The aggressive takeover of backyard bird feeders by non-native House Sparrows (Passer domesticus) frustrates bird enthusiasts. Introduced to North America in the mid-19th century, these birds often displace native songbirds, consuming large quantities of feed and dominating feeding areas. Selective deterrence is possible through strategic food choices, specialized feeder designs, and thoughtful placement, allowing native species to feed without constant competition.
Understanding Why House Sparrows Dominate Feeders
The success of House Sparrows at feeders is rooted in their biology and social behavior. They are highly adaptable, generalist seed-eaters who thrive in close proximity to human settlements, allowing them to quickly exploit consistent food sources like bird feeders.
Their flocking behavior creates a powerful numerical advantage; they often arrive in large groups, enabling them to monopolize a feeder and deter smaller, solitary native birds. They also exhibit aggressive dominance, readily displacing other species, even those larger than themselves, from feeding spots. House Sparrows are also ground-feeding birds, which means they easily access and consume spilled seed, reinforcing their presence in the feeding area.
Using Seed Selection to Discourage Sparrows
One of the most effective, non-physical strategies to reduce House Sparrow presence is to eliminate the inexpensive fillers they prefer. House Sparrows are primarily grain-eaters, showing a strong preference for seeds and grains like millet, cracked corn, and milo, which are common ingredients in low-quality bird mixes. Switching to seeds that are physically difficult for them to eat or that they find unappealing can make the feeder less attractive.
The following seeds and feeding methods are less appealing to sparrows:
- Safflower seed: Many sparrows dislike its bitter taste and find the hard hull challenging to crack. Native birds like Northern Cardinals and chickadees readily consume it.
- Nyjer (thistle) seed: This seed is rarely eaten by sparrows due to its small size and the specialized feeders required for its dispensation.
- Sunflower seeds: Offering pure, shelled black oil or larger striped sunflower seeds requires more effort to open than the small grains sparrows favor.
- Upside-down suet feeders: Presenting suet this way forces birds to cling, a posture sparrows are less comfortable with than species like woodpeckers.
Feeder Design and Modification Strategies
Physical modifications to the feeding station can exploit the behavioral and physical limitations of the House Sparrow. Sparrows prefer to stand firmly on a perch or a flat surface while feeding, unlike many native finches and chickadees that are adept at clinging.
Tube feeders with very short perches (less than 5/8 of an inch) force birds to adopt a clinging position, deterring sparrows but not most native species. The weight-activated feeder is another effective option; it uses a spring mechanism to close access ports when a weight threshold is exceeded. This design allows a single, light songbird to feed but shuts down when a flock of heavier sparrows lands simultaneously. Specialized Nyjer seed feeders often use small mesh or tiny ports accessible only to birds with small, pointed beaks, such as goldfinches and pine siskins. While exclusionary cages are sometimes used, sparrows are small enough to fit through openings intended for chickadees and finches, making them less reliable for sole deterrence.
Strategic Placement and Habitat Adjustments
The location and surrounding environment of the feeder influence House Sparrow activity. Sparrows are highly dependent on nearby cover, such as dense shrubs, hedges, or vines, which they use as staging areas to observe the feeder and as quick escape routes from predators. Moving feeders into more open areas, away from this dense, close-range cover, can reduce their feeling of safety and their flock-feeding intensity.
Since House Sparrows are avid ground-feeders, maintaining a clean area beneath the feeder is important. Regularly sweeping up spilled seed removes an easily accessible food source that encourages them to linger. Avoiding multiple, closely-spaced feeders discourages the formation of large, dominant flocks. The use of a pole-mounted feeder baffle or cone prevents sparrows from perching directly above the feeder, a common behavior they use to survey the area.