Animals with long lifespan and fewer offspring less vulnerable to climate change, study suggests

Smaller, fast reproducing species may require special conservation attention, scientists say

Animals with longer lifespans that give birth to a smaller number of offspring are less vulnerable to extreme weather than those that live for a short time and have many young, according to a new study.

Citing examples, researchers, including those from the University of Oxford, said long-lived animals such as African elephants, Siberian tigers, and chimpanzees were relatively less affected by extreme weather compared to creatures such as the olive grass mouse, Canadian lemming, and the Arctic fox.

The research, published in the journal eLife, assessed data on population fluctuations from 157 mammal species from around the world, and compared them with weather and climate data from the time the animal data were collected.

For each species, scientists said there were 10 or more years of data.

Based on the analysis, they found animals that lived longer were able to cope better with conditions such as prolonged drought.

Researchers say the ability of these animals to survive, reproduce, and raise their offspring is not affected to the same extent as the small, short-lived animals.

Large animals, they said, invest their energy into one offspring, or wait for better times when conditions become challenging, while small short-lived ones have more extreme population changes in the short term.

Large parts of the ecosystem food reserves of small animals – insects, flowers, fruits – may disappear rapidly in the event of extreme events such as droughts and they were left to starve since they have limited fat reserves, the researchers explained.

The study offered a point of view to understand how the planet’s animals will respond to the ongoing climate crisis, which would bring more extreme weather in the future, the scientists said.

“Long-lived mammals with smaller litter sizes had smaller absolute population responses to weather anomalies compared with their shorter living counterparts with larger litters,” researchers wrote in the study.

The scientists said the smaller, fast-reproducing species might require special conservation attention to prevent their extinction due to the increased frequency and magnitude of extreme weather events in the future.

“These results highlight the role of species-level life history in driving responses to the environment,” they added.