How Long Do Birds Sit on Unhatched Eggs? Exploring Egg-Sitting Behaviors and Factors


Bird nest or bird eggs

Eggs are a fundamental part of avian reproduction, representing the first stage of life for many bird species. However, not all eggs successfully hatch and result in viable offspring. Eggs that don’t hatch refer to those that fail to produce live young due to various reasons, such as infertility, genetic abnormalities, inadequate incubation conditions, or predation.

In this blog post, we will explore the intriguing behavior of birds sitting on eggs that don’t hatch. Despite the lack of potential offspring, some bird species exhibit a remarkable dedication to incubating these non-viable eggs. This behavior raises questions about the motivations and instincts that drive birds to invest time and energy in futile incubation efforts.

Why Do Birds Sit on Eggs That Don’t Hatch?

Why do birds sit on eggs that don't hatch?

The behavior of birds sitting on eggs that don’t hatch can be attributed to several factors. Firstly, birds have a strong maternal instinct and an innate drive to incubate their eggs. This instinct compels them to care for their offspring, even if the eggs are infertile or non-viable. The act of incubation is deeply ingrained in their behavior, and they may continue to sit on the eggs out of an instinctive need to nurture.

Additionally, birds sitting on non-viable eggs provide protection to their clutch. By remaining on the eggs, they shield them from potential predators and environmental factors that may harm or destroy them, improving the overall survival chances of the remaining eggs.

Some bird species also display persistence in incubating eggs, even when the likelihood of hatching is low. This behavior may stem from optimism and the hope that the eggs could still hatch, driven by an optimistic belief in the potential for success, despite the odds.

Hormonal factors also play a role in this behavior. During the incubation period, birds experience hormonal changes that influence their dedication to incubating the eggs, regardless of their viability.

Birds may not possess the ability to recognize whether an egg is infertile or non-viable. They may simply continue to incubate until they realize the eggs will not hatch or until they reach an internal biological threshold that signals the end of incubation.

Different Bird Species and Egg-Sitting Behaviors

Different bird species egg-sitting behaviors

Bird species exhibit a wide range of egg-sitting behaviors, influenced by factors such as nest type, habitat, and breeding strategies. Understanding these behaviors provides insights into the diverse ways birds care for their eggs. Here, we explore some examples:

Varying Egg-Sitting Behaviors

  1. Albatrosses: These magnificent seabirds have incredibly long incubation periods, lasting several months or even longer. They take turns incubating the egg, conserving energy during the extended period.

  2. Penguins: Penguins, particularly the Emperor penguins, display remarkable dedication to egg-sitting. In the harsh Antarctic conditions, male Emperor penguins incubate their eggs for approximately two months. This synchronized effort ensures the survival of their offspring.

  3. Ducks and Geese: Ducks and geese exhibit shorter incubation periods compared to albatrosses and penguins. The female generally takes primary responsibility for incubating the eggs, while the male guards the nest. This efficient division of labor allows the female to focus on incubation while the male provides security.

  4. Birds of Prey: In these species, the female typically assumes the role of incubation while the male provides food. The incubation period for birds of prey can vary, ensuring the survival and well-being of the entire family unit.

Examples of Species with Egg-Sitting Behaviors

Examples of bird species with egg-sitting behaviors

  1. Wandering Albatross (Diomedea exulans): These large seabirds have the longest wingspan of any bird species and take turns incubating their single egg.

  2. Emperor Penguin (Aptenodytes forsteri): Living in Antarctica, Emperor penguins incubate their eggs in extreme cold. The males balance the egg on their feet and cover it with a fold of skin called a brood pouch.

  3. Mallard Duck (Anas platyrhynchos): Mallard ducks incubate the eggs for approximately 26 to 30 days, while the males guard the nest.

  4. Bald Eagle (Haliaeetus leucocephalus): The female bald eagle incubates the eggs for approximately 35 days, while the male provides food and protection.

Understanding the diverse egg-sitting behaviors of different bird species allows us to appreciate the remarkable adaptations and strategies birds employ to ensure the survival of their offspring.

Reasons Birds Sit on Eggs That Don’t Hatch

Reasons for birds sitting on unhatched eggs

Birds exhibit various behaviors when it comes to sitting on non-viable eggs. These behaviors are influenced by biological, environmental, and social factors.

Biological Factors

Biological factors affecting bird egg-sitting

Maternal Instinct: Birds have a strong instinct to care for their eggs and offspring, even if the eggs don’t hatch. This instinct compels them to provide warmth and protection by continuing to sit on the eggs.

