Eggs of loons & grebes

Hide speculative eggs (3 eggs estimated from relatives)

19 eggs at true relative size, from the 33.9 mm egg of the Least Grebe to the 89 mm egg of the Yellow-billed Loon.

About this collection. 4,422 eggs, covering nearly every bird that nests in the Americas, from Canada and the United States through Mexico, Central America and the Caribbean to South America, plus a few famous eggs from elsewhere, like the Ostrich and the extinct Elephant Bird. Sizes come from published measurements wherever we found them; shapes and colours are our best estimates (how accurate these eggs are).

2,147 of them are marked Speculative: we haven't found documented descriptions or measurements of these eggs yet (for 133 of them, a source we checked reports the egg as undescribed), so they are estimated from their closest relatives. They are hidden unless you untick Hide speculative eggs. We keep adding sources and update the eggs as we go. Have you seen one of these eggs, or know a source? Message us.

Make a poster of these 19 eggs

Illustration of a Yellow-billed Loon (Gavia adamsii) egg, 89 × 56.9 mm — All 19 eggs at the same scale, largest first. Tap an egg to jump to it.

Illustration of a Common Loon (Gavia immer) egg, 88.9 × 56.2 mm — All 19 eggs at the same scale, largest first. Tap an egg to jump to it.

Arctic Loon

Gavia arctica

76 × 47 mm
Clutch: 1–3 eggs

Breeds in United States

Greenish olive to dark brown, with dark spots.

Sources of information

Size: Carboneras & Garcia, Arctic Loon, in Birds of the World (formerly Handbook of the Birds of the World).
Description: Cornell Lab of Ornithology, All About Birds: Arctic Loon, Life History.
Clutch: Cornell Lab of Ornithology, All About Birds.
Shape: Drawn from the length and width, with the taper estimated from the typical eggs of its group (how these eggs are drawn).

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Atitlan GrebeExtinct

Podilymbus gigas

43.4 × 30 mm (estimated)
Speculative: we haven't found a documented description of this egg yet, so we estimated its colours and markings and its size from related birds.

Breeds in Guatemala

No documented description found yet; drawn like the Pied-billed Grebe egg (same genus).

Sources of information

Size: Estimated, no measurements found: the median length and width of measured eggs of the same genus: Podilymbus podiceps.
Description: Estimated, no description found: drawn like a related egg (Pied-billed Grebe).
Shape: Drawn from the length and width, with the taper estimated from the typical eggs of its group (how these eggs are drawn).

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Clark's Grebe

Aechmophorus clarkii

58 × 37.5 mm (approx.)
Clutch: 2–3 eggs

Breeds in Canada, United States, Mexico

Pale bluish white, often stained brownish by sodden nest material.

Sources of information

Size: Average of 53 eggs: Bent, Life Histories of North American Diving Birds (U.S. National Museum Bulletin 107, 1919), p. 5.
Description: Bent, Life Histories of North American Diving Birds (U.S. National Museum Bulletin 107, 1919), p. 5.
Shape: Drawn from the length and width, with the taper estimated from the typical eggs of its group (how these eggs are drawn).

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Common Loon

Gavia immer

88.9 × 56.2 mm
Clutch: 1–2 eggs

Breeds in Canada, United States

Brown with dark splotches.

Sources of information

Size: Average of 41 eggs: Bent, Life Histories of North American Diving Birds (U.S. National Museum Bulletin 107, 1919), p. 50.
Agrees with: Cornell Lab of Ornithology, All About Birds: Common Loon, Life History.
Description: Cornell Lab of Ornithology, All About Birds: Common Loon, Life History.
Drawing checked against a photo: Wikimedia Commons photo; Bird Eggs of Canada photo (Royal Saskatchewan Museum).
Clutch: Cornell Lab of Ornithology, All About Birds.
Shape: Drawn from the length and width, with the taper estimated from the typical eggs of its group (how these eggs are drawn).

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Eared Grebe

Podiceps nigricollis

43.5 × 30 mm
Clutch: 1–8 eggs

Breeds in Canada, United States, Mexico

Whitish.

Sources of information

Size: Average of 55 eggs: Bent, Life Histories of North American Diving Birds (U.S. National Museum Bulletin 107, 1919), p. 30.
Agrees with: Cornell Lab of Ornithology, All About Birds: Eared Grebe, Life History.
Description: Cornell Lab of Ornithology, All About Birds: Eared Grebe, Life History.
Drawing checked against a photo: Bird Eggs of Canada photo (Royal Saskatchewan Museum).
Clutch: Cornell Lab of Ornithology, All About Birds.
Shape: Drawn from the length and width, with the taper estimated from the typical eggs of its group (how these eggs are drawn).

