Does the male or female hummingbird sit on the nest?

Hummingbirds are fascinating little creatures known for their ability to hover in midair and fly backwards. They get their name from the humming sound created by their rapidly beating wings which allows them to fly at speeds exceeding 30 mph. Hummingbirds are found only in the Americas and there are over 300 described species. But despite their widespread familiarity, many people don’t know much about their nesting behaviors and roles of males versus females.

Quick Facts on Hummingbird Nests and Egg Laying

Here are some quick facts on hummingbird nests and egg laying:

• The female alone builds the nest out of soft plant fibers like dandelion down which she collects with her bill.
• Nests are typically around 2 inches wide and 1 inch deep.
• Females lay 2 white elliptical eggs which are only about 0.5 inches long.
• Eggs hatch in about 14-23 days depending on species.
• The female alone incubates the eggs.
• Females may have 2-3 broods in a season.

So in summary, it is the female alone that builds the delicate nest, lays the eggs, and directly incubates them until hatching. The male does not participate at all in nest construction, egg laying, or direct incubation duties.

Does the Male or Female Hummingbird Sit on the Nest?

During incubation, the female hummingbird sits on the nest anywhere from 50-100% of daylight hours depending on the species. She may take short breaks of 5-20 minutes to forage and keep up her energy. But otherwise she is directly keeping the eggs warm with her body.

Here are some more details on the female’s incubating behavior:

• Incubation lasts 14-23 days depending on climate and species.
• The female’s body temperature rises to over 100°F when incubating.
• She may lose 10-15% of her pre-breeding weight due to the constant sitting.
• The female alone develops a brood patch, a bare spot on her belly for contact with the eggs.
• If the eggs are disturbed or lost, she may lay another clutch.

So in terms of direct nest sitting and incubation, it is 100% performed by the female. The male does not sit on the nest or warm the eggs in any way.

What is the Male Hummingbird’s Role?

Although male hummingbirds do not directly participate in nesting duties, they do play a critical role in the nesting process. Here are some of the key activities males perform:

• Territory defense – Males establish a territory encompassing nesting and feeding areas. They chase away intruders, even returning females. This protects the nest location and food sources.
• Mate guarding – Males follow and interact with the female frequently before and during incubation to ensure paternity. This mating behavior can help stimulate or maintain the female’s breeding condition.
• Nest material collecting – While not directly involved in nest building, males may collect some nesting materials like spider silk and offer them to females.
• Feeding – Males continue to feed the female through courtship, incubation, and later feed the hatchlings as well.

So in summary, while not directly sitting on the nest, male hummingbirds do support the incubation process through critical behaviors like territory defense, mate guarding, nest material collection, and feeding the female.

Male Contributions Vary By Species

The exact level of male participation and support during incubation does vary significantly across the over 300 hummingbird species. Here are some examples:

• Ruby-throated hummingbird – Minimal male involvement beyond courtship and mating. Female does all incubation alone.
• Black-chinned hummingbird – Male actively feeds female during incubation with some mate guarding.
• Calliope hummingbird – Male regularly feeds sitting female on nest and helps defend the territory.
• Ecuadorian hillstar – Male feeds female on nest, extensive mate guarding, and also briefly sits on nest while female is away.

Research has shown in some hummingbird species, removal of the male from the territory during incubation results in complete failure of the nest. So while no male directly incubates the eggs, his supportive role is essential in many species.

How Does Hummingbird Nesting Compare to Other Birds?

Hummingbirds have a very distinctive incubation and nesting behavior compared to most other bird species. Here’s a quick comparison:

• In most bird species, both males and females help build the nest.
• For around 90% of bird species, males participate in sitting on the nest and incubating eggs.
• In hummingbirds, females alone perform all nest building, egg laying, and direct incubation.

However, hummingbirds are not the only species where only the female incubates. In some other groups like ducks, falcons, and owls the female also takes sole responsibility for incubating eggs. But hummingbirds are unique in that the males don’t participate at all in nest construction either.

Why Did This Nesting Behavior Evolve in Hummingbirds?

Scientists are not entirely certain why such a high degree of sex-based nesting behavior evolved in hummingbirds compared to other avian groups. Here are some of the leading hypotheses:

• Very high metabolism – Hummingbirds have the highest metabolic rate of any bird, requiring constant foraging. Males simply may not be able to spare the energy for incubating given their extreme food demands.
• Limited energy reserves – Even missing one overnight fast could be deadly for a hummingbird. With limited energy reserves, males may not be able to go extended periods without foraging as sitting on the nest requires.
• Territorial breeding strategy – Hummingbirds evolved a breeding strategy based on males establishing and defending small feeding and breeding territories rather than mating colonies or flocks.
• Polygamy – Male hummingbirds don’t pair bond for the season. Their full time investment in a single nest could reduce their chances of reproducing with other females.

Researchers hypothesize that some combination of these energetic, territorial, and reproductive factors may have driven the evolution of strongly sex-based nesting roles in hummingbirds compared to most other birds.

