Ostriches
What’s not interesting about a flightless bird that can grow up to one metre taller than the average man, is heavier than an elephant calf, and has a stride that measures the same as a mid-sized family car!? [1], [2]
Ostriches are the tallest and heaviest of all birds, measuring up to 2.7 metres tall and weighing up to 159 kilograms. They have long, powerful legs that propel them up to two metres with each stride. Not only do their legs enable them to run fast (just over 40 miles an hour) they also provide ostriches with a brutal defence - the kick of an ostrich can kill a lion. However, if they have the option an ostrich will usually hide or run from danger rather than confront a threat to avoid injury. As they hide an ostrich lies low, spreading its long neck along the ground. Because of this stance people used to believe they buried their heads in the sand! [2]
Ostriches live in African savanna and desert lands alongside grazing animals such as wildebeest, zebras and antelope. As the grazers eat they disturb the ground, revealing insects and rodents – perfect food for an ostrich alongside their largely vegetarian diet. In return for providing a source of food, ostriches will alert the grazers of any threats. [2]
With no teeth you’d think this giant bird would have trouble eating. However, they have a great method for grinding up food which is initially stored in the crop at the top of the throat until there is a large enough lump to slide down. Mixed in with their diet is sand, pebbles and small stones that help grind up food in the gizzard - a muscular, thick-walled part of a bird’s stomach. [3], [4]
Furthermore, it may surprise you that ostrich herds have communal nests in which they lay the largest eggs of any living bird (up to 15 centimetres long). The dominant female will lay her eggs in the middle of this nest, where the eggs will be most protected, and will also incubate the eggs of the other hens (female ostriches). [2] The reason for this is that more eggs successfully hatch overall in a communal nest than if each female ostrich had her own nest to incubate and protect. The dominant brown/grey-coloured female incubates the nest during the day and the black-coloured dominant male (her mate) incubates the eggs at night – this provides the nest with optimal camouflage. [3]
There used to be five sub-species of ostrich, one of which is now extinct, with the North African ostrich (or red-necked ostrich) being the largest of the sub-species. [5] It has an unusually feathery head and the males have a bright pinky-red neck, making them look very different to the bald-headed and blue-necked ostriches in South Africa. Once widespread across Africa, this ostrich is now restricted to the western and southern Sahara and the Sahel, mainly because of feather and egg collection by humans and loss of habitat due to overgrazing. [6] Attempts have been made to reintroduce this species to its ancestral range and luckily there has been some success [7].
If you would like to find out more about this giant charismatic bird why not check out its strange booming mating call and extravagant mating dance.
Photograph: by Nicor, 2009, Male ostrich in Ngorongoro, via Wikimedia Commons.
[1] National Geographic, (2014), African Elephant, [online]. Available at: http://animals.nationalgeographic.com/animals/mammals/african-elephant/ Accessed 5 May 2014.
[2] National Geographic, 2014, Animals creature feature: ostriches, [online]. Available at: http://kids.nationalgeographic.com/kids/animals/creaturefeature/ostrich/, Accessed 5 May 2014.
[3] San Diego Zoo, (2014), Ostrich, [online], available at: http://animals.sandiegozoo.org/animals/ostrich#sthash.fbYfkMud.dpuf Accessed 5 May 2014.
[4] Oxford Dictionaries, (2014), Definition of Gizzard, [online], available at: http://www.oxforddictionaries.com/definition/english/gizzard Accessed 5 May 2014.
[5] Roots, C., (2006), Flightless Birds, Westport, Greenwood Press, p. 26. ISBN 0-313-33545-1
[6] Arkive, (2014), Ostrich (Struthio camelus), [online], available at: http://www.arkive.org/ostrich/struthio-camelus/ Accessed 5 May 2014.
[7] Marwell Wildlife, (2014), Ostrich reintroduction, [online], available at: http://www.marwell.org.uk/conservation/news_archive/redneckedostrichconservation.asp Accessed 5 May 2014.
