By Ian Randall For Mailonline
Published: 16:00 GMT, 17 November 2020 | Updated: 16:00 GMT, 17 November 2020
Changing climates and habits pose a greater risk to migrating animals — especially those that fly — because they 'live fast, die young' and are thus less able to adapt.
Experts from Exeter studied nearly 1,300 mammal and bird species — finding that those who migrate typically grow faster, have offspring earlier and die younger.
The findings could help to explain why many migrant species appear to be declining, as they are less able to, for example, delay breeding conditions are poor.
They could also help to predict how migrating species may respond to environmental shifts in the future.
The team also noted that migrating animals that swim or walk are typically larger than their non-migrating equivalents, while flying migrants are usually smaller
Changing climates and habits pose a greater risk to migrating animals — especially those that fly — because they 'live fast, die young' and are thus less able to adapt. Pictured, a flock of fruit bats migrates across the sky as the sun begins to set
'Many species migrate over long distances and this requires substantial amounts of energy,' said paper author and conservation biologist Andrea Soriano-Redondo of the University of Exeter.
'This energy cannot be used for other purposes such as self-maintenance or reproduction, so we would expect animals to adjust the amount of energy they use for these things,' she added.
'By prioritising reproduction over survival, "fast-living" species have the potential to increase numbers more rapidly — which may balance the long-term energy costs and short-term risks of migrating.'
In their study, Dr Soriano-Redondo and colleagues examined the so-called 'pace of life' of 1,296 species — looking at such metrics as longevity, the ages at which the female individuals reach sexual maturity and breeding frequencies.
'We have long thought that migration is a risky behaviour,' said paper author and animal ecologist Stuart Bearhop, also of the University of Exeter.