Hormonal Changes: During incubation, birds undergo hormonal changes that can override their logical understanding of egg viability. These changes influence their behavior and make them dedicated to the nest, regardless of hatching outcomes.

Environmental Factors

Incubation Period: The duration of incubation varies among bird species. If eggs haven’t hatched within the expected timeframe, birds may continue to incubate them, hoping for eventual hatching. Perception of the incubation period varies based on species and individual circumstances.

Unfavorable Conditions: Extreme weather, inadequate food supply, or predator threats can disrupt the incubation process. Despite challenges, birds may sit on the eggs to minimize risks or maintain a sense of normalcy in nesting behavior.

Social Factors

Mate Absence: When the mate is absent, birds may continue to sit on the eggs until the mate returns or until it becomes apparent that the eggs won’t hatch. The presence of the mate is crucial for successful incubation, prolonging the incubation period in their absence.

Nest Defense: Birds defend their nests as territories. Even with infertile eggs, birds sit on them to protect the nest from potential threats, preserving their investment and future breeding attempts.

Understanding the reasons why birds sit on non-viable eggs sheds light on their complex behaviors and instincts. Biological factors, environmental conditions, and social dynamics contribute to this behavior, showcasing the dedication and resilience of birds in their nesting habits.

Duration of Bird Egg-Sitting

Bird egg-sitting duration

The length of time birds sit on non-viable eggs varies depending on several factors, providing insights into their behavior and commitment to incubation. Different bird species exhibit diverse egg-sitting behaviors, contributing to variation in incubation periods.

Factors Influencing Egg-Sitting Duration

  1. Species: Each bird species has a distinct incubation period. For example, chickens have a relatively short period of around 21 days, while albatrosses can incubate their eggs for several months.

  2. Environmental Conditions: Ambient temperature and humidity play a crucial role in egg development. Birds in colder climates spend more time incubating to maintain optimal temperature, while warmer regions experience shorter incubation periods.

  3. Egg Fertility: The fertility of the eggs affects how long a bird will sit on them. If the eggs are infertile or damaged, birds may abandon them sooner to conserve energy and invest in more promising eggs.

  4. Predation Risk: The perceived risk of predation influences a bird’s decision to abandon non-viable eggs. High predator presence or frequent disturbances may lead birds to leave the eggs to protect themselves.

Examples of Egg-Sitting Behaviors in Various Species

Examples of egg-sitting behaviors in various bird species

  1. Albatrosses: These seabirds have prolonged incubation periods, with some species incubating their eggs for up to 80 days or longer. The parents take turns incubating while the other forages at sea, ensuring survival in the challenging marine environment.

  2. Penguins: Different penguin species exhibit varying incubation periods. Emperor penguins have a remarkably long period of around 64 days, with the male caring for the egg while the female replenishes her energy reserves at sea. Adélie penguins have a shorter period of approximately 35 days.

Understanding the factors influencing egg-sitting duration and observing diverse behaviors across bird species provides valuable insights into avian reproductive strategies. This knowledge aids researchers and conservationists in supporting and protecting bird populations.

Ways to Help Birds Sitting on Eggs That Don’t Hatch

Ways to help birds sitting on eggs that don't hatch

Birds that diligently sit on eggs that don’t hatch can benefit from our assistance. By taking certain actions, we can provide support and create a conducive environment for these dedicated brooding birds. Here are some ways to help:

Provide a Suitable Nesting Environment

Suitable nesting environment for birds

Ensuring a secure and comfortable nesting area is crucial for brooding birds. Install nesting boxes or platforms at appropriate heights and locations, well-protected from potential disturbances or predators. Research the specific requirements of bird species in your area to create an ideal nesting site.

Offer Supplementary Food and Water

During the incubation period, it’s essential to provide nourishment for the brooding bird. Place bird feeders nearby with a variety of seeds, fruits, or insects suitable for the specific bird species. This supplemental food source can help the bird meet its nutritional needs without straying too far from the nest. Additionally, provide a shallow water source, such as a birdbath, for drinking and bathing.

Minimize Disturbances

To reduce stress and disturbances for the brooding bird, minimize human and pet activities near the nesting area. Keep a respectful distance, avoid unnecessary interactions, and refrain from loud noises that could startle or disrupt the bird. Create a calm and quiet environment, allowing the bird to focus on its nesting duties without interruptions.

Monitor the Situation

Monitoring bird egg-sitting situation

Regularly monitor the brooding bird from a distance to assess its behavior and overall condition. If the bird appears distressed, weak, or injured, consider contacting a local wildlife rehabilitation center or bird expert for guidance and assistance. They can provide specific advice based on the bird species and the situation at hand.

