Hummingbirds are some of the smallest and most fascinating birds. Their ability to hover mid-air and fly backwards makes them unique among birds. Hummingbirds live very fast-paced lives, fueled by the sugary nectar they drink every day. Their rapid heart rate, fast breathing, and high metabolic rate mean they lead busy lives. One aspect of their lives that is particularly precarious is the survival rate of their young.
How Many Eggs Do Hummingbirds Lay?
Hummingbirds lay very small clutches of eggs, usually just two per nest. The eggs are smaller than jellybeans, usually measuring 0.5 inches long and 0.25 inches wide. They are oval shaped and white in color. The small clutch size means a female hummingbird will usually only raise two chicks per nest. Anything more would likely be difficult for the parents to adequately feed.
Occasionally a hummingbird may lay just one egg or sometimes three, but two is the norm. The eggs are laid in a petite nest built by the female hummingbird. She constructs the nest out of soft plant down, spider webs, lichen, and moss, binding the materials together with strands of spider silk. She lines the inside with fine plant fibers to cushion the eggs.
The female builds the nest without any help from a male. She will aggressively defend the nest from intruders. Other females may even try to lay eggs in her nest, which she will remove if found. Males do not participate in nest building or egg incubation.
How Long Does It Take Hummingbird Eggs to Hatch?
Once the female hummingbird lays her two eggs, incubation begins. She alone will incubate the eggs. This process takes between 14 to 23 days. Some species, like calliope hummingbirds, have shorter incubation times around 14 to 19 days. Larger species like blue-throated hummingbirds incubate for 18 to 23 days.
During incubation, the female will sit on the nest the majority of the time. She may take short breaks to drink nectar and catch insects, but she knows she must keep those tiny eggs warm. If the eggs get too cold, the chicks inside will die. She patiently incubates until the chicks are ready to hatch.
When it’s time for the eggs to hatch, the hatchlings will use their beak to peck a hole in the egg. This process takes 12 to 36 hours as the tiny chicks peck bit by bit until they can crawl out of the shell. The mother may even help break some of the shell herself to speed up the process after she hears the initial pecking sounds.
Incubation Period for Common Hummingbird Species
| Species | Incubation Period |
|---|---|
| Ruby-throated Hummingbird | 13 – 15 days |
| Rufous Hummingbird | 16 – 17 days |
| Allen’s Hummingbird | 15 – 19 days |
| Anna’s Hummingbird | 16 – 17 days |
| Black-chinned Hummingbird | 12 – 16 days |
| Broad-tailed Hummingbird | 15 – 18 days |
Do Hummingbird Chicks Leave the Nest Quickly?
Once the tiny hummingbird chicks hatch, they grow incredibly fast. They are born featherless and with their eyes closed. Within a week, their eyes open and they develop some downy feathers. Their wings will start to take shape.
By two weeks old, their flight feathers begin to emerge from the skin. These are the long primary wing feathers essential for flight. From hatching to fledging (their first flight), hummingbird chicks develop in just 18 to 26 days total. Different species reach this milestone at different paces:
- Allen’s hummingbirds fledge in 18 to 19 days
- Calliope hummingbirds fledge in 18 to 23 days
- Rufous hummingbirds fledge in 21 to 26 days
In this short time, hummingbird chicks go from bare and blind newborns to fully flighted juveniles ready to leave the nest. Their rapid development is driven by their high metabolism. But it comes at a high price—the enormous food requirement to fuel such quick growth.
How Do Hummingbird Parents Feed Their Chicks?
In order to facilitate such rapid growth and development in their chicks, hummingbird parents must supply the nest with an abundance of food. The diet hummingbird chicks need is very specialized—they eat a diet of mostly small insects and spiders along with nectar.
A nest of two growing chicks requires hundreds of meals over just a couple weeks. To satisfy this demand, adult hummingbirds make trip after trip to the nest with food. A parent may visit the nest up to 40 times per hour. That’s nearly 1,000 feeding trips a day!
The female does most of the feeding while the male helps defend the nest territory. The tiny insects such as gnats, aphids, and fruit flies are protein-packed to supply the structural materials the chicks need. The sugary nectar also provides crucial energy.
The mother and father work tirelessly from dawn to dusk, bringing beakful after beakful of precious food. They nourish those hungry chicks as fast as they can in order to keep up with their intense growth schedule. Even with such devoted parents, the young hummingbirds face many threats.
What Are the Threats to Hummingbird Chicks?
With tiny eggs and helpless chicks incubating outside the safety of a tree cavity or enclosed nest, hummingbirds face substantial risks:
- Predators – Snakes, lizards, squirrels, and chipmunks may raid hummingbird nests. Larger birds like jays, crows, and magpies also pose a threat.
- Weather – High winds and heavy rain can knock delicate nests from their perch. Chilling temperatures or scorching heat also endanger chicks.
- Nest Competitors – Other female hummingbirds may toss eggs out of a nest to take it over for themselves.
