The
egg of the
ostrich (genus Struthio) is the largest of any living
bird (being exceeded in size by those of the extinct
elephant bird genus Aepyornis). The shell has a long history of use by humans as a container and for decorative artwork, including
beads. The eggs are not commonly eaten.
Biology
The female common ostrich lays her fertilized
eggs in a single communal nest, a simple pit, 30 to 60 cm (12–24 in) deep and 3 m (9.8 ft) wide,[1] scraped in the ground by the male. The dominant female lays her eggs first, and when it is time to cover them for incubation she discards extra eggs from the weaker females, leaving about 20 in most cases.[2] A female common ostrich can distinguish her own eggs from the others in a communal nest.[3] Ostrich eggs are the largest of all eggs,[4] though they are actually the smallest eggs relative to the size of the adult bird — on average they are 15 cm (5.9 in) long, 13 cm (5.1 in) wide, and weigh 1.4 kilograms (3.1 lb), over 20 times the weight of a
chicken's egg and only 1 to 4% the size of the female.[5] They are glossy cream-colored, with thick shells marked by small pits.[6]
The eggs are incubated by the females by day and by the males by night. This uses the coloration of the two sexes to escape detection of the nest, as the drab female blends in with the sand, while the black male is nearly undetectable in the night.[6] The
incubation period is 35 to 45 days, which is rather short compared to other
ratites. This is believed to be the case due to the high rate of predation.[5] Typically, the male defends the hatchlings and teaches them to feed, although males and females cooperate in rearing chicks. Fewer than 10% of nests survive the 9 week period of laying and incubation, and of the surviving chicks, only 15% of those survive to 1 year of age.[7]
A possible origin for the myth that ostriches bury their heads in sand to avoid danger lies with the fact that ostriches keep their eggs in holes in the sand instead of nests, and must rotate them using their beaks during incubation; digging the hole, placing the eggs, and rotating them might each be mistaken for an attempt to bury their heads in the sand.[8]
Human uses
In
Thebes, Egypt, the tomb of Haremhab, dating to approximately 1420 BC, shows a depiction of a man carrying bowls of
ostrich eggs and other large eggs, presumably those of the
pelican, as offerings.[9]
Ostrich eggshells were used as containers in North Africa as early as the fourth millennium BC and in the
Royal Cemetery at Ur from the third millennium. From the first millennium in the
ancient Punic civilization, there are many examples of ostrich eggs decorated with painted geometric designs for use as cups and bowls. These have been found in
Carthage,
Sardinia,
Sicily, the
Iberian Peninsula and
Ibiza. The tradition of using ostrich eggs as containers (sometimes decorated) continues to the present among the
San people.[10]
In the
Middle Ages, ostrich eggs from
Ethiopia were exported through the port of
Bāḍiʿ on the
Red Sea.[11] During the
Renaissance in Europe (15th–16th centuries AD), ostrich eggs were mounted in silver as goblets for display in
cabinets of curiosities.[10] Decorated eggs continue to be widely displayed in
Eastern Orthodox churches, although their symbolism is disputed. They may symbolize the
Virgin Birth, since according to
Job 39:13–17 the ostrich lays its eggs in the sand and forgets, so they are hatched by the sun alone. This significance may lie behind the egg suspended above the
Virgin Mary in
Piero della FrancescaBrera Madonna painting.[12]
In 2020, studies of decorated ostrich eggs in the
British Museum showed that the methods by which they had been sourced, produced and traded were more complicated than had previously been imagined.[13]Isotope analysis showed that eggs from the same archaeological site had originated in different places. The studies suggested that, rather than the eggs having been laid by captive birds, almost all had most likely been collected in the wild; a potentially hazardous undertaking.[14]
Today, ostrich eggs are a special luxury food.[15]
^Davies, S.J.J.F. (2003). "Birds I Tinamous and Ratites to Hoatzins". In Hutchins, Michael (ed.). Grzimek's Animal Life Encyclopedia. Vol. 8 (2nd ed.). Farmington Hills, MI: Gale Group. pp. 99–101.
ISBN978-0-7876-5784-0.
^Davies, S. J. J. F.; Bertram, B. C. R. (2003).
"Ostrich". In Perrins, Christopher (ed.). Firefly Encyclopedia of Birds. Buffalo, NY: Firefly Books, Ltd. pp.
34–37.
ISBN978-1-55297-777-4.
^
abGordon Campbell, ed. (2006), "Ostrich eggs", The Grove Encyclopedia of Decorative Arts, Oxford University Press.
^Yusuf Fadl Hasan (1967), The Arabs and the Sudan: From the Seventh to the Early Sixteenth Century (Edinburgh University Press), pp. 64–66.
^Tom Devonshire Jones; Linda Murray; Peter Murray, eds. (2013), "Ostrich eggs", The Oxford Dictionary of Christian Art and Architecture (2nd ed.), Oxford University Press.