Resources for Further Information

Resources for information on bird egg-sitting

  1. Local Birding or Ornithology Groups: Reach out to local birding clubs or ornithology organizations in your area. Experienced members can provide valuable insights and recommendations on supporting birds in various situations, tailored to the bird species you encounter.

  2. Wildlife Rehabilitation Centers: Contact nearby wildlife rehabilitation centers or bird rescue organizations. Trained professionals specialize in caring for injured or distressed birds and can provide expert advice and assistance when the brooding bird requires extra help or intervention.

By implementing these actions and utilizing available resources, we can contribute to the well-being of birds sitting on eggs that don’t hatch. Our efforts create a safe and supportive environment, allowing these dedicated birds to perform their natural behaviors while increasing their chances of survival and future breeding success.

Remember, supporting brooding birds not only benefits the individuals involved but also contributes to the overall conservation of bird populations and biodiversity.


Bird nesting or bird eggs

Understanding why birds sit on eggs that don’t hatch provides valuable insights into avian behavior and the complex factors that influence their reproductive strategies. Throughout this article, we explored various aspects of this phenomenon, including different bird species and their egg-sitting behaviors, as well as the reasons behind this behavior. We also examined the typical duration of egg-sitting and ways to help birds in such situations.

Key Points

  • Different bird species exhibit a range of egg-sitting behaviors, with some incubating for extended periods and others abandoning the nest after a few weeks.
  • Biological factors, such as instinctual behavior and hormonal changes, as well as environmental factors like temperature and food availability, influence birds’ persistence in incubating eggs that don’t hatch. Social factors, including mate presence and competition, may also play a role.
  • The duration of egg-sitting varies among species, influenced by factors such as egg size, incubation period, and the bird’s overall health.
  • Providing suitable nesting habitats, including trees, shrubs, or birdhouses, is essential to help birds sitting on eggs that don’t hatch.
  • Offering bird-friendly environments with adequate food sources, such as bird feeders stocked with appropriate seeds, nectar, or suet, supports nesting birds in finding sustenance.
  • Disturbing nesting birds can disrupt their incubation process and lead to abandoned eggs, so it is crucial to respect their space and observe from a distance.
  • Conserving natural habitats and protecting nesting sites is vital for the long-term survival of bird populations.

Ways to Help Birds

Ways to help birds in their nesting process

You can make a difference by taking these actions to support birds sitting on eggs that don’t hatch:

  1. Create a suitable nesting habitat: Install birdhouses or nesting boxes and provide nesting materials like twigs, leaves, and grass.

  2. Offer food sources: Set up bird feeders with appropriate seeds, suet, or nectar, ensuring they are clean and regularly replenished.

  3. Minimize disturbances: Avoid approaching nesting birds closely or making sudden loud noises, and keep pets away from nesting areas.

  4. Support conservation efforts: Contribute to local and national conservation organizations and participate in community initiatives focused on preserving natural areas and raising awareness about bird conservation.

By implementing these steps, you can actively assist birds sitting on eggs that don’t hatch and contribute to the well-being of avian populations in your area. Remember, observing and appreciating birds from a respectful distance allows us to marvel at their remarkable behaviors while ensuring their welfare remains a top priority. Together, we can make a positive impact on the lives of these fascinating creatures and help conserve their habitats for future generations to enjoy.

Frequently Asked Questions

How long will a bird sit on eggs that don’t hatch?

Q1: How long will a bird sit on eggs that don’t hatch?

A1: The duration can vary depending on the species and individual circumstances. Some birds may abandon non-viable eggs within a few days, while others may persist for several weeks or even months.

Q2: Why do birds continue to sit on eggs that won’t hatch?

A2: Birds have a strong maternal instinct and an innate drive to incubate their eggs. They may continue to sit on non-viable eggs out of an instinctive need to nurture, protect the nest, or due to hormonal changes that influence their behavior.

Q3: Can birds recognize if their eggs won’t hatch?

A3: Birds may not possess the ability to recognize whether an egg is infertile or non-viable. They may continue to incubate until they realize the eggs will not hatch or until they reach an internal biological threshold that signals the end of incubation.

Q4: What factors influence how long a bird sits on non-viable eggs?

A4: The factors influencing the duration include the species, environmental conditions, egg fertility, and the perceived risk of predation. Ambient temperature, food availability, and mate presence can also affect the length of incubation.

Q5: How can I help birds sitting on eggs that won’t hatch?

A5: You can help by providing suitable nesting environments, offering supplementary food and water nearby, minimizing disturbances, and monitoring the bird’s condition. Consult local birding groups or wildlife rehabilitation centers for specific advice and assistance.






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