Feeders / Weight-activated
Weight-activated feeders
A spring, a sleeve and a calibration. It is the most elegant mechanism in the category and the one with the clearest boundary: it only stops animals heavy enough to trip it.
A weight-activated feeder holds a shroud or perch bar up on a spring; the weight of a squirrel pulls it down and closes the feeding ports. It reliably excludes gray squirrels and, when the trigger is adjustable, larger nuisance birds. It does not exclude chipmunks or red squirrels, which are too light to trip it.
The mechanism, in one paragraph
Two shapes implement the same idea. A shroud feeder — Brome's Squirrel Buster Plus is the archetype — surrounds the tube with a sleeve that drops over the ports under load. A perch bar feeder — Woodlink's Absolute line — hangs a horizontal bar in front of hopper openings; weight on the bar swings it down and shuts the doors.
The shroud is the more sensitive of the two and the one with the adjustable calibration. The bar is simpler, has fewer places for seed dust to jam, and is the better bet on a hopper of mixed seed.
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Quick picks
Ranked, with the trade-off named. Tap a row for the full write-up; the price button goes straight to Amazon.
| # | Product | Best for | Price |
|---|---|---|---|
| 1 | Brome Squirrel Buster PlusThe weight-activated shroud done properly: a squirrel's weight closes the ports, and the cardinal ring means the mechanism does not cost you the big birds. | Weight-activated, most capacity | Check price on Amazon |
| 2 | Woodlink Absolute II (7536)The big one: twelve pounds of seed, which changes refilling from a weekly job to a monthly one on most yards. | Highest capacity, double-sided | Check price on Amazon |
| 3 | Woodlink Absolute Squirrel-Resistant Feeder (23803)The hopper version of the weight idea: a perch bar drops the seed doors under weight. Fewer moving parts than a shroud, and correspondingly fewer failure points. | A simple weight-bar hopper | Check price on Amazon |
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The picks in full
Top pick Weight-activated, most capacity
Brome Squirrel Buster Plus
The weight-activated shroud done properly: a squirrel's weight closes the ports, and the cardinal ring means the mechanism does not cost you the big birds.
Published specifications
- Seed capacity
- 5.1 lb (published)
- Feeding ports
- 6
- Mechanism
- Weight-activated shroud, adjustable
- Included
- Cardinal ring
- Pole mounting
- Pole-mountable; pole adaptor sold separately
Trade-offs
- 5.1 lb capacity means fewer refills through a hard winter
- Adjustable weight setting, so you can shut out grackles without shutting out cardinals
- The cardinal ring is the fix for the usual complaint about shroud feeders
- The pole adaptor is a separate purchase, which is easy to miss at checkout
- A weight mechanism is a mechanism: it needs the occasional clean to keep moving freely
Who it is forThe default first purchase if you would rather solve the problem at the feeder than at the pole. It also pairs well with a baffle rather than replacing one.
Skip it ifYour problem is chipmunks or small red squirrels. A weight-activated shroud is calibrated for something heavier, and a light animal can feed under the trigger point. A caged feeder is the better answer there.
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Where these specifications came from
No. 2 Highest capacity, double-sided
Woodlink Absolute II (7536)
The big one: twelve pounds of seed, which changes refilling from a weekly job to a monthly one on most yards.
Published specifications
- Model
- 7536
- Seed capacity
- 12 lb (published)
- Type
- Hopper with weight-activated perch bar
Trade-offs
- 12 lb published capacity is the largest on this page by a wide margin
- Fewer refills means fewer trips out to a pole you would rather not disturb
- Twelve pounds of seed plus the feeder is real weight on a shepherd's hook
- Seed at the bottom of a big hopper can sit long enough to spoil in humid weather
Who it is forA busy yard, or anyone who has decided that refilling twice a week is the actual problem.
Skip it ifYou are hanging this from a thin hook. Check what your hook is rated for before you put twelve pounds of seed on it — a pole system is the honest answer at this capacity.
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Where these specifications came from
No. 3 A simple weight-bar hopper
Woodlink Absolute Squirrel-Resistant Feeder (23803)
The hopper version of the weight idea: a perch bar drops the seed doors under weight. Fewer moving parts than a shroud, and correspondingly fewer failure points.