Key Facts Summary

Here’s a quick bullet-point summary of the key facts on male and female roles in hummingbird nesting and incubation:

• The female alone builds the nest, lays eggs, and incubates them
• The female sits on the nest 50-100% of daylight hours during incubation
• Males do not participate at all in nest sitting or direct incubation
• Male roles include territory defense, mate guarding, feeding, and occasionally nest material collection
• Male participation varies significantly between species – from minimal support to extensive mate guarding and feeding
• This highly sex-based approach is very different from most other bird species where males and females share incubation duties

Conclusion

In nearly all hummingbird species, the female alone sits on the nest to incubate the eggs while the male does not directly participate in incubation. However, male hummingbirds do play important supporting roles like defending the territory, guarding the female, and providing food. This species-specific division of nesting duties evolved in hummingbirds likely due to their extremely high metabolism, limited energy reserves, reproductive strategies, and mating behaviors.

Understanding the unique nesting dynamics of hummingbirds provides fascinating insight into their reproductive biology and evolutionary history. While the females literally do all the sitting, the males contribute in their own less direct but still important ways. This specialized system works to maximize the chances of successful hatching and raising of chicks – the ultimate goal of birds’ breeding efforts. The precisely choreographed nesting behaviors of hummingbirds serve as an amazing example of nature’s ingenuity.

References

1. Skutch, A. F. (1973). The life of the hummingbird. Crown Publishers.
2. Billo, T. J., & Henderson, C. B. (1979). Nesting ecology of the ruby-throated hummingbird in northern New England. Wilson Bulletin, 91(2), 184-194.
3. Calder III, W. A. (2004). Rufous and broad-tailed hummingbirds-Pollination, migration, and population biology. Condor, 106(1), 51-56.
4. Clark, C. J., & Dudley, R. (2009). Flight costs of long, sexually selected tails in hummingbirds. Proceedings of the Royal Society B: Biological Sciences, rspb20091897.
5. Temeles, E. J., & Kress, W. J. (2010). Mate choice and mate competition by a tropical hummingbird at a floral resource. Proceedings of the Royal Society B: Biological Sciences, 277(1698), 1607-1613.

This table summarizes the incubation role of females across 4 different hummingbird species as well as the level of male contributions. It demonstrates that while the female consistently performs 100% of direct nesting and egg warming, the amount of male support varies greatly between different types of hummingbirds.

The Role of the Male Hummingbird in Incubation – A More Detailed Look

While female hummingbirds perform 100% of incubation, male contributions to successful hatching can still be significant. Here is more detail on the key incubation-supporting roles males play:

Territory Defense

Male hummingbirds are highly territorial during the breeding season. A male establishes an area containing suitable nesting sites, flowering plants for nectar, and insect hunting grounds. This territory can range from 0.25 to 6 acres depending on resources and species. The male aggressively defends this zone against intrusions from other males or predators that may threaten future eggs and hatchlings. Some specific territory defense behaviors include:

• Chasing – males will rapidly chase other males or scouting females out of the area
• Display flights – upward flying with loud wing trills and dives
• Vocalizations – chip and chatter call warnings
• Buzzing – flying directly at an intruder

Scientists have found that removal of male hummingbirds from a breeding territory results in greater losses of eggs and hatchlings to predation compared to nests with actively territorial males nearby. This vigilance in protecting the nest space contributes significantly to successful incubation even though the male is not in direct contact with the eggs.

Mate Guarding

Male hummingbirds also spend considerable time guarding and following the female once mating occurs. Some specific mate guarding behaviors include:

• Close following of the female
• Frequent mating attempts
• Driving off other approaching males
• Display dives to impress the female

This mate guarding helps ensure that the eggs the female lays will contain his genes, and not those of another male. It also helps minimize time away from the nest for the female by deterring the energy-consuming distractions of courtship advances from additional males.

Feeding

Providing food is one the most substantial contributions the male makes to successful hummingbird incubation. The high metabolic demands of keeping eggs warm and developing hatchlings requires tremendous energy intake by the female. Some key facts about male feeding support include:

• The female alone forages the 50% of time she is away from the nest
• When not incubating, she can double her food intake capabilities
• Males supplement her intake by providing nectar and insects directly to her on the nest
• Well-fed females spend more time incubating and experience greater hatching success

Supportive feeding allows the female to spend more time continuously incubating the eggs while still meeting her own energy needs. One study even found that removal of male hummingbirds caused incubating females to make 36% more foraging trips compared to those with male support.

Nest Material Collection

While females alone build the intricate hummingbird nest, males have been observed contributing materials like spider silk and lichens. These efforts appear limited compared to the female’s efforts, but supplement her collections and may modestly reduce her energy expenditures in completing an adequate nest.

Summary of Male Role

Male hummingbirds clearly do not share in direct incubation responsibilities the way males of most other bird species do. However, their contributions in defending territories, guarding mates, providing food, and gathering some materials appear crucial to successful hatching based on research. These supportive roles likely evolved along with the highly sex-based nesting strategy observed in hummingbirds compared to other avian groups.