Sex and segregation in temperate bats

Area of Science:

• Zoology
• Ecology
• Animal Behavior

Background:

• Temperate insectivorous bats exhibit sexual segregation during summer, congregating in pre-hibernation swarms for mating.
• This segregation is often linked to aerial insect availability, with females favoring lower elevations for food resources to support high reproductive costs.

Purpose of the Study:

• To investigate sexual segregation, including intra-male segregation, in the hawking and trawling bat species, Myotis daubentonii.
• To understand the impact of habitat exclusion on male foraging efficiency and mating success.
• To explore how seasonal changes influence mating strategies and paternity advantage.

Main Methods:

• Observational study of Myotis daubentonii populations during summer and pre-hibernation swarming periods.
• Analysis of foraging efficiency and roosting behavior in relation to habitat quality and sex.
• Assessment of mating success and paternity advantage based on summer roosting and swarming behavior.

Main Results:

• Myotis daubentonii exhibits both inter-sexual and intra-male segregation during summer, with most males excluded from high-quality habitats.
• Males excluded from prime habitats show reduced foraging efficiency and mating success compared to males roosting with females.
• While swarming offers all males a mating chance, males that roosted with females in summer retain a paternity advantage.

Conclusions:

• Habitat availability and quality significantly influence male foraging success and reproductive opportunities in Myotis daubentonii.
• Intra-male segregation is driven by the exclusion of subordinate males from optimal resources.
• Despite seasonal behavioral shifts, early access to females provides a lasting reproductive advantage for some males.