Higher and bigger: How riparian bats react to climate change

Area of Science:

• Ecology
• Climate Change Biology
• Zoology

Background:

• Animal distribution and body size shifts are key climate change indicators.
• Bats' sensitivity to temperature makes them vital indicators of climate change.
• Long-term studies on bat responses to climate change are scarce.

Purpose of the Study:

• To investigate the 24-year altitudinal distribution and body size changes of Myotis daubentonii.
• To test hypotheses regarding upward shifts in female bat altitude limits and body size increases due to climate change.
• To assess the impact of altered thermal gradients on bat reproduction and growth.

Main Methods:

• Long-term monitoring of Myotis daubentonii over 24 years along a river course in Central Italy.
• Analysis of altitudinal distribution, focusing on sexual segregation and female altitude limits.
• Measurement of bat body size and condition, correlated with temperature data and riparian vegetation status.

Main Results:

• Females exhibited a 175-m upward shift in their maximum altitude limit.
• A significant increase in bat body size was observed, but not in body condition.
• Increased temperatures correlated with the upward range shift and increased newborn body mass, while riparian vegetation remained stable.

Conclusions:

• Climate warming has facilitated an upward altitudinal shift for female bats, increasing their reproductive range.
• Observed increases in body size suggest successful adaptation to warmer conditions, potentially impacting offspring.
• Future conservation efforts must consider potential disruptions to bat social structures and food availability due to climate-driven range shifts.