Keeping Cats From Killing Feeder Birds

A well-stocked feeder is not a gift to the birds if a cat is waiting in the shrubbery below it. Free-roaming domestic cats kill between 1.4 and 3.7 billion birds per year in the United States (Loss, Will & Marra, Nature Communications, 2013). That figure, drawn from a systematic review of predation studies across North America, makes the domestic cat the single largest direct human-mediated source of bird mortality on the continent. Window collisions account for roughly one billion bird deaths per year in the US, a problem covered in Window Strike Prevention. Vehicle strikes account for around 200 million. The cat is not a small problem, and understating it does not help the birds.

This post expands the cat section of the Complete Attracting Guide into a full set of evidence-ranked interventions, feeder geometry rules, and one essential medical fact that applies whenever a cat catches a bird.

Quick answer: Keep the cat indoors or in an enclosed catio. Those are the two interventions with strong, peer-reviewed support for dramatically reducing bird predation.

Best first step: Adjust feeder geometry before buying any deterrent product. Move the feeder to within 3m of dense escape cover or beyond 10m from the nearest cover to remove the ambush zone from the station layout.

Avoid: Relying on a bell collar alone. Bell collars reduce successful predation in some cats and not at all in others. Cats learn to stalk without triggering them. They are not an adequate substitute for structural interventions.

The Scale

The canonical citation is Loss, Will & Marra (2013), published in Nature Communications (vol. 4, article 1396, DOI: 10.1038/ncomms2380). The paper aggregates predation rates from field studies and applies them to US cat population estimates. The central estimate is approximately 2.4 billion birds killed per year, with a plausible range of 1.4 to 3.7 billion. Unowned cats (feral, stray, and barn cats) kill more birds per individual than owned pets, but owned pets are far more numerous and contribute substantially to the total.

The authors concluded that free-ranging cats are "likely the single greatest source of anthropogenic mortality for US birds and mammals." Habitat loss is the dominant long-term driver of bird population decline, but the cat is the largest source of direct, recurring kill.

In the United Kingdom, the BTO estimates that cats catch at least 55 million birds per year, of which approximately 27 million die. This figure is widely considered conservative. Unlike the US, feral cat populations in Britain are relatively small; the majority of predation is from owned pets.

Interventions, Ranked by Evidence

Keep Cats Indoors

The only intervention with strong, consistent published evidence of near-total elimination of predation. Indoor cats also live substantially longer: an average of 12 to 18 years compared to 2 to 5 years for free-roaming cats, due to reduced exposure to vehicle strikes, infectious disease (FIV, FeLV), rival-cat injuries, and coyote or fox predation.

The objection that indoor confinement is cruel rests on a comparison with unrestricted outdoor access. It does not account for the shortened lifespan, elevated disease risk, or the enrichment potential of indoor environments. Vertical climbing space, puzzle feeders, window perches, and supervised outdoor time on a harness or in a catio address the behavioural needs that confinement would otherwise fail to meet.

Catios and Enclosed Runs

An enclosed catio gives the cat outdoor air, weather, and stimulation while preventing access to birds and other wildlife. Designs range from simple window-box extensions to full garden runs with multiple shelves and perches. Wire mesh with no gap larger than 25mm prevents birds from entering and being preyed upon inside. Effectiveness for bird predation approaches that of full indoor confinement.

Birdsbesafe Collar Covers

The Birdsbesafe collar cover is a brightly coloured ruff worn over a standard quick-release collar. It reduces predation by improving bird detection of the approaching cat, using birds' four-channel colour vision (which extends into the ultraviolet range). Cats, like most mammals, have two-channel colour vision and receive no warning signal from the cover.

Hall et al. (2015) in Applied Animal Behaviour Science tested three colour variants across 114 owned cats in suburban Western Australia over two years. Captures of birds and colour-sensitive fauna fell by 54% in year one and 47% combined across both years. Rainbow-patterned covers outperformed red and yellow designs. A separate US study found that collar covers reduced spring bird kills to one-nineteenth the rate of uncollared cats, with a smaller but still significant reduction in autumn.

Important caveat: Birdsbesafe covers do not reduce mammal predation, since most mammals have limited colour vision. They are also less effective if the collar is not worn consistently or if the cat hunts primarily at night.

Bell Collars

Published evidence on bell collars is inconsistent. Some studies find up to 50% reduction in successful predation. Others find no significant effect. The mechanism is auditory warning, but cats adjust their gait to minimise bell noise during the stalk, particularly after the first few weeks. Bell collars should not be treated as a primary protective measure.

Restricting Outdoor Time

Dawn and dusk are the periods of highest bird activity at feeders and highest cat hunting success. Keeping cats indoors during these windows removes the most dangerous hours. Cats hunt successfully through midday, however, and this approach alone produces only a modest reduction in annual predation.

Feeder and Habitat Geometry

The geometry of your feeder station matters as much as any deterrent product. The core rule, described in full in Predator-proofing Feeders, is: place feeders within 3m of dense escape cover or more than 10m from the nearest cover.

At under 3m, a flushed bird can reach cover in under a second. Beyond 10m, the bird has enough open air to gain altitude before reaching any ambush point. The dangerous zone is 3 to 10m: cat launches from cover, bird cannot reach safety before being intercepted.