Published specifications
- Model
- 23803
- Type
- Hopper with weight-activated perch bar
- Brand line
- Heritage Farms Absolute
Trade-offs
- A single hinged bar is about as simple as a weight mechanism gets
- Hopper format holds and dispenses mixed seed better than a narrow tube
- Woodlink does not publish a seed capacity for this SKU in the listing
- A hopper is a bigger silhouette than a tube on a small pole
Who it is forSomebody who wants the weight mechanism without a shroud to keep clean, on a pole or a hook.
Skip it ifYou feed nyjer or fine seed. A hopper with a drop bar is built around larger mixed seed.
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Where these specifications came from
What we would skip
A weight-activated feeder in a chipmunk yard
The trigger will never fire. Buy a caged feeder instead — this is a mismatch of mechanism to animal, not a product quality question.
What the adjustment is actually for
The adjustable trigger on the Squirrel Buster Plus is usually described as a squirrel setting. It is more useful than that. A squirrel trips almost any setting; the adjustment is really about which birds you let through.
- Set light — cardinals, jays and doves feed comfortably, and so do grackles and starlings.
- Set heavy — grackles and starlings are shut out, and so, eventually, are the larger birds you wanted.
- The cardinal ring is the way out of that trade: it gives large birds a perch position that spreads their weight, so the trigger can sit heavier without excluding them.
Capacity and where it can hang
The Squirrel Buster Plus publishes 5.1 lb; Woodlink's Absolute II publishes 12 lb. That is a genuinely different product experience — the Absolute II turns refilling into a monthly job on most yards.
It also becomes a structural question. Twelve pounds of seed plus a hopper is more than a decorative shepherd's hook was designed for. If you want that capacity, put it on a pole system with an auger anchor and stop worrying about it.
Keeping the mechanism working
- Empty and dry the feeder before long storage. Damp seed dust is what gums a shroud.
- Check the sleeve slides freely by hand every few refills. If it sticks, it is not excluding anything.
- Do not overfill a hopper past its stated capacity — the door mechanism relies on seed flowing rather than packing.
- Keep the ground clear underneath. Spilled seed is a separate meal that the mechanism cannot touch.
It is still second to placement
Cornell puts feeders at least 10 feet from jumping-off points. A weight mechanism placed six feet from a fence is a mechanism being tested every day by an animal with time on its hands. Fix the distance and the feeder rarely has to do anything at all — the clearance guide has the numbers.
How we picked
- We sorted by mechanism first: weight, cage or spin. Those three exclude different animals, and the choice between them is not a quality judgment.
- We used published figures only — seed capacity, port count, dimensions, mechanism. Where a maker publishes nothing, the spec row says so.
- We checked each mechanism against the animal it is calibrated for. A weight trigger tuned for a gray squirrel does not fire for a chipmunk, and we say so rather than implying it does.
- We named at least one product to skip on every page, with the reason.
- We have not tested any of these. How we pick sets out what that does and does not cover.
Everyone in this category says they tested twenty of these. We have not tested any, and we say so. What we did instead: read the manuals, compiled the published specifications, worked out the clearance geometry, and cited every source. The full method is published.
Questions people actually ask
- How does a weight-activated bird feeder work?
- A shroud or perch bar is held up by a spring. Bird weight leaves it open; the heavier weight of a squirrel pulls it down and closes the feeding ports. Removing the weight reopens them.
- Will a weight-activated feeder stop chipmunks?
- No. They are too light to trip the mechanism and feed under it. A caged feeder is the correct answer for chipmunks and red squirrels.
- What is a cardinal ring for?
- It gives large birds a perch position that spreads their weight, so the trigger can be set heavy enough to exclude grackles without also excluding cardinals.
- Why has my weight-activated feeder stopped working?
- Usually because the mechanism has stopped sliding freely. Seed dust and damp are the culprits. Empty it, clean the sleeve or bar, and check it moves by hand.
Sources
Read next
- Weight-activated vs caged feeders
Mass versus geometry: which mechanism stops which animal, and what each one costs you in birds.
- The best squirrel-proof bird feeders
Seven feeders ranked by mechanism and published capacity, and which animal each one actually excludes.
- How high should a squirrel baffle be?
Four to five feet high, eight to ten feet clear. The sourced numbers, the arithmetic, and the popular page that gets it wrong.
- The best squirrel-proof bird feeder poles
Pole systems ranked on baffle height, anchoring and the ten-foot setback one maker actually publishes.
- Squirrel-Proof Feeders
Weight-activated, caged and spinning feeders, sorted by which animal each mechanism actually keeps out.