The
egg of the
ostrich (genus Struthio) is the largest of any living
bird (being exceeded in size by those of the extinct
elephant bird genus Aepyornis). The shell has a long history of use by humans as a container and for decorative artwork, including
beads. The eggs are not commonly eaten.
Biology
The female common ostrich lays her fertilized
eggs in a single communal nest, a simple pit, 30 to 60 cm (12–24 in) deep and 3 m (9.8 ft) wide,[1] scraped in the ground by the male. The dominant female lays her eggs first, and when it is time to cover them for incubation she discards extra eggs from the weaker females, leaving about 20 in most cases.[2] A female common ostrich can distinguish her own eggs from the others in a communal nest.[3] Ostrich eggs are the largest of all eggs,[4] though they are actually the smallest eggs relative to the size of the adult bird — on average they are 15 cm (5.9 in) long, 13 cm (5.1 in) wide, and weigh 1.4 kilograms (3.1 lb), over 20 times the weight of a
chicken's egg and only 1 to 4% the size of the female.[5] They are glossy cream-colored, with thick shells marked by small pits.[6]
The eggs are incubated by the females by day and by the males by night. This uses the coloration of the two sexes to escape detection of the nest, as the drab female blends in with the sand, while the black male is nearly undetectable in the night.[6] The
incubation period is 35 to 45 days, which is rather short compared to other
ratites. This is believed to be the case due to the high rate of predation.[5] Typically, the male defends the hatchlings and teaches them to feed, although males and females cooperate in rearing chicks. Fewer than 10% of nests survive the 9 week period of laying and incubation, and of the surviving chicks, only 15% of those survive to 1 year of age.[7]
A possible origin for the myth that ostriches bury their heads in sand to avoid danger lies with the fact that ostriches keep their eggs in holes in the sand instead of nests, and must rotate them using their beaks during incubation; digging the hole, placing the eggs, and rotating them might each be mistaken for an attempt to bury their heads in the sand.[8]
Human uses
In
Thebes, Egypt, the tomb of Haremhab, dating to approximately 1420 BC, shows a depiction of a man carrying bowls of
ostrich eggs and other large eggs, presumably those of the
pelican, as offerings.[9]
Ostrich eggshells were used as containers in North Africa as early as the fourth millennium BC and in the
Royal Cemetery at Ur from the third millennium. From the first millennium in the
ancient Punic civilization, there are many examples of ostrich eggs decorated with painted geometric designs for use as cups and bowls. These have been found in
Carthage,
Sardinia,
Sicily, the
Iberian Peninsula and
Ibiza. The tradition of using ostrich eggs as containers (sometimes decorated) continues to the present among the
San people.[10]
In the
Middle Ages, ostrich eggs from
Ethiopia were exported through the port of
Bāḍiʿ on the
Red Sea.[11] During the
Renaissance in Europe (15th–16th centuries AD), ostrich eggs were mounted in silver as goblets for display in
cabinets of curiosities.[10] Decorated eggs continue to be widely displayed in
Eastern Orthodox churches, although their symbolism is disputed. They may symbolize the
Virgin Birth, since according to
Job 39:13–17 the ostrich lays its eggs in the sand and forgets, so they are hatched by the sun alone. This significance may lie behind the egg suspended above the
Virgin Mary in
Piero della FrancescaBrera Madonna painting.[12]
In 2020, studies of decorated ostrich eggs in the
British Museum showed that the methods by which they had been sourced, produced and traded were more complicated than had previously been imagined.[13]Isotope analysis showed that eggs from the same archaeological site had originated in different places. The studies suggested that, rather than the eggs having been laid by captive birds, almost all had most likely been collected in the wild; a potentially hazardous undertaking.[14]
Today, ostrich eggs are a special luxury food.[15]
^Davies, S.J.J.F. (2003). "Birds I Tinamous and Ratites to Hoatzins". In Hutchins, Michael (ed.). Grzimek's Animal Life Encyclopedia. Vol. 8 (2nd ed.). Farmington Hills, MI: Gale Group. pp. 99–101.
ISBN978-0-7876-5784-0.
^Davies, S. J. J. F.; Bertram, B. C. R. (2003).
"Ostrich". In Perrins, Christopher (ed.). Firefly Encyclopedia of Birds. Buffalo, NY: Firefly Books, Ltd. pp.
34–37.
ISBN978-1-55297-777-4.
^
abGordon Campbell, ed. (2006), "Ostrich eggs", The Grove Encyclopedia of Decorative Arts, Oxford University Press.
^Yusuf Fadl Hasan (1967), The Arabs and the Sudan: From the Seventh to the Early Sixteenth Century (Edinburgh University Press), pp. 64–66.
^Tom Devonshire Jones; Linda Murray; Peter Murray, eds. (2013), "Ostrich eggs", The Oxford Dictionary of Christian Art and Architecture (2nd ed.), Oxford University Press.