08/14/2025
About quail eggs but some very helpful information regarding egg hatching and humidity levels.
HUMIDITY
I just had a super smart quail colleague of mine ask me about the science behind the humidity we incubate and hatch at, and I thought it would make a good post.
Humidity plays a critical role in quail egg incubation because it controls how much moisture is lost from the egg over the incubation period — and that directly affects embryo development and hatch success.
Here’s how it works:
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1. The basics: moisture loss
• Inside every quail egg is a fixed amount of water when laid.
• Over the 17–18 day incubation period, some of that water must evaporate so the air cell (the empty pocket at the fat end of the egg) grows to the correct size.
• The chick uses that air cell for its first breath before hatching.
• Too much or too little water loss can cause serious hatch problems.
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2. How humidity controls water loss
• Relative humidity (RH) in the incubator affects how quickly moisture leaves the egg:
• Low humidity → eggs lose moisture too fast → chicks may be small, weak, or stuck inside the shell because membranes dry out.
• High humidity → eggs lose too little moisture → chicks may be swollen, drown in excess fluid, or have trouble pipping (breaking the shell).
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3. Typical humidity guidelines for quail
• Days 1–14 (setting period): around 45% RH (some breeders use a “dry incubation” approach closer to 40% in humid climates).
• Days 15–18 (lockdown period): raise to 55-60% RH to keep membranes moist during hatching so chicks can turn and push out.
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4. Signs humidity was off
• Low humidity signs: large air cells, chicks shrink-wrapped in membrane, difficulty hatching.
• High humidity signs: small air cells, chicks pipped but drowned, mushy unabsorbed yolk.
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5. Why “lockdown humidity” matters
In the last few days, the chick is using up the last of the egg’s fluids, breathing through the air cell, and preparing to hatch. Extra humidity at this stage:
• Prevents membranes from drying out and sticking to the chick.
• Gives them more time to push free without exhausting themselves.
But remember, having too much humidity at lockdown can also cause serious issues, so you’ll want to monitor closely!