Evidence of declining fertility in humans and wildlife is growing. While chemicals in our environment have been identified as a major cause, our new research shows there is another looming threat to animal fertility: climate change.

We know animals can die when temperatures rise to extremes they cannot endure. However, our research suggests males of some species can become infertile even at less extreme temperatures.

This means the distribution of species may be limited by the temperatures at which they can reproduce, rather than the temperatures at which they can survive.

These findings are important, because they mean we may be underestimating the impacts of climate change on animals – and failing to identify the species most likely to become extinct.

Feeling heat

Researchers have known for some time that animal fertility is sensitive to heat stress.

For example, research shows a 2 degrees Celsius temperature rise dramatically reduces the production of sperm bundles and egg size in corals. And in many beetle and bee species, fertilisation success drops sharply at high temperatures.

High temperatures have also been shown to affect fertilisation or sperm count in cows, pigs, fish and birds.

However, temperatures that cause infertility have not been incorporated into predictions about how climate change will affect biodiversity. Our research aims to address this.

Focus on flies

The paper published today involved researchers from the United Kingdom, Sweden and Australia, including…

Read more