple generations per year, while in colder areas, typically only one generation develops annually. The longer growing season in hot, tropical areas means that host plants for caterpillars remain available for more months, providing extended feeding opportunities. Similarly, nectar-producing flowers for adult moths also stay in bloom longer, offering a prolonged food source throughout the year.
Once hatched, the caterpillars feed on the host plant leaves for about 20 to 30 days, growing quickly and developing distinctive stripes and a horn on their rear. Once fully grown, they pupate in loose cocoons buried in leaf litter or soil, where they remain for approximately two to three weeks before emerging as adult moths. In colder climates, or near the end of the season, these pupae will overwinter in the soil with adult moths hatching once the warm season returns.
In terms of behavior, hummingbird hawk moths are famous for their ability to hover in mid-air while feeding on nectar, just like their namesake. Unlike other moth species, they are diurnal, meaning that they are active during the day. Hummingbird Hawk Moths use their long proboscis to reach deep into flowers, making them important daytime pollinators. Adults typically live for a few weeks to several months, depending on the species and environment. Their flight agility, including rapid wing beats and hovering capability, is a key adaptation that allows them to efficiently feed and avoid predators, showing fascinating convergent evolution with hummingbirds.
Where and When You Can See Hummingbird Hawk Moths in Hong Kong
I've seen Hummingbird Hawk Moths ranging from the New Territories all the way to Hong Kong Island! They can be found in dense woodlands, mountain peaks, or even urban parks!
Basically, anywhere in the city where they can find an abundance of flowering plants is where you'll find these wonderful little moths!
Look for them from March through November as they don't appear in the cooler months.
