Hummingbirds are known for their beautiful, iridescent plumage and their ability to hover and fly backwards. Despite their small size, they are fiercely territorial, especially when it comes to food sources like flower beds and feeders.
Territorial Behavior
Hummingbirds chase each other away from feeders due to their highly territorial nature. Here are some key reasons why they exhibit this behavior:
- Limited food sources – Hummingbirds need frequent access to high-energy nectar to survive. Feeders provide a concentrated source of food that multiple birds may compete for.
- Breeding season – Male hummingbirds become extra aggressive in defending flower and feeder food sources to feed themselves and impress potential mates.
- Establishing dominance – Dominant, older males will chase younger males and females away to maintain priority access to the feeder.
- Defending territory – Hummingbirds establish feeding territories and will defend them against intruders, even birds of the same species.
This territoriality ensures dominant hummingbirds get adequate nutrition. It also reduces crowding around limited nectar sources, allowing different birds to access the feeder at different times.
How Hummingbirds Interact at Feeders
When multiple hummingbirds attempt to feed at the same feeder, chasing and aggressive behavior ensues in the following typical fashion:
- An “alpha” male stakes claim to the feeder as part of his feeding territory. He perches nearby waiting for intruders.
- When another hummingbird approaches, the alpha male makes chase and dives aggressively at the intruder.
- The intruder is chased away and forced to find another food source. If it persists, the alpha male may continue diving and chasing until the intruder leaves.
- Younger males and females are most often chased away. They must wait for an opening to dart in and feed when the alpha male is absent.
- If another mature male challenges the alpha, fierce aerial battles may ensue until one backs down.
The alpha male maintains his status through persistent guarding and aggression. He will spend more time chasing others away than actually feeding. Immature birds are lowest in the pecking order and may be chased repeatedly before getting a chance to feed.
Strategies to Reduce Aggressive Behavior
If aggressive bird behavior becomes problematic around your feeders, there are some steps you can take to reduce it:
- Increase feeder numbers/spacing – With more feeding stations spread apart, dominant birds cannot easily guard them all.
- Use feeder types that limit space – Saucer-style feeders with multiple ports or feeders with short perches make it hard for one bird to control.
- Provide flowering plants – Beds of native flowers give more feeding opportunities apart from the feeders.
- Use feeder moats – Some feeders have moats of water that birds must cross, which deters hovering guarding.
- Try different feeder locations – Moving feeders to different spots periodically may reduce territorial behavior.
With some strategic feeder placement and additions, you can enjoy watching hummingbirds come and go without constant squabbling at a single feeder.
Behavioral Differences Among Hummingbird Species
There are over 300 species of hummingbirds worldwide, and some variations exist in their level of territorial aggression:
| Species | Level of Aggression | Behavior Notes |
|---|---|---|
| Anna’s Hummingbird | High | Males are very territorial and chase other males and females from feeders. |
| Ruby-throated Hummingbird | Moderate | Males defend feeders against intruders but less persistently than Anna’s. |
| Rufous Hummingbird | High | Known for their aggressive defense of feeding patches during migration. |
| Calliope Hummingbird | Low-Moderate | Fairly tolerant of other small hummers at feeders. |
In general, differences in aggression relate to breeding behaviors, food needs, and the level of sexual dimorphism between males and females of each species.
The Role of Testosterone
Research has shown a correlation between testosterone levels and aggressive chasing in hummingbirds defending feeders. Key findings include:
- Male Anna’s hummingbirds showed the highest testosterone levels that peaked during breeding season.
- Higher testosterone correlated with more chasing behavior and reactions to decoy intruders.
- Juvenile males with lower testosterone showed less aggression and could feed more often.
- Females had the lowest testosterone and rarely participated in chasing displays.
These findings indicate that testosterone drives territorial aggression related to breeding. This leads older males to guard food sources needed to support reproduction. Younger, subordinate males cannot compete and get chased away.
Impact of Chasing on Hummingbird Health
The frequent chasing and dodging during hummingbird territorial disputes does take an energetic toll. Research shows some potential health consequences:
- Increased metabolic costs – The rapid hovering, flying, and direction changes burn extra calories from the limited nectar diet.
- Reduced feeding opportunities – Time spent chasing means less time actually feeding for protein and mineral intake.
- Higher mortality risk – Some juvenile birds starve or are killed by collisions during intense chasing by adults.
- Greater predation vulnerability – Birds spending more time battling are less alert and more exposed to predators.
However, hummingbirds have high metabolisms and must feed frequently, so outright starvation from chasing is rare. The greater threat is to young birds unable to feed enough to support growth and development.
Feeder Designs and Placement
Certain feeder features and placement strategies can help reduce hummingbird aggression:
Feeder Design Elements
- Multiple feeding ports – Allows more birds to feed at once.
- ports – Prevents one bird from monopolizing the feeder.
- Perch barriers – Stops dominant birds from perching near ports.
- Moats – Makes hovering and chasing near feeder more difficult.
Feeder Location Tips
- Avoid placing near trees/perches – Reduces guarding ability.
- Rotate locations – Makes birds search for moved feeders rather than guard.
- Separate widely – Allows territorial birds to establish distinct zones.
With some thoughtful feeder selection and placement, you can enjoy hummer activity with less squabbling and improved feeding access for all.
Conclusion
Territorial behavior leads hummingbirds to aggressively chase others away from feeders, especially during breeding season. Dominant males establish claim over feeders and make daring chases when other birds approach. This ensures their own nourishment needs are met first to support higher energy demands. Females and juveniles are most often chased away and must carefully wait their turn to dart in and feed. While chasing does burn extra calories, outright starvation is uncommon. Setting up feeders properly can minimize needless aggression so peaceful hummingbird watching and feeding can be enjoyed.
