What is territorial behavior in hummingbirds?

Hummingbirds are known for their small size, incredible flying abilities, and beautiful iridescent plumage. What many people may not realize is that these tiny birds are also fiercely territorial. Territorial behavior is when an animal actively defends an area against intruders or competitors. For hummingbirds, defending territories is crucial to their survival and reproduction.

Why are hummingbirds territorial?

Hummingbirds exhibit territorial behavior for several key reasons:

• To defend feeding areas – Hummingbirds need to eat frequently to support their high metabolism. Feeding territories contain vital food resources like nectar-producing flowers and insect populations. By defending these areas, they ensure reliable access to nutrition.
• To defend nesting sites – Hummingbirds build delicate nests in trees, shrubs, and other sheltered spots. These prime nesting locations are rare. Territorial behavior allows them to claim and protect safe nesting sites.
• To attract mates – Male hummingbirds perform elaborate courtship displays within their territories to attract females. Unmated males fiercely guard territories to display for and mate with visiting females.

Controlling territories allows hummingbirds to efficiently meet their needs for food, shelter, and reproduction. Given their small size, chasing rivals out of these areas helps minimize risky fights with competitors.

How do hummingbirds defend territories?

Male hummingbirds are the primary territory defenders though females may also occasionally participate. Depending on the species, hummingbirds use a variety of tactics to deter intruders:

• Aerial chasing – Aggressive males will pursue intruders in fast-paced aerial dogfights. Using their supreme flying skills, they try driving the trespasser out of the territory.
• Dive bombing – A territorial male will make steep dive-bombing runs at intruders to scare them away. They may actually strike the trespasser with their beak or feet while diving.
• Display perching – The resident male will perch prominently at the highest point in his territory like a treetop or wire. From there he can survey his domain and rapidly chase any encroaching males.
• Aggressive displays – Males use vocalizations and visual displays to threaten intruders. For example, the Allen’s hummingbird performs a threatening pendulum display by flying in a wide arc with its tail feathers spread.

These confrontational behaviors tend to escalate until one bird concedes defeat and leaves the territory. Actual physical fights are rare though males may occasionally grapple in midair with their feet and bills. The most aggressive species establish territories around reliable food supplies that may be as small as a single tree or bush.

When are hummingbirds territorial?

The intensity of territorial behavior in hummingbirds depends on a few key factors:

• Breeding season – Hummingbirds are most territorial when breeding. Males become extremely aggressive from late winter through summer as they try to attract mates and guard nest sites.
• Food availability – When fewer flowers are in bloom, feeding territories become more fiercely defended.
• Population density – In areas with high densities of hummingbirds competing for limited habitat, territorial behavior increases.
• Age – Younger males are generally less capable of securing the best territories so adult males tend to be the most aggressive defenders.

Territorial behavior is largely driven by circulating testosterone levels in males that peak during the breeding season. When breeding ends in late summer, testosterone levels drop off and males become much less territorial.

Some tropical species may defend territories to some degree year-round though this is less pronounced than during the breeding season. Food-rich territories may also see year-round residents. Certain migratory species like the ruby-throated hummingbird exhibit almost no territorial behavior outside of the breeding season.

How large are hummingbird territories?

The size of hummingbird territories varies by habitat and species. Some key factors determining territory size include:

• Food availability – In areas with abundant nectar sources, territories can be small. In more marginal habitats with fewer flowers, larger areas are defended to meet nutritional needs.
• Nesting opportunities – Territories must be large enough to include adequate nesting sites for raising young.
• Population density – With higher densities of competitors, defended territories are compressed in size.
• Species – Larger hummingbird species tend to claim bigger territories than smaller types.

As examples, some typical breeding territory sizes for common North American hummingbirds are:

In tropical areas where food is abundant year-round, some hummingbird species may defend extremely small feeding territories centered around a single flowering bush.

How do hummingbirds know and remember their territories?

Researchers believe hummingbirds rely on a few methods to identify, memorize, and navigate their territories:

• Visual cues – Hummingbirds have excellent vision and remember prominent landmarks in their territories like particular trees, bushes, feeders, or buildings.
• Memory – Individuals appear capable of remembering the locations and boundaries of their territories over multiple seasons.
• Smell – Hummingbirds may associate scents in their environment with their territorial boundaries.
• Magnetic senses – Some evidence suggests hummingbirds can detect magnetic fields and may use this information to navigate territories.

Hummingbirds likely process and integrate multiple sensory cues to form a mental “map” of their defended areas. When intruders are detected, the residents already know the landscape and can quickly move to intercept.

Do females defend territories?

Female hummingbirds are generally much less territorial than males. However, they may still defend critical resources in some circumstances:

• Nest sites – Females may defend the immediate area around their nest while incubating eggs and raising nestlings.
• Feeders – In habitats with feeders providing supplemental food, females sometimes claim individual feeders as feeding territories.
• Food-rich patches – Groups of females have been observed forming loosely defended feeding territories in areas with exceptional food abundance.
• During migration – Stopover sites with limited food may see territorial behavior in migrating females defending flowering patches.

