The bald-necked and bald-legged ostrich may not be winning any beauty contests, but they are certainly extreme survivors.
Main Notes and Takeaways
- Adult ostrich are excellent survivors of the dry and hot grasslands and deserts they call home (more below).
- Young ostriches have a very low survival rate. In captivity, only about half of eggs hatch, and only half of the hatchlings reach a year of age. In the wild survival is even less.
- They have a very unique method of raising chicks involving one hen sitting on eggs, but multiple females using the nest (more below).
- The neck of an ostriches is an excellent radiator to get rid of excess heat.
- Due to their leafy diet, they need very little extra water but still do need a constant source of water nearby.
- Lay the largest egg of any bird, but the smallest in comparison to body size.
Female ostrich are not brightly colored, allowing them to blend into their environment while sitting on the nest. The bold-markings of the male means he can only safely babysit at night under the cover of darkness.
Our Favorite Notes from This Episode
Ostrich: Extreme Survivors
These heavy bodied birds with bald legs and necks may not be winning any beauty contests, but they sure are excellent survivors. They can safely regulate their body temperature even when exposed to 56C (132F) external temperatures for several hours. The main way they keep cool is through an extreme respiratory system which can move air at 20 m/sec or even more. Their long neck allows them to remove heat from their bodies very effectively.
When it comes to water, ostriches need very little. They not only eat a lot of leafy vegetation but can actually process salt water which is common in their habitat in ponds and pools. Ostriches can process water that is composed of up to 25% salt. It is a common misconception that ostriches don’t need free-standing water at all, but that is not true. However, they can go over a week without water.
Ostrich Nests: Babysitting and Betrayal
Ostriches live in male-led harems with multiple females that he will mate with but one “Hen Major” who sits on the nest. She is the lead female, and will take on parental duties during the day while the male watches at night. This Hen Major doesn’t do her duties without benefits though. She ensures that her young survive by keeping her own eggs in the middle of the nest where they are safest. According to National Geographic’s “Strangest Bird Alive” documentary, she will even lay out decoy eggs of the other females’ for predators to take in order to protect the main nest.
This unique nest behavior ensures the highest chance of success for the most eggs, and can lead to a pair of ostrich looking after a few dozen babies. These young ostrich are fragile, and their parents must lead them to food and water quickly if they are to survive. From the book, “Ostrich”, by Davies (2003): “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.”
- “Strangest Bird Alive”. 2016. National Geographic. Documentary.
- Schou, M.F., Bonato, M., Engelbrecht, A. et al. Extreme temperatures compromise male and female fertility in a large desert bird. Nat Commun 12, 666 (2021). https://doi.org/10.1038/s41467-021-20937-7
- Knut Schmidt-Nielsen, John Kanwisher, Robert C. Lasiewski, Jerome E. Cohn, William L. Bretz, Temperature Regulation and Respiration in the Ostrich, The Condor, Volume 71, Issue 4, 1 October 1969, Pages 341–352.
- Cloudsey-Thompson, J. L., & Mohamed, E. R. M. (1967). Water Economy of the Ostrich. Nature, 216(5119), 1040–1040.
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