Based on the species and environmental factors, a bird can lay multiple times in a year. The factors that influence the egg-laying process are temperature, daylight length, and food availability. They also have unique breeding stages and to understand the egg-laying process, you must go through the bird’s reproductive habits.
Bird’s Breeding Habits
Most birds lay eggs at least twice a year during the breeding season which tends to vary from one species to another and location. However, the most common scenario is bird’s breed during spring or summer when the weather is favorable and abundant food is available.
Factors Affecting Bird Breeding Pattern
The breeding pattern of birds is highly influenced by environmental conditions, such as humidity, rainfall, and temperature, which have a great impact on the frequency of egg laying as well. Also, time and availability of food are crucial as a bird needs a steady supply of nutrients after it lays the egg. If there is limited access to food then egg production decreases, also nest abandonment increases.
Hormonal changes such the production of estrogen and progesterone are involved in the development of ovarian follicles in birds which is essential for egg laying. Genetic mutation can also affect the number of eggs laid by a female bird.
Breeding Strategies
Three breeding strategies are seen among birds: monogamy, polygamy and polyandry.
- In monogamy, the female and male birds pair for the breeding season, such as the bald eagle.
- In polygamy the male mates with multiple females, such as the Red-winged blackbird.
- In polyandry the female bird mates with multiple males such as Jacana.
Reproductive Cycle of the Bird
During the reproductive cycle of the bird, it goes through a sequence of courtship, nest building and egg laying. During courtship the male bird performs a mating dance to attract the female and after they form a pair they build a nest. The eggs are typically laid one per day and the number of days to complete a clutch varies among species. Some can lay one egg while others can lay dozens. The time of egg laying also varies, some prefer early morning to lay an egg, while others late afternoon.
After all the eggs are laid, the incubation responsibilities are taken by both parents, depending on the species. After the egg hatches, the parents need to feed and take care of the chicks.
Frequency of egg-laying
Frequency in egg laying varies among species and is based on certain factors, such as their size. A large bird generally lays fewer eggs per year than smaller birds. The frequency of eggling also depends on environmental conditions.
Egg Laying Cycle in Birds
You have to go through the bird egg-laying cycle to understand the frequency of bird egg-laying. Right before laying eggs, a bird tends to build a nest and incubate the eggs until they hatch.
Stages of Egg Laying Cycle
There are three stages of egg laying cycle:
- Pre-laying stage – where the female bird is prepared to lay eggs, starts building a nest and also marks the territories.
- Laying stage – where the nest-building task is complete. The female lays the eggs and typically it takes 2 to 3 days for the full clutch to get complete.
- Incubation period – after all the eggs have been laid the females sit on the egg to keep them warm and also protect them from predators, which is the incubation stage.
The frequency of egg laying seen among common barn owls is 6 times a year, whereas an American crow legs only once every year.
Factors Affecting the Number of Clutches
Factors affecting the number of clutches laid by a bird are the time of the year, whether it is spring or summer, whether the bird is younger or older based on the reproductive system functions, the size of the bird’s territory, as the larger the territory the multiple clutches are laid.
Factors Affecting Frequency of Egg Laying
Here are the factors affecting the frequency of egg-laying among birds:
Environment
The environment has a crucial role to play during the egg-laying process. The frequency of eggs increases during warm temperatures and during cold temperatures it decreases and can also get inhibited. Only high temperatures can stimulate the hormonal changes in birds that would help in the maturation and development of eggs.
Daylight
Daylight also influences bird egg laying as most of the birds are photoperiodic, so they rely on changes in daylight length which regulates their reproductive cycle. Birds start to breed and lay eggs when there are longer days. While shorter days are indications that the breeding season is coming to an end.
Food
Food influences the egg-laying frequency if the food is scarce birds do not lay eggs and when the resources become available again they start to lay eggs.
Season
It has been said that 80% of the birds lay eggs during the spring which is April, May and June. While others prefer early winter, where the least number of birds are found to lay eggs, during September. The birds that decide to nest either during early spring or late spring. The ones who choose early spring are called early nesters and the majority happen in April, for example, American Robin. Late nesters come back north after winter and then start to build their nest for example House wren and Barn swallow.
Latitude
The time when the bird would lay eggs depends on latitude. The location of the bird also affects the bird’s egg-laying process. The ones living in higher latitudes have less mating and egg-laying time, whereas the ones living in lower latitudes, living in the south have more, as the days are shortened which limits the time for finding mates and building nests.
Fitness of the Bird
In terms of biology fitness refers to the reproductive success of a bird and the ability to lay eggs. Birds who prefer early nesting have a higher chance of survival rate. Also, if the bird wants to lay another class at another time of the year, they can do so easily.
Different Types of Egg-Laying Birds
Birds can be divided into two types, based on egg laying:
Annual Clutch Species
Annual clutch species are usually seen living in harsh environments and the food is scarce in these places. Also, multiple clutches put too much stress on the female body and also lead to starvation, so these birds tend to avoid it.
Multiple Clutch Species
Multiple clutch species are not vulnerable to predators, as if one of their clutches gets affected, they would still have more chances to lay another clutch. They usually have smaller offspring, as the females do not have much time to devote to one clutch and need to prepare for the next one.
Can You Encourage Birds to Lay More Eggs in Your Backyard?
Yes, you can encourage birds to lay more eggs by providing them with a supportive environment. You need to provide the bird with adequate food, water and shelter. There should be native plants, so that if the hummingbird decides to lay eggs, then it can easily get nectar. You need to avoid pesticides or other chemicals in your backyard. It is your duty to keep the birds healthy and safe so that they can have reproductive success.
What is the Average Number of Eggs Laid by Birth?
The average number of eggs laid by birds is 6 to 12 for waterfowl, the predatory birds lay 2 to 24 eggs in a single clutch, whereas Galliformes lay 24 eggs in a clutch.
