Great Blue Heron eggs
Pale blue, unmarked, about 2.20–2.95 inches long — about 2.7 times the width of a US quarter. A Great Blue Heron lays 2–7 eggs, and they hatch after 25–30 days.
- Color
- Pale blue, unmarked
- Length
- 2.20–2.95 in (56–75 mm)
- Width
- 1.57–1.89 in (40–48 mm)
- Eggs per clutch
- 2–7 eggs
- Incubation
- 25–30 days
- Broods per year
- 1 per season
- Nest
- Stick platform high in trees, usually in colonies
How to recognise a Great Blue Heron egg
- Color: pale blue, unmarked. There are no markings on a fresh egg, though eggs pick up stains from the nest as incubation goes on.
- Size: 56–75 mm long by 40–48 mm wide. For scale, a US quarter is 24.3 mm across, so this egg is about 2.7 times the width of a US quarter.
- Where you find it: stick platform high in trees, usually in colonies. Great blue herons do not normally use nest boxes.
- Clutch: 2–7 eggs. A nest with far more eggs than this may hold eggs from two females, or a cowbird egg laid by a brood parasite.
Eggs that look similar
These species lay eggs in the same color group, sorted by how close they are in length. Size and nest site usually settle it.
| Species | Egg | Length |
|---|---|---|
| Great Blue Heron | pale blue, unmarked | 56–75 mm |
| European Starling | pale blue or greenish white, unmarked | 27–32 mm |
| American Robin | sky blue or blue-green, unmarked | 28–30 mm |
| Wood Thrush | pale blue or blue-green, unmarked | 24–28 mm |
| Gray Catbird | turquoise or greenish blue, unmarked | 21–26 mm |
When great blue herons lay eggs, state by state
Laying starts earliest in Alabama (Jan) and latest in Alberta (Mar). Months are estimates from regional breeding data shifted for latitude.
From egg to fledgling
Eggs hatch after 25–30 days and the young leave 49–81 days later. See the full baby Great Blue Heron guide for nestling stages and what to do if you find one on the ground.
Found eggs in your yard?
- Leave them. Parents often step away for long stretches, especially before the full clutch is laid, because most songbirds do not start incubating until the last or second-to-last egg.
- A single egg on the ground is usually lost for good. Eggs cannot be hatched at home, and possession of native bird eggs is illegal without a permit.
- If a nest is somewhere inconvenient, wait it out. Most small songbirds are done in three to five weeks.
- Watch from a distance and keep pets indoors. Repeated visits can lead predators to the nest.
Questions
Frequently asked
What color are Great Blue Heron eggs?
Pale blue, unmarked.
How big is a Great Blue Heron egg?
About 2.20–2.95 in long and 1.57–1.89 in wide (56–75 × 40–48 mm) — about 2.7 times the width of a US quarter.
How many eggs does a Great Blue Heron lay?
2–7 eggs per clutch, usually one egg a day, with 1 per season.
How long until Great Blue Heron eggs hatch?
Incubation takes 25–30 days. The young then stay in the nest 49–81 days — about 74–111 days from incubation to leaving.
Can I move or touch a Great Blue Heron nest with eggs?
No. Native birds, their nests and eggs are protected under the Migratory Bird Treaty Act. Wait until the young have left before removing an old nest.
Sources
- Cornell Lab of Ornithology — All About Birds: Great Blue Heron life history
- U.S. Fish & Wildlife Service — Migratory Bird Treaty Act
Timing reflects typical patterns for the region as a whole; local dates vary with elevation and year. Check the linked eBird bar charts for your county.