Additional placement rules for cat-exposed gardens:

• Remove brush piles and dense low vegetation directly adjacent to feeder poles. These function as cat ambush positions, not bird refuges.
• Avoid feeders near fence lines and low rooflines, which are primary cat approach corridors.
• Raise bird baths to 1m or above on a smooth pole that cats cannot grip. Avoid rough-textured or stepped poles.
• Do not scatter seed on the ground if cats access the garden. Ground-feeding birds are head-down and slow to react.
• Dense, thorny native shrubs at 3 to 5m from the feeder provide escape cover while deterring cat entry. See Native Shrubs for Nesting for species with the best thorn architecture and stem density for this purpose.

For feeder type selection in high-cat-risk gardens, tube feeders that position birds vertically above ground are preferable to platform feeders that hold birds at ground level for extended periods. See Choosing the Right Feeder for the full comparison.

Discouraging Cats From the Property

These measures apply when the problem is a neighbour's cat rather than an owned pet.

Motion-activated sprinklers are among the most effective non-contact deterrents available. A burst of water on approach conditions the cat to avoid specific zones. Effectiveness decreases as the cat habituates, so rotate the sprinkler position regularly and combine it with habitat modifications that remove ambush cover.

Citrus peel and scent repellents have very limited published support. They may marginally deter approach along specific paths but should not be the primary measure.

Cat-repellent plants such as Coleus canina are sold as deterrents. Published evidence for any significant territorial deterrence is weak.

Coyote urine sprays are marketed as cat deterrents, but controlled evidence of effectiveness against domestic cats is lacking.

Do not use spring-loaded traps, snares, or poisons. In most jurisdictions, harming a cat is illegal regardless of the wildlife damage the cat causes. If a specific unowned cat is repeatedly accessing the garden, contact your local council or animal control authority rather than acting directly.

When a Cat Catches a Bird

This is the medical point that feeder operators most often get wrong.

If you recover a bird from a cat, contact a licensed wildlife rehabilitator immediately, regardless of how the bird appears. Cat saliva contains Pasteurella multocida, a gram-negative bacterium that causes rapid and typically fatal septicaemia in birds. A capture that leaves no visible wound still introduces the bacterium through punctures too small to see with the naked eye. Fatal infection can develop within 24 to 72 hours in a bird that appeared uninjured at the time of recovery.

The first-aid protocol for stunned or injured birds is at How to Revive a Stunned Bird. Note the cat-saliva exception described there: do not apply the standard wait-and-release approach to a cat-caught bird. Call the rehabilitator first.

If you cannot reach a rehabilitator immediately, place the bird in a ventilated cardboard box lined with a cloth (no loose threads), in a warm, dark, quiet space. Do not offer food or water. Do not handle it more than necessary. Seek professional help within hours, not days.

TNR and Feral Cat Colonies

Trap-Neuter-Return programmes reduce the reproductive rate of feral cat colonies and, over years or decades, can reduce total colony size. They have legitimate value as a population management tool.

TNR is not a bird-protection strategy. Neutered cats continue to kill birds at the same per-individual rate. Colony size reduction reduces total predation over a multi-decade horizon, but surviving cats in a managed colony are no safer for birds today than intact cats. The Complete Attracting Guide is direct on this point: TNR does not protect the birds at your feeder this season.

The Legal Position

United States: Wild birds are protected under the Migratory Bird Treaty Act. Cat owners are not typically prosecuted for cat predation under this Act. Intentionally harming or killing a cat, even in defence of protected wildlife, is typically illegal under state animal cruelty statutes. Contact animal control rather than acting directly.

United Kingdom: Wild birds are protected under the Wildlife and Countryside Act 1981. Cats are property under the Cats Act 1991. The RSPB and BTO recommend physical deterrents only, not any action that could harm the animal.

Australia: Several states and territories now require cat registration and impose mandatory containment, with outdoor roaming restricted or prohibited in some areas. Australian law reflects the acute impact of cats on endemic bird species and is substantially stricter than either US or UK frameworks.

Common Mistakes

1. Treating a bell collar as adequate mitigation. Bell collars reduce predation in some cats and not at all in others. Cats suppress the sound in their stalk. They are not a substitute for structural change.

2. Placing the feeder mid-range from cover. A feeder 4 to 8m from a hedge sits in the cat ambush zone. Move it under 3m or beyond 10m. See Predator-proofing Feeders for the geometry.

3. Using a brush pile as escape cover. Loose brush piles directly beside feeders are hiding positions for cats, not refuges for birds. Escape cover should be dense thorny shrubs.

4. Waiting to see if a cat-caught bird recovers. The Pasteurella infection window is short. A bird that looks fine today can be dead within 48 hours. Contact a rehabilitator as soon as the bird is recovered.

5. Expecting visitor numbers to recover immediately after a predation event. Birds that have been repeatedly flushed or predated take time to return to a station. If numbers drop and remain low, see Why Have My Birds Disappeared for the full diagnostic and recovery timeline.

6. Treating TNR as equivalent to confinement for bird safety. TNR is a population tool on a multi-decade timescale. It does not protect feeder birds this season.

See Also

• Predator-proofing Feeders: feeder geometry covering cats, hawks, and window strikes together, with the 3-metre rule explained in full.
• The Complete Attracting Guide: the full cross-species reference covering cats in the broader context of garden bird mortality.
• Window Strike Prevention: the second-largest source of direct bird mortality in the US, with the same evidence-first approach.
• How to Revive a Stunned Bird: the 60-minute box protocol for collision survivors, and the cat-saliva exception that overrides the wait-and-release rule.
• Native Shrubs for Nesting: thorn architecture and stem density for escape cover that genuinely deters cats.
• Why Have My Birds Disappeared: diagnostic and recovery timeline when a predation event clears the feeder station.