Mentoring

Olivia Bond

2025

Johns Hopkins University

School for International Training
Project: Microclimate drivers of thermoregulatory behaviors in spectacled flying-foxes (Pteropus conspicillatus)

Abstract
As climate change makes heat waves more frequent and intense, vulnerable species are pushed closer to their limits of thermal tolerance. The spectacled flying-fox (Pteropus conspicillatus) is an endangered megabat that plays a crucial role in pollination and seed dispersal for rainforest trees in northeast Australia. These bats are particularly vulnerable to extreme heat because they roost high in the canopy during the day.

Several studies have documented their thermoregulatory responses to high ambient temperatures, but temperature is only one factor influencing thermal stress, and the role of other microclimate drivers remains understudied.

This project combined focal behavioral observations with microclimate measurements to identify the conditions that exacerbate heat stress. Behavioral responses were modeled using boosted regression trees, revealing that high temperatures alone did not always trigger active thermoregulation. The most extreme responses occurred when high temperatures coincided with high solar exposure, highlighting solar exposure as a critical but often overlooked driver of thermal stress.

These findings emphasize the need to consider the complexity of microclimate in predicting species’ vulnerability to extreme heat events.