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Great Grebe

Podiceps major

57.98 × 38.07 mm

Breeds in Argentina, Brazil, Chile, Ecuador, Peru, Uruguay

Pale greenish-blue shell under a chalky white coat, glossless; stained yellowish to earthy brown with incubation.

Sources of information

Size: Average of 3 eggs: Stoddard, M. C., et al. 2017. Avian egg shape: form, function, and evolution. Science 356: 1249-1254 (Data S1, MVZ egg collection).
Description: Oates 1901 (BM Egg Catalogue vol 1).
Shape: Drawn from the length and width, with the taper estimated from the typical eggs of its group (how these eggs are drawn).

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Hooded Grebe

Podiceps gallardoi

46.8 × 31.4 mm
Clutch: 2 eggs

Breeds in Argentina

Elliptical, white, unmarked (chalky grebe coat).

Sources of information

Size: Average of 19 eggs: de la Peña, M. R. 2025. Aves Argentinas: descripción, comportamiento, reproducción y distribución. Comunicaciones del Museo Provincial de Ciencias Naturales "Florentino Ameghino" (Nueva Serie). Santa Fe., tomo 2, p. 45.
Description: de la Peña 2025 (Aves Argentinas tomo 2).
Shape: Drawn from the length and width, with the taper estimated from the typical eggs of its group (how these eggs are drawn).

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Horned Grebe

Podiceps auritus

44 × 30 mm
Clutch: 3–8 eggs

Breeds in Canada, United States

White to brownish or bluish green.

Sources of information

Size: Average of 45 eggs: Bent, Life Histories of North American Diving Birds (U.S. National Museum Bulletin 107, 1919), p. 24.
Description: Cornell Lab of Ornithology, All About Birds: Horned Grebe, Life History.
Drawing checked against a photo: Bird Eggs of Canada photo (Royal Saskatchewan Museum).
Clutch: Cornell Lab of Ornithology, All About Birds.
Shape: Drawn from the length and width, with the taper estimated from the typical eggs of its group (how these eggs are drawn).

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Junin Grebe

Podiceps taczanowskii

45.7 × 30.7 mm (estimated)
Speculative: we haven't found a documented description of this egg yet, so we estimated its colours and markings and its size from related birds.

Breeds in Peru

No documented description found yet; drawn like the Hooded Grebe egg (same genus).

Sources of information

Size: Estimated, no measurements found: the median length and width of measured eggs of the same genus: Podiceps auritus, Podiceps gallardoi, Podiceps grisegena, Podiceps major, Podiceps nigricollis ….
Description: Estimated, no description found: drawn like a related egg (Hooded Grebe).
Shape: Drawn from the length and width, with the taper estimated from the typical eggs of its group (how these eggs are drawn).

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Least Grebe

Tachybaptus dominicus

33.9 × 23.4 mm
Clutch: 3–7 eggs

Breeds in United States, Mexico, Central America (7 countries), the Caribbean and South America (12 countries)

show all 26

Canada & United States: United States
Mexico: Mexico
Central America: Belize, Costa Rica, El Salvador, Guatemala, Honduras, Nicaragua, Panama
The Caribbean: Aruba, Bonaire, Sint Eustatius and Saba, Curaçao, Trinidad and Tobago, Caribbean islands
South America: Argentina, Bolivia, Brazil, Colombia, Ecuador, French Guiana, Guyana, Paraguay, Peru, Suriname, Uruguay, Venezuela

Whitish, or pale blue or green.

Sources of information

Size: Average of 49 eggs: Bent, Life Histories of North American Diving Birds (U.S. National Museum Bulletin 107, 1919), p. 37.
Description: Cornell Lab of Ornithology, All About Birds: Least Grebe, Life History.
Clutch: Cornell Lab of Ornithology, All About Birds.
Shape: Drawn from the length and width, with the taper estimated from the typical eggs of its group (how these eggs are drawn).

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Pacific Loon

Gavia pacifica

75.5 × 47 mm
Clutch: 1–2 eggs

Breeds in Canada, United States

Variable shades of buff, brown, and olive-green.

Sources of information

Size: Average of 41 eggs: Bent, Life Histories of North American Diving Birds (U.S. National Museum Bulletin 107, 1919), p. 68.
Description: Cornell Lab of Ornithology, All About Birds: Pacific Loon, Life History.
Drawing checked against a photo: Bird Eggs of Canada photo (University of Saskatchewan Department of Biology Natural History Collection).
Clutch: Cornell Lab of Ornithology, All About Birds.
Shape: Drawn from the length and width, with the taper estimated from the typical eggs of its group (how these eggs are drawn).

