The world has approximately 10,000 avian species, and each breed has a different bird gestation period. The rule of thumb is that the smaller the bird, the lesser the gestation time. And when birds are bigger, the incubation period is longer. Normally, the gestation period will last from 7 days to 24 days, varying among different birds.
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The Gestation Period of Birds
The gestation period of the birds is the amount of time that the fertilized egg requires to form completely. But unlike humans, the gestation process takes place in the nest. And so before laying eggs, the female birds ease into a comfortable position inside the nest.
Most Popular Birds and Their Gestation Period
Bird enthusiasts never have to wonder ‘how long is a bird pregnant?’ because they don’t. The avians copulate with their opposite sexes, and the females lay eggs. And the gestation period varies per bird breed. Let’s look at seven avian species and check out their incubation time.
Bird #1: American Robin
The female American Robin is capable of laying 3-5 eggs, and there are typically up to three broods in one breeding season. And once the eggs are laid, the incubation period takes 12-14 days. The eggs are blue-green or sky blue, and they stay as nestlings for 13 days prior to living a juvenile life.
Bird #2: Mourning Doves
There are only two eggs in one brood for the mourning doves, and the incubation period is two weeks.
The female doves can lay white and unmarked eggs up to six times in one nesting season.
And once hatched, the baby birds are ready to fly on their own after 12-15 days.
Bird #3: Parrot
Once a year, the parrot species lays 2-4 eggs.
They can lay unfertilized eggs, incubating between 24 and 28 days.
Bird #4: Red-billed Quelea
The red-billed quelea typically has three to five eggs, and both male and female birds incubate during the day.
And for this bird species, the incubation and hatching is very short, within nine to ten days only.
Bird #5: Domestic Chicken
The gestation period of poultry birds called domestic chicken is 20 to 30 days.
After hatching, the hens start laying their own eggs after a year and a half. And in one year, there are approximately 250 eggs laid.
Bird #6: Yellow-rumped Warbler
There is no pregnant bird in the yellow-rumped warbler species. It lays eggs instead, once or twice during mating seaon.
Females lay up to six eggs, with an incubation period of 12-13 days.
Bird #7: Chipping Sparrow
There is no such thing as a bird pregnancy since avians lay eggs through their cloaca. And the chipping sparrow is capable of brooding up to three times, where they lay 2-7 eggs each time.
Plus, the gestation period is between 10 to 15 days.
Egg Development During Gestation
Avians produce the natural amniotic substance to aid in the development of the eggs. The amniotic fluid protects the nucleus, which is secured inside the amniotic sack. This chamber is attached to the white section of the eggs, which is called albumin.
During the incubation period, the embryo receives sustenance from the umbilical vesicle. And thanks to the hard shells, the female avians can sit above her eggs without crushing them. This process is needed for incubation since the eggs require heat and warmth for gestation.
Once the eggs are released from the cloaca, the incubation process begins. And for proper incubation, the eggs need to maintain 100-112 degrees Fahrenheit temperature. The gestation period can take 10 to 56 days, depending on the avian breed.
Do All Eggs Hatch After Incubation
The incubation period in birds starts when all the eggs are hatched. Keep in mind that female avians sometimes do not lay their eggs at one time. It takes days for the whole clutch to come out in many cases. And every egg is out, and the incubation begins.
Conclusion
The bird gestation period varies with every bird species. Female avians take care of the incubation process, and it all starts when every egg is pushed out of the cloaca.
Once the incubation is done, not all eggs hatch, but mostly they do. And the male birds take care of their family by guarding their territories from the beast of prey, and feeding the young chicks.
Besides, discover other interesting topics of bird behavior:
George and I became friends after a birdwatching trip with our new group. And we have been enjoying every adventure together. When he told me the idea of establishing a site that shares our experiences and fun, I immediately agreed. After trials and errors, here we have Thayerbirding.