Small Body, Short Clock
A zebra finch weighs about as much as a couple of coins and runs a fast metabolism to match, feeding in short, frequent visits through the day and roosting through the night on what the day provided. That arithmetic is why a finch not eating today is never a wait-and-see problem: there is very little reserve, and a bird that misses a day of feeding can become weak quickly. Treat the empty bowl as a same-day task — first the mechanical causes that are famous in finch keeping, then the bird himself.
Blow Across the Seed Before Anything Else
The classic finch trap is a dish that looks full and is not. Zebra finches hull their seed as they eat, dropping the empty husks back into the dish, and over a day those husks build into a pale layer that hides how little whole seed remains underneath. From standing height the hopper looks stocked; at finch height there is nothing to eat. Blow gently across the surface — husks lift and drift like chaff while real seed stays put — then tip the dish out, discard the lot, and refill with fresh seed so you know exactly what is available.
Run the same suspicion over the water. A sipper tube can block or a dish can be fouled or knocked dry, and a finch that cannot drink stops eating dry seed alongside it. Refill, check any tube actually releases water when touched, and watch your bird take a drink if you can.
Watch the Feeder Politics for Five Minutes
Zebra finches are flock birds with a pecking order, and a bird that is not eating may be a bird that is not being allowed to. A new cage mate, a breeding pair turning territorial, or one pushy male can keep a lower-ranking finch hovering and retreating while the dish itself is fine. Sit and watch a feeding period properly: does your finch approach and get chased, feed only in frantic snatches, or wait until others roost? If access is the issue, add a second seed dish and a second water point at the opposite end of the cage, widely separated so one bird cannot guard both, and consider separating the birds if the chasing is relentless.
Read the Bird Himself, Quickly
A finch that is merely locked out of the feeder is usually bright, active, and quick to eat once a safe dish appears. A finch that sits fluffed on the cage floor or a low perch, eyes closing, tail bobbing, or too weak to flutter up when approached is in trouble now, not later. Droppings that have nearly stopped confirm that nothing is going through.
Offer tempting, easy food alongside the fixed basics — a fresh spray of millet hung near where he sits is often accepted by a finch that will not travel to a dish — but treat it as a bridge to real help, not a cure.
Call the Vet Today, Not Tomorrow
Contact an avian vet today if your finch is fluffed, low, weak, or still not feeding once seed, water, warmth, and feeder access are all corrected, and say clearly that the bird has eaten nothing today, because that fact changes how urgently a small bird is seen. Keep him warm, quiet, and undisturbed for the journey, in a small covered container rather than a large cage. Tell the clinic about cage mates, recent changes, and what the seed dish actually contained when you tipped it out.
Noting his companions, cage layout, and feeding arrangement in KinsLe's Pet Passport means that in a fast-moving problem like this one, the details a vet asks for are already written down.