Rodent mothers increase vigilance behaviour when facing infanticide risk.

Area of Science:

• Behavioral Ecology
• Mammalian Reproduction
• Evolutionary Biology

Background:

• Infanticide, often driven by sexual conflict, is prevalent in mammals, particularly affecting females with exclusive maternal care.
• Females face fitness costs due to infanticide, suggesting adaptive benefits for recognizing and mitigating this risk.
• Understanding female counterstrategies to infanticide is crucial for comprehending reproductive success and social dynamics in mammals.

Purpose of the Study:

• To investigate if lactating female mammals adjust offspring protection behaviors in response to varying levels of infanticide risk.
• To examine how females modify their mate-searching behavior when exposed to cues indicating different infanticide threats.
• To determine the influence of litter size on female responses to infanticide risk and resource acquisition.

Main Methods:

• Utilized outdoor enclosures with the bank vole (Myodes glareolus) to simulate different infanticide risk levels.
• Presented females with scents of the litter's sire (lower risk) or a stranger male (higher risk) near the nest.
• Employed radiotracking to monitor female nest presence, activity levels, and spatial use in response to scent treatments.

Main Results:

• Females exhibited increased nest departures, activity, and proximity to the nest under higher infanticide risk (stranger male scent).
• These behavioral adjustments suggest enhanced offspring protection through heightened alertness and vigilance outside the nest.
• Litter size influenced scent investigation and space utilization, with larger litters prompting more engagement in the lower-risk (sire) scenario.

Conclusions:

• Female mammals can adaptively adjust offspring protection strategies based on perceived infanticide risk.
• Behavioral modifications, including increased vigilance and altered spatial use, serve as crucial counterstrategies against infanticide.
• The interplay between infanticide risk, litter investment, and female behavior highlights the adaptive significance of flexible reproductive strategies.