Amphibian Chytrid Fungus Infection Influences Calling Investment in Male Brown Toadlets

Area of Science:

• Amphibian biology
• Disease ecology
• Behavioral ecology

Background:

• Sublethal effects of disease on male advertisement behavior are poorly understood.
• The terminal investment hypothesis predicts increased reproductive effort in infected individuals with reduced future prospects.
• Some anurans increase calling activity when infected with amphibian chytrid fungus, but this response is not fully understood.

Purpose of the Study:

• To investigate the relationship between chytrid fungus infection and male calling behavior in Australian brown toadlets (Pseudophryne bibronii).
• To test the terminal investment hypothesis in a new anuran species.
• To examine how infection status affects advertisement call properties.

Main Methods:

• Field study across four populations of wild Australian brown toadlets.
• Correlational analysis of chytrid fungus infection status and male advertisement call properties (spectral and temporal).
• Statistical control for intrinsic and extrinsic factors influencing calling behavior.

Main Results:

• Infected male brown toadlets produced advertisement calls with a higher pulse count compared to uninfected males.
• This finding supports the terminal investment hypothesis.
• Chytrid fungus infection is shown to modify frog calling behavior.

Conclusions:

• The study provides evidence supporting the terminal investment hypothesis in Pseudophryne bibronii.
• Pathogen-induced changes in male calling behavior can influence host attractiveness, fitness, and disease transmission.
• This research contributes to the growing understanding of how pathogens impact host reproductive strategies.