Fall Bird Feeding: Restocking, Molt, Caching and Irruptions

The short answer

• Restock in September, before the first hard frost. Winter residents prospect for food sources as they arrive, and a feeder that is already running gets found weeks earlier than one hung in November.
• Ragged, patchy and even bald-headed birds in late summer and early autumn are molting, not sick. The distinguishing signs are behavioral: a molting bird still feeds and flushes normally.
• Seed disappearing far faster than the number of birds explains is usually caching. Chickadees, titmice, nuthatches and jays remove and store food rather than eating it on the spot.
• Irruption years announce themselves: red-breasted nuthatches turning up south of their range in late summer is the earliest reliable hint, followed by early siskins and purple finches.
• The pre-winter deep clean in October is the one maintenance job that cannot be done later, because a wet feeder that freezes cannot be taken apart until spring.

Autumn is when the feeding year is set up. Nothing you do in January will fix a feeder that was hung too late, cleaned badly, or filled with seed bought in August and stored in a hot garage. Two weekends in September and October carry most of the winter.

Restock in September, for a reason that is not about cold#

The instinct is to wait for frost. That is the wrong trigger, because the constraint is not hunger, it is discovery.

Winter residents arriving from the north spend their first days establishing a foraging circuit: which yards have food, which have water, which have cover. A feeder already running when they arrive gets written into that circuit straight away. A feeder first hung during a December cold snap has to be found from scratch, and a new feeder can sit for one to three weeks before anything commits to it, which is precisely the period when the delay costs the most.

Practical timing at about 40 degrees north:

• Mid September: seed feeders back to full capacity, nyjer up for the finches, water running.
• Late September to early October: suet back up, once daytime highs stay below about 70 °F.
• Early to mid October: peanut feeder up, ground tray back out, second suet cage if woodpeckers queue.

Add two to three weeks to all of that if you are in the Gulf states, and subtract two to three weeks in southern Canada and the northern tier. Nectar comes down two weeks after your last hummingbird sighting, which in most of the East is late September to early October: see hummingbird feeder timing for why leaving it up longer does no harm.

Why the birds look terrible#

From July into September, adult songbirds replace their feathers. Most do it gradually and just look scruffy. Some, particularly northern cardinals and blue jays, occasionally drop every head feather at once and turn up at the feeder with a bare black head, looking like a small vulture. It is normal and the feathers regrow in a few weeks.

The distinction that matters is between molt and illness, and it is behavioral rather than visual.

If you are seeing the right-hand column, especially crusty eyes on house finches or lethargic birds that will not flush, take the feeders down for two weeks, clean everything hard, and follow the guidance on bird diseases at feeders. Autumn is when birds start concentrating again, which is when transmission risk climbs.

Where your seed is actually going#

October is the month people conclude they have squirrels, or a leak.

Chickadees, titmice, nuthatches and jays are all caching species. They take food away and store it: wedged in bark, tucked under lichen, pushed into moss, buried in the ground. In autumn they do this at a rate that has nothing to do with what they can eat. A chickadee will take one seed, fly to cover, hide it, and be back at the port within seconds, for as long as the feeder holds out. Jays do it in bulk, carrying several nuts at once in throat and bill.

As a rough working figure, a sunflower tube that lasted a week in September can empty in two or three days in mid October, with no visible increase in the number of birds using it. Nothing is wrong. You are stocking a network of caches spread across your neighborhood, and those caches are part of how these birds survive January.

Two practical consequences:

• Sunflower hearts and shelled peanuts get cached fastest, because they are dense and easy to carry. If autumn seed cost is a concern, in-shell black oil slows the rate down.
• This is the month to buy seed in bulk, since it will actually turn over. Keep it cool, dry and sealed: see storing birdseed.

Is this an irruption year?#

Some winters the north sends its finches south in numbers, and a yard that normally holds house finches suddenly holds siskins, redpolls and evening grosbeaks. This is an irruption, and it is driven by failure of the boreal seed and cone crop, not by cold weather. Birds move because the food is not there, not because the temperature dropped.

Top top-tier favorite Yes eats readily Some takes occasionally Rare rarely No not a feeder food

The signals, in the order they usually appear:

1. Late July to August: red-breasted nuthatches turn up well south of where they belong. This is the earliest reliable hint that the northern conifer crop has failed, because they move before the finches do.
2. September: pine siskins and purple finches appear early and in groups rather than singly.
3. Autumn forecasts: annual winter finch forecasts assess the boreal cone and berry crop directly and are published each autumn.
4. October to December: evening grosbeaks, redpolls and crossbills push south, sometimes a long way south.

