Foaling Watch Update: Surprise’s Start-and-Stop Labor & Why Most Mares Foal at Night

Elusive Surprise (Day 334) had an eventful early morning. Around 5:30 AM, she appeared to enter Stage 1 labor, displaying signs such as pawing, shifting weight, and general restlessness. However, by 7:30 AM, she had settled back down and returned to eating hay comfortably.

With the cold winds continuing, she is only outside for a short period today, spending some time in the round pen—just in case she decides to foal during daylight hours. While most foals are born at night, 10-20% of mares foal during the day, so the possibility remains.

Can Mares Start and Stop Labor?

Yes, mares are known to experience delayed labor or foaling arrest, a unique ability that allows them to temporarily pause labor if conditions do not feel ideal. Unlike many other species, mares can stop labor before reaching active contractions.

Some common reasons for this include:
🔹 Environmental disruptions – Changes in routine, increased barn activity, or sudden weather shifts can influence a mare’s labor progression.
🔹 Feeling observed – Mares instinctively prefer to foal in quiet, undisturbed settings, which is why many wait for nighttime.
🔹 Foal positioning – If the foal is not in the optimal birth position, the mare may delay labor until proper alignment occurs.

While mares have this ability, Surprise’s early labor signs were likely part of her natural progression rather than a response to external disruptions. Unlike humans, where false labor contractions (Braxton Hicks) can occur for weeks, mares typically do not show extended pre-labor signs unless they are within hours or days of foaling. Some mares will display early labor behaviors, stop, and then resume within 24-48 hours.

Why Do Most Mares Foal at Night?

Surprise’s hesitation to foal this morning fits into a well-documented pattern—80-90% of foalings occur between dusk and dawn, with peak hours between 11 PM and 4 AM.

This nocturnal foaling pattern is believed to be an evolutionary adaptation to improve foal survival rates:

🌙 Darkness Provides Protection – In the wild, foaling at night would have reduced the risk of predator attacks.
🦉 Quiet Environment – Mares prefer to foal when the barn or pasture is calm and undisturbed.
🕒 Melatonin Influence – The hormone melatonin, released in response to darkness, may help trigger labor.
⏳ Delayed Labor Control – While mares have some ability to pause labor, they generally foal when their bodies are fully ready.

Is the Milk Test Still on Track?

Surprise’s milk test exceeded 200 PPM on Tuesday evening, which means:
✔️ 84% chance of foaling within 48 hours (which has now passed)
✔️ 98% chance of foaling within 72 hours (which ends tomorrow evening)

If Surprise does not foal tonight, this will be the first time the milk test has not accurately predicted a foaling window for us. However, with her restlessness, soft hind end, and continued behavioral changes, she remains well within the expected timeframe.

With these changes happening, now is the time to keep an even closer watch on the live cameras—tonight could be the night! 🎥🐴✨

Surprise in the round pen today looking VERY ready