A hummingbird feeder filled with fresh, sparkling nectar is both attractive to birders and appealing to hungry hummers, but how long does it stay that way? It is important for backyard birders to understand why and how nectar ferments and decays, and once you can recognize bad nectar, you will always be able to provide fresh, healthy nectar for your birds.
Why Nectar Goes Bad – And How It Can Hurt Birds
As an organic substance, nectar naturally breaks down and decays. The sugars in nectar ferment, and microscopic organisms feed on them, further breaking down the nectar. Different types of mold, mildew and fungus can develop in nectar, and even large quantities of nectar can go sour quickly in the right conditions.
When nectar is contaminated, it will ferment more quickly. Some contamination can come from the feeder itself – if even the smallest bit of mold, bacteria or other contaminants are present in a hummingbird feeder, the nectar will begin to decay as soon as the feeder is refilled. Even if a feeder is perfectly sterilized, however, as soon as a hummingbird inserts its bill and tongue into the feeding port, contaminants are introduced and decay will begin. Hot, sunny conditions will speed up the process, fermenting nectar even more quickly.
Decaying nectar is dangerous to birds in several ways…
- Mold and fungus can be fatal to hummingbirds as they ingest it.
- Older, decaying nectar has less nutritional value for the birds.
- Fermented nectar develops a strong smell that can attract less welcome wildlife.
- Sticky, old nectar can cause clogs or may become coated on birds’ bills or feathers.
While all nectar decays – even natural nectar produced by flowers – the small quantity of nectar in flowers has less opportunity to ferment before it is sipped away, minimizing the risks from fermentation. When large hummingbird feeders are used for just a few birds, however, the risk is magnified because the nectar may stay in the feeder for days, even weeks, getting worse for birds all the time.
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Recognizing Bad Nectar
While nectar may not show any visible signs of decay right away, by the time visual clues are obvious, the nectar should be changed and the feeder cleaned immediately.
- Nectar that is cloudy or murky rather than perfectly clear.
- Floating particles, including black or white specks or string-like structures.
- Sticky residue or crystals at the base of the feeding ports.
- Floating or drowned insects inside the nectar reservoir.
Even if nectar does not show visual signs of fermentation or decay, any strong smell is a problem. If hummingbirds have abandoned the feeder, that is another indication that the nectar is no longer as desirable. When in doubt, feeders should be cleaned and nectar replaced regularly. During cooler periods, cleaning the feeder weekly will help keep the nectar at its freshest, but during the hottest part of summer it should be cleaned and refreshed 2-3 times per week.
What to Do About Bad Nectar
When nectar goes bad, it is time to thoroughly clean and sterilize the feeder. Disassemble the feeder as much as possible so every nook and cranny can be effectively cleaned, and use small scrub brushes to be sure corners and crevices are all cleaned. Allow the feeder to dry completely before refilling, which will help minimize any residual contamination. At the same time, take a few moments to wipe down feeder hooks and poles and wash away any drips or spills below where the feeder hangs.
No matter how dirty a hummingbird feeder may have become or how quickly the nectar may ferment, if the feeders are cleaned and refilled with fresh nectar, hummingbirds will easily return to sip. As they learn how reliable a nectar source one feeding area is, they will gradually return more and more frequently, and bad nectar will be less of a concern – it will all be sipped away before it has a chance to become dangerous.