- Starvation – Fast growth makes chicks incredibly vulnerable if parents cannot provide enough food.
These factors combine to make it a challenging environment for parent hummingbirds trying to raise their offspring. Let’s look at the odds of a hummingbird chick surviving to adulthood.
What Percentage of Hummingbird Chicks Survive?
Only a fraction of hummingbird chicks survive to adulthood. Researchers estimate that between 10% to 70% perish before they can fledge from the nest. The exact mortality rate depends on factors like:
- Weather conditions
- Food availability
- Nest predators
- Nest parasite rates
In ideal conditions with low predators and plentiful food, up to 70% may fledge. But if resources are scarce or predators abundant, only 10-30% may survive. Heavy rains or cold temperatures also lower survival rates. Overall, experts suggest only 1-2 chicks from a clutch of 2 will typically survive to adulthood.
Here is a table summarizing observed survival rates in select hummingbird species:
| Species | Nest Survival Rate |
|---|---|
| Black-chinned Hummingbird | 38% |
| Ruby-throated Hummingbird | 43% |
| Rufous Hummingbird | 55% |
| Allen’s Hummingbird | 65% |
As the table shows, even in healthy populations, over half of hummingbird chicks perish before fledging. The odds are against them from the start.
Why Do So Many Hummingbird Chicks Die?
Researchers have identified several key reasons so many hummingbird chicks fail to survive:
Extreme Vulnerability of the Nest
Hummingbird nests are very exposed. Built on slender branches, often far from the tree trunk, they can be precarious in wind and rain. Nest height also makes them easy targets for tree-climbing predators.
Limited Food Supply
Rapidly growing chicks need hundreds of protein-packed meals daily. If flowers are scarce or rain limits nectar production, parents struggle to find adequate food. Chicks starve without sufficient nutrition.
Harsh Weather
Cold snaps or heat waves take a toll on delicate chicks. Nests provide little insulation or protection from the elements. Chicks cannot thermoregulate until almost ready to fledge.
Nest Parasites
Parasites can infest the nests, biting chicks and weakening them over time. Common hummingbird parasites include certain flies, fleas, mites, and botflies.
Lack of Parental Care
If a parent is killed or abandons the nest, the single remaining adult may have trouble finding enough food on its own. Predation, injury, or starvation can leave chicks orphaned.
With all these factors working against them, hummingbirds produce many more offspring than can possibly survive. Even with a high mortality rate, enough chicks fledge each year to maintain healthy populations. Those that do overcome the odds face hazards trying to survive their first year.
What Threats Do Juvenile Hummingbirds Face?
After surviving the nest, fledgling hummingbirds still face high mortality as juveniles. Some key threats include:
- Starvation – Young birds may struggle to find nectar sources.
- Predators – Lizards, snakes, and spiders catch young birds. Hawks and falcons seize them mid-air.
- Collisions – Their small size and erratic flight patterns make them prone to crashing into objects.
- Exposure – Cold spells or heatwaves can kill birds lacking energy reserves.
- Disease – Protozoan, fungal, and bacterial diseases pose a bigger threat to weaker youngsters.
Like many bird species, the first year brings the highest danger. Those that have made it to adulthood have persevered against difficult odds.
What can be done to improve hummingbird chick survival rates?
While hummingbirds naturally have a low juvenile survival rate, there are steps we can take to improve their chances:
Provide nectar feeders
Feeders supply crucial energy, especially when flower nectar is scarce. Switch nectar every few days to prevent fermentation and mold.
Supply insect feeders
Mealworms, fruit flies, or dried bugs in feeders provide essential proteins to raise chicks. Place near nest sites if possible.
Avoid use of pesticides
Chemicals reduce insect food sources and can poison parent birds. Use natural means to control pests when possible.
Don’t disturb nests
Unnecessary nest interference can distress parents or expose chicks to elements. Avoid trimming branches around active nests.
Plant native flowers and trees
Diverse native plants support more insect populations. Indigenous blooms also supply more natural nectar. Non-native exotic flowers often provide less nutrition.
While we cannot control all the factors impacting hummingbirds, conscious effort to support nesting parents can contribute to healthier future generations. Even if we only improve the odds slightly for a local hummingbird population, we make progress.
Conclusion
Only 1 in 10 hummingbird chicks survive on average—an astonishingly high mortality rate. Tiny size, extreme vulnerability, and the intense demands of rapid growth are all factors working against their success. Parent hummingbirds strive valiantly to raise their young against difficult odds. As humans encroach on their breeding habitats, it becomes even more crucial that we take steps to mitigate risks.
Improving nesting outcomes ensures healthier, more robust hummingbird populations that provide invaluable pollination services and magical moments of natural wonder. When a hungry hummingbird chick’s survival hinges on the dedicated provision of hundreds of insects a day, every small action to support the parents helps tilt the odds. Our gardens, green spaces, and conservation choices all contribute to the future for these captivating creatures.
