The world's largest bird, the ostrich, has problems reproducing when the temperature deviates by 5 degrees or more from the ideal temperature of 20 °C. The research, from Lund University in Sweden, is published in Nature Communications.
The results show that the females lay up to 40 percent fewer eggs if the temperature has fluctuated in the days before laying eggs. Both male and female production of gametes is also negatively affected.
"Many believe that ostriches can reproduce anywhere, but they are actually very sensitive to changes in temperature. Climate change means that temperatures will fluctuate even more, and that could be a challenge for the ostrich", says Mads Schou, researcher at Lund University who wrote the article together with colleague Charlie Cornwallis.
The threat of climate change is often described in terms of higher temperatures in the future. The researchers instead emphasize that fluctuations are a major issue that many species have to contend with already. In addition, both warmer and colder temperatures affect reproduction.
However, while more temperature variations pose a threat to ostriches, there may be hope. The results show that a small proportion of the females thrive at more extreme temperatures. The researchers believe the underlying reasons for this could be genetic.
"It would be fascinating if it were genetic, because then it can be passed on to future generations. But we need to do more research to be sure that this is the case", says Mads Schou.
The study was conducted on a farm in South Africa, where the researchers collected data from 1,300 ostriches over a period of 20 years.
Publication in Nature Communications: Extreme temperatures compromise male and female fertility in a large desert bird