If two or more of those line up, prepare: put up extra nyjer capacity for siskins, keep a platform or hopper running for grosbeaks, and expect the seed bill to rise noticeably. A siskin flock is not a subtle visitor. And be strict about hygiene during an irruption, because dense flocks of siskins are associated with salmonellosis outbreaks in some winters, and the standard response is to take feeders down on agency advice and disinfect.

The order the winter set arrives#

Roughly, at 40 degrees north. Shift earlier going north, later going south.

That November change, mixed flocks moving through in waves, is why a feeder can look deserted for an hour and then hold a crowd for ten minutes. Chickadees lead those flocks and the nuthatches, woodpeckers, titmice and kinglets follow.

The pre-winter deep clean#

Do this in October, before the first hard freeze, because a feeder that ices up cannot be disassembled until March.

1. Empty every feeder completely. Bin the bottom inch, whatever it looks like.
2. Take everything apart, down to individual perches, ports and lids, then run the standard wash, disinfect and dry routine on how to clean a bird feeder. Do not skip the wire of a suet cage or the inside of a tube.
3. Rake and remove the summer's seed debris from under the feeders, and move the debris off site.
4. Inspect hardware: cracked plastic, split seams, worn hooks, a pole that has gone loose in softening ground. Repair now, not in January. See feeder repair and maintenance.

Handing over to winter#

Once suet is back up, the peanut feeder is running and the ground tray is out, you are in the winter routine: fill before dusk, keep water open, and clean every three to four weeks while it stays frozen. That routine and the energy reasoning behind it are on winter bird feeding, and the whole year in one table is on the bird feeding calendar.

Frequently asked questions#

When should I start feeding birds for the winter?

Mid September to early October in most of the middle of the continent, two to three weeks earlier in southern Canada and the northern tier. The reason is discovery, not need. Arriving winter residents spend their first days working out where the reliable food is, and a feeder that is already stocked and clean gets added to the circuit immediately. A feeder first hung during a December cold snap can take one to three weeks to be found, which is exactly when the delay costs the most.

Why does my cardinal or blue jay have a bald head?

It is molting. Most songbirds replace their feathers after breeding, usually between July and September, and a few individuals drop all their head feathers at once instead of gradually. The result looks alarming: a black-skinned, vulture-headed cardinal or jay. It is not disease and not mites in most cases, and the feathers grow back within a few weeks. A molting bird behaves normally, feeds actively and flies off strongly when disturbed.

Why is my feeder emptying so fast in October when I see so few birds?

Caching. Chickadees, titmice, nuthatches and jays remove food and store it in bark crevices, under lichen and in the ground, and they do it hardest in autumn. One chickadee working a feeder can take a seed every few seconds for long stretches, and almost none of it is being eaten there and then. As a working figure, October turnover on a sunflower tube commonly runs two to three times the September rate with no visible increase in bird numbers.

What is an irruption year and how do I know if one is coming?

An irruption is a mass southward movement of northern finches and a few other species, driven by failure of the boreal seed and cone crop rather than by cold. The early signals are visible in late summer and early autumn: red-breasted nuthatches appearing well south of their usual range from July onwards, then pine siskins and purple finches showing up early and in numbers, then evening grosbeak reports. Annual winter finch forecasts published each autumn read the northern cone crop directly.

In what order do winter birds arrive?

Roughly: blackbird and grackle flocks move out first, then sparrows and juncos filter in from late September to late October, then the irruptive finches, if they come at all, arrive from late October through December. Woodpeckers, chickadees, titmice and nuthatches were there all along but become far more visible once leaf cover drops and insects thin out. At 40 N the first junco under the feeder usually lands in the first two weeks of October.

What cleaning does a feeder need before winter?

A full strip-down before the first hard freeze: every part separated, hot soapy water and a brush into every corner, a ten minute soak in one part household bleach to nine parts water, a complete rinse and drying all the way through. Then repair or replace anything cracked, because a feeder that fails in January is a feeder you fix with cold hands. Rake and remove the summer's seed debris from the ground below at the same time.

Sources and further reading

1. All About Birds species guide Cornell Lab of Ornithology Molt, caching behavior and range for the species named here
2. Feeding Birds Cornell Lab of Ornithology, Project FeederWatch Autumn restocking, foods and winter feeder preparation; Deep clean method and disinfection ratio
3. Birds Canada Birds Canada Boreal seed crops and irruptive winter finch movements