What Bird Lays the Largest Egg?


During my ornithological research, I had the privilege of encountering the majestic ostrich and its monumental egg. My experience in avian biology has afforded me a deep appreciation for these creatures.

Observing an ostrich delicately nurturing its massive egg amidst harsh savannah conditions was awe-inspiring. I believe that the ostrich’s reproductive strategy, with such a large investment in a single egg, showcases evolution’s masterful design.

The resilience of these eggs, a subject of my studies, reveals nature’s intricate adaptations for survival. Ostrich eggs, with their formidable size, are a testament to the wonders of the bird world that I’ve been fortunate to explore.

Key Takeaways

  • Ostrich eggs are the largest eggs on the planet, weighing up to 2 kilograms and can feed around 10 people.
  • Kiwis lay the largest eggs relative to their body size, with female brown kiwis laying eggs that weigh up to one-fifth of their own mass.
  • Emperor penguins lay substantial eggs, weighing as much as 4 pounds, and male penguins play a critical role in incubating and caring for the eggs.
  • Cassowaries lay the second largest eggs among living avians, with southern cassowary eggs measuring about 14cm in length, and male cassowaries take on the nurturing role of incubating the eggs.

The Ostrich Egg Marvel

A realistic image of a massive, textured ostrich egg cradled gently in a nest of twigs, with a life-sized comparison to a cluster of various smaller bird eggs nearby

The ostrich, a true giant among birds, lays the largest eggs on the planet, each one a marvel of nature tipping the scales at up to 2 kilograms.

As the largest bird, the Common ostrich’s eggs are a phenomenon in themselves. Averaging 1.4 kilograms, these creamy white eggs measure about 15cm in length, with a substantial shell around 3.5mm thick.

Remarkably, the ostrich egg is the biggest egg relative to body size among birds, second only to the female brown kiwis.

Exhibits in National Museums often feature these eggs, emphasizing their grandeur. And practically speaking, one ostrich egg can feed around 10 people, making it not just an ornithological marvel, but a substantial source of nutrition.

Kiwi: Small Bird, Big Egg

Bird next to its disproportionately large egg, nested in a forest underbrush with ferns and twigs, showcasing the egg's size relative to the bird in a serene, natural New Zealand habitat

Kiwi birds, despite their diminutive size, lay eggs that are astonishingly large in proportion to their body weight, with a single egg from the female brown kiwi weighing up to one-fifth of her own mass. This staggering statistic places the kiwi at the top when you consider which bird lays the biggest egg compared to the size of its body.

Here are some intriguing facts about these New Zealand natives:

  • The North Island Brown Kiwi’s reproductive strategy defies expectations.
  • A female kiwi lays eggs that challenge her body’s limits.
  • Island brown kiwi eggs encapsulate the marvels of avian reproduction.
  • The kiwi lays the largest eggs, making each birth a monumental feat relative to body size.

This reproductive phenomenon showcases the kiwi’s unique place in the avian world.

Emperor Penguins’ Icy Eggs

E an image of an Emperor Penguin beside a large, solitary egg on a snowy, icy Antarctic landscape, with soft dawn light casting shadows

Amid the icy expanses of Antarctica, emperor penguins lay the most substantial eggs of their kind, with each one weighing as much as 4 pounds. As the largest penguin species, these remarkable birds have a unique strategy for their progeny. Each penguin lays just one large egg, and the male takes on the critical role of incubating it within his brood pouch.

Here’s a snapshot of their fascinating egg-related facts:

WeightUp to 4 poundsHeaviest of all penguin eggs
Incubation~65 daysMale’s duty in the brood pouch
SizeUp to 4 inches in lengthImpressive given the bird’s size

This reproductive adaptation ensures the survival of emperor penguins in the harsh climate of Antarctica and the sub-Antarctic.

Cassowary Eggs Unveiled

, close-up view of a large, glossy green cassowary egg nestled among dense, tropical rainforest foliage, with a shadowy silhouette of the elusive bird in the background

Diving into the world of cassowaries, you’ll discover that these formidable birds lay the second largest eggs among living avians, with the Southern cassowary’s eggs being notably impressive in size and color.

  • Majestic Size: Southern cassowary large eggs measure about 14cm in length—a testament to their grand scale.
  • Unique Hue: The eggs are pear-shaped with a striking dark green color, setting them apart visually.
  • Parental Care: Unlike some large birds, male cassowaries take on the nurturing role, incubating these exceptional eggs.
  • Habitat Connection: Native to the dense rainforests of New Guinea, cassowary eggs reflect the bird’s adaptation to a secluded life.

Although less aggressive than ostriches, the Southern cassowary still stands as the second largest bird in the world that lay the largest eggs, with a remarkable green color that captivates and intrigues.

Frequently Asked Questions

What Is the Second Largest Bird Egg?

You’re likely curious about the second largest bird egg. It’s the emu’s, native to Australia, with eggs weighing up to 3 pounds and measuring 12 inches long, impressive yet smaller than the ostrich’s.

What Is the World Record Largest Bird Egg?

You’d be amazed to know the world record for the largest bird egg is 2.589kg, laid by an ostrich, measuring 15cm by 12.5cm, with a notably thick shell of about 3.5mm.

What Is the Biggest Egg Ever Laid?

You’re looking at the extinct elephant bird for the biggest egg ever laid, with some reaching over 30cm in length and weighing more than 10 kilograms—far surpassing any egg from today’s birds.

What Lays the Largest Egg I Can’t Fly?

You’re curious about non-flying creatures with big eggs? The ostrich, despite being flightless, lays the largest eggs—impressive 3-pounders! No other bird’s eggs come close in size to what these giants produce.


In conclusion, you’ve discovered the ostrich reigns supreme in the avian world, laying the largest eggs. Despite their size, kiwis surprise with disproportionately large eggs for their body. Emperor penguins endure extreme conditions to incubate their sizable icy treasures. Cassowaries, too, contribute uniquely colored, large eggs.

Each species’ egg-laying capacity is a marvel of evolution, showcasing nature’s diversity and adaptability. Isn’t it fascinating how these birds, large and small, have evolved to produce such extraordinary eggs?