Compared to males though, female territorial behavior tends to be relatively uncommon, weaker in intensity, and centered around critical resources for breeding rather than establishing broader all-purpose territories.

Do hummingbirds actually fight when defending territories?

Outright fighting is fairly rare as hummingbirds usually settle disputes through displays, chasing, and forced retreats. However, some physical altercations do occasionally occur:

• Mid-air grappling – Males will sometimes briefly grapple with feet and bills while flying to show dominance.
• Beak fencing – Opponents face off hanging in air and fence with their bills. This allows combat without excessive energy expenditure during disputes.
• Chest poking – A male may stab its bill against an intruder’s chest to establish itself as the victor.
• Injuries – True physical clashes can lead to feathers being pulled out or other minor injuries but fatal fights practically never happen.

Actual physical contact is risky and energy-intensive for these small birds. Most contests are symbolic jousting matches establishing who is willing to escalate more until one bird yields. Serious injuries or deaths from territorial fights would defeat the whole purpose of defending a territory in the first place.

What happens if a territorial hummingbird leaves its territory?

If a territorial hummingbird leaves its territory even briefly, a few things can happen:

• Takeover attempt – Opportunistic bachelor males may try to claim the territory.
• Intrusion by neighbors – Adjacent territorial males may expand their boundaries into the vacant areas.
• Reclamation – The original territory holder usually reclaims its territory quickly upon return.
• Abandonment – If a male disappears for good, competitors will divide up and establish new boundaries in the area.

Territories are frequently tested in the owner’s absence. But healthy adult males rarely relinquish their territories for long before returning and re-establishing dominance. However, injured, ill, or aging birds may reach a point where they can no longer adequately defend their territory leading to permanent turnover.

What hummingbird species are the most territorial?

Some North American hummingbird species known for particularly aggressive territorial behavior include:

• Anna’s hummingbird – Year-round residents fiercely defend feeding territories in California and the Southwest.
• Costa’s hummingbird – Large intimidating males vigilantly guard breeding territories.
• Rufous hummingbird – Known for chasing birds of all types from feeding grounds.
• Allen’s hummingbird – Males make dramatic pendulum displays and rapid dive-bomb attacks.
• Broad-tailed hummingbird – Found at higher altitudes where food is limited, leading to fierce competition for flower-rich meadows.

In general, tropical species that don’t migrate tend to be among the most territorial hummingbirds. With year-round food supplies, they can establish permanent all-purpose territories and defend them with lifelong site familiarity.

What plants do territorial hummingbirds prefer?

Hummingbirds seek to incorporate certain plants into their territories that support their key needs:

• Nectar plants – Abundant flowering plants like sage, lilies, and nectar-rich exotics that provide food.
• Insect attractors – Plants like butterfly bushes which draw flies and gnats that hummingbirds eat.
• Sheltered perches – Trees and tall shrubs for perching high and surveying the territory.
• Nest sites – Trees and shrubs with suitable stable branches to build nests on.

Ideally, a territory will contain a mixture of these elements like a meadow with wildflowers and perimeter trees. Hummingbirds also readily incorporate feeders filled with sugary nectar into a territory if available.

Do hummingbirds ever share territories?

Hummingbirds are highly solitary. But some rare circumstances may lead to semi-shared spaces:

• Courting pairs – A male may allow a new female into his territory once paired up.
• Family groups – Recently fledged young may briefly remain in their parents’ territory.
• Habitat overlaps – Neighboring birds may tolerate slight overlaps along their boundaries.
• Abundant resources – With excess food, a few individuals may occupy the same general area.

Full cohabitation is extremely uncommon though. Even paired or related birds maintain their own zones and perches within a territory. And non-family groups rarely cooperate or co-defend shared space due to the hyper-territorial nature of hummingbirds.

Do other animals impact hummingbird territories?

A few other animals may factor into hummingbird territorial behavior:

• Insects – Bees and other pollinators compete for some of the same food flowers.
• Nectar robbers – Orioles sometimes puncture flowers for nectar reducing food supplies.
• Predators – Hawks, falcons, and other birds of prey may hunt hummingbirds, limiting their activity.
• Squirrels – They can disturb nest sites and damage some flowers.

Hummingbirds don’t directly fight these animals but may be forced to expand or modify territories if they excessively disrupt key resources. However, strong competition between hummingbird species usually has a far greater impact on territorial behavior than these secondary factors.

Conclusion

Territoriality is an essential component of hummingbird behavior and ecology. By aggressively controlling exclusive areas centered around food, shelter, and breeding resources, they ensure their survival even as tiny birds with minimal physical defenses besides flight. The intensity and duration of territorial behavior varies between species and individuals based on factors like seasonal breeding cycles, habitat quality, and population density. But during peak times, hummingbirds will bravely defend territories many times their own size against all encroaching rivals. This explains why your backyard feeder may host an aggressive male for months on end that refuses to share. Their territorial nature leads hummingbirds to have a profound intolerance of their own kind in close proximity as they each demand their own domain.