Size at Birth, Postnatal Growth, and Reproductive Timing in an Australian Microbat

Area of Science:

• Ecology
• Zoology
• Wildlife Biology

Background:

• Reproductive phenology, size at birth, and postnatal growth are key life history traits indicating parental investment.
• Documenting these traits aids in identifying and managing at-risk wildlife populations.
• Australian microbats, like Gould's wattled bat (Chalinolobus gouldii), are crucial for ecological balance.

Purpose of the Study:

• To examine reproductive traits in Chalinolobus gouldii over two years and two sites.
• To derive growth curves and age estimation equations for this species.
• To understand how environmental factors influence reproductive strategies and parental investment.

Main Methods:

• Field study of Chalinolobus gouldii reproductive traits over two years.
• Analysis of birth size, postnatal growth rates, and birth dates.
• Correlation of reproductive timing with environmental conditions (temperature, precipitation).

Main Results:

• No significant differences were found in birth size or postnatal growth rates between male and female offspring.
• Bats born in 2018 were smaller at birth but exhibited faster postnatal growth compared to 2017 births.
• Bats born in 2018 had later median birthdates and more dispersed birth periods, potentially linked to cooler, wetter weather during gestation.

Conclusions:

• Environmental conditions, such as weather during gestation, can significantly impact bat reproductive phenology.
• Reproductive plasticity in widespread species like Chalinolobus gouldii provides insights into managing threatened microbats.
• Growth curves and age estimation equations are valuable tools for wildlife population studies and conservation efforts.