How big are the hummingbirds in California?

Hummingbirds are some of the smallest birds found in nature, and the ones that live in California are no exception. Their tiny size allows them to hover in midair as they drink nectar from flowers, making them a joy to watch. But exactly how small are the hummingbirds in California?

Average Length of California Hummingbirds

There are 8 regular species of hummingbirds that live in California. The smallest is the Calliope Hummingbird, which reaches lengths of just 2.75-3.5 inches. The largest is the Rufous Hummingbird, which can reach 3.5-4.3 inches in length. Here are the average sizes of the main hummingbird species found in California:

As you can see, even the largest hummingbird species in California barely exceeds 4 inches in total length. The smallest species, the Calliope Hummingbird, is only about as long as a person’s thumb!

Wingspan of California Hummingbirds

In addition to their petite bodies, hummingbirds have very small wingspans compared to other birds. Here are the average wingspans for common hummingbird species in California:

Again, we see that even the largest wingspans top out around 4.7 inches, with the smallest species coming in at just over 3 inches across. This compact wingspan allows the birds to precisely control their rapid wing beats as they hover and dart between flowers.

Weight of California Hummingbirds

Completing the profile of their petite sizes, hummingbirds found in California are extremely light. Here are the average weight ranges for common species:

To put their tiny weights into perspective, a penny weighs about 2.5 grams. So even the heaviest hummingbirds weigh only a little more than 2 pennies!

Male vs Female Size

In all hummingbird species, the males are slightly smaller than the females. Here are the average size differences between males and females:

• Length – Females are about 5-10% longer than males
• Wingspan – Female wingspans are 5-15% larger than male wingspans
• Weight – Females typically weigh 10-25% more than males

This size dimorphism is common among bird species where the females do all the nesting and rearing of the young. The extra size of the females allows them to produce more eggs and better endure the demands of nesting and caring for hatchlings.

Size Comparisons

It’s hard to grasp just how tiny California hummingbirds are until you see them compared side-by-side with more familiar objects:

• A calliope hummingbird is about the same size as a butterfly
• An Anna’s hummingbird is slightly smaller than an adult human thumb
• A black-chinned hummingbird is roughly the same dimensions as a golf ball
• The nest of a Allen’s hummingbird is about the size of half a walnut shell
• A rufous hummingbird weighs slightly less than a U.S. nickel
• The egg of a Costa’s hummingbird is roughly the size of a coffee bean

These comparisons really highlight the incredibly small scale of these energetic little pollinators. Their tiny size belies the huge role they play in California’s ecology.

Changes in Size by Season

A hummingbird’s size can fluctuate over the course of a year as it prepares for and recovers from breeding. Here are some size changes hummingbirds may undergo:

• In spring, male hummingbirds are at their smallest size before bulking up over the summer
• Females may gain 25-40% in weight in late winter/early spring before breeding
• After breeding, females lose a significant amount of weight and may shrink slightly in length
• Males may decrease in mass by 10-15% over the course of the breeding season
• Juvenile hummingbirds start out much smaller than adults, weighing only 1-2 grams at birth
• By 2-4 weeks after leaving the nest, juveniles reach almost adult size

So while the size ranges listed earlier capture the adult hummingbird’s general dimensions, there can be some fluctuation across the seasons and as the birds mature.

Factors Influencing Size

Several factors contribute to the tiny size of hummingbirds in California and elsewhere:

• Small size allows maneuverability and hovering flight around flowers
• A high metabolism sustaining rapid heartbeats requires a small body
• Shortages of food like nectar may stunt growth in young hummingbirds
• The availability of small insects influences size – more insects allows greater growth
• Climate extremes like drought can negatively impact development
• Inter-species competition forces small specialized niches
• Being smaller reduces energy needs and allows survival in lean times

Evolution has precisely tuned the size of hummingbirds to allow them to thrive in specialized nectar-feeding and hover-hunting lifestyles. Their energetic way of life demands a tiny, lightweight body that gets the most from every drop of fuel.

Changes in Size Over Time

Analysis of fossil records indicates that hummingbirds have shrunk in size over the past 30 million years:

• Ancestors may have been as large as today’s swifts and swallows
• Steady miniaturization occurred from the early Miocene onwards
• By the Pleistocene (2mya to 11,000ya) most species were close to modern dimensions
• Specialized flower-feeding played a role in driving smaller sizes
• Climate changes selected for smaller, more resilient birds
• Fossils show a faster heartrate and wingbeat emerged as size decreased

While they may have begun more moderately sized, the evolutionary path of hummingbirds has consistently led to tinier, finer-tuned avian machines specialized for extreme efficiency and maneuverability.

Role of Size in Hummingbird Classification

Due to their small size, hummingbirds are sometime grouped taxonomically with another family of tiny birds called swifts. However, research has shown that similarities in size are a case of convergent evolution, and hummingbirds are not actually closely related to swifts. Ornithologists use differences like these to classify hummingbirds:

• Distinct wing structure specialized for hovering
• Small feet capable of perching but not walking
• Extremely rapid metabolism and heartrate
• Long, specially adapted tongue for nectar-feeding
• Lack of size dimorphism seen in swifts

While size is certainly a characteristic of hummingbirds, ornithologists focus on anatomical traits and DNA analysis to study evolutionary relationships between bird families.

Unique Adaptations Related to Size

Hummingbirds’ tiny size has led to many special adaptations that help them survive despite their small stature:

• Rapid wing beats enabling precise hovering in place
• A rapid heartrate and breathing rate
• High efficiency kidneys to concentrate dilute nectar
• Lightweight bills to balance their head while perching
• Miniscule leg muscles with locked ankles for stable perching
• Tiny nests intricately woven from plant down and spider silk
• Migration ability allowing movement between ideal habitats

Without these unique adaptations, hummingbirds’ miniature size would make survival difficult. Instead, the birds thrive thanks to evolutionary innovations enabling them to live life in the fast lane.

Summary and Conclusion

To summarize key points about the tiny scale of California hummingbirds:

• Length ranges from 2.75-4.3 inches
• Wingspans reach only 3.1-4.7 inches
• Weights are miniscule – from 2.4-6 grams
• Females are 5-15% larger than males
• They are smaller than butterflies, coins, thumbs and other tiny objects
• Size varies across seasons and with maturity
• They have steadily miniaturized over evolutionary time
• Their size enables specialized lifestyle and adaptations

The diminutive size of California hummingbirds belies the enormous contribution they make to plant pollination and ecological balance. Though tiny, hummingbirds’ speed, agility and energetic lifestyle make them one of nature’s most captivating marvels.