Weather-driven dynamics in a dual-migrant system: moths and bats

Area of Science:

• Ecology
• Animal Behavior
• Climate Science

Background:

• Animal migrations create biomass fluctuations vital for predator-prey interactions.
• Continent-scale weather patterns drive these interactions, posing research challenges.
• Few studies examine multiple trophic levels or multi-seasonal migratory animal dynamics.

Purpose of the Study:

• To investigate the relationship between weather patterns, moth migration, and bat foraging behavior.
• To assess the impact of seasonal weather on agricultural pest moth populations.
• To understand how climate change may affect these migratory ecological interactions.

Main Methods:

• Tracking migrations of three noctuid moth species over three autumn seasons (2010-2012).
• Monitoring a large colony of migratory Brazilian free-tailed bats (Tadarida brasiliensis) in Texas.
• Correlating moth abundance, bat mass, and bat activity with weather events like cold fronts and wind direction.

Main Results:

• Moth abundance and bat activity correlated with cold front passages and northerly winds.
• Moth species and seasonal responses to weather varied, with peaks in September-October after cold fronts.
• Bat cave use shifted from maternity roosts to migratory stopover sites, influencing bat mass and behavior.

Conclusions:

• Weather-driven animal migrations are vulnerable to climate change.
• Changes in bat and moth migration patterns due to climate change could significantly impact agriculture and ecosystem services.
• Understanding these complex interactions is crucial for predicting future ecological shifts.