Hummingbirds are some of the smallest birds in the world, so it comes as no surprise that their eggs and babies are tiny as well. In this article, we’ll take a close look at the size of hummingbird eggs and hatchlings and explore how their diminutive size helps them survive.
How big are hummingbird eggs?
Hummingbird eggs are very small, though the exact size can vary slightly by species. Most measure about the size of a jellybean, generally 0.5 inches long by 0.25 inches wide (13 mm x 6 mm). That’s smaller than a dime! Here are some more specifics on hummingbird egg sizes:
| Species | Egg Size |
|---|---|
| Ruby-throated Hummingbird | 0.6 in x 0.4 in (13 mm x 8 mm) |
| Rufous Hummingbird | 0.5 in x 0.3 in (12 mm x 6 mm) |
| Calliope Hummingbird | 0.4 in x 0.25 in (11 mm x 5 mm) |
| Anna’s Hummingbird | 0.5 in x 0.33 in (14 mm x 7 mm) |
As you can see, even eggs from larger hummingbird species are smaller than a penny. The tiny Calliope hummingbird lays the smallest eggs of all North American hummingbirds.
What do hummingbird eggs look like?
Hummingbird eggs are oval or elliptical in shape. Their shells are fragile and smooth, with very little texture or markings. Most eggs are a plain white or creamy white color. However, some species lay eggs with a very slight pinkish or reddish tinge.
Within a clutch, hummingbird egg colors can vary slightly. Some have tiny speckles in shades of brown, purple, or gray scattered across the shell. But heavy spotting or blotching is uncommon.
How much do hummingbird eggs weigh?
With their tiny size, hummingbird eggs are extremely lightweight. Here are some average egg weights for common North American species:
| Species | Egg Weight |
|---|---|
| Ruby-throated Hummingbird | 0.365 g |
| Black-chinned Hummingbird | 0.3 g |
| Anna’s Hummingbird | 0.45 g |
| Rufous Hummingbird | 0.25 g |
| Calliope Hummingbird | 0.2 g |
To put that in perspective, a penny weighs about 2.5 grams. So even the largest hummingbird eggs weigh less than a quarter of a penny!
Why are hummingbird eggs so small?
There are a few key reasons hummingbird eggs are teeny-tiny:
- Small birds have small eggs. Hummingbirds are the smallest birds, so it makes sense their eggs are proportionately mini as well.
- Their nests are tiny. Hummingbird nests are only 2-3 inches wide – built to precisely cradle their petite eggs.
- It takes less energy to incubate smaller eggs. With a high metabolism, hummingbirds conserve resources with tiny eggs.
- Smaller eggs allow for quicker incubation. The average hummingbird egg hatches in just 14-16 days.
By laying small eggs that develop rapidly, hummingbirds maximize their chances of breeding success. The fast incubation helps get chicks grown and out of the nest quicker, reducing threats from predators and weather.
How big are baby hummingbirds?
Newly hatched hummingbirds are about the size of a bumblebee – just over 1 inch long (2.5 cm), weighing approximately 0.1 to 0.2 grams. Their bodies lack feathers and their eyes are closed at birth. Here are the hatchling sizes for some common species:
| Species | Hatchling Size |
|---|---|
| Ruby-throated Hummingbird | 1.1 in (2.8 cm) |
| Black-chinned Hummingbird | 0.8 in (2 cm) |
| Anna’s Hummingbird | 1 in (2.5 cm) |
| Rufous Hummingbird | 0.75 in (2 cm) |
| Calliope Hummingbird | 0.6 in (1.5 cm) |
You can see the Rufous and Calliope hummingbird babies are exceptionally tiny, which matches the small size of their eggs. Within one week, these tiny hummers will quadruple in size!
How do the babies grow so quickly?
To fuel their rapid growth, newborn hummingbirds need to consume high-energy food as soon as possible. Within a day after hatching, the mother begins feeding them a protein-rich diet of regurgitated nectar and insects.
Some fascinating facts about hummingbird growth:
- Their weight increases 5-10 times in the first week.
- Feathers start sprouting within 5 days of hatching.
- Eyes open after 7 days.
- By 2 weeks old, nestlings are nearly adult size.
- They fledge the nest at 3 weeks old.
This swift development allows young hummingbirds to fly within a month after hatching. If the babies grew any slower, they’d be vulnerable in the nest and less likely to survive until breeding.
How small is the smallest baby hummingbird?
The Calliope hummingbird lays the smallest eggs and thus has the tiniest newborns of any North American hummer. These itty-bitty chicks hatch out at just 0.6 inches long and weigh 0.1 grams.
For perspective, that’s about the same length as a paperclip! It’s incredible that such a teensy bird can thrive and grow so rapidly in just a few weeks. The diminutive Calliope serves as a reminder of the amazing adaptability of hummingbirds.
Do bigger hummingbird species have larger babies?
Yes, there is a correlation between adult hummingbird size and the size of their hatchlings. Larger species like Buff-bellied Hummingbirds and Violet-crowned Hummingbirds produce bigger nestlings than their more petite cousins. Here are some specs on newborn size for some of the heftier hummingbird species:
| Species | Hatchling Size |
|---|---|
| Buff-bellied Hummingbird | 1.5 in (3.5 cm) |
| Blue-throated Hummingbird | 1.2 in (3 cm) |
| Violet-crowned Hummingbird | 1.3 in (3.5 cm) |
However, all hummingbird hatchlings are still tiny compared to songbirds, doves, or other backyard birds. Even the largest baby hummer can fit inside a teaspoon!
Do the eggs and babies grow at the same rate?
While hummingbird eggs are minuscule, they do contain everything needed for a chick to develop. The egg holds the tiny embryo along with nutrients such as fats, proteins, vitamins and minerals to power its growth once hatched.
However, most of the actual size increase happens after hatching. While an embryo may slowly grow inside the egg, the most rapid growth occurs in the nestling phase. This allows hummers to fledge in just 2-3 weeks.
So in summary, the eggs themselves do not enlarge much, but rather hold genetic material and food resources to fuel the chick’s later growth spurt.
How can we help these tiny babies survive?
Hummingbird nests often face threats from predators and harsh weather. Here are some tips for supporting their fragile eggs and tiny hatchlings:
- Avoid trimming trees and bushes with nests from March to August.
- Install nesting material like soft plant fibers nearby.
- Provide nectar feeders so mothers can easily fuel milk for chicks.
- Add fruit feeders to provide insects that chicks need for protein.
- Gently mist nests during heat waves to prevent overheating.
- Keep outdoor cats indoors, as kittens are a threat.
With a little help, even the most miniature hummingbird young can continue their incredible growth journey to take flight!
Conclusion
While hummingbird eggs and hatchlings are teeny-tiny, they are perfectly equipped to fulfill their brief nesting phase. Their small size at birth enables rapid development into their adult form within weeks. By providing excellent nutrition and keeping nests safe, we can ensure these littlest hummingbirds survive to continue amazing us with their hovering flight and fiery personalities. The next time you see a darting hummer, remember its humble beginnings as one of nature’s littlest babies!