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Pied-billed Grebe

Podilymbus podiceps

43.4 × 30 mm
Clutch: 2–10 eggs

Breeds in Canada and United States, Mexico, Central America (6 countries), the Caribbean and South America (13 countries)

show all 27

Canada & United States: Canada, United States
Mexico: Mexico
Central America: Belize, Costa Rica, El Salvador, Guatemala, Honduras, Nicaragua
The Caribbean: Aruba, Bonaire, Sint Eustatius and Saba, Curaçao, Trinidad and Tobago, Caribbean islands
South America: Argentina, Bolivia, Brazil, Chile, Colombia, Ecuador, French Guiana, Guyana, Paraguay, Peru, Suriname, Uruguay, Venezuela

Bluish white to greenish white, rarely turquoise, and unmarked.

Sources of information

Size: Average of 48 eggs: Bent, Life Histories of North American Diving Birds (U.S. National Museum Bulletin 107, 1919), p. 43.
Agrees with: Cornell Lab of Ornithology, All About Birds: Pied-billed Grebe, Life History.
Description: Cornell Lab of Ornithology, All About Birds: Pied-billed Grebe, Life History.
Drawing checked against a photo: Bird Eggs of Canada photo (Royal Alberta Museum).
Clutch: Cornell Lab of Ornithology, All About Birds.
Shape: Drawn from the length and width, with the taper estimated from the typical eggs of its group (how these eggs are drawn).

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Red-necked Grebe

Podiceps grisegena

53.7 × 34.5 mm
Clutch: 1–9 eggs

Breeds in Canada, United States

Light blue.

Sources of information

Size: Average of 60 eggs: Bent, Life Histories of North American Diving Birds (U.S. National Museum Bulletin 107, 1919), p. 12.
Description: Cornell Lab of Ornithology, All About Birds: Red-necked Grebe, Life History.
Drawing checked against a photo: Bird Eggs of Canada photo (Royal Saskatchewan Museum).
Clutch: Cornell Lab of Ornithology, All About Birds.
Shape: Drawn from the length and width, with the taper estimated from the typical eggs of its group (how these eggs are drawn).

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Red-throated Loon

Gavia stellata

72.5 × 45 mm
Clutch: 1–2 eggs

Breeds in Canada, United States

Elongated, with variable color ranging from brown to olive, with blotches or speckles.

Sources of information

Size: Average of 58 eggs: Bent, Life Histories of North American Diving Birds (U.S. National Museum Bulletin 107, 1919), p. 75.
Agrees with: Cornell Lab of Ornithology, All About Birds: Red-throated Loon, Life History.
Description: Cornell Lab of Ornithology, All About Birds: Red-throated Loon, Life History.
Drawing checked against a photo: Bird Eggs of Canada photo (Royal Alberta Museum).
Clutch: Cornell Lab of Ornithology, All About Birds.
Shape: Drawn from the length and width, with the taper estimated from the typical eggs of its group (how these eggs are drawn).

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Silvery Grebe

Podiceps occipitalis

44.6 × 28.7 mm
Clutch: 4–6 eggs

Breeds in Argentina, Bolivia, Chile, Colombia, Ecuador, Falkland Islands, Peru

Elliptical, yellowish white or cream, unmarked, chalky.

Sources of information

Size: Average of 76 eggs: de la Peña, M. R. 2025. Aves Argentinas: descripción, comportamiento, reproducción y distribución. Comunicaciones del Museo Provincial de Ciencias Naturales "Florentino Ameghino" (Nueva Serie). Santa Fe., tomo 2, p. 40.
Description: de la Peña 2025 (Aves Argentinas tomo 2).
Drawing checked against a photo: de la Peña 2025, Aves Argentinas tomo 2, p. 41.
Shape: Drawn from the length and width, with the taper estimated from the typical eggs of its group (how these eggs are drawn).

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Titicaca Grebe

Rollandia microptera

51.6 × 33.6 mm
Speculative: we haven't found a documented description of this egg yet, so we estimated its colours and markings from related birds.

Breeds in Bolivia, Peru

No documented description found yet; drawn like the White-tufted Grebe egg (same genus).

Sources of information

Size: Average of 7 eggs: Schönwetter, M. 1960–1992. Handbuch der Oologie (ed. W. Meise), Lieferung 1. Akademie-Verlag, Berlin., p. 57.
Description: Estimated, no description found: drawn like a related egg (White-tufted Grebe).
Shape: Drawn from the length and width, with the taper estimated from the typical eggs of its group (how these eggs are drawn).

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